Identification

Name
Fosphenytoin
Accession Number
DB01320
Type
Small Molecule
Groups
Approved, Investigational
Description

Fosphenytoin is a water-soluble phenytoin prodrug used only in hospitals for the treatment of epileptic seizures. It works by slowing down impulses in the brain that cause seizures. Its main mechanism is to block frequency-dependent, use-dependent and voltage-dependent neuronal sodium channels, and therefore limit repetitive firing of action potentials.

Structure
Thumb
Synonyms
  • (3-Phosphoryloxymethyl)phenytoin
  • Fosfenitoina
  • Fosphenytoin
  • Fosphenytoine
  • Fosphenytoinum
Product Ingredients
IngredientUNIICASInChI Key
Fosphenytoin sodium7VLR55452Z92134-98-0GQPXYJNXTAFDLT-UHFFFAOYSA-L
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
CerebyxLiquid75 mgIntramuscular; IntravenousErfa Canada 2012 Inc2000-03-01Not applicableCanada
CerebyxInjection, solution50 mg/mLIntramuscular; IntravenousPfizer Laboratories Div Pfizer Inc.2013-10-28Not applicableUs
CerebyxInjection, solution50 mg/mLIntramuscular; IntravenousPfizer Laboratories Div Pfizer Inc.2013-10-28Not applicableUs
CerebyxInjection, solution50 mg/mLIntramuscular; IntravenousPfizer Laboratories Div Pfizer Inc.2013-10-28Not applicableUs
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
FosphenytoinInjection, solution50 mg/mLIntramuscular; IntravenousFresenius Kabi2009-12-14Not applicableUs
Fosphenytoin SodiumInjection50 mg/mLIntramuscular; IntravenousAmneal Biosciences2016-07-25Not applicableUs
Fosphenytoin SodiumInjection50 mg/mLIntramuscular; IntravenousWest Ward Pharmaceutical2007-08-06Not applicableUs
Fosphenytoin SodiumInjection, solution50 mg/mLIntramuscular; IntravenousHospira, Inc.2007-08-062017-09-02Us
Fosphenytoin SodiumInjection50 mg/mLIntramuscular; IntravenousAmneal Pharmaceuticals of New York Llc2013-05-17Not applicableUs
Fosphenytoin SodiumInjection50 mg/mLIntramuscular; IntravenousWockhardt2007-08-06Not applicableUs
Fosphenytoin SodiumInjection, solution50 mg/mLIntramuscular; IntravenousSun Pharma Global FZE2009-08-142017-01-27Us
Fosphenytoin SodiumInjection, solution50 mg/mLIntramuscular; IntravenousMylan Institutional2016-12-06Not applicableUs
Fosphenytoin SodiumInjection50 mg/mLIntramuscular; IntravenousAmneal Biosciences2016-07-25Not applicableUs
Fosphenytoin SodiumInjection, solution50 mg/mLIntramuscular; IntravenousWest Ward Pharmaceutical2009-12-02Not applicableUs
International/Other Brands
Cerebyx / Prodilantin
Categories
UNII
B4SF212641
CAS number
93390-81-9
Weight
Average: 362.2739
Monoisotopic: 362.066772734
Chemical Formula
C16H15N2O6P
InChI Key
XWLUWCNOOVRFPX-UHFFFAOYSA-N
InChI
InChI=1S/C16H15N2O6P/c19-14-16(12-7-3-1-4-8-12,13-9-5-2-6-10-13)17-15(20)18(14)11-24-25(21,22)23/h1-10H,11H2,(H,17,20)(H2,21,22,23)
IUPAC Name
[(2,5-dioxo-4,4-diphenylimidazolidin-1-yl)methoxy]phosphonic acid
SMILES
OP(O)(=O)OCN1C(=O)NC(C1=O)(C1=CC=CC=C1)C1=CC=CC=C1

Pharmacology

Indication

For the control of generalized convulsive status epilepticus and prevention and treatment of seizures occurring during neurosurgery. It can also be substituted, short-term, for oral phenytoin.

Structured Indications
Pharmacodynamics

Fosphenytoin is a water-soluble phenytoin prodrug used only in hospitals for the treatment of epileptic seizures. Following parenteral administration of fosphenytoin, fosphenytoin is converted to the anticonvulsant phenytoin by endogenous phosphatases. For every mmol of fosphenytoin administered, one mmol of phenytoin is produced. The pharmacological and toxicological effects of fosphenytoin include those of phenytoin.

