Identification

Name
Phenytoin
Accession Number
DB00252  (APRD00241)
Type
Small Molecule
Groups
Approved, Vet Approved
Description

An anticonvulsant that is used in a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. [PubChem]

Structure
Thumb
Synonyms
  • 5,5-Diphenyl-imidazolidine-2,4-dione
  • 5,5-diphenylimidazolidine-2,4-dione
  • 5,5-diphenyltetrahydro-1H-2,4-imidazoledione
  • 5,5-Diphenyltetrahydro-1H-2,4-imidazoledione
  • Diphenylhydantoin
  • Fenitoina
  • Phentytoin
  • Phenytoine
  • Phenytoinum
External IDs
NSC-8722
Product Ingredients
IngredientUNIICASInChI Key
Phenytoin sodium4182431BJH630-93-3FJPYVLNWWICYDW-UHFFFAOYSA-M
Product Images
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
DilantinCapsule100 mgOralPfizer1951-12-31Not applicableCanada
DilantinCapsule30 mgOralPfizer1951-12-31Not applicableCanada
Dilantin InfatabsTablet50 mgOralPfizer1952-12-31Not applicableCanada
Dilantin Inj 50mg/mlLiquid250 mgIntramuscular; IntravenousParke Davis Division, Warner Lambert Canada Inc.1972-12-311996-09-10Canada
Dilantin-125Suspension125 mg/5mLOralParke Davis Div Of Pfizer Inc1953-01-06Not applicableUs
Dilantin-125 SuspensionSuspension125 mgOralPfizer1953-12-31Not applicableCanada
Dilantin-30 SuspensionSuspension30 mgOralPfizer1968-12-31Not applicableCanada
Novo-phenytoin Cap 100mgCapsule100 mgOralNovopharm Limited1966-12-31Not applicableCanada
PhenytoinSuspension125 mg/5mLOralGreenstone, Llc2012-10-09Not applicableUs
Phenytoin Sodium Inj 50mg/ml USPSolution50 mgIntramuscular; IntravenousHospira, Inc.1989-12-31Not applicableCanada
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Apo-phenytoin SodiumCapsule100 mgOralApotex Corporation2017-08-16Not applicableCanada
DilantinCapsule, extended release100 mg/1OralParke Davis Div Of Pfizer Inc1976-08-27Not applicableUs
DilantinCapsule, extended release100 mg/1OralA S Medication Solutions1976-08-272017-06-20Us
DilantinCapsule100 mg/1OralRemedy Repack2011-07-082017-04-14Us00071 0369 24 nlmimage10 e51572cb
DilantinCapsule, extended release100 mg/1OralAphena Pharma Solutions Tennessee, Inc.1976-08-27Not applicableUs
DilantinCapsule, extended release30 mg/1OralKaiser Foundations Hospitals2009-09-20Not applicableUs
DilantinCapsule, extended release30 mg/1OralCarilion Materials Management1976-08-27Not applicableUs
DilantinCapsule, extended release30 mg/1OralPhysicians Total Care, Inc.2003-08-19Not applicableUs00071 3740 66 nlmimage10 e815741b
DilantinTablet, chewable50 mg/1OralRemedy Repack2011-08-182016-11-08Us
DilantinCapsule, extended release30 mg/1OralRemedy Repack2011-05-052016-10-18Us
Unapproved/Other Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
PhenytoinTablet, chewable50 mg/1OralRemedy Repack2017-11-10Not applicableUs
International/Other Brands
Epanutin ( Pfizer) / Eptoin
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
Dilantin W Phenobarbital 15mgPhenytoin sodium (100 mg) + Phenobarbital (15 mg)CapsuleOralParke Davis Division, Warner Lambert Canada Inc.1951-12-311999-04-08Canada
Dilantin W Phenobarbital 30mg CapPhenytoin sodium (100 mg) + Phenobarbital (30 mg)CapsuleOralParke Davis Division, Warner Lambert Canada Inc.1969-12-311997-08-25Canada
Categories
UNII
6158TKW0C5
CAS number
57-41-0
Weight
Average: 252.268
Monoisotopic: 252.089877638
Chemical Formula
C15H12N2O2
InChI Key
CXOFVDLJLONNDW-UHFFFAOYSA-N
InChI
InChI=1S/C15H12N2O2/c18-13-15(17-14(19)16-13,11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10H,(H2,16,17,18,19)
IUPAC Name
5,5-diphenylimidazolidine-2,4-dione
SMILES
O=C1NC(=O)C(N1)(C1=CC=CC=C1)C1=CC=CC=C1

Pharmacology

Indication

For the control of generalized tonic-clonic (grand mal) and complex partial (psychomotor, temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery.

Structured Indications
Pharmacodynamics

Phenytoin is an antiepileptic drug which can be useful in the treatment of epilepsy. The primary site of action appears to be the motor cortex where spread of seizure activity is inhibited. Phenytoin reduces the maximal activity of brain stem centers responsible for the tonic phase of tonic-clonic (grand mal) seizures. Phenytoin acts to dampen the unwanted, runaway brain activity seen in seizure by reducing electrical conductance among brain cells. It lacks the sedation effects associated with phenobarbital. There are some indications that phenytoin has other effects, including anxiety control and mood stabilization, although it has never been approved for those purposes by the FDA. Phenytoin is primarily metabolized by CYP2C9.

Mechanism of action

Phenytoin acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. By promoting sodium efflux from neurons, phenytoin tends to stabilize the threshold against hyperexcitability caused by excessive stimulation or environmental changes capable of reducing membrane sodium gradient. This includes the reduction of post-tetanic potentiation at synapses. Loss of post-tetanic potentiation prevents cortical seizure foci from detonating adjacent cortical areas.

TargetActionsOrganism
ASodium channel protein type 5 subunit alpha
inhibitor
Human
ASodium channel protein type 1 subunit alpha
inhibitor
Human
UNuclear receptor subfamily 1 group I member 2Not AvailableHuman
USodium channel subunit beta-1Not AvailableHuman
USodium channel protein type 3 subunit alphaNot AvailableHuman
Absorption

Bioavailability 70-100% oral, 24.4% rectal. Rapid rate of absorption with peak blood concentration expected in 1½ to 3 hours.

Volume of distribution
Not Available
Protein binding

Highly protein bound, 90%

Metabolism

Primarily hepatic. The majority of the dose (up to 90%) is metabolized to 5-(4'-hydroxyphenyl)-5-phenylhydantoin (p-HPPH). This metabolite undergoes further glucuronidation and is excreted into the urine. CYP2C19 and CYP2C9 catalyze the aforementioned reaction.

Route of elimination

Most of the drug is excreted in the bile as inactive metabolites which are then reabsorbed from the intestinal tract and excreted in the urine. Urinary excretion of phenytoin and its metabolites occurs partly with glomerular filtration but, more importantly, by tubular secretion.

Half life

22 hours (range of 7 to 42 hours)

Clearance
Not Available
Toxicity

Oral, mouse: LD50 = 150 mg/kg; Oral, rat: LD50 = 1635 mg/kg. Symptoms of overdose include coma, difficulty in pronouncing words correctly, involuntary eye movement, lack of muscle coordination, low blood pressure, nausea, sluggishness, slurred speech, tremors, and vomiting.

Affected organisms
  • Humans and other mammals
Pathways
PathwayCategory
Fosphenytoin (Antiarrhythmic) Metabolism PathwayDrug metabolism
Phenytoin (Antiarrhythmic) Action PathwayDrug action
Fosphenytoin (Antiarrhythmic) Action PathwayDrug action
Pharmacogenomic Effects/ADRs
Interacting Gene/EnzymeAllele nameGenotype(s)Defining Change(s)Type(s)DescriptionDetails
Cytochrome P450 2C9CYP2C9*3(C;C) / (A;C)C AlleleEffect Directly StudiedPatients with this genotype have reduced metabolism of phenytoin.Details
HLA class I histocompatibility antigen, B-15 alpha chainHLA-B*15:02Not AvailableHLA-B*15ADR Directly StudiedThe presence of this genotype in HLA-B is associated with an increased risk of Stevens-Johnson syndrome and toxic epidermal necrolysis when treated with phenytoin.Details
Cytochrome P450 2C19CYP2C19*2ANot Available681G>AADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*2BNot Available681G>AADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*3Not Available636G>AADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*4Not Available1A>GADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*5Not Available1297C>TADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*6Not Available395G>AADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*7Not Available19294T>AADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*22Not Available557G>C / 991A>GADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*24Not Available99C>T / 991A>G  … show all ADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C19CYP2C19*35Not Available12662A>GADR InferredPoor drug metabolizer, risk of drug toxicity.Details
Cytochrome P450 2C9CYP2C9*2Not Available430C>TADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*3Not Available1075A>CADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*4Not Available1076T>CADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*5Not Available1080C>GADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*8Not Available449G>AADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*11Not Available1003C>TADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*12Not Available1465C>TADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*13Not Available269T>CADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*14Not Available374G>AADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*16Not Available895A>GADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*18Not Available1075A>C / 1190A>C  … show all ADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*26Not Available389C>GADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*28Not Available641A>TADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*30Not Available1429G>AADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*33Not Available395G>AADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*6Not Available818delAADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*15Not Available485C>AADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*25Not Available353_362delAGAAATGGAAADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*35Not Available374G>T / 430C>TADR InferredPoor drug metabolizer, risk of drug toxicity. Consider lower dose.Details
Cytochrome P450 2C9CYP2C9*6Not Available818delAEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*15Not Available485C>AEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*25Not Available353_362delAGAAATGGAAEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*35Not Available374G>T / 430C>TEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*2Not Available430C>TEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*4Not Available1076T>CEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*5Not Available1080C>GEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*8Not Available449G>AEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*11Not Available1003C>TEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*12Not Available1465C>TEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*13Not Available269T>CEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*14Not Available374G>AEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*16Not Available895A>GEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*18Not Available1075A>C / 1190A>C  … show all Effect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*26Not Available389C>GEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*28Not Available641A>TEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*30Not Available1429G>AEffect InferredPoor drug metabolizer, lower dose requirementsDetails
Cytochrome P450 2C9CYP2C9*33Not Available395G>AEffect InferredPoor drug metabolizer, lower dose requirementsDetails

