Identification

Name
Phentolamine
Accession Number
DB00692  (APRD00615)
Type
Small Molecule
Groups
Approved
Description

A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of raynaud disease and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease. [PubChem]

Structure
Thumb
Synonyms
  • 2-(N-(m-Hydroxyphenyl)-P-toluidinomethyl)imidazoline
  • Fentolamina
  • Phentolamin
  • Phentolamine
  • Phentolamine mesylate
  • Phentolaminum
  • Regitina
  • Vesomax
Product Ingredients
IngredientUNIICASInChI Key
Phentolamine MesylateNot AvailableNot AvailableNot applicable
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
OraverseSolution0.4 mgSubmucosalSeptodont2014-09-17Not applicableCanada
OraverseInjection, solution.235 mg/mLSubmucosalSeptodont2011-06-01Not applicableUs
Phentolamine Mesylate Injection Sandoz StandardSolution5 mgIntramuscular; IntravenousSandoz Canada Incorporated2001-06-15Not applicableCanada
RogitineSolution10 mgIntramuscular; IntravenousPaladin Labs Inc2000-12-18Not applicableCanada
Rogitine 5mg/vialPowder, for solution5 mgIntramuscular; IntravenousNovartis1953-12-31Not applicableCanada
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Phentolamine MesylateInjection5 mg/1Intramuscular; IntravenousPrecision Dose, Inc.2017-07-15Not applicableUs
Phentolamine MesylateInjection5 mg/1Intramuscular; IntravenousTAGI Pharma, Inc.2017-07-15Not applicableUs
Phentolamine MesylateInjection, powder, for solution5 mg/mLIntramuscular; IntravenousWest Ward Pharmaceutical1998-05-15Not applicableUs
International/Other Brands
Regitin (Novartis) / Regitina (Novartis) / Regitine (Novartis) / Rogitine / Vigamed (Grupo Cimed)
Categories
UNII
Z468598HBV
CAS number
50-60-2
Weight
Average: 281.3523
Monoisotopic: 281.152812245
Chemical Formula
C17H19N3O
InChI Key
MRBDMNSDAVCSSF-UHFFFAOYSA-N
InChI
InChI=1S/C17H19N3O/c1-13-5-7-14(8-6-13)20(12-17-18-9-10-19-17)15-3-2-4-16(21)11-15/h2-8,11,21H,9-10,12H2,1H3,(H,18,19)
IUPAC Name
3-[(4,5-dihydro-1H-imidazol-2-ylmethyl)(4-methylphenyl)amino]phenol
SMILES
CC1=CC=C(C=C1)N(CC1=NCCN1)C1=CC(O)=CC=C1

Pharmacology

Indication

Used as an aid for the diagnosis of pheochromocytoma, and may be administered immediately prior to or during pheochromocytomectomy to prevent or control paroxysmal hypertension resulting from anesthesia, stress, or operative manipulation of the tumor. Phentolamine has also been used to treat hypertensive crisis caused by sympathomimetic amines or catecholamine excess by certain foods or drugs in patients taking MAO inhibitors, or by clonidine withdrawal syndrome. Other indications include the prevention of dermal necrosis and sloughing following IV administration or extravasation of norepinephrine, decrease in impedance to left ventricular ejection and the infarct size in patients with MI associated with left ventricular failure, treatment of erectile dysfunction through self-injection of small doses combined with papaverine hydrochloride into the corpus cavernosum, and as an adjunct to the management of cocaine overdose to reverse coronary vasoconstriction following use of oxygen, benzodiazepines,and nitroglycerin.

Associated Conditions
Associated Therapies
Pharmacodynamics

Phentolamine is indicated for the control of episodes of hypertension and sweating that occur with a disease called pheochromocytoma. If tachycardia is excessive, it may be necessary to use a beta-blocking agent concomitantly. Phentolamine is a long-acting, adrenergic, alpha-receptor blocking agent which can produce and maintain "chemical sympathectomy" by oral administration. It increases blood flow to the skin, mucosa and abdominal viscera, and lowers both supine and erect blood pressures. It has no effect on the parasympathetic system. Phentolamine works by blocking alpha receptors in certain parts of the body. Alpha receptors are present in the muscle that lines the walls of blood vessels. When the receptors are blocked by Phentolamine, the muscle relaxes and the blood vessels widen. This widening of the blood vessels results in a lowering of blood pressure.

Mechanism of action

Phentolamine produces its therapeutic actions by competitively blocking alpha-adrenergic receptors (primarily excitatory responses of smooth muscle and exocrine glands), leading to a muscle relaxation and a widening of the blood vessels. This widening of the blood vessels results in a lowering of blood pressure. The action of phentolamine on the alpha adrenergic receptors is relatively transient and the blocking effect is incomplete. The drug is more effective in antagonizing responses to circulating epinephrine and/or norepinephrine than in antagonizing responses to mediator released at the adrenergic nerve ending. Phentolamine also stimulates β-adrenergic receptors and produces a positive inotropic and chronotropic effect on the heart and increases cardiac output.

TargetActionsOrganism
AAlpha-2A adrenergic receptor
antagonist
Human
AAlpha-1A adrenergic receptor
antagonist
Human
UAlpha-1B adrenergic receptor
antagonist
Human
UAlpha-1D adrenergic receptor
antagonist
Human
Absorption
Not Available
Volume of distribution
Not Available
Protein binding
Not Available
Metabolism
Not Available
Route of elimination

10-13% of the drug is excreted unchanged in urine, and the fate of the remainder of the drug is unknown.