Mechanism of action

Fosphenytoin is a prodrug of phenytoin and accordingly, its anticonvulsant effects are attributable to phenytoin. 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
Absorption

Fosphenytoin is completely bioavailable following lM administration.

Volume of distribution
  • 4.3 to 10.8 L
Protein binding

Extensively bound (95% to 99%) to human plasma proteins, primarily albumin.

Metabolism

Hepatic.

Route of elimination

Phenytoin derived from administration of Cerebyx is extensively metabolized in the liver and excreted in urine primarily as 5-(p-hydroxyphenyl)-5-phenylhydantoin and its glucuronide; little unchanged phenytoin (1%–5% of the Cerebyx dose) is recovered in urine.

Half life

Fosphenytoin has a half-life of approximately 15 minutes.

Clearance
Not Available
Toxicity

Nausea, vomiting, lethargy, tachycardia, bradycardia, asystole, cardiac arrest, hypotension, syncope, hypocalcemia, metabolic acidosis, and death have been reported in cases of overdosage with fosphenytoin. The median lethal dose of fosphenytoin given intravenously in mice and rats was 156 mg PE/kg and approximately 250 mg PE/kg, or about 0.6 and 2 times, respectively, the maximum human loading dose on a mg/m2 basis. Signs of acute toxicity in animals included ataxia, labored breathing, ptosis, and hypoactivity.

Affected organisms
  • Humans and other mammals
Pathways
PathwayCategory
Fosphenytoin (Antiarrhythmic) Metabolism PathwayDrug metabolism
Fosphenytoin (Antiarrhythmic) Action PathwayDrug action
Pharmacogenomic Effects/ADRs
Not Available

Interactions

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

References

Synthesis Reference

Volker Kirsch, "Process for the preparation of sodium fosphenytoin." U.S. Patent US20050272706, issued December 08, 2005.