Interactions

Drug Interactions
DrugInteractionDrug group
16-BromoepiandrosteroneThe serum concentration of 16-Bromoepiandrosterone can be decreased when it is combined with Phenytoin.Investigational
19-norandrostenedioneThe serum concentration of 19-norandrostenedione can be decreased when it is combined with Phenytoin.Experimental, Illicit
2-HYDROXY-1,4-NAPHTHOQUINONEThe serum concentration of Phenytoin can be increased when it is combined with 2-HYDROXY-1,4-NAPHTHOQUINONE.Experimental
2-mercaptobenzothiazoleThe serum concentration of Phenytoin can be increased when it is combined with 2-mercaptobenzothiazole.Vet Approved
2,5-Dimethoxy-4-ethylamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with 2,5-Dimethoxy-4-ethylamphetamine.Experimental, Illicit
3,4-MethylenedioxyamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with 3,4-Methylenedioxyamphetamine.Experimental, Illicit
4-Bromo-2,5-dimethoxyamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with 4-Bromo-2,5-dimethoxyamphetamine.Experimental, Illicit
5-androstenedioneThe serum concentration of 5-androstenedione can be decreased when it is combined with Phenytoin.Experimental, Illicit
7-NitroindazoleThe risk or severity of adverse effects can be increased when 7-Nitroindazole is combined with Phenytoin.Experimental
AbemaciclibThe serum concentration of Abemaciclib can be decreased when it is combined with Phenytoin.Approved
AbirateroneThe serum concentration of Phenytoin can be increased when it is combined with Abiraterone.Approved
AceclofenacThe metabolism of Aceclofenac can be increased when combined with Phenytoin.Approved, Investigational
AcenocoumarolPhenytoin may increase the anticoagulant activities of Acenocoumarol.Approved
AcepromazineThe risk or severity of adverse effects can be increased when Acepromazine is combined with Phenytoin.Approved, Vet Approved
AceprometazineThe risk or severity of adverse effects can be increased when Aceprometazine is combined with Phenytoin.Approved
AcetaminophenThe serum concentration of Acetaminophen can be decreased when it is combined with Phenytoin.Approved
AcetazolamideThe risk or severity of adverse effects can be increased when Acetazolamide is combined with Phenytoin.Approved, Vet Approved
Acetylsalicylic acidThe metabolism of Acetylsalicylic acid can be increased when combined with Phenytoin.Approved, Vet Approved
AdinazolamThe metabolism of Adinazolam can be increased when combined with Phenytoin.Approved
AdipiplonThe risk or severity of adverse effects can be increased when Adipiplon is combined with Phenytoin.Investigational
AgomelatineThe risk or severity of adverse effects can be increased when Agomelatine is combined with Phenytoin.Approved, Investigational
AlaproclateThe risk or severity of adverse effects can be increased when Phenytoin is combined with Alaproclate.Experimental
AlbendazoleThe serum concentration of the active metabolites of Albendazole can be reduced when Albendazole is used in combination with Phenytoin resulting in a loss in efficacy.Approved, Vet Approved
AlclometasoneThe metabolism of Alclometasone can be increased when combined with Phenytoin.Approved
AldosteroneThe serum concentration of Aldosterone can be decreased when it is combined with Phenytoin.Experimental, Investigational
AlfaxaloneThe risk or severity of adverse effects can be increased when Alfaxalone is combined with Phenytoin.Vet Approved
AlfentanilThe metabolism of Alfentanil can be increased when combined with Phenytoin.Approved, Illicit
AlfuzosinThe metabolism of Alfuzosin can be increased when combined with Phenytoin.Approved, Investigational
AliskirenThe metabolism of Aliskiren can be increased when combined with Phenytoin.Approved, Investigational
AllopregnanoloneThe risk or severity of adverse effects can be increased when Allopregnanolone is combined with Phenytoin.Investigational
AllylestrenolThe metabolism of Allylestrenol can be increased when combined with Phenytoin.Approved
AlmotriptanThe metabolism of Almotriptan can be increased when combined with Phenytoin.Approved, Investigational
AlogliptinThe metabolism of Alogliptin can be increased when combined with Phenytoin.Approved
AlosetronThe metabolism of Alosetron can be increased when combined with Phenytoin.Approved, Withdrawn
AlphacetylmethadolThe risk or severity of adverse effects can be increased when Alphacetylmethadol is combined with Phenytoin.Experimental, Illicit
AlphaprodineThe risk or severity of adverse effects can be increased when Alphaprodine is combined with Phenytoin.Illicit
AlprazolamThe serum concentration of Phenytoin can be increased when it is combined with Alprazolam.Approved, Illicit, Investigational
AmbrisentanThe metabolism of Ambrisentan can be increased when combined with Phenytoin.Approved, Investigational
AmbroxolThe metabolism of Ambroxol can be increased when combined with Phenytoin.Approved, Investigational
Ambroxol acefyllinateThe serum concentration of Ambroxol acefyllinate can be decreased when it is combined with Phenytoin.Experimental, Investigational
AmcinonideThe serum concentration of Amcinonide can be decreased when it is combined with Phenytoin.Approved
AminophenazoneThe metabolism of Aminophenazone can be increased when combined with Phenytoin.Approved, Withdrawn
AminophyllineThe serum concentration of Aminophylline can be decreased when it is combined with Phenytoin.Approved
AmiodaroneThe serum concentration of Amiodarone can be decreased when it is combined with Phenytoin.Approved, Investigational
AmisulprideThe risk or severity of adverse effects can be increased when Amisulpride is combined with Phenytoin.Approved, Investigational
AmitriptylineThe metabolism of Amitriptyline can be increased when combined with Phenytoin.Approved
AmlodipineThe serum concentration of Phenytoin can be increased when it is combined with Amlodipine.Approved
AmobarbitalThe risk or severity of adverse effects can be increased when Amobarbital is combined with Phenytoin.Approved, Illicit
AmodiaquineThe metabolism of Amodiaquine can be increased when combined with Phenytoin.Approved, Investigational
AmorolfineThe serum concentration of Phenytoin can be increased when it is combined with Amorolfine.Approved, Investigational
AmoxapineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Amoxapine.Approved
AmoxicillinThe metabolism of Amoxicillin can be increased when combined with Phenytoin.Approved, Vet Approved
AmperozideThe risk or severity of adverse effects can be increased when Amperozide is combined with Phenytoin.Experimental
AmphetamineThe serum concentration of Phenytoin can be decreased when it is combined with Amphetamine.Approved, Illicit
Amphotericin BThe serum concentration of Phenytoin can be increased when it is combined with Amphotericin B.Approved, Investigational
AmprenavirThe metabolism of Amprenavir can be increased when combined with Phenytoin.Approved
AmrinoneThe serum concentration of Phenytoin can be increased when it is combined with Amrinone.Approved
AndrostenedioneThe serum concentration of Androstenedione can be decreased when it is combined with Phenytoin.Experimental, Illicit
AnecortaveThe serum concentration of Anecortave can be decreased when it is combined with Phenytoin.Investigational
anecortave acetateThe serum concentration of anecortave acetate can be decreased when it is combined with Phenytoin.Investigational
AnidulafunginThe serum concentration of Phenytoin can be increased when it is combined with Anidulafungin.Approved, Investigational
AntipyrineThe metabolism of Antipyrine can be increased when combined with Phenytoin.Approved
ApixabanThe serum concentration of Apixaban can be decreased when it is combined with Phenytoin.Approved
ApremilastThe serum concentration of Apremilast can be decreased when it is combined with Phenytoin.Approved, Investigational
AprepitantThe serum concentration of Phenytoin can be increased when it is combined with Aprepitant.Approved, Investigational
Arachidonic AcidThe metabolism of Arachidonic Acid can be increased when combined with Phenytoin.Experimental
ArformoterolThe metabolism of Arformoterol can be increased when combined with Phenytoin.Approved, Investigational
ArgatrobanThe metabolism of Argatroban can be increased when combined with Phenytoin.Approved, Investigational
AripiprazoleThe serum concentration of Aripiprazole can be decreased when it is combined with Phenytoin.Approved, Investigational
ArmodafinilThe metabolism of Phenytoin can be decreased when combined with Armodafinil.Approved, Investigational
ArtemetherThe serum concentration of Phenytoin can be increased when it is combined with Artemether.Approved
ArticaineThe risk or severity of adverse effects can be increased when Articaine is combined with Phenytoin.Approved
AsenapineThe metabolism of Asenapine can be increased when combined with Phenytoin.Approved
AstemizoleThe metabolism of Astemizole can be increased when combined with Phenytoin.Approved, Withdrawn
AtamestaneThe serum concentration of Atamestane can be decreased when it is combined with Phenytoin.Investigational
AtazanavirThe metabolism of Atazanavir can be increased when combined with Phenytoin.Approved, Investigational
AtomoxetineThe metabolism of Atomoxetine can be increased when combined with Phenytoin.Approved
AtorvastatinThe serum concentration of Atorvastatin can be decreased when it is combined with Phenytoin.Approved
Atracurium besylatePhenytoin may decrease the neuromuscular blocking activities of Atracurium besylate.Approved
AvanafilThe metabolism of Avanafil can be increased when combined with Phenytoin.Approved
AxitinibThe serum concentration of Axitinib can be decreased when it is combined with Phenytoin.Approved, Investigational
AzaperoneThe risk or severity of adverse effects can be increased when Azaperone is combined with Phenytoin.Investigational, Vet Approved
AzelastinePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Azelastine.Approved
AzelnidipineThe serum concentration of Phenytoin can be increased when it is combined with Azelnidipine.Approved, Investigational
AzimilideThe serum concentration of Phenytoin can be increased when it is combined with Azimilide.Investigational
AzithromycinThe metabolism of Azithromycin can be increased when combined with Phenytoin.Approved
BaclofenThe risk or severity of adverse effects can be increased when Baclofen is combined with Phenytoin.Approved
Bafilomycin A1The serum concentration of Phenytoin can be increased when it is combined with Bafilomycin A1.Experimental
BanoxantroneThe metabolism of Banoxantrone can be increased when combined with Phenytoin.Investigational
BarbitalThe risk or severity of adverse effects can be increased when Barbital is combined with Phenytoin.Illicit
BarnidipineThe serum concentration of Phenytoin can be increased when it is combined with Barnidipine.Approved
BazedoxifeneThe serum concentration of Bazedoxifene can be decreased when it is combined with Phenytoin.Approved, Investigational
Beclomethasone dipropionateThe serum concentration of Beclomethasone dipropionate can be decreased when it is combined with Phenytoin.Approved, Investigational
BedaquilineThe serum concentration of Bedaquiline can be decreased when it is combined with Phenytoin.Approved
BencyclaneThe serum concentration of Phenytoin can be increased when it is combined with Bencyclane.Experimental
BenidipineThe serum concentration of Phenytoin can be increased when it is combined with Benidipine.Approved, Investigational
BenperidolThe risk or severity of adverse effects can be increased when Benperidol is combined with Phenytoin.Investigational
BenzatropineThe metabolism of Benzatropine can be increased when combined with Phenytoin.Approved
BenzocaineThe risk or severity of adverse effects can be increased when Benzocaine is combined with Phenytoin.Approved
Benzoic AcidThe serum concentration of Phenytoin can be increased when it is combined with Benzoic Acid.Approved
BenzphetamineThe serum concentration of Phenytoin can be decreased when it is combined with Benzphetamine.Approved, Illicit
Benzyl alcoholThe metabolism of Benzyl alcohol can be increased when combined with Phenytoin.Approved
BepridilThe serum concentration of Phenytoin can be increased when it is combined with Bepridil.Approved, Withdrawn
BeraprostThe metabolism of Beraprost can be increased when combined with Phenytoin.Investigational
BetamethasoneThe serum concentration of Betamethasone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
BexaroteneThe metabolism of Bexarotene can be increased when combined with Phenytoin.Approved, Investigational
BezafibrateThe metabolism of Bezafibrate can be increased when combined with Phenytoin.Approved
BicalutamideThe metabolism of Bicalutamide can be increased when combined with Phenytoin.Approved
BifonazoleThe serum concentration of Phenytoin can be increased when it is combined with Bifonazole.Approved, Investigational
BisoprololThe metabolism of Bisoprolol can be increased when combined with Phenytoin.Approved
BleomycinThe serum concentration of Phenytoin can be decreased when it is combined with Bleomycin.Approved
BMS-906024The serum concentration of Phenytoin can be increased when it is combined with BMS-906024.Investigational
BoceprevirThe serum concentration of Boceprevir can be decreased when it is combined with Phenytoin.Approved, Withdrawn
BortezomibThe serum concentration of Bortezomib can be decreased when it is combined with Phenytoin.Approved, Investigational
BosentanThe serum concentration of Phenytoin can be decreased when it is combined with Bosentan.Approved, Investigational
BosutinibThe serum concentration of Bosutinib can be decreased when it is combined with Phenytoin.Approved
Brefeldin AThe serum concentration of Phenytoin can be increased when it is combined with Brefeldin A.Experimental
Brentuximab vedotinThe serum concentration of Brentuximab vedotin can be decreased when it is combined with Phenytoin.Approved
BrexpiprazoleThe serum concentration of Brexpiprazole can be decreased when it is combined with Phenytoin.Approved
BrigatinibThe serum concentration of Brigatinib can be decreased when it is combined with Phenytoin.Approved
BrimonidineBrimonidine may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
BrinzolamideThe metabolism of Brinzolamide can be increased when combined with Phenytoin.Approved
BrivaracetamThe metabolism of Brivaracetam can be increased when combined with Phenytoin.Approved, Investigational
BromazepamThe serum concentration of Phenytoin can be increased when it is combined with Bromazepam.Approved, Illicit
BromisovalThe risk or severity of adverse effects can be increased when Bromisoval is combined with Phenytoin.Experimental
BromocriptineThe metabolism of Bromocriptine can be increased when combined with Phenytoin.Approved, Investigational
BromperidolThe risk or severity of adverse effects can be increased when Bromperidol is combined with Phenytoin.Investigational
BrompheniramineThe metabolism of Brompheniramine can be increased when combined with Phenytoin.Approved
BrotizolamThe risk or severity of adverse effects can be increased when Brotizolam is combined with Phenytoin.Approved, Investigational, Withdrawn
BudesonideThe metabolism of Budesonide can be increased when combined with Phenytoin.Approved
BumetanidePhenytoin may decrease the diuretic activities of Bumetanide.Approved
BupivacaineThe metabolism of Bupivacaine can be increased when combined with Phenytoin.Approved, Investigational
BuprenorphinePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Buprenorphine.Approved, Illicit, Investigational, Vet Approved
BupropionThe metabolism of Bupropion can be increased when combined with Phenytoin.Approved
BuspironeThe metabolism of Buspirone can be increased when combined with Phenytoin.Approved, Investigational
BusulfanThe serum concentration of Busulfan can be decreased when it is combined with Phenytoin.Approved, Investigational
ButabarbitalThe risk or severity of adverse effects can be increased when Butabarbital is combined with Phenytoin.Approved, Illicit
ButacaineThe risk or severity of adverse effects can be increased when Butacaine is combined with Phenytoin.Vet Approved
ButalbitalThe risk or severity of adverse effects can be increased when Butalbital is combined with Phenytoin.Approved, Illicit
ButambenThe risk or severity of adverse effects can be increased when Butamben is combined with Phenytoin.Approved
ButenafineThe serum concentration of Phenytoin can be increased when it is combined with Butenafine.Approved
ButethalThe risk or severity of adverse effects can be increased when Butethal is combined with Phenytoin.Approved, Illicit
ButoconazoleThe serum concentration of Phenytoin can be increased when it is combined with Butoconazole.Approved
ButorphanolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Phenytoin.Approved, Illicit, Vet Approved
CabazitaxelThe metabolism of Cabazitaxel can be increased when combined with Phenytoin.Approved
CabergolineThe metabolism of Cabergoline can be increased when combined with Phenytoin.Approved
CabozantinibThe serum concentration of Cabozantinib can be decreased when it is combined with Phenytoin.Approved
CaffeineThe metabolism of Caffeine can be increased when combined with Phenytoin.Approved
CalcitriolThe metabolism of Calcitriol can be increased when combined with Phenytoin.Approved, Nutraceutical
CamazepamThe serum concentration of Phenytoin can be increased when it is combined with Camazepam.Approved, Illicit
CanagliflozinThe serum concentration of Canagliflozin can be decreased when it is combined with Phenytoin.Approved
CandesartanThe metabolism of Candesartan can be increased when combined with Phenytoin.Experimental
Candesartan cilexetilThe metabolism of Candesartan cilexetil can be increased when combined with Phenytoin.Approved
CandicidinThe serum concentration of Phenytoin can be increased when it is combined with Candicidin.Withdrawn
CanertinibThe risk or severity of adverse effects can be increased when Canertinib is combined with Phenytoin.Investigational
CannabidiolThe serum concentration of Cannabidiol can be decreased when it is combined with Phenytoin.Approved, Investigational
CapecitabineThe serum concentration of Phenytoin can be increased when it is combined with Capecitabine.Approved, Investigational
Capric acidThe serum concentration of Phenytoin can be increased when it is combined with Capric acid.Experimental
CarbamazepineThe serum concentration of Phenytoin can be decreased when it is combined with Carbamazepine.Approved, Investigational
CarbinoxamineThe metabolism of Carbinoxamine can be increased when combined with Phenytoin.Approved
CarboplatinThe serum concentration of Phenytoin can be decreased when it is combined with Carboplatin.Approved
CarboxyamidotriazoleThe serum concentration of Phenytoin can be increased when it is combined with Carboxyamidotriazole.Investigational
CarfentanilThe risk or severity of adverse effects can be increased when Carfentanil is combined with Phenytoin.Illicit, Investigational, Vet Approved
CariprazineThe metabolism of Cariprazine can be increased when combined with Phenytoin.Approved
CarisoprodolThe metabolism of Carisoprodol can be increased when combined with Phenytoin.Approved
CaroverineThe serum concentration of Phenytoin can be increased when it is combined with Caroverine.Experimental
CarvedilolThe metabolism of Carvedilol can be increased when combined with Phenytoin.Approved, Investigational
CaspofunginThe serum concentration of Caspofungin can be decreased when it is combined with Phenytoin.Approved
CE-326597The serum concentration of Phenytoin can be increased when it is combined with CE-326597.Investigational
CefazolinThe protein binding of Phenytoin can be decreased when combined with Cefazolin.Approved
CelecoxibThe metabolism of Celecoxib can be increased when combined with Phenytoin.Approved, Investigational
CeliprololThe metabolism of Celiprolol can be increased when combined with Phenytoin.Approved, Investigational
CephalexinThe metabolism of Cephalexin can be increased when combined with Phenytoin.Approved, Vet Approved
CeritinibThe serum concentration of Phenytoin can be increased when it is combined with Ceritinib.Approved
CerivastatinThe serum concentration of Cerivastatin can be decreased when it is combined with Phenytoin.Withdrawn
CeruleninThe serum concentration of Phenytoin can be increased when it is combined with Cerulenin.Approved
CetirizineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Cetirizine.Approved
CevimelineThe metabolism of Cevimeline can be increased when combined with Phenytoin.Approved
Chenodeoxycholic acidThe metabolism of Chenodeoxycholic acid can be increased when combined with Phenytoin.Approved
Chloral hydrateThe risk or severity of adverse effects can be increased when Chloral hydrate is combined with Phenytoin.Approved, Illicit, Vet Approved
ChloramphenicolThe metabolism of Phenytoin can be decreased when combined with Chloramphenicol.Approved, Vet Approved
ChlordiazepoxideThe serum concentration of Phenytoin can be increased when it is combined with Chlordiazepoxide.Approved, Illicit
ChlormezanoneThe risk or severity of adverse effects can be increased when Chlormezanone is combined with Phenytoin.Approved, Investigational, Withdrawn
ChloroprocaineThe risk or severity of adverse effects can be increased when Chloroprocaine is combined with Phenytoin.Approved
ChloroquineThe metabolism of Chloroquine can be increased when combined with Phenytoin.Approved, Vet Approved
ChlorotrianiseneThe therapeutic efficacy of Chlorotrianisene can be decreased when used in combination with Phenytoin.Investigational, Withdrawn
ChloroxineThe serum concentration of Phenytoin can be increased when it is combined with Chloroxine.Approved
ChlorphenamineThe serum concentration of Phenytoin can be increased when it is combined with Chlorphenamine.Approved
ChlorphentermineThe serum concentration of Phenytoin can be decreased when it is combined with Chlorphentermine.Illicit, Withdrawn
ChlorpromazineThe metabolism of Chlorpromazine can be increased when combined with Phenytoin.Approved, Vet Approved
ChlorpropamideThe metabolism of Chlorpropamide can be increased when combined with Phenytoin.Approved
ChlorprothixeneThe risk or severity of adverse effects can be increased when Chlorprothixene is combined with Phenytoin.Approved, Investigational, Withdrawn
ChlorzoxazoneThe metabolism of Chlorzoxazone can be increased when combined with Phenytoin.Approved
CholecalciferolThe metabolism of Cholecalciferol can be increased when combined with Phenytoin.Approved, Nutraceutical
CiclesonideThe metabolism of Ciclesonide can be increased when combined with Phenytoin.Approved, Investigational
CiclopiroxThe serum concentration of Phenytoin can be increased when it is combined with Ciclopirox.Approved, Investigational
CilnidipineThe serum concentration of Phenytoin can be increased when it is combined with Cilnidipine.Approved, Investigational
CilostazolThe metabolism of Cilostazol can be increased when combined with Phenytoin.Approved
CimetidineThe risk or severity of adverse effects can be increased when Cimetidine is combined with Phenytoin.Approved
CinacalcetThe metabolism of Cinacalcet can be increased when combined with Phenytoin.Approved
CinchocaineThe risk or severity of adverse effects can be increased when Cinchocaine is combined with Phenytoin.Approved, Vet Approved
CinnarizineThe serum concentration of Phenytoin can be increased when it is combined with Cinnarizine.Approved, Investigational
CiprofloxacinThe therapeutic efficacy of Phenytoin can be decreased when used in combination with Ciprofloxacin.Approved, Investigational
CisaprideThe metabolism of Cisapride can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
CisplatinThe serum concentration of Phenytoin can be decreased when it is combined with Cisplatin.Approved
CitalopramThe metabolism of Citalopram can be increased when combined with Phenytoin.Approved
ClarithromycinThe serum concentration of the active metabolites of Clarithromycin can be increased when Clarithromycin is used in combination with Phenytoin.Approved
ClemastineThe metabolism of Phenytoin can be decreased when combined with Clemastine.Approved
ClevidipineThe serum concentration of Phenytoin can be increased when it is combined with Clevidipine.Approved
ClidiniumThe risk or severity of adverse effects can be increased when Phenytoin is combined with Clidinium.Approved
ClindamycinThe metabolism of Clindamycin can be increased when combined with Phenytoin.Approved, Vet Approved
ClobazamThe serum concentration of Phenytoin can be increased when it is combined with Clobazam.Approved, Illicit
ClobetasolThe serum concentration of Clobetasol can be decreased when it is combined with Phenytoin.Investigational
Clobetasol propionateThe serum concentration of Clobetasol propionate can be decreased when it is combined with Phenytoin.Approved
ClobetasoneThe serum concentration of Clobetasone can be decreased when it is combined with Phenytoin.Approved
ClocortoloneThe serum concentration of Clocortolone can be decreased when it is combined with Phenytoin.Approved
ClofazimineThe metabolism of Clofazimine can be increased when combined with Phenytoin.Approved, Investigational
ClofibrateThe metabolism of Clofibrate can be increased when combined with Phenytoin.Approved, Investigational