Half life

19 minutes

Clearance
Not Available
Toxicity
Not Available
Affected organisms
  • Humans and other mammals
Pathways
Not Available
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
DrugInteractionDrug group
4-MethoxyamphetaminePhentolamine may decrease the vasoconstricting activities of 4-Methoxyamphetamine.Experimental, Illicit
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline may increase the hypotensive activities of Phentolamine.Experimental
AcebutololAcebutolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
AcemetacinThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Acemetacin.Approved, Experimental, Investigational
AcepromazinePhentolamine may increase the antihypertensive activities of Acepromazine.Approved, Vet Approved
AdrafinilPhentolamine may decrease the vasoconstricting activities of Adrafinil.Withdrawn
AgmatineThe therapeutic efficacy of Agmatine can be decreased when used in combination with Phentolamine.Experimental, Investigational
AldesleukinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Aldesleukin.Approved
AlfuzosinAlfuzosin may increase the hypotensive activities of Phentolamine.Approved, Investigational
AliskirenPhentolamine may increase the hypotensive activities of Aliskiren.Approved, Investigational
AlprenololAlprenolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Withdrawn
AmbrisentanPhentolamine may increase the hypotensive activities of Ambrisentan.Approved, Investigational
AmibegronPhentolamine may decrease the vasoconstricting activities of Amibegron.Investigational
AmifostinePhentolamine may increase the hypotensive activities of Amifostine.Approved, Investigational
AmilorideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Amiloride.Approved
AmiodaroneThe risk or severity of hypotension can be increased when Phentolamine is combined with Amiodarone.Approved, Investigational
AmitrazPhentolamine may decrease the vasoconstricting activities of Amitraz.Vet Approved
AmitriptylineAmitriptyline may increase the antihypertensive activities of Phentolamine.Approved
AmlodipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Amlodipine.Approved
AmobarbitalAmobarbital may increase the hypotensive activities of Phentolamine.Approved, Illicit
AmoxapineAmoxapine may increase the antihypertensive activities of Phentolamine.Approved
AmphetamineAmphetamine may increase the hypotensive activities of Phentolamine.Approved, Illicit, Investigational
AmrinoneThe risk or severity of hypotension can be increased when Phentolamine is combined with Amrinone.Approved
Amyl NitriteThe risk or severity of adverse effects can be increased when Phentolamine is combined with Amyl Nitrite.Approved
AnisodaminePhentolamine may decrease the vasoconstricting activities of Anisodamine.Investigational
ApomorphineThe risk or severity of adverse effects can be increased when Apomorphine is combined with Phentolamine.Approved, Investigational
ApraclonidineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Apraclonidine.Approved
AranidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Aranidipine.Approved, Investigational
ArbutaminePhentolamine may decrease the vasoconstricting activities of Arbutamine.Approved
ArformoterolPhentolamine may decrease the vasoconstricting activities of Arformoterol.Approved, Investigational
AripiprazoleAripiprazole may increase the hypotensive activities of Phentolamine.Approved, Investigational
ArotinololArotinolol may increase the orthostatic hypotensive activities of Phentolamine.Investigational
Arsenic trioxideThe risk or severity of adverse effects can be increased when Arsenic trioxide is combined with Phentolamine.Approved, Investigational
AsenapineAsenapine may increase the antihypertensive activities of Phentolamine.Approved
AtenololAtenolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
AvanafilAvanafil may increase the hypotensive activities of Phentolamine.Approved
AzelnidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Azelnidipine.Approved, Investigational
Azilsartan medoxomilThe risk or severity of adverse effects can be increased when Phentolamine is combined with Azilsartan medoxomil.Approved, Investigational
AzimilideThe risk or severity of hypotension can be increased when Phentolamine is combined with Azimilide.Investigational
BambuterolPhentolamine may decrease the vasoconstricting activities of Bambuterol.Approved, Investigational
BarbexacloneBarbexaclone may increase the hypotensive activities of Phentolamine.Experimental
BarbitalBarbital may increase the hypotensive activities of Phentolamine.Illicit
BarnidipinePhentolamine may increase the antihypertensive activities of Barnidipine.Approved
BefunololBefunolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
BenazeprilBenazepril may increase the hypotensive activities of Phentolamine.Approved, Investigational
BencyclaneThe risk or severity of hypotension can be increased when Phentolamine is combined with Bencyclane.Experimental
BendroflumethiazideBendroflumethiazide may increase the hypotensive activities of Phentolamine.Approved
BenidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Benidipine.Approved, Investigational
BenmoxinBenmoxin may increase the hypotensive activities of Phentolamine.Withdrawn
BenzphetamineThe therapeutic efficacy of Benzphetamine can be decreased when used in combination with Phentolamine.Approved, Illicit
BepridilThe risk or severity of hypotension can be increased when Phentolamine is combined with Bepridil.Approved, Withdrawn
BetaxololBetaxolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
BethanidineBethanidine may increase the hypotensive activities of Phentolamine.Approved
BevantololBevantolol may increase the antihypertensive activities of Phentolamine.Approved
BietaserpineBietaserpine may increase the hypotensive activities of Phentolamine.Experimental
BimatoprostPhentolamine may increase the hypotensive activities of Bimatoprost.Approved, Investigational
BioallethrinThe risk or severity of hypotension can be increased when Phentolamine is combined with Bioallethrin.Approved, Experimental
BisoprololBisoprolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
BitolterolPhentolamine may decrease the vasoconstricting activities of Bitolterol.Withdrawn
BopindololBopindolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
BortezomibThe risk or severity of adverse effects can be increased when Bortezomib is combined with Phentolamine.Approved, Investigational
BosentanBosentan may increase the hypotensive activities of Phentolamine.Approved, Investigational
BQ-123Phentolamine may increase the hypotensive activities of BQ-123.Investigational
BretyliumPhentolamine may increase the hypotensive activities of Bretylium.Approved
BrexpiprazolePhentolamine may increase the antihypertensive activities of Brexpiprazole.Approved, Investigational
BrimonidineBrimonidine may increase the antihypertensive activities of Phentolamine.Approved
BrofaromineBrofaromine may increase the hypotensive activities of Phentolamine.Experimental
BromocriptineThe risk or severity of adverse effects can be increased when Bromocriptine is combined with Phentolamine.Approved, Investigational
BucindololBucindolol may increase the antihypertensive activities of Phentolamine.Investigational
BufuralolBufuralol may increase the orthostatic hypotensive activities of Phentolamine.Experimental, Investigational
BumetanideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Bumetanide.Approved
BunazosinBunazosin may increase the antihypertensive activities of Phentolamine.Investigational
BupivacaineThe risk or severity of adverse effects can be increased when Bupivacaine is combined with Phentolamine.Approved, Investigational
BupranololBupranolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
CadralazineCadralazine may increase the hypotensive activities of Phentolamine.Experimental
CafedrinePhentolamine may increase the hypotensive activities of Cafedrine.Investigational
CanagliflozinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Canagliflozin.Approved
CandesartanPhentolamine may increase the hypotensive activities of Candesartan.Experimental
Candesartan cilexetilPhentolamine may increase the hypotensive activities of Candesartan cilexetil.Approved
CandoxatrilCandoxatril may increase the hypotensive activities of Phentolamine.Experimental
CaptoprilPhentolamine may increase the hypotensive activities of Captopril.Approved