US20050272706
General References
  1. Johnson J, Wrenn K: Inappropriate fosphenytoin use in the ED. Am J Emerg Med. 2001 Jul;19(4):293-4. [PubMed:11447516]
  2. Applebaum J, Levine J, Belmaker RH: Intravenous fosphenytoin in acute mania. J Clin Psychiatry. 2003 Apr;64(4):408-9. [PubMed:12716241]
  3. McCleane GJ: Intravenous infusion of fosphenytoin produces prolonged pain relief: a case report. J Pain. 2002 Apr;3(2):156-8. [PubMed:14622802]
  4. Browne TR, Kugler AR, Eldon MA: Pharmacology and pharmacokinetics of fosphenytoin. Neurology. 1996 Jun;46(6 Suppl 1):S3-7. [PubMed:8649612]
  5. Luszczki JJ: Third-generation antiepileptic drugs: mechanisms of action, pharmacokinetics and interactions. Pharmacol Rep. 2009 Mar-Apr;61(2):197-216. [PubMed:19443931]
External Links
Human Metabolome Database
HMDB0015417
KEGG Compound
C07840
PubChem Compound
56339
PubChem Substance
46505168
ChemSpider
50839
ChEBI
5165
ChEMBL
CHEMBL1201336
Therapeutic Targets Database
DAP000520
PharmGKB
PA164746820
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
Wikipedia
Fosphenytoin
ATC Codes
N03AB05 — Fosphenytoin
AHFS Codes
  • 28:12.12 — Hydantoins
FDA label
Download (820 KB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
2CompletedTreatmentNonconvulsive Seizures1
3CompletedTreatmentEpilepsies1
3RecruitingTreatmentBenzodiazepine Refractory Status Epilepticus1
3RecruitingTreatmentEpilepsies / Refractory seizure disorders1
4CompletedTreatmentGrand mal Generalized tonic-clonic seizure1
Not AvailableRecruitingNot AvailableAcute Bacterial Exacerbation of Chronic Bronchitis (ABECB) / Acute Bacterial Sinusitis (ABS) / Acute Decompensated Heart Failure (ADHF) / Acute Pyelonephritis / Adenovirus / Adjunct to general anesthesia therapy / Adrenal Insufficiency / Airway Swelling / Anaesthesia therapy / Anxiolysis / Arterial Hypotension / Autism, Early Infantile / Autistic Disorder / Bartonellosis / Benzodiazepine Withdrawal / Benzodiazepines / Bipolar Disorder (BD) / Bloodstream Infections / Bone and Joint Infections / Brain Swelling / Bronchospasm / Brucellosis / Cardiac Arrest / Central Nervous System Infections / Cholera / Chronic Bacterial Prostatitis / Community Acquired Pneumonia (CAP) / Complicated Urinary Tract Infections / Convulsions / Cyanide Poisoning / Cytomegalovirus Retinitis / Drug hypersensitivity reaction / Early-onset Schizophrenia Spectrum Disorders / Edema / Epilepsies / Feeling Anxious / Flu caused by Influenza / Gastroparesis / GYNAECOLOGICAL INFECTION / Headaches / Herpes Simplex Virus / High Blood Cholesterol Level / High Blood Pressure (Hypertension) / Hospital-acquired bacterial pneumonia / Hyperlipidemias / Infantile Hemangiomas / Infection NOS / Inflammatory Conditions / Inflammatory Reaction / Influenza Treatment or Prophylaxis / Inhalational Anthrax (Post-Exposure) / Intra-Abdominal Infections / Life-threatening Fungal Infections / Lower Respiratory Tract Infection (LRTI) / Meningitis, Bacterial / Migraines / Muscle Spasms / Nausea / Opioid Addiction / Pain / Plague / Pneumonia / Prophylaxis / Psittacosis / Q Fever / Reflux / Relapsing Fever / Rocky Mountain Spotted Fever / Schizophrenic Disorders / Sedation therapy / Seizures / Sepsis / Skeletal Muscle Spasms / Skin and Subcutaneous Tissue Bacterial Infections / Skin Structures and Soft Tissue Infections / Stable Angina (SA) / Thromboprophylaxis / Thrombosis / Trachoma / Treatment-resistant Schizophrenia / Tularemia / Typhus Fever / Uncomplicated Skin and Skin Structure Infections / Uncomplicated Urinary Tract Infections / Urinary Tract Infections (UTIs) / Vomiting / Withdrawal1
Not AvailableTerminatedPreventionTraumatic Brain Injury (TBI)1
Not AvailableTerminatedTreatmentSubarachnoid Hemorrhage1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Dosage forms
FormRouteStrength
LiquidIntramuscular; Intravenous75 mg
InjectionIntramuscular; Intravenous50 mg/mL
Injection, solutionIntramuscular; Intravenous50 mg/mL
Prices
Unit descriptionCostUnit
Cerebyx 500 mg pe/10 ml vial8.63USD ml
Fosphenytoin 500 mg pe/10 ml0.61USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Not Available

Properties

State
Solid
Experimental Properties
Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.145 mg/mLALOGPS
logP1.08ALOGPS
logP1.67ChemAxon
logS-3.4ALOGPS
pKa (Strongest Acidic)1.46ChemAxon
pKa (Strongest Basic)-9.7ChemAxon
Physiological Charge-2ChemAxon
Hydrogen Acceptor Count5ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area116.17 Å2ChemAxon
Rotatable Bond Count5ChemAxon
Refractivity87.05 m3·mol-1ChemAxon
Polarizability33.23 Å3ChemAxon
Number of Rings3ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption-0.5244
Blood Brain Barrier+0.9215
Caco-2 permeable-0.639
P-glycoprotein substrateSubstrate0.5
P-glycoprotein inhibitor INon-inhibitor0.7952
P-glycoprotein inhibitor IINon-inhibitor0.8466
Renal organic cation transporterNon-inhibitor0.8731
CYP450 2C9 substrateNon-substrate0.7094
CYP450 2D6 substrateNon-substrate0.9116
CYP450 3A4 substrateNon-substrate0.6873
CYP450 1A2 substrateNon-inhibitor0.8477
CYP450 2C9 inhibitorNon-inhibitor0.7802
CYP450 2D6 inhibitorNon-inhibitor0.8859
CYP450 2C19 inhibitorNon-inhibitor0.7169
CYP450 3A4 inhibitorNon-inhibitor0.7672
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.9083
Ames testNon AMES toxic0.614
CarcinogenicityNon-carcinogens0.7835
BiodegradationNot ready biodegradable0.9674
Rat acute toxicity2.4215 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9578
hERG inhibition (predictor II)Non-inhibitor0.7299
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Not Available
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSNot Available
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