clomethiazoleThe metabolism of clomethiazole can be increased when combined with Phenytoin.Investigational
ClomipramineThe metabolism of Clomipramine can be increased when combined with Phenytoin.Approved, Vet Approved
ClonazepamThe serum concentration of Phenytoin can be increased when it is combined with Clonazepam.Approved, Illicit
ClonidineThe metabolism of Clonidine can be increased when combined with Phenytoin.Approved
ClopenthixolThe risk or severity of adverse effects can be increased when Clopenthixol is combined with Phenytoin.Experimental
ClopidogrelThe metabolism of Clopidogrel can be increased when combined with Phenytoin.Approved, Nutraceutical
ClorazepateThe serum concentration of Phenytoin can be increased when it is combined with Clorazepate.Approved, Illicit
ClorindionePhenytoin may increase the anticoagulant activities of Clorindione.Experimental
ClothiapineThe risk or severity of adverse effects can be increased when Clothiapine is combined with Phenytoin.Experimental
ClotiazepamThe metabolism of Clotiazepam can be increased when combined with Phenytoin.Approved, Illicit
ClotrimazoleThe serum concentration of Phenytoin can be increased when it is combined with Clotrimazole.Approved, Vet Approved
ClozapineThe serum concentration of Clozapine can be decreased when it is combined with Phenytoin.Approved
CobicistatThe serum concentration of Cobicistat can be decreased when it is combined with Phenytoin.Approved
CobimetinibThe serum concentration of Cobimetinib can be decreased when it is combined with Phenytoin.Approved
CocaineThe metabolism of Cocaine can be increased when combined with Phenytoin.Approved, Illicit
CodeineThe metabolism of Codeine can be increased when combined with Phenytoin.Approved, Illicit
ColchicineThe metabolism of Colchicine can be increased when combined with Phenytoin.Approved
ColesevelamThe serum concentration of Phenytoin can be decreased when it is combined with Colesevelam.Approved
ConivaptanThe serum concentration of Phenytoin can be increased when it is combined with Conivaptan.Approved, Investigational
Conjugated estrogensThe therapeutic efficacy of Conjugated estrogens can be decreased when used in combination with Phenytoin.Approved
CopanlisibThe metabolism of Copanlisib can be increased when combined with Phenytoin.Approved
CordycepinThe serum concentration of Phenytoin can be increased when it is combined with Cordycepin.Investigational
Cortexolone 17α-propionateThe serum concentration of Cortexolone 17α-propionate can be decreased when it is combined with Phenytoin.Investigational
CorticosteroneThe serum concentration of Corticosterone can be decreased when it is combined with Phenytoin.Experimental
Cortisone acetateThe metabolism of Cortisone acetate can be increased when combined with Phenytoin.Approved
CrisaboroleThe metabolism of Phenytoin can be decreased when combined with Crisaborole.Approved
CrizotinibThe serum concentration of Crizotinib can be decreased when it is combined with Phenytoin.Approved
CyclizineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Cyclizine.Approved
CyclobenzaprineThe metabolism of Cyclobenzaprine can be increased when combined with Phenytoin.Approved
CyclophosphamideThe metabolism of Cyclophosphamide can be increased when combined with Phenytoin.Approved, Investigational
CyclosporineThe metabolism of Cyclosporine can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
CyproheptadineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Cyproheptadine.Approved
CytarabineThe metabolism of Cytarabine can be increased when combined with Phenytoin.Approved, Investigational
DabrafenibThe serum concentration of Phenytoin can be decreased when it is combined with Dabrafenib.Approved
DaclatasvirThe serum concentration of Daclatasvir can be decreased when it is combined with Phenytoin.Approved
DantroleneThe metabolism of Dantrolene can be increased when combined with Phenytoin.Approved
DapagliflozinThe metabolism of Dapagliflozin can be increased when combined with Phenytoin.Approved
DapiprazoleThe risk or severity of adverse effects can be increased when Dapiprazole is combined with Phenytoin.Approved
DapoxetineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Dapoxetine.Investigational
DapsoneThe risk or severity of adverse effects can be increased when Dapsone is combined with Phenytoin.Approved, Investigational
DarifenacinThe metabolism of Darifenacin can be increased when combined with Phenytoin.Approved, Investigational
DarodipineThe serum concentration of Phenytoin can be increased when it is combined with Darodipine.Experimental
DarunavirThe serum concentration of Phenytoin can be decreased when it is combined with Darunavir.Approved
DasabuvirThe metabolism of Dasabuvir can be increased when combined with Phenytoin.Approved
DasatinibThe serum concentration of Dasatinib can be decreased when it is combined with Phenytoin.Approved, Investigational
DaunorubicinThe metabolism of Daunorubicin can be increased when combined with Phenytoin.Approved
DeferasiroxThe serum concentration of Deferasirox can be decreased when it is combined with Phenytoin.Approved, Investigational
DeflazacortThe metabolism of Deflazacort can be increased when combined with Phenytoin.Approved
DelavirdineThe serum concentration of Delavirdine can be decreased when it is combined with Phenytoin.Approved
DelorazepamThe serum concentration of Phenytoin can be increased when it is combined with Delorazepam.Approved, Illicit, Investigational
DeramciclaneThe risk or severity of adverse effects can be increased when Deramciclane is combined with Phenytoin.Investigational
DesfluraneThe risk or severity of adverse effects can be increased when Desflurane is combined with Phenytoin.Approved
DesipramineThe metabolism of Desipramine can be increased when combined with Phenytoin.Approved
DesloratadineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Desloratadine.Approved, Investigational
DesogestrelThe therapeutic efficacy of Desogestrel can be decreased when used in combination with Phenytoin.Approved
DesonideThe serum concentration of Desonide can be decreased when it is combined with Phenytoin.Approved, Investigational
DesoximetasoneThe serum concentration of Desoximetasone can be decreased when it is combined with Phenytoin.Approved
Desoxycorticosterone acetateThe serum concentration of Desoxycorticosterone acetate can be decreased when it is combined with Phenytoin.Approved
Desoxycorticosterone PivalateThe serum concentration of Desoxycorticosterone Pivalate can be decreased when it is combined with Phenytoin.Experimental, Vet Approved
DesvenlafaxineThe metabolism of Desvenlafaxine can be increased when combined with Phenytoin.Approved
DetomidineThe risk or severity of adverse effects can be increased when Detomidine is combined with Phenytoin.Vet Approved
DeutetrabenazineThe metabolism of Deutetrabenazine can be increased when combined with Phenytoin.Approved, Investigational
DexamethasoneThe serum concentration of Dexamethasone can be decreased when it is combined with Phenytoin.Approved, Investigational, Vet Approved
Dexamethasone isonicotinateThe serum concentration of Dexamethasone isonicotinate can be decreased when it is combined with Phenytoin.Vet Approved
DexbrompheniramineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Dexbrompheniramine.Approved
Dexchlorpheniramine maleateThe metabolism of Dexchlorpheniramine maleate can be increased when combined with Phenytoin.Approved
DexketoprofenThe risk or severity of adverse effects can be increased when Dexketoprofen is combined with Phenytoin.Approved, Investigational
DexlansoprazoleThe metabolism of Dexlansoprazole can be increased when combined with Phenytoin.Approved
DexmedetomidineThe risk or severity of adverse effects can be increased when Dexmedetomidine is combined with Phenytoin.Approved, Vet Approved
DexmethylphenidateThe serum concentration of Phenytoin can be increased when it is combined with Dexmethylphenidate.Approved
DextroamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with Dextroamphetamine.Approved, Illicit
DextromethorphanThe metabolism of Dextromethorphan can be increased when combined with Phenytoin.Approved
DextromoramideThe risk or severity of adverse effects can be increased when Dextromoramide is combined with Phenytoin.Experimental, Illicit
DextropropoxypheneThe metabolism of Dextropropoxyphene can be increased when combined with Phenytoin.Approved, Illicit, Investigational, Withdrawn
DezocineThe risk or severity of adverse effects can be increased when Dezocine is combined with Phenytoin.Approved, Investigational
DiazepamThe serum concentration of Phenytoin can be increased when it is combined with Diazepam.Approved, Illicit, Vet Approved
DiazoxideThe serum concentration of Phenytoin can be decreased when it is combined with Diazoxide.Approved
DichloropheneThe serum concentration of Phenytoin can be increased when it is combined with Dichlorophene.Vet Approved
DiclofenacThe serum concentration of Diclofenac can be decreased when it is combined with Phenytoin.Approved, Vet Approved
DiclofenamideThe risk or severity of adverse effects can be increased when Diclofenamide is combined with Phenytoin.Approved
DicoumarolPhenytoin may increase the anticoagulant activities of Dicoumarol.Approved
DienestrolThe therapeutic efficacy of Dienestrol can be decreased when used in combination with Phenytoin.Approved, Investigational
DienogestThe therapeutic efficacy of Dienogest can be decreased when used in combination with Phenytoin.Approved
Diethyl etherThe risk or severity of adverse effects can be increased when Diethyl ether is combined with Phenytoin.Experimental
DiethylpropionThe serum concentration of Phenytoin can be decreased when it is combined with Diethylpropion.Approved, Illicit
DiethylstilbestrolThe therapeutic efficacy of Diethylstilbestrol can be decreased when used in combination with Phenytoin.Approved, Investigational
DifenoxinThe risk or severity of adverse effects can be increased when Phenytoin is combined with Difenoxin.Approved, Illicit
DiflorasoneThe serum concentration of Diflorasone can be decreased when it is combined with Phenytoin.Approved
DifluocortoloneThe serum concentration of Difluocortolone can be decreased when it is combined with Phenytoin.Approved, Investigational
DifluprednateThe serum concentration of Difluprednate can be decreased when it is combined with Phenytoin.Approved
DigitoxinThe metabolism of Digitoxin can be increased when combined with Phenytoin.Approved, Investigational
DigoxinThe metabolism of Digoxin can be increased when combined with Phenytoin.Approved
DihydrocodeineThe metabolism of Dihydrocodeine can be increased when combined with Phenytoin.Approved, Illicit
DihydroergotamineThe metabolism of Dihydroergotamine can be increased when combined with Phenytoin.Approved
DihydroetorphineThe risk or severity of adverse effects can be increased when Dihydroetorphine is combined with Phenytoin.Experimental, Illicit
DihydromorphineThe risk or severity of adverse effects can be increased when Dihydromorphine is combined with Phenytoin.Experimental, Illicit
DiltiazemThe serum concentration of Phenytoin can be increased when it is combined with Diltiazem.Approved
DimenhydrinateThe risk or severity of adverse effects can be increased when Phenytoin is combined with Dimenhydrinate.Approved
DiphenadionePhenytoin may increase the anticoagulant activities of Diphenadione.Experimental
DiphenhydramineThe metabolism of Diphenhydramine can be increased when combined with Phenytoin.Approved
DiphenoxylateThe risk or severity of adverse effects can be increased when Diphenoxylate is combined with Phenytoin.Approved, Illicit
DisopyramideThe serum concentration of Disopyramide can be decreased when it is combined with Phenytoin.Approved
DisulfiramThe serum concentration of Phenytoin can be increased when it is combined with Disulfiram.Approved
DixyrazineThe risk or severity of adverse effects can be increased when Dixyrazine is combined with Phenytoin.Experimental
DocetaxelThe metabolism of Docetaxel can be increased when combined with Phenytoin.Approved, Investigational
DoconexentThe metabolism of Doconexent can be increased when combined with Phenytoin.Approved, Investigational
DofetilideThe metabolism of Dofetilide can be increased when combined with Phenytoin.Approved
DolasetronThe metabolism of Dolasetron can be increased when combined with Phenytoin.Approved
DolutegravirThe serum concentration of Dolutegravir can be decreased when it is combined with Phenytoin.Approved
DomperidoneThe metabolism of Domperidone can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
DonepezilThe metabolism of Donepezil can be increased when combined with Phenytoin.Approved
DopamineThe metabolism of Dopamine can be increased when combined with Phenytoin.Approved
DoramectinThe risk or severity of adverse effects can be increased when Doramectin is combined with Phenytoin.Vet Approved
DorzolamideThe metabolism of Dorzolamide can be increased when combined with Phenytoin.Approved
DosulepinThe metabolism of Phenytoin can be decreased when combined with Dosulepin.Approved
DotarizineThe serum concentration of Phenytoin can be increased when it is combined with Dotarizine.Investigational
DoxazosinThe metabolism of Doxazosin can be increased when combined with Phenytoin.Approved
DoxefazepamThe serum concentration of Phenytoin can be increased when it is combined with Doxefazepam.Experimental
DoxepinThe metabolism of Doxepin can be increased when combined with Phenytoin.Approved
DoxofyllineThe serum concentration of Doxofylline can be decreased when it is combined with Phenytoin.Approved
DoxorubicinThe serum concentration of Doxorubicin can be decreased when it is combined with Phenytoin.Approved, Investigational
DoxorubicinThe metabolism of Doxorubicin can be increased when combined with Phenytoin.Approved, Investigational
DoxycyclineThe serum concentration of Doxycycline can be decreased when it is combined with Phenytoin.Approved, Investigational, Vet Approved
DoxylamineDoxylamine may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved, Vet Approved
DPDPEThe risk or severity of adverse effects can be increased when DPDPE is combined with Phenytoin.Experimental
DronabinolDronabinol may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved, Illicit
DronedaroneThe serum concentration of Dronedarone can be decreased when it is combined with Phenytoin.Approved
DroperidolDroperidol may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved, Vet Approved
DrospirenoneThe therapeutic efficacy of Drospirenone can be decreased when used in combination with Phenytoin.Approved
DrotebanolThe risk or severity of adverse effects can be increased when Drotebanol is combined with Phenytoin.Experimental, Illicit
DuloxetineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Duloxetine.Approved
DutasterideThe metabolism of Dutasteride can be increased when combined with Phenytoin.Approved, Investigational
DyclonineThe risk or severity of adverse effects can be increased when Dyclonine is combined with Phenytoin.Approved
DyphyllineThe serum concentration of Dyphylline can be decreased when it is combined with Phenytoin.Approved
EcgonineThe risk or severity of adverse effects can be increased when Ecgonine is combined with Phenytoin.Experimental, Illicit
EconazoleThe serum concentration of Phenytoin can be increased when it is combined with Econazole.Approved
EcopipamThe risk or severity of adverse effects can be increased when Ecopipam is combined with Phenytoin.Investigational
EfavirenzThe serum concentration of Efavirenz can be decreased when it is combined with Phenytoin.Approved, Investigational
EfinaconazoleThe serum concentration of Phenytoin can be increased when it is combined with Efinaconazole.Approved
EfonidipineThe serum concentration of Phenytoin can be increased when it is combined with Efonidipine.Approved, Investigational
ElbasvirThe metabolism of Elbasvir can be increased when combined with Phenytoin.Approved
EletriptanThe metabolism of Eletriptan can be increased when combined with Phenytoin.Approved, Investigational
EliglustatThe serum concentration of Eliglustat can be decreased when it is combined with Phenytoin.Approved
EltanoloneThe risk or severity of adverse effects can be increased when Eltanolone is combined with Phenytoin.Investigational
EltrombopagThe metabolism of Eltrombopag can be increased when combined with Phenytoin.Approved
ElvitegravirThe serum concentration of Elvitegravir can be decreased when it is combined with Phenytoin.Approved
EnalaprilThe metabolism of Enalapril can be increased when combined with Phenytoin.Approved, Vet Approved
EnasidenibThe metabolism of Enasidenib can be increased when combined with Phenytoin.Approved
EnfluraneThe risk or severity of adverse effects can be increased when Enflurane is combined with Phenytoin.Approved, Investigational, Vet Approved
EnfuvirtideThe metabolism of Enfuvirtide can be increased when combined with Phenytoin.Approved, Investigational
EntacaponeThe risk or severity of adverse effects can be increased when Phenytoin is combined with Entacapone.Approved, Investigational
EnzalutamideThe serum concentration of Phenytoin can be decreased when it is combined with Enzalutamide.Approved
EperisoneThe serum concentration of Phenytoin can be increased when it is combined with Eperisone.Approved, Investigational
EpinastineThe metabolism of Epinastine can be increased when combined with Phenytoin.Approved, Investigational
EplerenoneThe metabolism of Eplerenone can be increased when combined with Phenytoin.Approved
EpoprostenolThe metabolism of Epoprostenol can be increased when combined with Phenytoin.Approved
EquileninThe serum concentration of Equilenin can be decreased when it is combined with Phenytoin.Experimental
EquilinThe serum concentration of Equilin can be decreased when it is combined with Phenytoin.Approved
ErgocalciferolThe metabolism of Ergocalciferol can be increased when combined with Phenytoin.Approved, Nutraceutical
Ergoloid mesylateThe metabolism of Ergoloid mesylate can be increased when combined with Phenytoin.Approved
ErgonovineThe metabolism of Ergonovine can be increased when combined with Phenytoin.Approved
ErgotamineThe metabolism of Ergotamine can be increased when combined with Phenytoin.Approved
ErlotinibThe serum concentration of Erlotinib can be decreased when it is combined with Phenytoin.Approved, Investigational
ErythromycinThe metabolism of Erythromycin can be increased when combined with Phenytoin.Approved, Vet Approved
EscitalopramThe metabolism of Escitalopram can be increased when combined with Phenytoin.Approved, Investigational
Eslicarbazepine acetateThe serum concentration of Eslicarbazepine acetate can be decreased when it is combined with Phenytoin.Approved
EsomeprazoleThe metabolism of Esomeprazole can be increased when combined with Phenytoin.Approved, Investigational
EstazolamThe serum concentration of Phenytoin can be increased when it is combined with Estazolam.Approved, Illicit
EstradiolThe therapeutic efficacy of Estradiol can be decreased when used in combination with Phenytoin.Approved, Investigational, Vet Approved
Estradiol valerate/DienogestThe metabolism of Estradiol valerate/Dienogest can be increased when combined with Phenytoin.Approved, Investigational
EstramustineThe therapeutic efficacy of Estramustine can be decreased when used in combination with Phenytoin.Approved
Estrogens, esterifiedThe therapeutic efficacy of Estrogens, esterified can be decreased when used in combination with Phenytoin.Approved
EstroneThe metabolism of Estrone can be increased when combined with Phenytoin.Approved
Estrone sulfateThe therapeutic efficacy of Estrone sulfate can be decreased when used in combination with Phenytoin.Approved
EszopicloneThe metabolism of Eszopiclone can be increased when combined with Phenytoin.Approved
Etacrynic acidPhenytoin may decrease the diuretic activities of Etacrynic acid.Approved
EthanolEthanol may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
EthchlorvynolThe risk or severity of adverse effects can be increased when Ethchlorvynol is combined with Phenytoin.Approved, Illicit, Withdrawn
Ethinyl EstradiolThe therapeutic efficacy of Ethinyl Estradiol can be decreased when used in combination with Phenytoin.Approved
EthosuximideEthosuximide may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
EthotoinThe risk or severity of adverse effects can be increased when Phenytoin is combined with Ethotoin.Approved
EthoxzolamideThe risk or severity of adverse effects can be increased when Ethoxzolamide is combined with Phenytoin.Withdrawn
Ethyl biscoumacetatePhenytoin may increase the anticoagulant activities of Ethyl biscoumacetate.Withdrawn
Ethyl carbamateThe risk or severity of adverse effects can be increased when Ethyl carbamate is combined with Phenytoin.Withdrawn
Ethyl chlorideThe risk or severity of adverse effects can be increased when Ethyl chloride is combined with Phenytoin.Experimental, Investigational
Ethyl loflazepateThe risk or severity of adverse effects can be increased when Ethyl loflazepate is combined with Phenytoin.Approved, Illicit
EthylmorphineThe metabolism of Ethylmorphine can be increased when combined with Phenytoin.Approved, Illicit
Ethynodiol diacetateThe therapeutic efficacy of Ethynodiol diacetate can be decreased when used in combination with Phenytoin.Approved
EtidocaineThe risk or severity of adverse effects can be increased when Etidocaine is combined with Phenytoin.Approved
EtifoxineThe risk or severity of adverse effects can be increased when Etifoxine is combined with Phenytoin.Investigational, Withdrawn
EtizolamThe serum concentration of Phenytoin can be increased when it is combined with Etizolam.Approved
EtodolacThe metabolism of Etodolac can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
EtomidateThe risk or severity of adverse effects can be increased when Etomidate is combined with Phenytoin.Approved
EtonogestrelThe therapeutic efficacy of Etonogestrel can be decreased when used in combination with Phenytoin.Approved, Investigational
EtoperidoneThe risk or severity of adverse effects can be increased when Phenytoin is combined with Etoperidone.Withdrawn
EtoposideThe serum concentration of Etoposide can be decreased when it is combined with Phenytoin.Approved
EtoricoxibThe metabolism of Etoricoxib can be increased when combined with Phenytoin.Approved, Investigational
EtorphineThe risk or severity of adverse effects can be increased when Etorphine is combined with Phenytoin.Illicit, Vet Approved
EtravirineThe serum concentration of Etravirine can be decreased when it is combined with Phenytoin.Approved
EverolimusThe serum concentration of Everolimus can be decreased when it is combined with Phenytoin.Approved
ExemestaneThe serum concentration of Exemestane can be decreased when it is combined with Phenytoin.Approved, Investigational
EzogabineThe serum concentration of Ezogabine can be decreased when it is combined with Phenytoin.Approved
FamciclovirThe metabolism of Famciclovir can be increased when combined with Phenytoin.Approved
FamotidineThe metabolism of Famotidine can be increased when combined with Phenytoin.Approved
FelbamateThe serum concentration of Phenytoin can be increased when it is combined with Felbamate.Approved
FelodipineThe serum concentration of Phenytoin can be increased when it is combined with Felodipine.Approved, Investigational
FencamfamineThe risk or severity of adverse effects can be increased when Fencamfamine is combined with Phenytoin.Approved, Illicit, Withdrawn
FendilineThe serum concentration of Phenytoin can be increased when it is combined with Fendiline.Withdrawn
FenofibrateThe metabolism of Fenofibrate can be increased when combined with Phenytoin.Approved
FentanylThe serum concentration of Fentanyl can be decreased when it is combined with Phenytoin.Approved, Illicit, Investigational, Vet Approved
FenticonazoleThe serum concentration of Phenytoin can be increased when it is combined with Fenticonazole.Experimental
FesoterodineThe metabolism of Fesoterodine can be increased when combined with Phenytoin.Approved
FexofenadineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Fexofenadine.Approved
FinasterideThe metabolism of Finasteride can be increased when combined with Phenytoin.Approved
FingolimodThe metabolism of Fingolimod can be increased when combined with Phenytoin.Approved, Investigational
FlibanserinThe serum concentration of Flibanserin can be decreased when it is combined with Phenytoin.Approved
FloxuridineThe serum concentration of Phenytoin can be increased when it is combined with Floxuridine.Approved
FluanisoneThe risk or severity of adverse effects can be increased when Fluanisone is combined with Phenytoin.Experimental
fluasteroneThe serum concentration of fluasterone can be decreased when it is combined with Phenytoin.Investigational
FluconazoleThe serum concentration of Phenytoin can be increased when it is combined with Fluconazole.Approved
FlucytosineThe serum concentration of Phenytoin can be increased when it is combined with Flucytosine.Approved
FludiazepamThe serum concentration of Phenytoin can be increased when it is combined with Fludiazepam.Approved, Illicit