CarbetocinThe risk or severity of adverse effects can be increased when Carbetocin is combined with Phentolamine.Approved, Investigational
CarboxyamidotriazoleThe risk or severity of hypotension can be increased when Phentolamine is combined with Carboxyamidotriazole.Investigational
CaroverineThe risk or severity of hypotension can be increased when Phentolamine is combined with Caroverine.Experimental
CaroxazoneCaroxazone may increase the hypotensive activities of Phentolamine.Withdrawn
CarteololCarteolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
CarvedilolCarvedilol may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Phentolamine.Approved, Investigational
CeliprololCeliprolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
ChlorothiazidePhentolamine may increase the hypotensive activities of Chlorothiazide.Approved, Vet Approved
ChlorpromazinePhentolamine may increase the antihypertensive activities of Chlorpromazine.Approved, Investigational, Vet Approved
ChlorthalidoneChlorthalidone may increase the hypotensive activities of Phentolamine.Approved
CicletaninePhentolamine may increase the hypotensive activities of Cicletanine.Investigational
CilazaprilPhentolamine may increase the hypotensive activities of Cilazapril.Approved
CilnidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Cilnidipine.Approved, Investigational
CinnarizineThe risk or severity of hypotension can be increased when Phentolamine is combined with Cinnarizine.Approved, Investigational
CirazolinePhentolamine may decrease the vasoconstricting activities of Cirazoline.Experimental
ClenbuterolPhentolamine may decrease the vasoconstricting activities of Clenbuterol.Approved, Investigational, Vet Approved
ClevidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Clevidipine.Approved, Investigational
ClofarabineThe risk or severity of adverse effects can be increased when Clofarabine is combined with Phentolamine.Approved, Investigational
ClomipramineThe risk or severity of adverse effects can be increased when Clomipramine is combined with Phentolamine.Approved, Investigational, Vet Approved
ClonidineClonidine may increase the hypotensive activities of Phentolamine.Approved
CloranololCloranolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
ClozapineClozapine may increase the antihypertensive activities of Phentolamine.Approved
ConivaptanThe risk or severity of adverse effects can be increased when Conivaptan is combined with Phentolamine.Approved, Investigational
CryptenaminePhentolamine may increase the hypotensive activities of Cryptenamine.Approved
CyclandelateThe risk or severity of hypotension can be increased when Phentolamine is combined with Cyclandelate.Approved
CyclopenthiazidePhentolamine may increase the hypotensive activities of Cyclopenthiazide.Experimental
DapagliflozinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Dapagliflozin.Approved
DapiprazoleDapiprazole may increase the antihypertensive activities of Phentolamine.Approved
DapoxetineDapoxetine may increase the orthostatic hypotensive activities of Phentolamine.Investigational
DarodipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Darodipine.Experimental
DebrisoquinDebrisoquin may increase the hypotensive activities of Phentolamine.Approved, Investigational
DelaprilPhentolamine may increase the hypotensive activities of Delapril.Investigational
DeserpidinePhentolamine may increase the hypotensive activities of Deserpidine.Approved
DesfluraneThe risk or severity of adverse effects can be increased when Desflurane is combined with Phentolamine.Approved
DesipramineDesipramine may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
DetomidinePhentolamine may decrease the vasoconstricting activities of Detomidine.Vet Approved
DexmedetomidineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Dexmedetomidine.Approved, Vet Approved
DexniguldipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Dexniguldipine.Experimental
DextroamphetaminePhentolamine may increase the antihypertensive activities of Dextroamphetamine.Approved, Illicit
DexverapamilThe risk or severity of hypotension can be increased when Phentolamine is combined with Dexverapamil.Experimental
DiazoxideDiazoxide may increase the hypotensive activities of Phentolamine.Approved
DiclofenacThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Diclofenac.Approved, Vet Approved
DiclofenamideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Diclofenamide.Approved, Investigational
DiethylnorsperminePhentolamine may increase the hypotensive activities of Diethylnorspermine.Investigational
DihydralazineDihydralazine may increase the hypotensive activities of Phentolamine.Approved, Investigational
DihydroergotaminePhentolamine may decrease the vasoconstricting activities of Dihydroergotamine.Approved, Investigational
DiltiazemThe risk or severity of hypotension can be increased when Phentolamine is combined with Diltiazem.Approved, Investigational
DinutuximabThe risk or severity of adverse effects can be increased when Phentolamine is combined with Dinutuximab.Approved, Investigational
DipivefrinPhentolamine may decrease the vasoconstricting activities of Dipivefrin.Approved
DipyridamoleDipyridamole may increase the hypotensive activities of Phentolamine.Approved
DL-MethylephedrinePhentolamine may decrease the vasoconstricting activities of DL-Methylephedrine.Approved
DobutaminePhentolamine may decrease the vasoconstricting activities of Dobutamine.Approved
DopexaminePhentolamine may decrease the vasoconstricting activities of Dopexamine.Approved, Investigational
DorzolamidePhentolamine may increase the hypotensive activities of Dorzolamide.Approved
DotarizineThe risk or severity of hypotension can be increased when Phentolamine is combined with Dotarizine.Investigational
DoxazosinDoxazosin may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Phentolamine.Approved
DoxepinDoxepin may increase the antihypertensive activities of Phentolamine.Approved, Investigational
DoxofyllinePhentolamine may decrease the vasoconstricting activities of Doxofylline.Approved, Investigational
DronedaroneDronedarone may increase the antihypertensive activities of Phentolamine.Approved
DroperidolDroperidol may increase the antihypertensive activities of Phentolamine.Approved, Vet Approved
DroxidopaPhentolamine may decrease the vasoconstricting activities of Droxidopa.Approved, Investigational
DuloxetinePhentolamine may increase the orthostatic hypotensive activities of Duloxetine.Approved
EfonidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Efonidipine.Approved, Investigational
EmopamilThe risk or severity of hypotension can be increased when Phentolamine is combined with Emopamil.Experimental
EmpagliflozinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Empagliflozin.Approved
EnalaprilatPhentolamine may increase the hypotensive activities of Enalaprilat.Approved
EndralazineEndralazine may increase the hypotensive activities of Phentolamine.Experimental
EpanololEpanolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
EperisoneThe risk or severity of hypotension can be increased when Phentolamine is combined with Eperisone.Approved, Investigational
EphedraPhentolamine may decrease the vasoconstricting activities of Ephedra.Approved, Nutraceutical, Withdrawn
EphedrinePhentolamine may decrease the vasoconstricting activities of Ephedrine.Approved
EpinastinePhentolamine may decrease the vasoconstricting activities of Epinastine.Approved, Investigational
EpinephrinePhentolamine may increase the antihypertensive activities of Epinephrine.Approved, Vet Approved
EplerenoneThe risk or severity of adverse effects can be increased when Phentolamine is combined with Eplerenone.Approved
EpoprostenolPhentolamine may increase the hypotensive activities of Epoprostenol.Approved
EprosartanPhentolamine may increase the hypotensive activities of Eprosartan.Approved
ErgonovinePhentolamine may decrease the vasoconstricting activities of Ergonovine.Approved
ErgotaminePhentolamine may decrease the vasoconstricting activities of Ergotamine.Approved
EsatenololEsatenolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
EscitalopramEscitalopram may increase the antihypertensive activities of Phentolamine.Approved, Investigational
EsmololEsmolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
Etacrynic acidThe risk or severity of adverse effects can be increased when Phentolamine is combined with Etacrynic acid.Approved, Investigational