Taxonomy

Description
This compound belongs to the class of organic compounds known as diphenylmethanes. These are compounds containing a diphenylmethane moiety, which consists of a methane wherein two hydrogen atoms are replaced by two phenyl groups.
Kingdom
Organic compounds
Super Class
Benzenoids
Class
Benzene and substituted derivatives
Sub Class
Diphenylmethanes
Direct Parent
Diphenylmethanes
Alternative Parents
Alpha amino acids and derivatives / N-acyl ureas / Monoalkyl phosphates / Imidazolinones / Isoureas / Propargyl-type 1,3-dipolar organic compounds / Carboximidamides / Azacyclic compounds / Organopnictogen compounds / Organic oxides
show 2 more
Substituents
Diphenylmethane / Alpha-amino acid or derivatives / N-acyl urea / Ureide / Monoalkyl phosphate / Imidazolinone / Organic phosphoric acid derivative / Phosphoric acid ester / Alkyl phosphate / 2-imidazoline
show 16 more
Molecular Framework
Aromatic heteromonocyclic compounds
External Descriptors
imidazolidine-2,4-dione (CHEBI:5165)

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. 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]
  2. 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]
  3. Lenkowski PW, Ko SH, Anderson JD, Brown ML, Patel MK: Block of human NaV1.5 sodium channels by novel alpha-hydroxyphenylamide analogues of phenytoin. Eur J Pharm Sci. 2004 Apr;21(5):635-44. [PubMed:15066664]
  4. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352]

Enzymes

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. Kim KA, Park JY: Inhibitory effect of glyburide on human cytochrome p450 isoforms in human liver microsomes. Drug Metab Dispos. 2003 Sep;31(9):1090-2. [PubMed:12920163]
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. Anderson GD: Pharmacokinetic, pharmacodynamic, and pharmacogenetic targeted therapy of antiepileptic drugs. Ther Drug Monit. 2008 Apr;30(2):173-80. doi: 10.1097/FTD.0b013e318167d11b. [PubMed:18367977]
  2. Hennessy S, Leonard CE, Freeman CP, Metlay JP, Chu X, Strom BL, Bilker WB: CYP2C9, CYP2C19, and ABCB1 genotype and hospitalization for phenytoin toxicity. J Clin Pharmacol. 2009 Dec;49(12):1483-7. doi: 10.1177/0091270009343006. Epub 2009 Jul 17. [PubMed:19617466]
  3. Klotz U: The role of pharmacogenetics in the metabolism of antiepileptic drugs: pharmacokinetic and therapeutic implications. Clin Pharmacokinet. 2007;46(4):271-9. [PubMed:17375979]
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. Wang H, Faucette S, Moore R, Sueyoshi T, Negishi M, LeCluyse E: Human constitutive androstane receptor mediates induction of CYP2B6 gene expression by phenytoin. J Biol Chem. 2004 Jul 9;279(28):29295-301. Epub 2004 Apr 28. [PubMed:15123723]
  2. 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]
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
CYP2C9
Uniprot ID
P11712
Uniprot Name
Cytochrome P450 2C9
Molecular Weight
55627.365 Da
References
  1. Sahi J, Shord SS, Lindley C, Ferguson S, LeCluyse EL: Regulation of cytochrome P450 2C9 expression in primary cultures of human hepatocytes. J Biochem Mol Toxicol. 2009 Jan-Feb;23(1):43-58. doi: 10.1002/jbt.20264. [PubMed:19202563]
  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. Goldstein JA: Clinical relevance of genetic polymorphisms in the human CYP2C subfamily. Br J Clin Pharmacol. 2001 Oct;52(4):349-55. [PubMed:11678778]
  4. Klotz U: The role of pharmacogenetics in the metabolism of antiepileptic drugs: pharmacokinetic and therapeutic implications. Clin Pharmacokinet. 2007;46(4):271-9. [PubMed:17375979]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
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. Zhou SF: Drugs behave as substrates, inhibitors and inducers of human cytochrome P450 3A4. Curr Drug Metab. 2008 May;9(4):310-22. [PubMed:18473749]

Carriers

Kind
Protein
Organism
Human
Pharmacological action
No
Actions
Other/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. Walker MC, Patsalos PN: Clinical pharmacokinetics of new antiepileptic drugs. Pharmacol Ther. 1995;67(3):351-84. [PubMed:8577822]

Drug created on June 30, 2007 11:18 / Updated on February 13, 2018 09:46