FludrocortisoneThe serum concentration of Fludrocortisone can be decreased when it is combined with Phenytoin.Approved
FluindionePhenytoin may increase the anticoagulant activities of Fluindione.Investigational
FlumazenilThe serum concentration of Phenytoin can be increased when it is combined with Flumazenil.Approved
FlumethasoneThe serum concentration of Flumethasone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
FlunarizineThe serum concentration of Flunarizine can be decreased when it is combined with Phenytoin.Approved
FlunisolideThe metabolism of Flunisolide can be increased when combined with Phenytoin.Approved, Investigational
FlunitrazepamThe serum concentration of Phenytoin can be increased when it is combined with Flunitrazepam.Approved, Illicit
Fluocinolone AcetonideThe serum concentration of Fluocinolone Acetonide can be decreased when it is combined with Phenytoin.Approved, Investigational, Vet Approved
FluocinonideThe serum concentration of Fluocinonide can be decreased when it is combined with Phenytoin.Approved, Investigational
FluocortoloneThe serum concentration of Fluocortolone can be decreased when it is combined with Phenytoin.Approved, Withdrawn
FluorometholoneThe metabolism of Fluorometholone can be increased when combined with Phenytoin.Approved
FluorouracilThe serum concentration of Phenytoin can be increased when it is combined with Fluorouracil.Approved
FluoxetineThe serum concentration of Phenytoin can be increased when it is combined with Fluoxetine.Approved, Vet Approved
FlupentixolThe risk or severity of adverse effects can be increased when Flupentixol is combined with Phenytoin.Approved, Withdrawn
FluphenazineThe risk or severity of adverse effects can be increased when Fluphenazine is combined with Phenytoin.Approved
FluprednideneThe serum concentration of Fluprednidene can be decreased when it is combined with Phenytoin.Approved, Withdrawn
FluprednisoloneThe serum concentration of Fluprednisolone can be decreased when it is combined with Phenytoin.Approved
FlurandrenolideThe serum concentration of Flurandrenolide can be decreased when it is combined with Phenytoin.Approved
FlurazepamThe serum concentration of Phenytoin can be increased when it is combined with Flurazepam.Approved, Illicit
FlurbiprofenThe metabolism of Flurbiprofen can be increased when combined with Phenytoin.Approved, Investigational
FluspirileneThe risk or severity of adverse effects can be increased when Fluspirilene is combined with Phenytoin.Approved, Investigational
FlutamideThe metabolism of Flutamide can be increased when combined with Phenytoin.Approved
Fluticasone furoateThe metabolism of Fluticasone furoate can be increased when combined with Phenytoin.Approved
Fluticasone propionateThe metabolism of Fluticasone propionate can be increased when combined with Phenytoin.Approved
FlutrimazoleThe serum concentration of Phenytoin can be increased when it is combined with Flutrimazole.Experimental
FluvastatinThe serum concentration of Fluvastatin can be decreased when it is combined with Phenytoin.Approved
FluvoxamineThe serum concentration of Phenytoin can be increased when it is combined with Fluvoxamine.Approved, Investigational
Folic AcidThe serum concentration of Phenytoin can be decreased when it is combined with Folic Acid.Approved, Nutraceutical, Vet Approved
FormestaneThe serum concentration of Formestane can be decreased when it is combined with Phenytoin.Approved, Investigational, Withdrawn
FormoterolThe metabolism of Formoterol can be increased when combined with Phenytoin.Approved, Investigational
FosamprenavirThe serum concentration of Phenytoin can be decreased when it is combined with Fosamprenavir.Approved
FosaprepitantThe serum concentration of Phenytoin can be increased when it is combined with Fosaprepitant.Approved
FosphenytoinThe metabolism of Phenytoin can be increased when combined with Fosphenytoin.Approved
FospropofolThe risk or severity of adverse effects can be increased when Fospropofol is combined with Phenytoin.Approved, Illicit, Investigational
FulvestrantThe metabolism of Fulvestrant can be increased when combined with Phenytoin.Approved, Investigational
FurosemidePhenytoin may decrease the diuretic activities of Furosemide.Approved, Vet Approved
Fusidic AcidThe serum concentration of Phenytoin can be increased when it is combined with Fusidic Acid.Approved
GabapentinThe serum concentration of Phenytoin can be increased when it is combined with Gabapentin.Approved, Investigational
Gabapentin EnacarbilThe risk or severity of adverse effects can be increased when Phenytoin is combined with Gabapentin Enacarbil.Approved
GalantamineThe metabolism of Galantamine can be increased when combined with Phenytoin.Approved
GallopamilThe serum concentration of Phenytoin can be increased when it is combined with Gallopamil.Investigational
Gamma Hydroxybutyric AcidThe risk or severity of adverse effects can be increased when Gamma Hydroxybutyric Acid is combined with Phenytoin.Approved, Illicit, Investigational
GavestinelThe metabolism of Gavestinel can be increased when combined with Phenytoin.Investigational
GefitinibThe serum concentration of Gefitinib can be decreased when it is combined with Phenytoin.Approved, Investigational
GemfibrozilThe metabolism of Gemfibrozil can be increased when combined with Phenytoin.Approved
GepefrineThe serum concentration of Phenytoin can be decreased when it is combined with Gepefrine.Experimental
GepironeThe risk or severity of adverse effects can be increased when Gepirone is combined with Phenytoin.Investigational
GestodeneThe therapeutic efficacy of Gestodene can be decreased when used in combination with Phenytoin.Approved, Investigational
GliclazideThe metabolism of Gliclazide can be increased when combined with Phenytoin.Approved
GlimepirideThe metabolism of Glimepiride can be increased when combined with Phenytoin.Approved
GlipizideThe metabolism of Glipizide can be increased when combined with Phenytoin.Approved
GlucosamineThe metabolism of Glucosamine can be increased when combined with Phenytoin.Approved
GlutethimideThe risk or severity of adverse effects can be increased when Glutethimide is combined with Phenytoin.Approved, Illicit
GlyburideThe metabolism of Glyburide can be increased when combined with Phenytoin.Approved
GlyphosateThe serum concentration of Phenytoin can be increased when it is combined with Glyphosate.Experimental
GranisetronThe metabolism of Granisetron can be increased when combined with Phenytoin.Approved, Investigational
GrazoprevirThe metabolism of Grazoprevir can be increased when combined with Phenytoin.Approved
GrepafloxacinThe metabolism of Grepafloxacin can be increased when combined with Phenytoin.Investigational, Withdrawn
GriseofulvinThe serum concentration of Phenytoin can be increased when it is combined with Griseofulvin.Approved, Vet Approved
GuanfacineThe serum concentration of Guanfacine can be decreased when it is combined with Phenytoin.Approved, Investigational
HachimycinThe serum concentration of Phenytoin can be increased when it is combined with Hachimycin.Experimental
HalazepamThe risk or severity of adverse effects can be increased when Halazepam is combined with Phenytoin.Approved, Illicit, Withdrawn
HalcinonideThe serum concentration of Halcinonide can be decreased when it is combined with Phenytoin.Approved, Investigational, Withdrawn
HalofantrineThe metabolism of Halofantrine can be increased when combined with Phenytoin.Approved
HaloperidolThe metabolism of Haloperidol can be increased when combined with Phenytoin.Approved
HaloproginThe serum concentration of Phenytoin can be increased when it is combined with Haloprogin.Approved, Withdrawn
HalothaneThe serum concentration of Phenytoin can be increased when it is combined with Halothane.Approved, Vet Approved
HE3286The serum concentration of HE3286 can be decreased when it is combined with Phenytoin.Investigational
HeroinThe risk or severity of adverse effects can be increased when Heroin is combined with Phenytoin.Approved, Illicit, Investigational
HexestrolThe therapeutic efficacy of Hexestrol can be decreased when used in combination with Phenytoin.Withdrawn
HexetidineThe serum concentration of Phenytoin can be increased when it is combined with Hexetidine.Approved, Investigational
HexobarbitalThe metabolism of Hexobarbital can be increased when combined with Phenytoin.Approved
HistamineThe metabolism of Histamine can be increased when combined with Phenytoin.Approved, Investigational
HyaluronidaseThe therapeutic efficacy of Phenytoin can be decreased when used in combination with Hyaluronidase.Approved, Investigational
HydrocodonePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Hydrocodone.Approved, Illicit
HydrocortisoneThe serum concentration of Hydrocortisone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
HydromorphoneThe metabolism of Hydromorphone can be increased when combined with Phenytoin.Approved, Illicit
HydroxyamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with Hydroxyamphetamine.Approved
Hydroxyprogesterone caproateThe metabolism of Hydroxyprogesterone caproate can be increased when combined with Phenytoin.Approved
HydroxyzineHydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
IbrutinibThe serum concentration of Ibrutinib can be decreased when it is combined with Phenytoin.Approved
IbuprofenThe metabolism of Ibuprofen can be increased when combined with Phenytoin.Approved
IcotinibThe metabolism of Icotinib can be increased when combined with Phenytoin.Approved, Investigational
IdarubicinThe metabolism of Idarubicin can be increased when combined with Phenytoin.Approved
IfosfamideThe serum concentration of the active metabolites of Ifosfamide can be increased when Ifosfamide is used in combination with Phenytoin.Approved
IloperidoneThe metabolism of Iloperidone can be increased when combined with Phenytoin.Approved
ImatinibThe serum concentration of Imatinib can be decreased when it is combined with Phenytoin.Approved
ImidafenacinThe metabolism of Imidafenacin can be increased when combined with Phenytoin.Approved, Investigational
ImipramineThe metabolism of Imipramine can be increased when combined with Phenytoin.Approved
ImiquimodThe metabolism of Imiquimod can be increased when combined with Phenytoin.Approved, Investigational
IndacaterolThe metabolism of Indacaterol can be increased when combined with Phenytoin.Approved
IndalpineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Indalpine.Investigational, Withdrawn
IndapamideThe metabolism of Indapamide can be increased when combined with Phenytoin.Approved
IndinavirThe metabolism of Indinavir can be increased when combined with Phenytoin.Approved
IndiplonThe risk or severity of adverse effects can be increased when Indiplon is combined with Phenytoin.Investigational
indisulamThe metabolism of indisulam can be increased when combined with Phenytoin.Investigational
IndomethacinThe metabolism of Indomethacin can be increased when combined with Phenytoin.Approved, Investigational
Iofetamine I-123The serum concentration of Phenytoin can be decreased when it is combined with Iofetamine I-123.Approved
Ipratropium bromideThe metabolism of Ipratropium bromide can be increased when combined with Phenytoin.Approved
IrbesartanThe metabolism of Irbesartan can be increased when combined with Phenytoin.Approved, Investigational
IrinotecanThe serum concentration of Irinotecan can be decreased when it is combined with Phenytoin.Approved, Investigational
IsavuconazoniumThe serum concentration of the active metabolites of Isavuconazonium can be reduced when Isavuconazonium is used in combination with Phenytoin resulting in a loss in efficacy.Approved, Investigational
IsoconazoleThe serum concentration of Phenytoin can be increased when it is combined with Isoconazole.Approved
IsofluraneThe metabolism of Isoflurane can be increased when combined with Phenytoin.Approved, Vet Approved
IsoniazidThe serum concentration of Phenytoin can be increased when it is combined with Isoniazid.Approved
Isosorbide DinitrateThe metabolism of Isosorbide Dinitrate can be increased when combined with Phenytoin.Approved
Isosorbide MononitrateThe metabolism of Isosorbide Mononitrate can be increased when combined with Phenytoin.Approved
IsradipineThe serum concentration of Phenytoin can be increased when it is combined with Isradipine.Approved
IstaroximeThe serum concentration of Istaroxime can be decreased when it is combined with Phenytoin.Investigational
ItraconazoleThe serum concentration of Phenytoin can be increased when it is combined with Itraconazole.Approved, Investigational
IvabradineThe serum concentration of Ivabradine can be decreased when it is combined with Phenytoin.Approved
IvacaftorThe serum concentration of Phenytoin can be increased when it is combined with Ivacaftor.Approved
IvermectinThe metabolism of Ivermectin can be increased when combined with Phenytoin.Approved, Vet Approved
IxabepiloneThe serum concentration of Ixabepilone can be decreased when it is combined with Phenytoin.Approved, Investigational
IxazomibThe serum concentration of Ixazomib can be decreased when it is combined with Phenytoin.Approved
KetamineThe metabolism of Ketamine can be increased when combined with Phenytoin.Approved, Vet Approved
KetazolamThe metabolism of Ketazolam can be increased when combined with Phenytoin.Approved
KetobemidoneThe metabolism of Ketobemidone can be increased when combined with Phenytoin.Approved, Investigational
KetoconazoleThe serum concentration of Phenytoin can be increased when it is combined with Ketoconazole.Approved, Investigational
KetoprofenThe metabolism of Ketoprofen can be increased when combined with Phenytoin.Approved, Vet Approved
LacidipineThe serum concentration of Phenytoin can be increased when it is combined with Lacidipine.Approved, Investigational
LacosamideThe serum concentration of Lacosamide can be decreased when it is combined with Phenytoin.Approved
LamotrigineThe serum concentration of Lamotrigine can be decreased when it is combined with Phenytoin.Approved, Investigational
LansoprazoleThe metabolism of Lansoprazole can be increased when combined with Phenytoin.Approved, Investigational
LapatinibThe serum concentration of Lapatinib can be decreased when it is combined with Phenytoin.Approved, Investigational
LaquinimodThe metabolism of Laquinimod can be increased when combined with Phenytoin.Investigational
LeflunomideThe metabolism of Leflunomide can be increased when combined with Phenytoin.Approved, Investigational
LenvatinibThe metabolism of Lenvatinib can be increased when combined with Phenytoin.Approved
LercanidipineThe serum concentration of Phenytoin can be increased when it is combined with Lercanidipine.Approved, Investigational
LesinuradThe metabolism of Lesinurad can be increased when combined with Phenytoin.Approved
LetrozoleThe metabolism of Letrozole can be increased when combined with Phenytoin.Approved, Investigational
LeucovorinThe serum concentration of Phenytoin can be decreased when it is combined with Leucovorin.Approved
LevetiracetamThe risk or severity of adverse effects can be increased when Phenytoin is combined with Levetiracetam.Approved, Investigational
LevobupivacaineThe metabolism of Levobupivacaine can be increased when combined with Phenytoin.Approved, Investigational
LevocabastineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Levocabastine.Approved
LevocetirizineThe metabolism of Levocetirizine can be increased when combined with Phenytoin.Approved
LevodopaThe therapeutic efficacy of Levodopa can be decreased when used in combination with Phenytoin.Approved
LevoleucovorinThe serum concentration of Phenytoin can be decreased when it is combined with Levoleucovorin.Approved
Levomefolic acidThe serum concentration of Phenytoin can be decreased when it is combined with Levomefolic acid.Approved
Levomethadyl AcetateThe metabolism of Levomethadyl Acetate can be increased when combined with Phenytoin.Approved, Investigational
LevomilnacipranThe metabolism of Levomilnacipran can be increased when combined with Phenytoin.Approved
LevonorgestrelThe therapeutic efficacy of Levonorgestrel can be decreased when used in combination with Phenytoin.Approved, Investigational
LevorphanolThe risk or severity of adverse effects can be increased when Levorphanol is combined with Phenytoin.Approved
LevothyroxineThe serum concentration of Levothyroxine can be decreased when it is combined with Phenytoin.Approved
LicofeloneThe metabolism of Licofelone can be increased when combined with Phenytoin.Investigational
LidocaineThe metabolism of Lidocaine can be increased when combined with Phenytoin.Approved, Vet Approved
LidoflazineThe serum concentration of Phenytoin can be increased when it is combined with Lidoflazine.Experimental
LinagliptinThe serum concentration of Linagliptin can be decreased when it is combined with Phenytoin.Approved
LiothyronineThe serum concentration of Liothyronine can be decreased when it is combined with Phenytoin.Approved, Vet Approved
LiotrixThe serum concentration of Liotrix can be decreased when it is combined with Phenytoin.Approved
LisdexamfetamineThe serum concentration of Phenytoin can be decreased when it is combined with Lisdexamfetamine.Approved, Investigational
LisurideThe metabolism of Lisuride can be increased when combined with Phenytoin.Approved, Investigational
LithiumThe risk or severity of adverse effects can be increased when Phenytoin is combined with Lithium.Approved
LobeglitazoneThe metabolism of Phenytoin can be decreased when combined with Lobeglitazone.Approved, Investigational
LofentanilThe risk or severity of adverse effects can be increased when Lofentanil is combined with Phenytoin.Illicit
LomitapideThe metabolism of Lomitapide can be increased when combined with Phenytoin.Approved
LoperamideThe metabolism of Loperamide can be increased when combined with Phenytoin.Approved
LopinavirThe serum concentration of Lopinavir can be decreased when it is combined with Phenytoin.Approved
LoprazolamThe risk or severity of adverse effects can be increased when Loprazolam is combined with Phenytoin.Experimental
LoratadineThe metabolism of Loratadine can be increased when combined with Phenytoin.Approved
LorazepamThe serum concentration of Phenytoin can be increased when it is combined with Lorazepam.Approved
LorcaserinThe metabolism of Lorcaserin can be increased when combined with Phenytoin.Approved
LormetazepamThe serum concentration of Phenytoin can be increased when it is combined with Lormetazepam.Approved
LornoxicamThe metabolism of Lornoxicam can be increased when combined with Phenytoin.Approved, Investigational
LosartanThe metabolism of Losartan can be increased when combined with Phenytoin.Approved
LoteprednolThe serum concentration of Loteprednol can be decreased when it is combined with Phenytoin.Approved
LovastatinThe serum concentration of Lovastatin can be decreased when it is combined with Phenytoin.Approved, Investigational
LoxapineThe risk or severity of adverse effects can be increased when Loxapine is combined with Phenytoin.Approved
LuliconazoleThe serum concentration of Phenytoin can be increased when it is combined with Luliconazole.Approved
LumacaftorThe serum concentration of Phenytoin can be increased when it is combined with Lumacaftor.Approved
LumefantrineThe serum concentration of Lumefantrine can be decreased when it is combined with Phenytoin.Approved
LumiracoxibThe metabolism of Lumiracoxib can be increased when combined with Phenytoin.Approved, Investigational
LurasidoneThe serum concentration of Lurasidone can be decreased when it is combined with Phenytoin.Approved
LynestrenolThe therapeutic efficacy of Lynestrenol can be decreased when used in combination with Phenytoin.Investigational
MacitentanThe serum concentration of Macitentan can be decreased when it is combined with Phenytoin.Approved
Magnesium SulfateThe serum concentration of Phenytoin can be increased when it is combined with Magnesium Sulfate.Approved, Vet Approved
MalathionThe metabolism of Malathion can be increased when combined with Phenytoin.Approved, Investigational
ManidipineThe serum concentration of Phenytoin can be increased when it is combined with Manidipine.Approved, Investigational
MaprotilineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Maprotiline.Approved
MaravirocThe serum concentration of Maraviroc can be decreased when it is combined with Phenytoin.Approved, Investigational
ME-609The serum concentration of ME-609 can be decreased when it is combined with Phenytoin.Investigational
MebendazoleThe serum concentration of Mebendazole can be decreased when it is combined with Phenytoin.Approved, Vet Approved
MebicarThe risk or severity of adverse effects can be increased when Mebicar is combined with Phenytoin.Experimental
MeclizineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Meclizine.Approved
MedazepamThe serum concentration of Phenytoin can be increased when it is combined with Medazepam.Experimental
MedetomidineThe risk or severity of adverse effects can be increased when Medetomidine is combined with Phenytoin.Vet Approved
Medroxyprogesterone acetateThe therapeutic efficacy of Medroxyprogesterone acetate can be decreased when used in combination with Phenytoin.Approved, Investigational
MedrysoneThe serum concentration of Medrysone can be decreased when it is combined with Phenytoin.Approved
Mefenamic acidThe metabolism of Mefenamic acid can be increased when combined with Phenytoin.Approved
MefloquineThe therapeutic efficacy of Phenytoin can be decreased when used in combination with Mefloquine.Approved
MelatoninThe metabolism of Melatonin can be increased when combined with Phenytoin.Approved, Nutraceutical, Vet Approved
MelengestrolThe serum concentration of Melengestrol can be decreased when it is combined with Phenytoin.Vet Approved
MeloxicamThe metabolism of Meloxicam can be increased when combined with Phenytoin.Approved, Vet Approved
MelperoneThe risk or severity of adverse effects can be increased when Melperone is combined with Phenytoin.Approved, Investigational
MepartricinThe serum concentration of Phenytoin can be increased when it is combined with Mepartricin.Experimental
MephedroneThe serum concentration of Phenytoin can be decreased when it is combined with Mephedrone.Investigational
MephentermineThe serum concentration of Phenytoin can be decreased when it is combined with Mephentermine.Approved
MephenytoinThe metabolism of Mephenytoin can be increased when combined with Phenytoin.Investigational, Withdrawn
MepivacaineThe risk or severity of adverse effects can be increased when Mepivacaine is combined with Phenytoin.Approved, Vet Approved
MeprobamateThe metabolism of Meprobamate can be increased when combined with Phenytoin.Approved, Illicit
MeptazinolThe risk or severity of adverse effects can be increased when Meptazinol is combined with Phenytoin.Experimental
MesoridazineThe risk or severity of adverse effects can be increased when Mesoridazine is combined with Phenytoin.Approved, Investigational
MestranolThe therapeutic efficacy of Mestranol can be decreased when used in combination with Phenytoin.Approved
MetaxaloneThe risk or severity of adverse effects can be increased when Phenytoin is combined with Metaxalone.Approved
MethadoneThe serum concentration of Methadone can be decreased when it is combined with Phenytoin.Approved
Methadyl AcetateThe risk or severity of adverse effects can be increased when Methadyl Acetate is combined with Phenytoin.Approved, Illicit
MethallenestrilThe therapeutic efficacy of Methallenestril can be decreased when used in combination with Phenytoin.Experimental
MethamphetamineThe serum concentration of Phenytoin can be decreased when it is combined with Methamphetamine.Approved, Illicit
MethapyrileneThe risk or severity of adverse effects can be increased when Methapyrilene is combined with Phenytoin.Withdrawn
MethaqualoneThe metabolism of Methaqualone can be increased when combined with Phenytoin.Illicit, Withdrawn
MethazolamideThe risk or severity of adverse effects can be increased when Methazolamide is combined with Phenytoin.Approved
MethocarbamolThe risk or severity of adverse effects can be increased when Phenytoin is combined with Methocarbamol.Approved, Vet Approved
MethohexitalThe risk or severity of adverse effects can be increased when Methohexital is combined with Phenytoin.Approved
MethotrexateThe serum concentration of Phenytoin can be decreased when it is combined with Methotrexate.Approved
MethotrimeprazinePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Methotrimeprazine.Approved
MethoxsalenThe metabolism of Methoxsalen can be increased when combined with Phenytoin.Approved
MethoxyfluraneThe metabolism of Methoxyflurane can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
MethoxyphenamineThe serum concentration of Phenytoin can be decreased when it is combined with Methoxyphenamine.Experimental
MethsuximideThe metabolism of Methsuximide can be increased when combined with Phenytoin.Approved
MethylecgonineThe risk or severity of adverse effects can be increased when Methylecgonine is combined with Phenytoin.Experimental
MethylphenidateThe serum concentration of Phenytoin can be increased when it is combined with Methylphenidate.Approved, Investigational
MethylphenobarbitalThe metabolism of Methylphenobarbital can be increased when combined with Phenytoin.Approved