EtafedrinePhentolamine may decrease the vasoconstricting activities of Etafedrine.Approved
EthosuximideThe risk or severity of hypotension can be increased when Phentolamine is combined with Ethosuximide.Approved
EtilefrinePhentolamine may decrease the vasoconstricting activities of Etilefrine.Withdrawn
EtomidateThe therapeutic efficacy of Etomidate can be decreased when used in combination with Phentolamine.Approved
FelodipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Felodipine.Approved, Investigational
FendilineThe risk or severity of hypotension can be increased when Phentolamine is combined with Fendiline.Withdrawn
FenoldopamPhentolamine may increase the hypotensive activities of Fenoldopam.Approved
FenoterolPhentolamine may decrease the vasoconstricting activities of Fenoterol.Approved, Investigational
Ferulic acidPhentolamine may increase the hypotensive activities of Ferulic acid.Experimental
FimasartanThe risk or severity of adverse effects can be increased when Fimasartan is combined with Phentolamine.Approved, Investigational
Fish oilThe risk or severity of hypotension can be increased when Phentolamine is combined with Fish oil.Approved, Nutraceutical
FlunarizineThe risk or severity of hypotension can be increased when Phentolamine is combined with Flunarizine.Approved
FlupentixolFlupentixol may increase the antihypertensive activities of Phentolamine.Approved, Investigational, Withdrawn
FluspirileneThe risk or severity of hypotension can be increased when Phentolamine is combined with Fluspirilene.Approved, Investigational
FormoterolPhentolamine may decrease the vasoconstricting activities of Formoterol.Approved, Investigational
FosinoprilFosinopril may increase the hypotensive activities of Phentolamine.Approved
FostamatinibFostamatinib may increase the hypotensive activities of Phentolamine.Approved, Investigational
FurazolidoneFurazolidone may increase the hypotensive activities of Phentolamine.Approved, Investigational, Vet Approved
FurosemideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Furosemide.Approved, Vet Approved
GabapentinThe risk or severity of hypotension can be increased when Phentolamine is combined with Gabapentin.Approved, Investigational
GallopamilThe risk or severity of hypotension can be increased when Phentolamine is combined with Gallopamil.Investigational
GuanabenzGuanabenz may increase the hypotensive activities of Phentolamine.Approved, Investigational
GuanadrelGuanadrel may increase the hypotensive activities of Phentolamine.Approved
GuanazodinePhentolamine may increase the hypotensive activities of Guanazodine.Experimental
GuanethidinePhentolamine may increase the hypotensive activities of Guanethidine.Approved
GuanfacineThe therapeutic efficacy of Guanfacine can be decreased when used in combination with Phentolamine.Approved, Investigational
GuanoclorPhentolamine may increase the hypotensive activities of Guanoclor.Experimental
GuanoxabenzPhentolamine may increase the hypotensive activities of Guanoxabenz.Experimental
GuanoxanPhentolamine may increase the hypotensive activities of Guanoxan.Experimental
HalothaneThe risk or severity of adverse effects can be increased when Halothane is combined with Phentolamine.Approved, Vet Approved
HexamethoniumPhentolamine may increase the hypotensive activities of Hexamethonium.Experimental
HexobarbitalHexobarbital may increase the hypotensive activities of Phentolamine.Approved
HexoprenalinePhentolamine may decrease the vasoconstricting activities of Hexoprenaline.Approved, Withdrawn
HigenaminePhentolamine may decrease the vasoconstricting activities of Higenamine.Investigational
HydralazineHydralazine may increase the hypotensive activities of Phentolamine.Approved
HydrochlorothiazidePhentolamine may increase the hypotensive activities of Hydrochlorothiazide.Approved, Vet Approved
HydroflumethiazidePhentolamine may increase the hypotensive activities of Hydroflumethiazide.Approved, Investigational
IbuprofenThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Ibuprofen.Approved
IloperidonePhentolamine may increase the antihypertensive activities of Iloperidone.Approved
IloprostThe risk or severity of adverse effects can be increased when Iloprost is combined with Phentolamine.Approved, Investigational
ImidaprilThe risk or severity of adverse effects can be increased when Imidapril is combined with Phentolamine.Investigational
ImipramineImipramine may increase the antihypertensive activities of Phentolamine.Approved
IndacaterolPhentolamine may decrease the vasoconstricting activities of Indacaterol.Approved
IndapamidePhentolamine may increase the hypotensive activities of Indapamide.Approved
IndenololIndenolol may increase the orthostatic hypotensive activities of Phentolamine.Withdrawn
IndoraminIndoramin may increase the antihypertensive activities of Phentolamine.Withdrawn
IproclozideIproclozide may increase the hypotensive activities of Phentolamine.Withdrawn
IproniazidIproniazid may increase the hypotensive activities of Phentolamine.Withdrawn
IrbesartanPhentolamine may increase the hypotensive activities of Irbesartan.Approved, Investigational
IsocarboxazidIsocarboxazid may increase the hypotensive activities of Phentolamine.Approved
IsoetarinePhentolamine may decrease the vasoconstricting activities of Isoetarine.Approved
IsofluraneThe risk or severity of adverse effects can be increased when Isoflurane is combined with Phentolamine.Approved, Vet Approved
IsometheptenePhentolamine may decrease the vasoconstricting activities of Isometheptene.Approved
IsoprenalinePhentolamine may decrease the vasoconstricting activities of Isoprenaline.Approved, Investigational
Isosorbide DinitrateThe risk or severity of adverse effects can be increased when Phentolamine is combined with Isosorbide Dinitrate.Approved, Investigational
Isosorbide MononitrateThe risk or severity of adverse effects can be increased when Phentolamine is combined with Isosorbide Mononitrate.Approved
IsoxsuprineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Isoxsuprine.Approved, Withdrawn
IsradipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Isradipine.Approved, Investigational
KetanserinKetanserin may increase the hypotensive activities of Phentolamine.Investigational
KetorolacThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Ketorolac.Approved
LabetalolLabetalol may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Phentolamine.Approved
LacidipinePhentolamine may increase the hypotensive activities of Lacidipine.Approved, Investigational
LamotrigineThe risk or severity of hypotension can be increased when Phentolamine is combined with Lamotrigine.Approved, Investigational
LandiololLandiolol may increase the orthostatic hypotensive activities of Phentolamine.Investigational
LatanoprostLatanoprost may increase the hypotensive activities of Phentolamine.Approved, Investigational
LercanidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Lercanidipine.Approved, Investigational
LevetiracetamThe risk or severity of hypotension can be increased when Phentolamine is combined with Levetiracetam.Approved, Investigational
LevobetaxololLevobetaxolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
LevobunololThe risk or severity of adverse effects can be increased when Phentolamine is combined with Levobunolol.Approved
LevobupivacaineThe risk or severity of adverse effects can be increased when Levobupivacaine is combined with Phentolamine.Approved, Investigational
LevodopaPhentolamine may increase the orthostatic hypotensive activities of Levodopa.Approved
LevosalbutamolPhentolamine may decrease the vasoconstricting activities of Levosalbutamol.Approved, Investigational
LevosimendanThe risk or severity of adverse effects can be increased when Levosimendan is combined with Phentolamine.Approved, Investigational
LidoflazineThe risk or severity of hypotension can be increased when Phentolamine is combined with Lidoflazine.Experimental
LinsidominePhentolamine may increase the hypotensive activities of Linsidomine.Experimental
LisdexamfetaminePhentolamine may increase the antihypertensive activities of Lisdexamfetamine.Approved, Investigational
LisinoprilPhentolamine may increase the hypotensive activities of Lisinopril.Approved, Investigational
LofexidinePhentolamine may increase the hypotensive activities of Lofexidine.Approved, Investigational
LomerizineThe risk or severity of hypotension can be increased when Phentolamine is combined with Lomerizine.Experimental