MethylprednisoloneThe serum concentration of Methylprednisolone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
MethyltestosteroneThe metabolism of Methyltestosterone can be increased when combined with Phenytoin.Approved
MetoprololThe metabolism of Metoprolol can be increased when combined with Phenytoin.Approved, Investigational
MetronidazoleThe serum concentration of Metronidazole can be decreased when it is combined with Phenytoin.Approved
MetyraponeThe serum concentration of Metyrapone can be decreased when it is combined with Phenytoin.Approved
MetyrosinePhenytoin may increase the sedative activities of Metyrosine.Approved
MevastatinThe serum concentration of Phenytoin can be increased when it is combined with Mevastatin.Experimental
MexiletineThe serum concentration of Mexiletine can be decreased when it is combined with Phenytoin.Approved
MianserinThe therapeutic efficacy of Phenytoin can be decreased when used in combination with Mianserin.Approved, Investigational
MibefradilThe serum concentration of Phenytoin can be increased when it is combined with Mibefradil.Investigational, Withdrawn
MicafunginThe serum concentration of Phenytoin can be increased when it is combined with Micafungin.Approved, Investigational
MiconazoleThe serum concentration of Phenytoin can be increased when it is combined with Miconazole.Approved, Investigational, Vet Approved
MidazolamThe serum concentration of Phenytoin can be increased when it is combined with Midazolam.Approved, Illicit
MidomafetamineThe serum concentration of Phenytoin can be decreased when it is combined with Midomafetamine.Experimental, Illicit, Investigational
MidostaurinThe metabolism of Midostaurin can be increased when combined with Phenytoin.Approved
MifepristoneThe serum concentration of Phenytoin can be increased when it is combined with Mifepristone.Approved, Investigational
MilnacipranThe risk or severity of adverse effects can be increased when Phenytoin is combined with Milnacipran.Approved
MiltefosineThe serum concentration of Phenytoin can be increased when it is combined with Miltefosine.Approved
MinocyclineMinocycline may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved, Investigational
MirabegronThe metabolism of Mirabegron can be increased when combined with Phenytoin.Approved
MirtazapinePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Mirtazapine.Approved
MitotaneThe serum concentration of Phenytoin can be decreased when it is combined with Mitotane.Approved
MivacuriumPhenytoin may decrease the neuromuscular blocking activities of Mivacurium.Approved
MMDAThe serum concentration of Phenytoin can be decreased when it is combined with MMDA.Experimental, Illicit
MoclobemideThe metabolism of Moclobemide can be increased when combined with Phenytoin.Approved
ModafinilThe metabolism of Modafinil can be increased when combined with Phenytoin.Approved, Investigational
MolindoneThe risk or severity of adverse effects can be increased when Molindone is combined with Phenytoin.Approved
MometasoneThe serum concentration of Mometasone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
MonensinThe serum concentration of Phenytoin can be increased when it is combined with Monensin.Vet Approved
MontelukastThe metabolism of Montelukast can be increased when combined with Phenytoin.Approved
MorphineThe metabolism of Morphine can be increased when combined with Phenytoin.Approved, Investigational
muraglitazarThe metabolism of muraglitazar can be increased when combined with Phenytoin.Investigational
Mycophenolate mofetilThe metabolism of Mycophenolate mofetil can be increased when combined with Phenytoin.Approved, Investigational
MyxothiazolThe serum concentration of Phenytoin can be increased when it is combined with Myxothiazol.Experimental
NabiloneNabilone may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved, Investigational
NaftifineThe serum concentration of Phenytoin can be increased when it is combined with Naftifine.Approved
NaftopidilThe serum concentration of Phenytoin can be increased when it is combined with Naftopidil.Investigational
NalbuphineThe risk or severity of adverse effects can be increased when Nalbuphine is combined with Phenytoin.Approved
NaloxegolThe serum concentration of Naloxegol can be decreased when it is combined with Phenytoin.Approved
NaloxoneThe metabolism of Naloxone can be increased when combined with Phenytoin.Approved, Vet Approved
NaproxenThe metabolism of Naproxen can be increased when combined with Phenytoin.Approved, Vet Approved
NatamycinThe serum concentration of Phenytoin can be increased when it is combined with Natamycin.Approved
NateglinideThe metabolism of Nateglinide can be increased when combined with Phenytoin.Approved, Investigational
NCX 1022The serum concentration of NCX 1022 can be decreased when it is combined with Phenytoin.Investigational
NedaplatinThe serum concentration of Phenytoin can be decreased when it is combined with Nedaplatin.Approved, Investigational
NefazodoneThe metabolism of Nefazodone can be increased when combined with Phenytoin.Approved, Withdrawn
NelfinavirThe serum concentration of Phenytoin can be decreased when it is combined with Nelfinavir.Approved
NeratinibThe metabolism of Neratinib can be increased when combined with Phenytoin.Approved, Investigational
NetazepideThe serum concentration of Phenytoin can be increased when it is combined with Netazepide.Investigational
NetupitantThe serum concentration of Phenytoin can be increased when it is combined with Netupitant.Approved
NevirapineThe metabolism of Phenytoin can be increased when combined with Nevirapine.Approved
NicardipineThe serum concentration of Phenytoin can be increased when it is combined with Nicardipine.Approved
NiclosamideThe metabolism of Niclosamide can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
NicotineThe metabolism of Nicotine can be increased when combined with Phenytoin.Approved
NifedipineThe serum concentration of Phenytoin can be increased when it is combined with Nifedipine.Approved
NifuratelThe serum concentration of Phenytoin can be increased when it is combined with Nifuratel.Experimental
NiguldipineThe serum concentration of Phenytoin can be increased when it is combined with Niguldipine.Experimental
Nikkomycin ZThe serum concentration of Phenytoin can be increased when it is combined with Nikkomycin Z.Investigational
NilotinibThe serum concentration of Nilotinib can be decreased when it is combined with Phenytoin.Approved, Investigational
NiludipineThe serum concentration of Phenytoin can be increased when it is combined with Niludipine.Experimental
NilutamideThe metabolism of Nilutamide can be increased when combined with Phenytoin.Approved
NilvadipineThe serum concentration of Phenytoin can be increased when it is combined with Nilvadipine.Approved, Investigational
NimesulideThe serum concentration of Phenytoin can be increased when it is combined with Nimesulide.Approved, Investigational, Withdrawn
NimodipineThe serum concentration of Phenytoin can be increased when it is combined with Nimodipine.Approved
NisoldipineThe serum concentration of Phenytoin can be increased when it is combined with Nisoldipine.Approved
NitrazepamThe serum concentration of Phenytoin can be increased when it is combined with Nitrazepam.Approved
NitrendipineThe serum concentration of Phenytoin can be increased when it is combined with Nitrendipine.Approved, Investigational
Nitric OxideThe risk or severity of adverse effects can be increased when Nitric Oxide is combined with Phenytoin.Approved
Nitrous oxideThe risk or severity of adverse effects can be increased when Nitrous oxide is combined with Phenytoin.Approved, Vet Approved
NitroxolineThe serum concentration of Phenytoin can be increased when it is combined with Nitroxoline.Approved
NorelgestrominThe therapeutic efficacy of Norelgestromin can be decreased when used in combination with Phenytoin.Approved
NorethisteroneThe metabolism of Norethisterone can be increased when combined with Phenytoin.Approved
NorfluraneThe risk or severity of adverse effects can be increased when Norflurane is combined with Phenytoin.Investigational
NorgestimateThe therapeutic efficacy of Norgestimate can be decreased when used in combination with Phenytoin.Approved
NorgestrelThe therapeutic efficacy of Norgestrel can be decreased when used in combination with Phenytoin.Approved
NormethadoneThe risk or severity of adverse effects can be increased when Normethadone is combined with Phenytoin.Approved, Illicit
NortriptylineThe metabolism of Nortriptyline can be increased when combined with Phenytoin.Approved
NOV-002The serum concentration of Phenytoin can be decreased when it is combined with NOV-002.Investigational
NystatinThe serum concentration of Phenytoin can be increased when it is combined with Nystatin.Approved, Vet Approved
OdanacatibThe metabolism of Odanacatib can be increased when combined with Phenytoin.Investigational
OlanzapineThe risk or severity of adverse effects can be increased when Olanzapine is combined with Phenytoin.Approved, Investigational
OlaparibThe serum concentration of Olaparib can be decreased when it is combined with Phenytoin.Approved
Oleoyl-estroneThe serum concentration of Oleoyl-estrone can be decreased when it is combined with Phenytoin.Investigational
OlodaterolThe metabolism of Olodaterol can be increased when combined with Phenytoin.Approved
OlopatadineThe metabolism of Olopatadine can be increased when combined with Phenytoin.Approved
OmbitasvirThe metabolism of Ombitasvir can be increased when combined with Phenytoin.Approved
OmeprazoleThe serum concentration of Omeprazole can be decreased when it is combined with Phenytoin.Approved, Investigational, Vet Approved
OmoconazoleThe serum concentration of Phenytoin can be increased when it is combined with Omoconazole.Experimental
OndansetronThe metabolism of Ondansetron can be increased when combined with Phenytoin.Approved
OpiumThe risk or severity of adverse effects can be increased when Opium is combined with Phenytoin.Approved, Illicit
OrlistatThe serum concentration of Phenytoin can be decreased when it is combined with Orlistat.Approved, Investigational
OrphenadrinePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Orphenadrine.Approved
OsanetantThe risk or severity of adverse effects can be increased when Osanetant is combined with Phenytoin.Investigational
OsimertinibThe serum concentration of Phenytoin can be increased when it is combined with Osimertinib.Approved
OspemifeneThe metabolism of Ospemifene can be increased when combined with Phenytoin.Approved
OtiloniumThe serum concentration of Phenytoin can be increased when it is combined with Otilonium.Experimental, Investigational
OxaliplatinThe serum concentration of Phenytoin can be decreased when it is combined with Oxaliplatin.Approved, Investigational
OxaprozinThe metabolism of Oxaprozin can be increased when combined with Phenytoin.Approved
OxazepamThe serum concentration of Phenytoin can be increased when it is combined with Oxazepam.Approved
OxcarbazepineThe serum concentration of the active metabolites of Oxcarbazepine can be reduced when Oxcarbazepine is used in combination with Phenytoin resulting in a loss in efficacy.Approved
OxethazaineThe risk or severity of adverse effects can be increased when Oxethazaine is combined with Phenytoin.Approved, Investigational
OxiconazoleThe serum concentration of Phenytoin can be increased when it is combined with Oxiconazole.Approved
OxprenololThe risk or severity of adverse effects can be increased when Oxprenolol is combined with Phenytoin.Approved
OxybuprocaineThe risk or severity of adverse effects can be increased when Oxybuprocaine is combined with Phenytoin.Approved
OxybutyninThe metabolism of Oxybutynin can be increased when combined with Phenytoin.Approved, Investigational
OxycodoneThe metabolism of Oxycodone can be increased when combined with Phenytoin.Approved, Illicit, Investigational
OxymorphoneThe metabolism of Oxymorphone can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
PaclitaxelThe metabolism of Paclitaxel can be increased when combined with Phenytoin.Approved, Vet Approved
pafuramidineThe serum concentration of Phenytoin can be increased when it is combined with pafuramidine.Investigational
PalbociclibThe serum concentration of Phenytoin can be increased when it is combined with Palbociclib.Approved
PaliperidoneThe risk or severity of adverse effects can be increased when Paliperidone is combined with Phenytoin.Approved
PalonosetronThe metabolism of Palonosetron can be increased when combined with Phenytoin.Approved, Investigational
PanobinostatThe serum concentration of Panobinostat can be decreased when it is combined with Phenytoin.Approved, Investigational
PantoprazoleThe metabolism of Pantoprazole can be increased when combined with Phenytoin.Approved
ParaldehydePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Paraldehyde.Approved, Investigational
ParamethadioneThe metabolism of Paramethadione can be increased when combined with Phenytoin.Approved
ParamethasoneThe metabolism of Paramethasone can be increased when combined with Phenytoin.Approved
ParecoxibThe metabolism of Parecoxib can be increased when combined with Phenytoin.Approved
ParicalcitolThe metabolism of Paricalcitol can be increased when combined with Phenytoin.Approved, Investigational
ParitaprevirThe metabolism of Paritaprevir can be increased when combined with Phenytoin.Approved
ParoxetineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Paroxetine.Approved, Investigational
PazopanibThe serum concentration of Pazopanib can be decreased when it is combined with Phenytoin.Approved
PenfluridolThe risk or severity of adverse effects can be increased when Penfluridol is combined with Phenytoin.Experimental
PentamidineThe serum concentration of Phenytoin can be increased when it is combined with Pentamidine.Approved
PentazocineThe risk or severity of adverse effects can be increased when Pentazocine is combined with Phenytoin.Approved, Vet Approved
PentobarbitalThe metabolism of Phenytoin can be increased when combined with Pentobarbital.Approved, Vet Approved
PerampanelThe serum concentration of Perampanel can be decreased when it is combined with Phenytoin.Approved
PerazineThe risk or severity of adverse effects can be increased when Perazine is combined with Phenytoin.Investigational
PergolideThe metabolism of Pergolide can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved, Withdrawn
PerhexilineThe serum concentration of Phenytoin can be increased when it is combined with Perhexiline.Approved, Investigational
PermethrinThe metabolism of Permethrin can be increased when combined with Phenytoin.Approved, Investigational
PerospironeThe metabolism of Perospirone can be increased when combined with Phenytoin.Approved
PerphenazineThe metabolism of Perphenazine can be increased when combined with Phenytoin.Approved
PethidineThe serum concentration of Pethidine can be decreased when it is combined with Phenytoin.Approved
PF-477736The serum concentration of Phenytoin can be increased when it is combined with PF-477736.Investigational
PhenacetinThe metabolism of Phenacetin can be increased when combined with Phenytoin.Withdrawn
PhenazocineThe risk or severity of adverse effects can be increased when Phenazocine is combined with Phenytoin.Experimental
PhenibutThe risk or severity of adverse effects can be increased when Phenibut is combined with Phenytoin.Experimental
PhenindionePhenytoin may increase the anticoagulant activities of Phenindione.Approved, Investigational
PhenobarbitalPhenytoin may increase the central nervous system depressant (CNS depressant) activities of Phenobarbital.Approved
PhenoperidineThe risk or severity of adverse effects can be increased when Phenoperidine is combined with Phenytoin.Experimental
PhenoxybenzamineThe metabolism of Phenoxybenzamine can be increased when combined with Phenytoin.Approved
PhenoxyethanolThe risk or severity of adverse effects can be increased when Phenoxyethanol is combined with Phenytoin.Approved
PhenprocoumonPhenytoin may increase the anticoagulant activities of Phenprocoumon.Approved, Investigational
PhentermineThe serum concentration of Phenytoin can be decreased when it is combined with Phentermine.Approved, Illicit
PhenylbutazoneThe metabolism of Phenylbutazone can be increased when combined with Phenytoin.Approved, Vet Approved
PilocarpineThe metabolism of Pilocarpine can be increased when combined with Phenytoin.Approved
PimecrolimusThe metabolism of Pimecrolimus can be increased when combined with Phenytoin.Approved, Investigational
PimozideThe metabolism of Pimozide can be increased when combined with Phenytoin.Approved
PinacidilThe metabolism of Pinacidil can be increased when combined with Phenytoin.Withdrawn
PinaveriumThe serum concentration of Phenytoin can be increased when it is combined with Pinaverium.Approved
PioglitazoneThe metabolism of Pioglitazone can be increased when combined with Phenytoin.Approved, Investigational
PipamperoneThe risk or severity of adverse effects can be increased when Pipamperone is combined with Phenytoin.Approved, Investigational
PipotiazineThe metabolism of Pipotiazine can be increased when combined with Phenytoin.Approved, Investigational
PirenzepineThe serum concentration of Phenytoin can be increased when it is combined with Pirenzepine.Approved
PiretanidePhenytoin may decrease the diuretic activities of Piretanide.Experimental
PiritramideThe risk or severity of adverse effects can be increased when Piritramide is combined with Phenytoin.Investigational
PiroxicamThe metabolism of Piroxicam can be increased when combined with Phenytoin.Approved, Investigational
PitavastatinThe serum concentration of Pitavastatin can be decreased when it is combined with Phenytoin.Approved
PizotifenThe risk or severity of adverse effects can be increased when Phenytoin is combined with Pizotifen.Approved
PodofiloxThe metabolism of Podofilox can be increased when combined with Phenytoin.Approved
PomalidomideThe metabolism of Pomalidomide can be increased when combined with Phenytoin.Approved
PonatinibThe serum concentration of Ponatinib can be decreased when it is combined with Phenytoin.Approved
PosaconazoleThe serum concentration of Phenytoin can be increased when it is combined with Posaconazole.Approved, Investigational, Vet Approved
PramipexolePhenytoin may increase the sedative activities of Pramipexole.Approved, Investigational
PramocaineThe risk or severity of adverse effects can be increased when Pramocaine is combined with Phenytoin.Approved
PrasteroneThe metabolism of Prasterone can be increased when combined with Phenytoin.Approved, Nutraceutical
Prasterone sulfateThe serum concentration of Prasterone sulfate can be decreased when it is combined with Phenytoin.Investigational
PrasugrelThe metabolism of Prasugrel can be increased when combined with Phenytoin.Approved
PravastatinThe serum concentration of Pravastatin can be decreased when it is combined with Phenytoin.Approved
PrazepamThe serum concentration of Phenytoin can be increased when it is combined with Prazepam.Approved, Illicit
PraziquantelThe serum concentration of Praziquantel can be decreased when it is combined with Phenytoin.Approved, Vet Approved
PrednicarbateThe serum concentration of Prednicarbate can be decreased when it is combined with Phenytoin.Approved
PrednisoloneThe serum concentration of Prednisolone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
PrednisoneThe serum concentration of Prednisone can be decreased when it is combined with Phenytoin.Approved, Vet Approved
PregabalinThe serum concentration of Phenytoin can be increased when it is combined with Pregabalin.Approved, Illicit, Investigational
PregnenoloneThe serum concentration of Pregnenolone can be decreased when it is combined with Phenytoin.Experimental, Investigational
PrenylamineThe serum concentration of Phenytoin can be increased when it is combined with Prenylamine.Withdrawn
PrilocaineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Prilocaine.Approved
PrimaquineThe metabolism of Primaquine can be increased when combined with Phenytoin.Approved
PrimidoneThe metabolism of Primidone can be increased when combined with Phenytoin.Approved, Vet Approved
ProcaineThe risk or severity of adverse effects can be increased when Procaine is combined with Phenytoin.Approved, Investigational, Vet Approved
ProchlorperazineThe metabolism of Prochlorperazine can be increased when combined with Phenytoin.Approved, Vet Approved
ProgesteroneThe metabolism of Progesterone can be increased when combined with Phenytoin.Approved, Vet Approved
ProguanilThe metabolism of Proguanil can be increased when combined with Phenytoin.Approved
PromazineThe metabolism of Promazine can be increased when combined with Phenytoin.Approved, Vet Approved
PromethazineThe metabolism of Promethazine can be increased when combined with Phenytoin.Approved
PropacetamolThe serum concentration of the active metabolites of Propacetamol can be reduced when Propacetamol is used in combination with Phenytoin resulting in a loss in efficacy.Approved, Investigational
PropafenoneThe serum concentration of Propafenone can be decreased when it is combined with Phenytoin.Approved
PropanididThe risk or severity of adverse effects can be increased when Propanidid is combined with Phenytoin.Experimental
ProparacaineThe risk or severity of adverse effects can be increased when Proparacaine is combined with Phenytoin.Approved, Vet Approved
PropofolThe metabolism of Propofol can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
PropoxycaineThe risk or severity of adverse effects can be increased when Propoxycaine is combined with Phenytoin.Approved
Propoxyphene napsylateThe metabolism of Propoxyphene napsylate can be increased when combined with Phenytoin.Approved
PropranololThe metabolism of Propranolol can be increased when combined with Phenytoin.Approved, Investigational
ProtriptylineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Protriptyline.Approved
ProxibarbalThe risk or severity of adverse effects can be increased when Proxibarbal is combined with Phenytoin.Experimental
PSD502The risk or severity of adverse effects can be increased when PSD502 is combined with Phenytoin.Investigational
PseudoephedrineThe serum concentration of Phenytoin can be decreased when it is combined with Pseudoephedrine.Approved
PyrazinamideThe metabolism of Pyrazinamide can be increased when combined with Phenytoin.Approved
PyridoxineThe metabolism of Phenytoin can be increased when combined with Pyridoxine.Approved, Nutraceutical, Vet Approved
PyrimethamineThe metabolism of Phenytoin can be decreased when combined with Pyrimethamine.Approved, Vet Approved
PyrrolnitrinThe serum concentration of Phenytoin can be increased when it is combined with Pyrrolnitrin.Experimental
QuazepamThe serum concentration of Phenytoin can be increased when it is combined with Quazepam.Approved, Illicit
QuetiapineThe serum concentration of Quetiapine can be decreased when it is combined with Phenytoin.Approved
QuinacrineThe metabolism of Quinacrine can be increased when combined with Phenytoin.Approved, Investigational
QuinidineThe serum concentration of Quinidine can be decreased when it is combined with Phenytoin.Approved
QuinineThe serum concentration of Quinine can be decreased when it is combined with Phenytoin.Approved
QuinisocaineThe risk or severity of adverse effects can be increased when Quinisocaine is combined with Phenytoin.Experimental
RabeprazoleThe metabolism of Rabeprazole can be increased when combined with Phenytoin.Approved, Investigational
RacloprideThe risk or severity of adverse effects can be increased when Raclopride is combined with Phenytoin.Investigational
RadicicolThe serum concentration of Phenytoin can be increased when it is combined with Radicicol.Experimental
RaloxifeneThe metabolism of Raloxifene can be increased when combined with Phenytoin.Approved, Investigational
RamelteonThe metabolism of Ramelteon can be increased when combined with Phenytoin.Approved, Investigational
RanitidineThe metabolism of Ranitidine can be increased when combined with Phenytoin.Approved
RanolazineThe serum concentration of Phenytoin can be increased when it is combined with Ranolazine.Approved, Investigational
RapacuroniumPhenytoin may decrease the neuromuscular blocking activities of Rapacuronium.Withdrawn
ReboxetineThe metabolism of Reboxetine can be increased when combined with Phenytoin.Approved, Investigational
RegorafenibThe serum concentration of Regorafenib can be decreased when it is combined with Phenytoin.Approved
RemifentanilThe risk or severity of adverse effects can be increased when Remifentanil is combined with Phenytoin.Approved
RemoxiprideThe risk or severity of adverse effects can be increased when Remoxipride is combined with Phenytoin.Approved, Withdrawn
RepaglinideThe metabolism of Repaglinide can be increased when combined with Phenytoin.Approved, Investigational
ReserpineThe risk or severity of adverse effects can be increased when Reserpine is combined with Phenytoin.Approved, Investigational
RetapamulinThe metabolism of Retapamulin can be increased when combined with Phenytoin.Approved
RibociclibThe serum concentration of Ribociclib can be decreased when it is combined with Phenytoin.Approved