LoperamideThe risk or severity of hypotension can be increased when Phentolamine is combined with Loperamide.Approved
LosartanLosartan may increase the hypotensive activities of Phentolamine.Approved
MacitentanPhentolamine may increase the hypotensive activities of Macitentan.Approved
Magnesium sulfateThe risk or severity of hypotension can be increased when Phentolamine is combined with Magnesium sulfate.Approved, Investigational, Vet Approved
ManidipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Manidipine.Approved, Investigational
MannitolThe risk or severity of adverse effects can be increased when Phentolamine is combined with Mannitol.Approved, Investigational
MebanazineMebanazine may increase the hypotensive activities of Phentolamine.Withdrawn
MecamylamineMecamylamine may increase the hypotensive activities of Phentolamine.Approved, Investigational
MedetomidinePhentolamine may decrease the vasoconstricting activities of Medetomidine.Vet Approved
MentholThe risk or severity of hypotension can be increased when Phentolamine is combined with Menthol.Approved
MephenterminePhentolamine may decrease the vasoconstricting activities of Mephentermine.Approved
MepindololMepindolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
MetaraminolPhentolamine may decrease the vasoconstricting activities of Metaraminol.Approved, Investigational
MethamphetaminePhentolamine may decrease the vasoconstricting activities of Methamphetamine.Approved, Illicit
MethazolamideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Methazolamide.Approved
MethohexitalMethohexital may increase the hypotensive activities of Phentolamine.Approved
MethoserpidinePhentolamine may increase the hypotensive activities of Methoserpidine.Experimental
MethotrimeprazineMethotrimeprazine may increase the antihypertensive activities of Phentolamine.Approved, Investigational
MethoxaminePhentolamine may decrease the vasoconstricting activities of Methoxamine.Approved, Investigational
MethoxyphenaminePhentolamine may decrease the vasoconstricting activities of Methoxyphenamine.Experimental
MethsuximideThe risk or severity of hypotension can be increased when Phentolamine is combined with Methsuximide.Approved
MethyclothiazideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Methyclothiazide.Approved
MethyldopaPhentolamine may increase the hypotensive activities of Methyldopa.Approved
Methylene blueMethylene blue may increase the hypotensive activities of Phentolamine.Approved, Investigational
MethylphenidateMethylphenidate may decrease the antihypertensive activities of Phentolamine.Approved, Investigational
MethylphenobarbitalMethylphenobarbital may increase the hypotensive activities of Phentolamine.Approved
MetipranololPhentolamine may increase the hypotensive activities of Metipranolol.Approved
MetoprololMetoprolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
MetyrosinePhentolamine may increase the hypotensive activities of Metyrosine.Approved
MibefradilThe risk or severity of hypotension can be increased when Phentolamine is combined with Mibefradil.Investigational, Withdrawn
MidodrinePhentolamine may decrease the vasoconstricting activities of Midodrine.Approved
MinaprineMinaprine may increase the hypotensive activities of Phentolamine.Approved
MinoxidilMinoxidil may increase the hypotensive activities of Phentolamine.Approved, Investigational
MirabegronPhentolamine may decrease the vasoconstricting activities of Mirabegron.Approved
MirodenafilMirodenafil may increase the hypotensive activities of Phentolamine.Investigational
MoclobemideMoclobemide may increase the hypotensive activities of Phentolamine.Approved, Investigational
MoexiprilMoexipril may increase the hypotensive activities of Phentolamine.Approved
MolsidomineMolsidomine may increase the hypotensive activities of Phentolamine.Approved, Investigational
MorphineThe risk or severity of adverse effects can be increased when Morphine is combined with Phentolamine.Approved, Investigational
MoxonidineMoxonidine may increase the hypotensive activities of Phentolamine.Approved, Investigational
MuzoliminePhentolamine may increase the hypotensive activities of Muzolimine.Experimental
NabiloneThe risk or severity of adverse effects can be increased when Nabilone is combined with Phentolamine.Approved, Investigational
NadololNadolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
NaftopidilThe risk or severity of hypotension can be increased when Phentolamine is combined with Naftopidil.Investigational
NaphazolineThe therapeutic efficacy of Naphazoline can be decreased when used in combination with Phentolamine.Approved
NaproxenThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Naproxen.Approved, Vet Approved
NebivololNebivolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
NefazodoneNefazodone may increase the antihypertensive activities of Phentolamine.Approved, Withdrawn
NesiritideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Nesiritide.Approved, Investigational
NialamideNialamide may increase the hypotensive activities of Phentolamine.Withdrawn
NicardipineNicardipine may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Phentolamine.Approved, Investigational
NicergolineNicergoline may increase the antihypertensive activities of Phentolamine.Approved, Investigational
NicorandilNicorandil may increase the hypotensive activities of Phentolamine.Approved, Investigational
NifedipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Nifedipine.Approved
NiguldipinePhentolamine may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Niguldipine.Experimental
NiludipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Niludipine.Experimental
NilvadipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Nilvadipine.Approved, Investigational
NimesulideThe risk or severity of hypotension can be increased when Phentolamine is combined with Nimesulide.Approved, Investigational, Withdrawn
NimodipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Nimodipine.Approved, Investigational
NisoldipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Nisoldipine.Approved
NitrendipineThe risk or severity of hypotension can be increased when Phentolamine is combined with Nitrendipine.Approved, Investigational
Nitric OxideThe risk or severity of adverse effects can be increased when Nitric Oxide is combined with Phentolamine.Approved
NitroglycerinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Nitroglycerin.Approved, Investigational
NitroprussideNitroprusside may increase the hypotensive activities of Phentolamine.Approved, Investigational
Nitrous acidThe risk or severity of adverse effects can be increased when Phentolamine is combined with Nitrous acid.Approved, Investigational
NorepinephrinePhentolamine may decrease the vasoconstricting activities of Norepinephrine.Approved
NorfenefrinePhentolamine may decrease the vasoconstricting activities of Norfenefrine.Experimental
NortriptylineNortriptyline may increase the antihypertensive activities of Phentolamine.Approved
NylidrinThe therapeutic efficacy of Nylidrin can be decreased when used in combination with Phentolamine.Approved
ObinutuzumabPhentolamine may increase the hypotensive activities of Obinutuzumab.Approved, Investigational
OctamoxinOctamoxin may increase the hypotensive activities of Phentolamine.Withdrawn
OctopaminePhentolamine may decrease the vasoconstricting activities of Octopamine.Experimental
OlanzapineOlanzapine may increase the antihypertensive activities of Phentolamine.Approved, Investigational
OlmesartanOlmesartan may increase the hypotensive activities of Phentolamine.Approved, Investigational
OlodaterolPhentolamine may decrease the vasoconstricting activities of Olodaterol.Approved
OmapatrilatPhentolamine may increase the hypotensive activities of Omapatrilat.Investigational
OrciprenalinePhentolamine may decrease the vasoconstricting activities of Orciprenaline.Approved
OtiloniumThe risk or severity of hypotension can be increased when Phentolamine is combined with Otilonium.Experimental, Investigational
OxprenololOxprenolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
OxyfedrinePhentolamine may decrease the vasoconstricting activities of Oxyfedrine.Experimental
OxymetazolineThe therapeutic efficacy of Oxymetazoline can be decreased when used in combination with Phentolamine.Approved, Investigational
PaclitaxelThe risk or severity of adverse effects can be increased when Paclitaxel is combined with Phentolamine.Approved, Vet Approved
PaliperidonePaliperidone may increase the antihypertensive activities of Phentolamine.Approved
PapaverineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Papaverine.Approved, Investigational
PargylinePargyline may increase the hypotensive activities of Phentolamine.Approved
PenbutololPenbutolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
PenfluridolThe risk or severity of hypotension can be increased when Phentolamine is combined with Penfluridol.Experimental
PentobarbitalPentobarbital may increase the hypotensive activities of Phentolamine.Approved, Investigational, Vet Approved
PentoliniumPhentolamine may increase the hypotensive activities of Pentolinium.Approved
PentoxifyllinePentoxifylline may increase the hypotensive activities of Phentolamine.Approved, Investigational
PergolidePhentolamine may decrease the vasoconstricting activities of Pergolide.Approved, Investigational, Vet Approved, Withdrawn
PerindoprilPhentolamine may increase the hypotensive activities of Perindopril.Approved
PhendimetrazinePhentolamine may decrease the vasoconstricting activities of Phendimetrazine.Approved, Illicit
PhenelzinePhenelzine may increase the hypotensive activities of Phentolamine.Approved
PheniprazinePheniprazine may increase the hypotensive activities of Phentolamine.Withdrawn
PhenobarbitalPhenobarbital may increase the hypotensive activities of Phentolamine.Approved, Investigational
PhenoxybenzaminePhenoxybenzamine may increase the antihypertensive activities of Phentolamine.Approved
PhenoxypropazinePhenoxypropazine may increase the hypotensive activities of Phentolamine.Withdrawn
PhenylephrineThe therapeutic efficacy of Phenylephrine can be decreased when used in combination with Phentolamine.Approved
PhenylpropanolaminePhentolamine may decrease the vasoconstricting activities of Phenylpropanolamine.Approved, Vet Approved, Withdrawn
PinacidilPinacidil may increase the hypotensive activities of Phentolamine.Approved
PinaveriumThe risk or severity of hypotension can be increased when Phentolamine is combined with Pinaverium.Approved
PindololPindolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
PipamperoneThe risk or severity of adverse effects can be increased when Phentolamine is combined with Pipamperone.Approved, Investigational
PirbuterolPhentolamine may decrease the vasoconstricting activities of Pirbuterol.Approved
PirlindolePirlindole may increase the hypotensive activities of Phentolamine.Approved
PivhydrazinePivhydrazine may increase the hypotensive activities of Phentolamine.Withdrawn
PizotifenPhentolamine may increase the antihypertensive activities of Pizotifen.Approved
Platelet Activating FactorPlatelet Activating Factor may increase the orthostatic hypotensive activities of Phentolamine.Experimental
PolythiazidePhentolamine may increase the hypotensive activities of Polythiazide.Approved
PractololPractolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
PramipexoleThe risk or severity of adverse effects can be increased when Phentolamine is combined with Pramipexole.Approved, Investigational
PrazosinPrazosin may increase the antihypertensive activities of Phentolamine.Approved
PrenalterolPhentolamine may decrease the vasoconstricting activities of Prenalterol.Experimental
PrenylamineThe risk or severity of hypotension can be increased when Phentolamine is combined with Prenylamine.Withdrawn
PrimidonePrimidone may increase the hypotensive activities of Phentolamine.Approved, Vet Approved
ProcaineProcaine may increase the hypotensive activities of Phentolamine.Approved, Investigational, Vet Approved
ProcarbazineProcarbazine may increase the hypotensive activities of Phentolamine.Approved, Investigational
ProcaterolPhentolamine may decrease the vasoconstricting activities of Procaterol.Approved, Investigational
PromazinePromazine may increase the antihypertensive activities of Phentolamine.Approved, Vet Approved
PropafenonePropafenone may increase the orthostatic hypotensive activities of Phentolamine.Approved
PropericiazinePhentolamine may increase the antihypertensive activities of Propericiazine.Approved, Investigational
PropiomazinePropiomazine may increase the antihypertensive activities of Phentolamine.Approved
PropiverinePhentolamine may increase the antihypertensive activities of Propiverine.Approved, Investigational
PropofolThe risk or severity of adverse effects can be increased when Phentolamine is combined with Propofol.Approved, Investigational, Vet Approved
PropranololPropranolol may increase the orthostatic hypotensive activities of Phentolamine.Approved, Investigational
ProtokylolPhentolamine may decrease the vasoconstricting activities of Protokylol.Approved, Vet Approved
PseudoephedrineThe therapeutic efficacy of Pseudoephedrine can be decreased when used in combination with Phentolamine.Approved
QuetiapineQuetiapine may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Phentolamine.Approved
QuinaprilPhentolamine may increase the hypotensive activities of Quinapril.Approved, Investigational
QuinidinePhentolamine may increase the antihypertensive activities of Quinidine.Approved, Investigational
QuinineQuinine may increase the hypotensive activities of Phentolamine.Approved
RacepinephrinePhentolamine may increase the antihypertensive activities of Racepinephrine.Approved
RactopaminePhentolamine may decrease the vasoconstricting activities of Ractopamine.Vet Approved
RamiprilRamipril may increase the hypotensive activities of Phentolamine.Approved
RasagilineRasagiline may increase the hypotensive activities of Phentolamine.Approved
RemifentanilThe risk or severity of adverse effects can be increased when Phentolamine is combined with Remifentanil.Approved
RemikirenRemikiren may increase the hypotensive activities of Phentolamine.Approved
ReproterolPhentolamine may decrease the vasoconstricting activities of Reproterol.Investigational
RescinnaminePhentolamine may increase the hypotensive activities of Rescinnamine.Approved
ReserpineReserpine may increase the hypotensive activities of Phentolamine.Approved, Investigational
RilmenidineRilmenidine may increase the hypotensive activities of Phentolamine.Approved, Investigational
RimiterolPhentolamine may decrease the vasoconstricting activities of Rimiterol.Experimental
RiociguatPhentolamine may increase the hypotensive activities of Riociguat.Approved
RisperidonePhentolamine may increase the hypotensive activities of Risperidone.Approved, Investigational
RitobegronPhentolamine may decrease the vasoconstricting activities of Ritobegron.Investigational
RitodrinePhentolamine may decrease the vasoconstricting activities of Ritodrine.Approved, Investigational
RituximabPhentolamine may increase the hypotensive activities of Rituximab.Approved
RomifidinePhentolamine may decrease the vasoconstricting activities of Romifidine.Vet Approved
RopiniroleThe therapeutic efficacy of Ropinirole can be decreased when used in combination with Phentolamine.Approved, Investigational
RopivacaineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Ropivacaine.Approved
RotigotineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Rotigotine.Approved
SacubitrilThe risk or severity of adverse effects can be increased when Phentolamine is combined with Sacubitril.Approved
SalbutamolThe therapeutic efficacy of Salbutamol can be decreased when used in combination with Phentolamine.Approved, Vet Approved
Salicylic acidThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Salicylic acid.Approved, Investigational, Vet Approved
SalmeterolThe therapeutic efficacy of Salmeterol can be decreased when used in combination with Phentolamine.Approved
SaprisartanPhentolamine may increase the hypotensive activities of Saprisartan.Experimental
SecobarbitalSecobarbital may increase the hypotensive activities of Phentolamine.Approved, Vet Approved
SelegilineSelegiline may increase the hypotensive activities of Phentolamine.Approved, Investigational, Vet Approved
SeletracetamThe risk or severity of hypotension can be increased when Phentolamine is combined with Seletracetam.Investigational
SelexipagPhentolamine may increase the hypotensive activities of Selexipag.Approved
SevofluraneThe risk or severity of adverse effects can be increased when Phentolamine is combined with Sevoflurane.Approved, Vet Approved
SildenafilSildenafil may increase the hypotensive activities of Phentolamine.Approved, Investigational
SilodosinSilodosin may increase the antihypertensive activities of Phentolamine.Approved