RifabutinThe metabolism of Phenytoin can be increased when combined with Rifabutin.Approved
RifampicinThe serum concentration of Phenytoin can be decreased when it is combined with Rifampicin.Approved
RifapentineThe metabolism of Phenytoin can be increased when combined with Rifapentine.Approved
RilpivirineThe serum concentration of Rilpivirine can be decreased when it is combined with Phenytoin.Approved
RimexoloneThe serum concentration of Rimexolone can be decreased when it is combined with Phenytoin.Approved
RimonabantThe metabolism of Rimonabant can be increased when combined with Phenytoin.Approved, Investigational
RiociguatThe metabolism of Riociguat can be increased when combined with Phenytoin.Approved
RisedronateThe serum concentration of Phenytoin can be increased when it is combined with Risedronate.Approved, Investigational
RisperidoneThe metabolism of Risperidone can be increased when combined with Phenytoin.Approved, Investigational
RitanserinThe risk or severity of adverse effects can be increased when Ritanserin is combined with Phenytoin.Investigational
RitobegronThe serum concentration of Phenytoin can be decreased when it is combined with Ritobegron.Investigational
RitonavirThe serum concentration of Ritonavir can be decreased when it is combined with Phenytoin.Approved, Investigational
RivaroxabanThe serum concentration of Rivaroxaban can be decreased when it is combined with Phenytoin.Approved
RofecoxibThe metabolism of Rofecoxib can be increased when combined with Phenytoin.Investigational, Withdrawn
RoflumilastThe serum concentration of Roflumilast can be decreased when it is combined with Phenytoin.Approved
RolapitantThe serum concentration of Rolapitant can be decreased when it is combined with Phenytoin.Approved
RomidepsinThe serum concentration of Romidepsin can be decreased when it is combined with Phenytoin.Approved, Investigational
RomifidineThe risk or severity of adverse effects can be increased when Romifidine is combined with Phenytoin.Vet Approved
RopinirolePhenytoin may increase the sedative activities of Ropinirole.Approved, Investigational
RopivacaineThe metabolism of Ropivacaine can be increased when combined with Phenytoin.Approved
RosiglitazoneThe metabolism of Rosiglitazone can be increased when combined with Phenytoin.Approved, Investigational
RosuvastatinThe serum concentration of Rosuvastatin can be decreased when it is combined with Phenytoin.Approved
RotigotinePhenytoin may increase the sedative activities of Rotigotine.Approved
RoxithromycinThe metabolism of Roxithromycin can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
RucaparibThe metabolism of Rucaparib can be increased when combined with Phenytoin.Approved, Investigational
RufinamideThe serum concentration of Phenytoin can be increased when it is combined with Rufinamide.Approved
RupatadineThe metabolism of Rupatadine can be increased when combined with Phenytoin.Approved
RuxolitinibThe metabolism of Ruxolitinib can be increased when combined with Phenytoin.Approved
SafinamideThe metabolism of Safinamide can be increased when combined with Phenytoin.Approved
Salicylhydroxamic AcidThe serum concentration of Phenytoin can be increased when it is combined with Salicylhydroxamic Acid.Experimental
Salicylic acidThe serum concentration of Phenytoin can be increased when it is combined with Salicylic acid.Approved, Vet Approved
SalmeterolThe metabolism of Salmeterol can be increased when combined with Phenytoin.Approved
SaquinavirThe metabolism of Saquinavir can be increased when combined with Phenytoin.Approved, Investigational
SatraplatinThe serum concentration of Phenytoin can be decreased when it is combined with Satraplatin.Investigational
SaxagliptinThe serum concentration of Saxagliptin can be decreased when it is combined with Phenytoin.Approved
ScopolamineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Scopolamine.Approved
SecobarbitalThe metabolism of Phenytoin can be increased when combined with Secobarbital.Approved, Vet Approved
SelegilineThe metabolism of Selegiline can be increased when combined with Phenytoin.Approved, Investigational, Vet Approved
SelexipagThe metabolism of Selexipag can be increased when combined with Phenytoin.Approved
SepranoloneThe risk or severity of adverse effects can be increased when Sepranolone is combined with Phenytoin.Investigational
SeratrodastThe metabolism of Seratrodast can be increased when combined with Phenytoin.Approved
SertaconazoleThe serum concentration of Phenytoin can be increased when it is combined with Sertaconazole.Approved
SertindoleThe metabolism of Sertindole can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
SertralineThe serum concentration of Phenytoin can be increased when it is combined with Sertraline.Approved
SevofluraneThe metabolism of Sevoflurane can be increased when combined with Phenytoin.Approved, Vet Approved
SibutramineThe metabolism of Sibutramine can be increased when combined with Phenytoin.Approved, Illicit, Investigational, Withdrawn
SildenafilThe metabolism of Sildenafil can be increased when combined with Phenytoin.Approved, Investigational
SilodosinThe metabolism of Silodosin can be increased when combined with Phenytoin.Approved
SiltuximabThe serum concentration of Phenytoin can be decreased when it is combined with Siltuximab.Approved
SimeprevirThe serum concentration of Phenytoin can be increased when it is combined with Simeprevir.Approved
SimvastatinThe serum concentration of Simvastatin can be decreased when it is combined with Phenytoin.Approved
SinefunginThe serum concentration of Phenytoin can be increased when it is combined with Sinefungin.Experimental
SirolimusThe serum concentration of Sirolimus can be decreased when it is combined with Phenytoin.Approved, Investigational
SitagliptinThe metabolism of Sitagliptin can be increased when combined with Phenytoin.Approved, Investigational
SitaxentanThe metabolism of Sitaxentan can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
SJG-136The serum concentration of Phenytoin can be increased when it is combined with SJG-136.Investigational
Sodium NitriteThe risk or severity of adverse effects can be increased when Phenytoin is combined with Sodium Nitrite.Approved
Sodium oxybateSodium oxybate may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
SolifenacinThe metabolism of Solifenacin can be increased when combined with Phenytoin.Approved
SonidegibThe serum concentration of Sonidegib can be decreased when it is combined with Phenytoin.Approved, Investigational
SorafenibThe serum concentration of Sorafenib can be decreased when it is combined with Phenytoin.Approved, Investigational
SpiramycinThe metabolism of Spiramycin can be increased when combined with Phenytoin.Approved
St. John's WortThe serum concentration of Phenytoin can be decreased when it is combined with St. John's Wort.Investigational, Nutraceutical
StiripentolThe serum concentration of Phenytoin can be decreased when it is combined with Stiripentol.Approved
SufentanilThe metabolism of Sufentanil can be increased when combined with Phenytoin.Approved, Investigational
SulconazoleThe serum concentration of Phenytoin can be increased when it is combined with Sulconazole.Approved
SulfadiazineThe metabolism of Sulfadiazine can be increased when combined with Phenytoin.Approved, Vet Approved
SulfamethoxazoleThe serum concentration of Phenytoin can be increased when it is combined with Sulfamethoxazole.Approved
SulfamoxoleThe metabolism of Sulfamoxole can be increased when combined with Phenytoin.Approved
SulfinpyrazoneThe metabolism of Sulfinpyrazone can be increased when combined with Phenytoin.Approved
SulfisoxazoleThe metabolism of Sulfisoxazole can be increased when combined with Phenytoin.Approved, Vet Approved
SulpirideThe risk or severity of adverse effects can be increased when Sulpiride is combined with Phenytoin.Approved, Investigational
SultoprideThe risk or severity of adverse effects can be increased when Sultopride is combined with Phenytoin.Experimental
SunitinibThe serum concentration of Sunitinib can be decreased when it is combined with Phenytoin.Approved, Investigational
SuprofenThe metabolism of Suprofen can be increased when combined with Phenytoin.Approved, Withdrawn
SuvorexantPhenytoin may increase the central nervous system depressant (CNS depressant) activities of Suvorexant.Approved
Synthetic Conjugated Estrogens, AThe therapeutic efficacy of Synthetic Conjugated Estrogens, A can be decreased when used in combination with Phenytoin.Approved
Synthetic Conjugated Estrogens, BThe metabolism of Synthetic Conjugated Estrogens, B can be increased when combined with Phenytoin.Approved
TacrolimusThe serum concentration of Tacrolimus can be decreased when it is combined with Phenytoin.Approved, Investigational
TadalafilThe serum concentration of Tadalafil can be decreased when it is combined with Phenytoin.Approved, Investigational
TamoxifenThe metabolism of Tamoxifen can be increased when combined with Phenytoin.Approved
TamsulosinThe metabolism of Tamsulosin can be increased when combined with Phenytoin.Approved, Investigational
TandospironeThe risk or severity of adverse effects can be increased when Tandospirone is combined with Phenytoin.Investigational
TapentadolTapentadol may increase the central nervous system depressant (CNS depressant) activities of Phenytoin.Approved
TasimelteonThe serum concentration of Tasimelteon can be decreased when it is combined with Phenytoin.Approved
TasosartanThe metabolism of Tasosartan can be increased when combined with Phenytoin.Approved
Taurochenodeoxycholic acidThe metabolism of Taurochenodeoxycholic acid can be increased when combined with Phenytoin.Experimental
TavaboroleThe serum concentration of Phenytoin can be increased when it is combined with Tavaborole.Approved
TazaroteneThe metabolism of Tazarotene can be increased when combined with Phenytoin.Approved, Investigational
TegafurThe serum concentration of Phenytoin can be increased when it is combined with Tegafur.Approved
TelaprevirThe serum concentration of Phenytoin can be increased when it is combined with Telaprevir.Approved, Withdrawn
TelithromycinThe metabolism of Telithromycin can be increased when combined with Phenytoin.Approved
TemazepamThe serum concentration of Phenytoin can be increased when it is combined with Temazepam.Approved
TemsirolimusThe serum concentration of Temsirolimus can be decreased when it is combined with Phenytoin.Approved
TeniposideThe serum concentration of Teniposide can be decreased when it is combined with Phenytoin.Approved
TenoxicamThe metabolism of Tenoxicam can be increased when combined with Phenytoin.Approved
TerbinafineThe serum concentration of Phenytoin can be increased when it is combined with Terbinafine.Approved, Investigational, Vet Approved
TerconazoleThe serum concentration of Phenytoin can be increased when it is combined with Terconazole.Approved
TerfenadineThe metabolism of Terfenadine can be increased when combined with Phenytoin.Withdrawn
TeriflunomideThe metabolism of Phenytoin can be decreased when combined with Teriflunomide.Approved
TerodilineThe serum concentration of Phenytoin can be increased when it is combined with Terodiline.Experimental
TesmilifeneThe metabolism of Tesmilifene can be increased when combined with Phenytoin.Investigational
TestosteroneThe metabolism of Testosterone can be increased when combined with Phenytoin.Approved, Investigational
TetrabenazineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Tetrabenazine.Approved
TetracaineThe risk or severity of adverse effects can be increased when Tetracaine is combined with Phenytoin.Approved, Vet Approved
TetracosactideTetracosactide may increase the hepatotoxic activities of Phenytoin.Approved
TetracyclineThe metabolism of Tetracycline can be increased when combined with Phenytoin.Approved, Vet Approved
TetrahydropalmatineThe serum concentration of Phenytoin can be increased when it is combined with Tetrahydropalmatine.Investigational
TetrodotoxinThe risk or severity of adverse effects can be increased when Tetrodotoxin is combined with Phenytoin.Investigational
ThalidomidePhenytoin may increase the central nervous system depressant (CNS depressant) activities of Thalidomide.Approved, Investigational, Withdrawn
TheophyllineThe serum concentration of Theophylline can be decreased when it is combined with Phenytoin.Approved
ThiamylalThe metabolism of Thiamylal can be increased when combined with Phenytoin.Approved, Vet Approved
ThiopentalThe risk or severity of adverse effects can be increased when Thiopental is combined with Phenytoin.Approved, Vet Approved
ThioridazineThe metabolism of Thioridazine can be increased when combined with Phenytoin.Approved, Withdrawn
ThiotepaThe metabolism of Thiotepa can be increased when combined with Phenytoin.Approved
ThiothixeneThe risk or severity of adverse effects can be increased when Thiothixene is combined with Phenytoin.Approved
ThymolThe serum concentration of Phenytoin can be increased when it is combined with Thymol.Approved
Thyroid, porcineThe serum concentration of Thyroid, porcine can be decreased when it is combined with Phenytoin.Approved
TiagabineThe metabolism of Tiagabine can be increased when combined with Phenytoin.Approved
TiaprideThe risk or severity of adverse effects can be increased when Tiapride is combined with Phenytoin.Approved, Investigational
TicagrelorThe serum concentration of the active metabolites of Ticagrelor can be reduced when Ticagrelor is used in combination with Phenytoin resulting in a loss in efficacy.Approved
TiclopidineThe serum concentration of Phenytoin can be increased when it is combined with Ticlopidine.Approved
TiletamineThe risk or severity of adverse effects can be increased when Tiletamine is combined with Phenytoin.Vet Approved
TilidineThe risk or severity of adverse effects can be increased when Tilidine is combined with Phenytoin.Experimental
TimololThe metabolism of Timolol can be increased when combined with Phenytoin.Approved
TinidazoleThe metabolism of Tinidazole can be increased when combined with Phenytoin.Approved, Investigational
TioclomarolPhenytoin may increase the anticoagulant activities of Tioclomarol.Experimental
TioconazoleThe serum concentration of Phenytoin can be increased when it is combined with Tioconazole.Approved
TiotropiumThe metabolism of Tiotropium can be increased when combined with Phenytoin.Approved
TipranavirThe serum concentration of Tipranavir can be decreased when it is combined with Phenytoin.Approved, Investigational
TixocortolThe serum concentration of Tixocortol can be decreased when it is combined with Phenytoin.Approved
TizanidineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Tizanidine.Approved
TocilizumabThe serum concentration of Phenytoin can be decreased when it is combined with Tocilizumab.Approved
TofacitinibThe serum concentration of Tofacitinib can be decreased when it is combined with Phenytoin.Approved, Investigational
TolbutamideThe metabolism of Tolbutamide can be increased when combined with Phenytoin.Approved
TolcaponeThe risk or severity of adverse effects can be increased when Phenytoin is combined with Tolcapone.Approved, Withdrawn
TolciclateThe serum concentration of Phenytoin can be increased when it is combined with Tolciclate.Experimental
Tolfenamic AcidThe serum concentration of Phenytoin can be increased when it is combined with Tolfenamic Acid.Approved
TolnaftateThe serum concentration of Phenytoin can be increased when it is combined with Tolnaftate.Approved, Vet Approved
TolterodineThe metabolism of Tolterodine can be increased when combined with Phenytoin.Approved, Investigational
TolvaptanThe serum concentration of Tolvaptan can be decreased when it is combined with Phenytoin.Approved
TopiramateThe serum concentration of Phenytoin can be increased when it is combined with Topiramate.Approved
TopiroxostatThe metabolism of Phenytoin can be decreased when combined with Topiroxostat.Approved, Investigational
TopotecanThe serum concentration of Topotecan can be decreased when it is combined with Phenytoin.Approved, Investigational
TorasemidePhenytoin may decrease the diuretic activities of Torasemide.Approved
ToremifeneThe serum concentration of Toremifene can be decreased when it is combined with Phenytoin.Approved, Investigational
TrabectedinThe serum concentration of Trabectedin can be decreased when it is combined with Phenytoin.Approved, Investigational
TramadolThe metabolism of Tramadol can be increased when combined with Phenytoin.Approved, Investigational
TranilastThe serum concentration of Phenytoin can be increased when it is combined with Tranilast.Approved, Investigational
Trans-2-PhenylcyclopropylamineThe risk or severity of adverse effects can be increased when Trans-2-Phenylcyclopropylamine is combined with Phenytoin.Experimental
TranylcypromineThe risk or severity of adverse effects can be increased when Tranylcypromine is combined with Phenytoin.Approved
Trastuzumab emtansineThe metabolism of Trastuzumab emtansine can be increased when combined with Phenytoin.Approved
TrazodoneThe serum concentration of Trazodone can be decreased when it is combined with Phenytoin.Approved, Investigational
TreprostinilThe serum concentration of Treprostinil can be decreased when it is combined with Phenytoin.Approved, Investigational
TretinoinThe metabolism of Tretinoin can be increased when combined with Phenytoin.Approved, Investigational, Nutraceutical
TriamcinoloneThe metabolism of Triamcinolone can be increased when combined with Phenytoin.Approved, Vet Approved
TriazolamThe serum concentration of Phenytoin can be increased when it is combined with Triazolam.Approved
Tricaine methanesulfonateThe risk or severity of adverse effects can be increased when Tricaine methanesulfonate is combined with Phenytoin.Vet Approved
TrichloroethyleneThe risk or severity of adverse effects can be increased when Trichloroethylene is combined with Phenytoin.Approved
TrifluoperazineThe risk or severity of adverse effects can be increased when Trifluoperazine is combined with Phenytoin.Approved
TrifluperidolThe risk or severity of adverse effects can be increased when Trifluperidol is combined with Phenytoin.Experimental
TriflupromazineThe risk or severity of adverse effects can be increased when Triflupromazine is combined with Phenytoin.Approved, Vet Approved
TrimethadioneThe metabolism of Trimethadione can be increased when combined with Phenytoin.Approved
TrimethoprimThe serum concentration of Phenytoin can be increased when it is combined with Trimethoprim.Approved, Vet Approved
TrimetrexateThe serum concentration of Phenytoin can be increased when it is combined with Trimetrexate.Approved, Investigational
TrimipramineThe metabolism of Trimipramine can be increased when combined with Phenytoin.Approved
TriprolidineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Triprolidine.Approved
TroglitazoneThe metabolism of Troglitazone can be increased when combined with Phenytoin.Investigational, Withdrawn
TroleandomycinThe metabolism of Troleandomycin can be increased when combined with Phenytoin.Approved
UbidecarenoneThe serum concentration of Ubidecarenone can be decreased when it is combined with Phenytoin.Approved, Investigational, Nutraceutical
UdenafilThe metabolism of Udenafil can be increased when combined with Phenytoin.Approved, Investigational
UlipristalThe serum concentration of Ulipristal can be decreased when it is combined with Phenytoin.Approved
UlobetasolThe serum concentration of Ulobetasol can be decreased when it is combined with Phenytoin.Approved
ValbenazineThe metabolism of Valbenazine can be increased when combined with Phenytoin.Approved, Investigational
ValdecoxibThe metabolism of Valdecoxib can be increased when combined with Phenytoin.Investigational, Withdrawn
Valproic AcidThe serum concentration of Phenytoin can be decreased when it is combined with Valproic Acid.Approved, Investigational
ValsartanThe metabolism of Valsartan can be increased when combined with Phenytoin.Approved, Investigational
VandetanibThe serum concentration of Vandetanib can be decreased when it is combined with Phenytoin.Approved
VanoxerineThe metabolism of Vanoxerine can be increased when combined with Phenytoin.Investigational
VardenafilThe metabolism of Vardenafil can be increased when combined with Phenytoin.Approved
VelpatasvirThe metabolism of Velpatasvir can be increased when combined with Phenytoin.Approved
VenetoclaxThe metabolism of Venetoclax can be increased when combined with Phenytoin.Approved
VenlafaxineThe metabolism of Venlafaxine can be increased when combined with Phenytoin.Approved
VeraliprideThe risk or severity of adverse effects can be increased when Veralipride is combined with Phenytoin.Experimental
VerapamilThe serum concentration of Phenytoin can be increased when it is combined with Verapamil.Approved
VicrivirocThe metabolism of Vicriviroc can be increased when combined with Phenytoin.Investigational
VigabatrinThe serum concentration of Phenytoin can be decreased when it is combined with Vigabatrin.Approved
VilanterolThe metabolism of Vilanterol can be increased when combined with Phenytoin.Approved
VilazodoneThe serum concentration of Vilazodone can be decreased when it is combined with Phenytoin.Approved
VinblastineThe metabolism of Vinblastine can be increased when combined with Phenytoin.Approved
VincristineThe serum concentration of Vincristine can be decreased when it is combined with Phenytoin.Approved, Investigational
VindesineThe serum concentration of Phenytoin can be decreased when it is combined with Vindesine.Approved, Investigational
VinorelbineThe metabolism of Vinorelbine can be increased when combined with Phenytoin.Approved, Investigational
VinpocetineThe serum concentration of Phenytoin can be increased when it is combined with Vinpocetine.Investigational
Vinyl etherThe risk or severity of adverse effects can be increased when Vinyl ether is combined with Phenytoin.Experimental
VismodegibThe metabolism of Vismodegib can be increased when combined with Phenytoin.Approved
VorapaxarThe serum concentration of Vorapaxar can be decreased when it is combined with Phenytoin.Approved
VoriconazoleThe serum concentration of Phenytoin can be increased when it is combined with Voriconazole.Approved, Investigational
VortioxetineThe serum concentration of Vortioxetine can be decreased when it is combined with Phenytoin.Approved
VoxilaprevirThe metabolism of Voxilaprevir can be increased when combined with Phenytoin.Approved
WarfarinPhenytoin may increase the anticoagulant activities of Warfarin.Approved
XenonThe risk or severity of adverse effects can be increased when Xenon is combined with Phenytoin.Experimental
XimelagatranThe metabolism of Ximelagatran can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
XylazineThe risk or severity of adverse effects can be increased when Xylazine is combined with Phenytoin.Vet Approved
XylometazolineThe serum concentration of Phenytoin can be increased when it is combined with Xylometazoline.Approved
YohimbineThe metabolism of Yohimbine can be increased when combined with Phenytoin.Approved, Vet Approved
ZafirlukastThe metabolism of Zafirlukast can be increased when combined with Phenytoin.Approved, Investigational
ZalcitabineThe metabolism of Zalcitabine can be increased when combined with Phenytoin.Approved, Investigational
ZaleplonThe serum concentration of Zaleplon can be decreased when it is combined with Phenytoin.Approved, Illicit, Investigational
ZaltoprofenThe metabolism of Zaltoprofen can be increased when combined with Phenytoin.Approved, Investigational
ZiconotideThe serum concentration of Phenytoin can be increased when it is combined with Ziconotide.Approved
ZidovudineThe metabolism of Zidovudine can be increased when combined with Phenytoin.Approved
ZileutonThe metabolism of Zileuton can be increased when combined with Phenytoin.Approved, Investigational, Withdrawn
ZimelidineThe risk or severity of adverse effects can be increased when Phenytoin is combined with Zimelidine.Withdrawn
ZiprasidoneThe metabolism of Ziprasidone can be increased when combined with Phenytoin.Approved
ZolazepamThe risk or severity of adverse effects can be increased when Zolazepam is combined with Phenytoin.Vet Approved
ZolpidemPhenytoin may increase the central nervous system depressant (CNS depressant) activities of Zolpidem.Approved
ZomepiracThe metabolism of Zomepirac can be increased when combined with Phenytoin.Withdrawn
ZonisamideThe serum concentration of Zonisamide can be decreased when it is combined with Phenytoin.Approved, Investigational
ZopicloneThe metabolism of Zopiclone can be increased when combined with Phenytoin.Approved
ZotepineThe risk or severity of adverse effects can be increased when Zotepine is combined with Phenytoin.Approved, Investigational
ZucapsaicinThe metabolism of Phenytoin can be decreased when combined with Zucapsaicin.Approved
ZuclopenthixolThe serum concentration of Zuclopenthixol can be decreased when it is combined with Phenytoin.Approved, Investigational
Food Interactions
  • Avoid alcohol.
  • Do not take calcium, aluminum, magnesium or Iron supplements within 2 hours of taking this medication.
  • Take with food to increase bioavailability and reduce irritation.

References

Synthesis Reference

Mahdi B. Fawzi, Anne K. Taylor, "Parenteral phenytoin preparations." U.S. Patent US4642316, issued April, 1981.

US4642316
General References
  1. Link [Link]
External Links
Human Metabolome Database
HMDB14397
KEGG Drug
D00512
KEGG Compound
C07443
PubChem Compound
1775
PubChem Substance
46508847
ChemSpider
1710
BindingDB
50003655
ChEBI
8107
ChEMBL
CHEMBL16
Therapeutic Targets Database
DAP000130
PharmGKB
PA450947
IUPHAR
2624
Guide to Pharmacology
GtP Drug Page
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
PDRhealth
PDRhealth Drug Page
Wikipedia
Phenytoin
ATC Codes
N03AB02 — PhenytoinN03AB52 — Phenytoin, combinations
AHFS Codes
  • 28:12.12 — Hydantoins
MSDS
Download (73.7 KB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
0CompletedPreventionCognitive Impairments1
0TerminatedPreventionEpilepsies / Traumatic Brain Injury (TBI)1
1CompletedNot AvailableHealthy Volunteers2
1CompletedBasic ScienceHealthy Volunteers1
1CompletedTreatmentCocaine-Related Disorders1
1CompletedTreatmentEpilepsies2
1CompletedTreatmentHealthy Participants1
1TerminatedTreatmentEpilepsies1
1, 2CompletedTreatmentChronic Myeloproliferative Disorders / Leukemias / Malignant Lymphomas / Multiple Myeloma and Plasma Cell Neoplasm / Myelodysplastic Syndromes / Myelodysplastic/Myeloproliferative Neoplasms / Precancerous Conditions1
2Active Not RecruitingTreatmentChronic Lymphocytic Leukaemia (CLL) / Lymphoma, Hodgkins / Lymphoma, Large B-Cell, Diffuse (DLBCL) / Lymphoma, Low-Grade / Lymphoma, Mantle-Cell / Small Lymphocytic Lymphoma (SLL) / T-Cell Lymphomas1
2CompletedPreventionHuman Immunodeficiency Virus (HIV) Infections / Mother to Child Transmission / Pregnancy1
2CompletedTreatmentDisseminated Sclerosis / Optic Neuritis1
2RecruitingTreatmentOptic Neuritis1
2RecruitingTreatmentRe-Epithelialization / Wound site1
2TerminatedTreatmentHaemoglobinopathies congenital / Sickle Cell Disorders / Thalassaemic disorders1
2TerminatedTreatmentNonconvulsive Electrographic Seizures1
2Unknown StatusTreatmentNodding Syndrome1
3CompletedTreatmentCraniocerebral Injuries / Post-Traumatic Seizure Disorder1
3CompletedTreatmentEpilepsies1
3CompletedTreatmentGrand Mal Status Epilepticus / Non-convulsive Status Epilepticus1
3CompletedTreatmentHealthy Volunteers1
3TerminatedTreatmentAnxiety Disorders / Dementias / Depression / Psychosomatic Disorders / Schizophrenic Disorders1
4CompletedOtherCognitive Measures / Driving Simulator Performance1
4CompletedTreatmentBronchial Asthma1
4CompletedTreatmentDepression1
4CompletedTreatmentGrand mal Generalized tonic-clonic seizure1
4CompletedTreatmentSubarachnoid Hemorrhage / Traumatic Brain Injury (TBI)1
4Enrolling by InvitationTreatmentEpilepsies1
4RecruitingTreatmentEpilepsies1
4TerminatedTreatmentEpilepsies1
4TerminatedTreatmentSeizures1
4Unknown StatusPreventionMeningitis, Pneumococcal / Seizures1
Not AvailableCompletedNot AvailableHealthy Volunteers1
Not AvailableCompletedTreatmentCysticercosis / Epilepsies1
Not AvailableCompletedTreatmentOsteonecrosis Due to Drugs, Jaw1
Not AvailableRecruitingNot AvailableEpilepsies1
Not AvailableRecruitingOtherHealthy Volunteers2
Not AvailableTerminatedPreventionTraumatic Brain Injury (TBI)1
Not AvailableTerminatedTreatmentSubarachnoid Hemorrhage1
Not AvailableUnknown StatusTreatmentImpulsive Aggression / Posttraumatic Stress Disorders1