SitaxentanPhentolamine may increase the hypotensive activities of Sitaxentan.Approved, Investigational, Withdrawn
SolabegronPhentolamine may decrease the vasoconstricting activities of Solabegron.Investigational
SotalolSotalol may increase the orthostatic hypotensive activities of Phentolamine.Approved
SpiraprilPhentolamine may increase the hypotensive activities of Spirapril.Approved
SpironolactoneThe risk or severity of adverse effects can be increased when Phentolamine is combined with Spironolactone.Approved
StreptokinaseThe risk or severity of adverse effects can be increased when Phentolamine is combined with Streptokinase.Approved, Investigational
SufentanilThe risk or severity of adverse effects can be increased when Phentolamine is combined with Sufentanil.Approved, Investigational
SulfasalazineThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Sulfasalazine.Approved
SulindacThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Sulindac.Approved, Investigational
SynephrinePhentolamine may decrease the vasoconstricting activities of Synephrine.Experimental
TadalafilTadalafil may increase the hypotensive activities of Phentolamine.Approved, Investigational
TalinololTalinolol may increase the orthostatic hypotensive activities of Phentolamine.Investigational
TamsulosinTamsulosin may increase the antihypertensive activities of Phentolamine.Approved, Investigational
TelmisartanPhentolamine may increase the hypotensive activities of Telmisartan.Approved, Investigational
TemocaprilPhentolamine may increase the hypotensive activities of Temocapril.Experimental, Investigational
TerazosinTerazosin may increase the antihypertensive activities of Phentolamine.Approved
TerbutalineTerbutaline may increase the orthostatic hypotensive activities of Phentolamine.Approved
TerlipressinPhentolamine may increase the hypotensive activities of Terlipressin.Approved, Investigational
TerodilineThe risk or severity of hypotension can be increased when Phentolamine is combined with Terodiline.Experimental
TertatololTertatolol may increase the orthostatic hypotensive activities of Phentolamine.Experimental
TetrahydropalmatineThe risk or severity of hypotension can be increased when Phentolamine is combined with Tetrahydropalmatine.Investigational
TetrandrineThe risk or severity of hypotension can be increased when Phentolamine is combined with Tetrandrine.Experimental
TetryzolinePhentolamine may decrease the vasoconstricting activities of Tetryzoline.Approved
ThalidomideThe risk or severity of adverse effects can be increased when Phentolamine is combined with Thalidomide.Approved, Investigational, Withdrawn
TheodrenalinePhentolamine may increase the hypotensive activities of Theodrenaline.Investigational
TheophyllineTheophylline may increase the hypotensive activities of Phentolamine.Approved
ThiamylalThiamylal may increase the hypotensive activities of Phentolamine.Approved, Vet Approved
ThiopentalThiopental may increase the hypotensive activities of Phentolamine.Approved, Vet Approved
ThioproperazinePhentolamine may increase the antihypertensive activities of Thioproperazine.Approved
ThioridazineThioridazine may increase the antihypertensive activities of Phentolamine.Approved, Withdrawn
TibolonePhentolamine may increase the hypotensive activities of Tibolone.Approved, Investigational
TicrynafenPhentolamine may increase the hypotensive activities of Ticrynafen.Withdrawn
TimololTimolol may increase the orthostatic hypotensive activities of Phentolamine.Approved
TizanidineThe risk or severity of adverse effects can be increased when Phentolamine is combined with Tizanidine.Approved, Investigational
TolazolineTolazoline may increase the antihypertensive activities of Phentolamine.Approved, Vet Approved
TolcaponeThe risk or severity of adverse effects can be increased when Phentolamine is combined with Tolcapone.Approved, Withdrawn
Tolfenamic AcidThe risk or severity of hypotension can be increased when Phentolamine is combined with Tolfenamic Acid.Approved, Investigational
TolonidinePhentolamine may increase the hypotensive activities of Tolonidine.Experimental
ToloxatoneToloxatone may increase the hypotensive activities of Phentolamine.Approved
TorasemideTorasemide may increase the hypotensive activities of Phentolamine.Approved
TrandolaprilTrandolapril may increase the hypotensive activities of Phentolamine.Approved
TranilastThe risk or severity of hypotension can be increased when Phentolamine is combined with Tranilast.Approved, Investigational
TranylcypromineTranylcypromine may increase the hypotensive activities of Phentolamine.Approved, Investigational
TravoprostTravoprost may increase the hypotensive activities of Phentolamine.Approved
TrazodoneTrazodone may increase the antihypertensive activities of Phentolamine.Approved, Investigational
TreprostinilTreprostinil may increase the hypotensive activities of Phentolamine.Approved, Investigational
TretinoinThe risk or severity of adverse effects can be increased when Phentolamine is combined with Tretinoin.Approved, Investigational, Nutraceutical
TretoquinolPhentolamine may decrease the vasoconstricting activities of Tretoquinol.Experimental
TriamtereneThe risk or severity of adverse effects can be increased when Phentolamine is combined with Triamterene.Approved
TrichlormethiazidePhentolamine may increase the hypotensive activities of Trichlormethiazide.Approved, Vet Approved
TrifluoperazineTrifluoperazine may increase the antihypertensive activities of Phentolamine.Approved, Investigational
TrimazosinTrimazosin may increase the antihypertensive activities of Phentolamine.Experimental
TrimebutineThe risk or severity of hypotension can be increased when Phentolamine is combined with Trimebutine.Approved
TrimethadioneThe risk or severity of hypotension can be increased when Phentolamine is combined with Trimethadione.Approved
TrimethaphanTrimethaphan may increase the hypotensive activities of Phentolamine.Approved, Investigational
TrimipramineTrimipramine may increase the antihypertensive activities of Phentolamine.Approved
Trolamine salicylateThe therapeutic efficacy of Phentolamine can be decreased when used in combination with Trolamine salicylate.Approved
TulobuterolPhentolamine may decrease the vasoconstricting activities of Tulobuterol.Investigational
UdenafilUdenafil may increase the hypotensive activities of Phentolamine.Approved, Investigational
UnoprostonePhentolamine may increase the hypotensive activities of Unoprostone.Approved, Investigational
UrapidilUrapidil may increase the antihypertensive activities of Phentolamine.Investigational
ValsartanValsartan may increase the hypotensive activities of Phentolamine.Approved, Investigational
VardenafilVardenafil may increase the hypotensive activities of Phentolamine.Approved
VerapamilPhentolamine may increase the orthostatic hypotensive, hypotensive, and antihypertensive activities of Verapamil.Approved
VilanterolPhentolamine may decrease the vasoconstricting activities of Vilanterol.Approved
VincaminePhentolamine may increase the hypotensive activities of Vincamine.Experimental
VinpocetineThe risk or severity of hypotension can be increased when Phentolamine is combined with Vinpocetine.Investigational
WIN 55212-2The risk or severity of hypotension can be increased when Phentolamine is combined with WIN 55212-2.Experimental
XamoterolPhentolamine may decrease the vasoconstricting activities of Xamoterol.Experimental
XipamidePhentolamine may increase the hypotensive activities of Xipamide.Experimental
XylazinePhentolamine may decrease the vasoconstricting activities of Xylazine.Vet Approved
XylometazolinePhentolamine may increase the hypotensive activities of Xylometazoline.Approved, Investigational
YohimbineYohimbine may decrease the antihypertensive activities of Phentolamine.Approved, Investigational, Vet Approved
ZiconotideThe risk or severity of hypotension can be increased when Phentolamine is combined with Ziconotide.Approved
ZiprasidoneZiprasidone may increase the antihypertensive activities of Phentolamine.Approved
ZofenoprilPhentolamine may increase the hypotensive activities of Zofenopril.Experimental
ZonisamideThe risk or severity of hypotension can be increased when Phentolamine is combined with Zonisamide.Approved, Investigational
ZuclopenthixolZuclopenthixol may increase the antihypertensive activities of Phentolamine.Approved, Investigational
Food Interactions
Not Available