Pharmacoeconomics

Manufacturers
  • Parke davis div warner lambert co
  • Actavis mid atlantic llc
  • Taro pharmaceutical industries ltd
  • Vistapharm inc
  • Wockhardt eu operations (swiss) ag
  • Pfizer pharmaceuticals ltd
  • Lannett co inc
  • Amneal pharmaceuticals ny llc
  • Barr laboratories inc
  • Mylan pharmaceuticals inc
  • Pliva inc
  • Sun pharmaceutical industries ltd
  • Wockhardt ltd
  • Wockhardt usa inc
  • Watson laboratories inc
  • Pharmeral inc
  • Ivax pharmaceuticals inc sub teva pharmaceuticals usa
  • Parke davis pharmaceutical research div warner lambert co
  • App pharmaceuticals llc
  • Baxter healthcare corp
  • Hikma farmaceutica (portugal) sa
  • Hospira inc
  • Marsam pharmaceuticals llc
  • Pharmaforce inc
  • Smith and nephew solopak div smith and nephew
  • Solopak medical products inc
  • Warner chilcott div warner lambert co
Packagers
Dosage forms
FormRouteStrength
CapsuleOral30 mg
Capsule, extended releaseOral100 mg/1
Capsule, extended releaseOral30 mg/1
Tablet, chewableOral50 mg/1
TabletOral50 mg
LiquidIntramuscular; Intravenous250 mg
CapsuleOral
SuspensionOral125 mg
SuspensionOral30 mg
CapsuleOral100 mg
Capsule, extended releaseOral300 mg/1
SuspensionOral100 mg/4mL
SuspensionOral125 mg/5mL
CapsuleOral100 mg/1
Capsule, extended releaseOral200 mg/1
InjectionIntramuscular; Intravenous250 mg/5mL
InjectionIntramuscular; Intravenous50 mg/mL
InjectionIntravenous50 mg/mL
Injection, solutionIntramuscular; Intravenous50 mg/mL
LiquidIntramuscular; Intravenous50 mg
SolutionIntramuscular; Intravenous50 mg
Prices
Unit descriptionCostUnit
Dilantin 125 mg/5ml Suspension 237ml Bottle69.28USD bottle
Phenytoin Sodium 50 mg/ml2.64USD ml
Phenytek 300 mg capsule1.47USD capsule
Phenytoin sod ext 300 mg capsule1.2USD capsule
Phenytoin sodium powder1.16USD g
Phenytek 200 mg capsule0.98USD capsule
Phenytoin 50 mg/ml ampul0.96USD ml
Phenytoin sod ext 200 mg capsule0.8USD capsule
Phenytoin 50 mg/ml vial0.67USD ml
Phenytoin 100 mg/2 ml vial0.6USD ml
Dilantin Infatabs 50 mg Chew Tabs0.6USD tab
Dilantin 100 mg capsule0.51USD capsule
Phenytoin 100 mg/4 ml susp0.48USD ml
Dilantin 30 mg capsule0.46USD capsule
Phenytoin 250 mg/5 ml vial0.45USD ml
Dilantin 50 mg infatab0.44USD each
Dilantin 100 mg kapseal0.39USD each
Dilantin 30 mg kapseal0.39USD each
Phenytoin Sodium Extended 100 mg capsule0.36USD capsule
Phenytoin sod ext 100 mg capsule0.34USD capsule
Phenytoin powder0.23USD g
Phenytoin 125 mg/5ml Suspension0.15USD ml
Dilantin Infatabs 50 mg Chewable Tablet0.08USD tablet
Dilantin 100 mg Capsule0.08USD capsule
Dilantin 30 mg Capsule0.06USD capsule
Dilantin-125 25 mg/ml Suspension0.05USD ml
Dilantin-30 6 mg/ml Suspension0.04USD ml
Taro-Phenytoin 25 mg/ml Suspension0.03USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Not Available

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)286 °CPhysProp
water solubility32 mg/L (at 22 °C)YALKOWSKY,SH & DANNENFELSER,RM (1992)
logP2.47HANSCH,C ET AL. (1995)
Caco2 permeability-4.57ADME Research, USCD
pKa8.33SANGSTER (1994)
Predicted Properties
PropertyValueSource
Water Solubility0.0711 mg/mLALOGPS
logP2.26ALOGPS
logP2.15ChemAxon
logS-3.6ALOGPS
pKa (Strongest Acidic)9.47ChemAxon
pKa (Strongest Basic)-9ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area58.2 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity70.18 m3·mol-1ChemAxon
Polarizability25.48 Å3ChemAxon
Number of Rings3ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9909
Blood Brain Barrier+0.976
Caco-2 permeable+0.8867
P-glycoprotein substrateNon-substrate0.5593
P-glycoprotein inhibitor INon-inhibitor0.8782
P-glycoprotein inhibitor IINon-inhibitor0.987
Renal organic cation transporterNon-inhibitor0.8995
CYP450 2C9 substrateNon-substrate0.733
CYP450 2D6 substrateSubstrate0.8911
CYP450 3A4 substrateNon-substrate0.7591
CYP450 1A2 substrateNon-inhibitor0.9045
CYP450 2C9 inhibitorNon-inhibitor0.8304
CYP450 2D6 inhibitorNon-inhibitor0.935
CYP450 2C19 inhibitorNon-inhibitor0.9026
CYP450 3A4 inhibitorNon-inhibitor0.8309
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.8994
Ames testNon AMES toxic0.9132
CarcinogenicityNon-carcinogens0.855
BiodegradationNot ready biodegradable0.992
Rat acute toxicity2.1567 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9793
hERG inhibition (predictor II)Non-inhibitor0.8916
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Download (9.46 KB)
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSNot Available
GC-MS Spectrum - EI-BGC-MSsplash10-003r-7930000000-447969b9c242748dd943
GC-MS Spectrum - CI-BGC-MSsplash10-0udi-0090000000-4176043a7a73caee2667
GC-MS Spectrum - EI-BGC-MSsplash10-0zgi-5960000000-e1dcb47a1c082f04f456
GC-MS Spectrum - CI-BGC-MSsplash10-0udi-1390000000-22c71a7e4dbf9c7acab5
GC-MS Spectrum - CI-BGC-MSsplash10-0udi-2190000000-50174e33af92b04d1a6e
Mass Spectrum (Electron Ionization)MSsplash10-0f89-4940000000-2a0dda513d9f63dc6610
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSNot Available
LC-MS/MS Spectrum - LC-ESI-qTof , PositiveLC-MS/MSNot Available
LC-MS/MS Spectrum - LC-ESI-qTof , PositiveLC-MS/MSNot Available
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0090000000-aaae845342f345f89695
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0390000000-f8da1896c569c120faa2
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0920000000-07c872b05aade63c402b
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0900000000-be6790637be99260525e
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0900000000-9a17fa0b243c8282f3ba
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0udi-0900000000-69302626996b2b24c153
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0fai-0690000000-f9eeceb82d117127f6ea
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-001i-0910000000-9edcfc62014a6aa7778f
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-001i-0900000000-d4dde5db680fb7722a49
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0ue9-0900000000-482874b33812389ae726
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0udi-0900000000-44f07dc29daf8cdf80c2
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0udi-1900000000-1241292d531ed37544c7
MS/MS Spectrum - , positiveLC-MS/MSsplash10-001i-0950000000-a80521d4dc3976a29b2c
MS/MS Spectrum - , positiveLC-MS/MSsplash10-0ue9-2900000000-a58471ae75fa7319c03d
1H NMR Spectrum1D NMRNot Applicable
13C NMR Spectrum1D NMRNot Applicable

Taxonomy

Description
This compound belongs to the class of organic compounds known as phenylhydantoins. These are heterocyclic aromatic compounds containing an imiazolidinedione moiety substituted by a phenyl group.
Kingdom
Organic compounds
Super Class
Organoheterocyclic compounds
Class
Azolidines
Sub Class
Imidazolidines
Direct Parent
Phenylhydantoins
Alternative Parents
Diphenylmethanes / Phenylimidazolidines / Alpha amino acids and derivatives / 5-monosubstituted hydantoins / N-acyl ureas / Dicarboximides / Azacyclic compounds / Organopnictogen compounds / Organonitrogen compounds / Organic oxides
show 2 more
Substituents
Diphenylmethane / 5-phenylhydantoin / Phenylimidazolidine / Alpha-amino acid or derivatives / 5-monosubstituted hydantoin / N-acyl urea / Ureide / Monocyclic benzene moiety / Benzenoid / Dicarboximide
show 13 more
Molecular Framework
Aromatic heteromonocyclic compounds
External Descriptors
imidazolidine-2,4-dione (CHEBI:8107)

Targets

Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Inhibitor
General Function
Voltage-gated sodium channel activity involved in sa node cell action potential
Specific Function
This protein mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the pr...
Gene Name
SCN5A
Uniprot ID
Q14524
Uniprot Name
Sodium channel protein type 5 subunit alpha
Molecular Weight
226937.475 Da
References
  1. Mitiushin VM, Kozyreva EV: [Several types of mitochondrial ultrastructure in animal cell mitochondria and their relationship to energy production]. Tsitologiia. 1978 Apr;20(4):371-9. [PubMed:150666]
  2. Swadron SP, Rudis MI, Azimian K, Beringer P, Fort D, Orlinsky M: A comparison of phenytoin-loading techniques in the emergency department. Acad Emerg Med. 2004 Mar;11(3):244-52. [PubMed:15001403]
Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Inhibitor
General Function
Voltage-gated sodium channel activity
Specific Function
Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a...
Gene Name
SCN1A
Uniprot ID
P35498
Uniprot Name
Sodium channel protein type 1 subunit alpha
Molecular Weight
228969.49 Da
References
  1. Tate SK, Depondt C, Sisodiya SM, Cavalleri GL, Schorge S, Soranzo N, Thom M, Sen A, Shorvon SD, Sander JW, Wood NW, Goldstein DB: Genetic predictors of the maximum doses patients receive during clinical use of the anti-epileptic drugs carbamazepine and phenytoin. Proc Natl Acad Sci U S A. 2005 Apr 12;102(15):5507-12. Epub 2005 Apr 1. [PubMed:15805193]
  2. Tate SK, Singh R, Hung CC, Tai JJ, Depondt C, Cavalleri GL, Sisodiya SM, Goldstein DB, Liou HH: A common polymorphism in the SCN1A gene associates with phenytoin serum levels at maintenance dose. Pharmacogenet Genomics. 2006 Oct;16(10):721-6. [PubMed:17001291]
  3. Mantegazza M, Curia G, Biagini G, Ragsdale DS, Avoli M: Voltage-gated sodium channels as therapeutic targets in epilepsy and other neurological disorders. Lancet Neurol. 2010 Apr;9(4):413-24. doi: 10.1016/S1474-4422(10)70059-4. [PubMed:20298965]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
General Function
Zinc ion binding
Specific Function
Nuclear receptor that binds and is activated by variety of endogenous and xenobiotic compounds. Transcription factor that activates the transcription of multiple genes involved in the metabolism an...
Gene Name
NR1I2
Uniprot ID
O75469
Uniprot Name
Nuclear receptor subfamily 1 group I member 2
Molecular Weight
49761.245 Da
References
  1. Faucette SR, Wang H, Hamilton GA, Jolley SL, Gilbert D, Lindley C, Yan B, Negishi M, LeCluyse EL: Regulation of CYP2B6 in primary human hepatocytes by prototypical inducers. Drug Metab Dispos. 2004 Mar;32(3):348-58. [PubMed:14977870]
  2. Kobayashi K, Yamagami S, Higuchi T, Hosokawa M, Chiba K: Key structural features of ligands for activation of human pregnane X receptor. Drug Metab Dispos. 2004 Apr;32(4):468-72. [PubMed:15039302]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
General Function
Voltage-gated sodium channel activity involved in purkinje myocyte action potential
Specific Function
Crucial in the assembly, expression, and functional modulation of the heterotrimeric complex of the sodium channel. The subunit beta-1 can modulate multiple alpha subunit isoforms from brain, skele...
Gene Name
SCN1B
Uniprot ID
Q07699
Uniprot Name
Sodium channel subunit beta-1
Molecular Weight
24706.955 Da
References
  1. Lucas PT, Meadows LS, Nicholls J, Ragsdale DS: An epilepsy mutation in the beta1 subunit of the voltage-gated sodium channel results in reduced channel sensitivity to phenytoin. Epilepsy Res. 2005 May;64(3):77-84. [PubMed:15922564]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
General Function
Voltage-gated sodium channel activity
Specific Function
Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a...
Gene Name
SCN3A
Uniprot ID
Q9NY46
Uniprot Name
Sodium channel protein type 3 subunit alpha
Molecular Weight
226291.905 Da
References
  1. Lucas PT, Meadows LS, Nicholls J, Ragsdale DS: An epilepsy mutation in the beta1 subunit of the voltage-gated sodium channel results in reduced channel sensitivity to phenytoin. Epilepsy Res. 2005 May;64(3):77-84. [PubMed:15922564]

Enzymes

Details
1. Cytochrome P450 2C9
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
Inhibitor
Inducer
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2C9
Uniprot ID
P11712
Uniprot Name
Cytochrome P450 2C9
Molecular Weight
55627.365 Da
References
  1. Levy RH: Cytochrome P450 isozymes and antiepileptic drug interactions. Epilepsia. 1995;36 Suppl 5:S8-13. [PubMed:8806399]
  2. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
  3. Tate SK, Depondt C, Sisodiya SM, Cavalleri GL, Schorge S, Soranzo N, Thom M, Sen A, Shorvon SD, Sander JW, Wood NW, Goldstein DB: Genetic predictors of the maximum doses patients receive during clinical use of the anti-epileptic drugs carbamazepine and phenytoin. Proc Natl Acad Sci U S A. 2005 Apr 12;102(15):5507-12. Epub 2005 Apr 1. [PubMed:15805193]
  4. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
  5. Komatsu T, Yamazaki H, Asahi S, Gillam EM, Guengerich FP, Nakajima M, Yokoi T: Formation of a dihydroxy metabolite of phenytoin in human liver microsomes/cytosol: roles of cytochromes P450 2C9, 2C19, and 3A4. Drug Metab Dispos. 2000 Nov;28(11):1361-8. [PubMed:11038165]
  6. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
Inducer
General Function
Steroid hydroxylase activity
Specific Function
Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and im...
Gene Name
CYP2C19
Uniprot ID
P33261
Uniprot Name
Cytochrome P450 2C19
Molecular Weight
55930.545 Da
References
  1. Levy RH: Cytochrome P450 isozymes and antiepileptic drug interactions. Epilepsia. 1995;36 Suppl 5:S8-13. [PubMed:8806399]
  2. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
  3. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
  4. Komatsu T, Yamazaki H, Asahi S, Gillam EM, Guengerich FP, Nakajima M, Yokoi T: Formation of a dihydroxy metabolite of phenytoin in human liver microsomes/cytosol: roles of cytochromes P450 2C9, 2C19, and 3A4. Drug Metab Dispos. 2000 Nov;28(11):1361-8. [PubMed:11038165]
  5. Kaminsky LS, Zhang ZY: Human P450 metabolism of warfarin. Pharmacol Ther. 1997;73(1):67-74. [PubMed:9014207]
  6. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
Inducer
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2C8
Uniprot ID
P10632
Uniprot Name
Cytochrome P450 2C8
Molecular Weight
55824.275 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
  2. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inducer
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2B6
Uniprot ID
P20813
Uniprot Name
Cytochrome P450 2B6
Molecular Weight
56277.81 Da
References
  1. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
Inducer
General Function
Vitamin d3 25-hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation react...
Gene Name
CYP3A4
Uniprot ID
P08684
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2C18
Uniprot ID
P33260
Uniprot Name
Cytochrome P450 2C18
Molecular Weight
55710.075 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inducer
General Function
Oxygen binding
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP3A5
Uniprot ID
P20815
Uniprot Name
Cytochrome P450 3A5
Molecular Weight
57108.065 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inducer
General Function
Oxygen binding
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP3A7
Uniprot ID
P24462
Uniprot Name
Cytochrome P450 3A7
Molecular Weight
57525.03 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Steroid 11-beta-monooxygenase activity
Specific Function
Has steroid 11-beta-hydroxylase activity. In addition to this activity, the 18 or 19-hydroxylation of steroids and the aromatization of androstendione to estrone have also been ascribed to cytochro...
Gene Name
CYP11B1
Uniprot ID
P15538
Uniprot Name
Cytochrome P450 11B1, mitochondrial
Molecular Weight
57572.44 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]

Carriers

Kind
Protein
Organism
Human
Pharmacological action
Unknown
General Function
Toxic substance binding
Specific Function
Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloid...
Gene Name
ALB
Uniprot ID
P02768
Uniprot Name
Serum albumin
Molecular Weight
69365.94 Da
References
  1. Chen J, Ohnmacht C, Hage DS: Studies of phenytoin binding to human serum albumin by high-performance affinity chromatography. J Chromatogr B Analyt Technol Biomed Life Sci. 2004 Sep 25;809(1):137-45. [PubMed:15282104]
  2. Ohnmacht CM, Chen S, Tong Z, Hage DS: Studies by biointeraction chromatography of binding by phenytoin metabolites to human serum albumin. J Chromatogr B Analyt Technol Biomed Life Sci. 2006 May 19;836(1-2):83-91. Epub 2006 Apr 18. [PubMed:16621742]

Transporters

Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Thyroid hormone transmembrane transporter activity
Specific Function
Mediates the Na(+)-independent high affinity transport of organic anions such as the thyroid hormones thyroxine (T4) and rT3. Other potential substrates, such as triiodothyronine (T3), 17-beta-gluc...
Gene Name
SLCO1C1
Uniprot ID
Q9NYB5
Uniprot Name
Solute carrier organic anion transporter family member 1C1
Molecular Weight
78695.625 Da
References
  1. Westholm DE, Stenehjem DD, Rumbley JN, Drewes LR, Anderson GW: Competitive inhibition of organic anion transporting polypeptide 1c1-mediated thyroxine transport by the fenamate class of nonsteroidal antiinflammatory drugs. Endocrinology. 2009 Feb;150(2):1025-32. doi: 10.1210/en.2008-0188. Epub 2008 Oct 9. [PubMed:18845642]
  2. Berman HM, Westbrook J, Feng Z, Gilliland G, Bhat TN, Weissig H, Shindyalov IN, Bourne PE: The Protein Data Bank. Nucleic Acids Res. 2000 Jan 1;28(1):235-42. [PubMed:10592235]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Xenobiotic-transporting atpase activity
Specific Function
Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells.
Gene Name
ABCB1
Uniprot ID
P08183
Uniprot Name
Multidrug resistance protein 1
Molecular Weight
141477.255 Da
References
  1. Baltes S, Gastens AM, Fedrowitz M, Potschka H, Kaever V, Loscher W: Differences in the transport of the antiepileptic drugs phenytoin, levetiracetam and carbamazepine by human and mouse P-glycoprotein. Neuropharmacology. 2007 Feb;52(2):333-46. Epub 2006 Oct 10. [PubMed:17045309]
  2. Luna-Tortos C, Fedrowitz M, Loscher W: Several major antiepileptic drugs are substrates for human P-glycoprotein. Neuropharmacology. 2008 Dec;55(8):1364-75. doi: 10.1016/j.neuropharm.2008.08.032. Epub 2008 Sep 11. [PubMed:18824002]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Organic anion transmembrane transporter activity
Specific Function
Mediates hepatobiliary excretion of numerous organic anions. May function as a cellular cisplatin transporter.
Gene Name
ABCC2
Uniprot ID
Q92887
Uniprot Name
Canalicular multispecific organic anion transporter 1
Molecular Weight
174205.64 Da
References
  1. Baltes S, Gastens AM, Fedrowitz M, Potschka H, Kaever V, Loscher W: Differences in the transport of the antiepileptic drugs phenytoin, levetiracetam and carbamazepine by human and mouse P-glycoprotein. Neuropharmacology. 2007 Feb;52(2):333-46. Epub 2006 Oct 10. [PubMed:17045309]

Drug created on June 13, 2005 07:24 / Updated on December 10, 2017 17:18