References

General References
Not Available
External Links
Human Metabolome Database
HMDB0014830
PubChem Compound
5775
PubChem Substance
46506535
ChemSpider
5571
BindingDB
31046
ChEBI
8081
ChEMBL
CHEMBL597
Therapeutic Targets Database
DAP000299
PharmGKB
PA450926
IUPHAR
502
Guide to Pharmacology
GtP Drug Page
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
Wikipedia
Phentolamine
ATC Codes
V03AB36 — PhentolamineC04AB01 — Phentolamine
AHFS Codes
  • 12:16.04.04 — Non-selective Alfa-adrenergic Blocking Agents
  • 12:16.00 — Sympatholytic (Adrenergic Blocking) Agents
MSDS
Download (73.3 KB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
1RecruitingBasic ScienceBMI >30 kg/m2 / Healthy Volunteers / Insulin Resistance1
1RecruitingBasic ScienceCardiovascular System Disease / Drug-Related Side Effects and Adverse Reactions1
1RecruitingBasic ScienceChronic Obstructive Pulmonary Disease (COPD) / Heart Failure, Unspecified / High Blood Pressure (Hypertension) / Pulmonary Arterial Hypertension (PAH)1
2CompletedSupportive CareProstate Cancer1
2CompletedTreatmentAnesthesia, Dental1
2CompletedTreatmentNight Vision Complaints1
2CompletedTreatmentSoft Tissue Anesthesia (Numbness)1
3CompletedTreatmentAnesthesia, Dental2
4CompletedTreatmentAnesthesia, Dental / Anesthesia, Reversal / Local Anesthesia1
4RecruitingTreatmentLocal Anesthesia1
Not AvailableCompletedTreatmentCVA (Cerebrovascular Accident) / Intracerebral Hemorrhage / Intracranial Hemorrhages1
Not AvailableCompletedTreatmentSoft Tissue Anaesthesia1
Not AvailableRecruitingBasic ScienceHypoglycemia / Type1diabetes1
Not AvailableUnknown StatusNot AvailableCongestive Heart Failure (CHF)1

Pharmacoeconomics

Manufacturers
  • Novalar pharmaceuticals inc
  • Bedford laboratories div ben venue laboratories inc
  • Novartis pharmaceuticals corp
  • Sanofi aventis us llc
  • Glaxosmithkline
  • Perrigo co
  • Ranbaxy laboratories ltd
  • Mcneil consumer healthcare
Packagers
  • Bedford Labs
  • Ben Venue Laboratories Inc.
  • Novalar Pharmaceuticals Inc.
  • Novartis AG
  • Novocol Pharmaceutical Canada
Dosage forms
FormRouteStrength
Injection, solutionSubmucosal.235 mg/mL
SolutionSubmucosal0.4 mg
InjectionIntramuscular; Intravenous5 mg/1
Injection, powder, for solutionIntramuscular; Intravenous5 mg/mL
SolutionIntramuscular; Intravenous5 mg
SolutionIntramuscular; Intravenous10 mg
Powder, for solutionIntramuscular; Intravenous5 mg
Prices
Unit descriptionCostUnit
Phentolamine 5 mg vial84.0USD vial
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Patent NumberPediatric ExtensionApprovedExpires (estimated)
US6764678No2001-05-112021-05-11Us
US7569230No2003-10-172023-10-17Us
US6872390No2001-05-112021-05-11Us
US7229630No2003-06-202023-06-20Us
US7575757No2005-04-212025-04-21Us

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)174.5 °CPhysProp
logP3.3Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.272 mg/mLALOGPS
logP2.91ALOGPS
logP2.52ChemAxon
logS-3ALOGPS
pKa (Strongest Acidic)9.78ChemAxon
pKa (Strongest Basic)9.02ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area47.86 Å2ChemAxon
Rotatable Bond Count4ChemAxon
Refractivity84.25 m3·mol-1ChemAxon
Polarizability31.37 Å3ChemAxon
Number of Rings3ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9293
Blood Brain Barrier+0.838
Caco-2 permeable-0.6104
P-glycoprotein substrateSubstrate0.772
P-glycoprotein inhibitor INon-inhibitor0.9329
P-glycoprotein inhibitor IIInhibitor0.8031
Renal organic cation transporterInhibitor0.7497
CYP450 2C9 substrateNon-substrate0.6892
CYP450 2D6 substrateNon-substrate0.5668
CYP450 3A4 substrateNon-substrate0.6313
CYP450 1A2 substrateNon-inhibitor0.9046
CYP450 2C9 inhibitorNon-inhibitor0.9071
CYP450 2D6 inhibitorInhibitor0.8931
CYP450 2C19 inhibitorNon-inhibitor0.8454
CYP450 3A4 inhibitorNon-inhibitor0.831
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.7661
Ames testNon AMES toxic0.6266
CarcinogenicityNon-carcinogens0.8555
BiodegradationNot ready biodegradable1.0
Rat acute toxicity2.4366 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Strong inhibitor0.6149
hERG inhibition (predictor II)Inhibitor0.59
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
MS/MS Spectrum - , positiveLC-MS/MSsplash10-03di-4890000000-37817fa5f0f18f71350d

Taxonomy

Description
This compound belongs to the class of organic compounds known as alkyldiarylamines. These are tertiary alkylarylamines having two aryl and one alkyl groups attached to the amino group.
Kingdom
Organic compounds
Super Class
Organic nitrogen compounds
Class
Organonitrogen compounds
Sub Class
Amines
Direct Parent
Alkyldiarylamines
Alternative Parents
m-Aminophenols / Aniline and substituted anilines / Aminotoluenes / 1-hydroxy-4-unsubstituted benzenoids / 1-hydroxy-2-unsubstituted benzenoids / Imidolactams / Imidazolines / Propargyl-type 1,3-dipolar organic compounds / Carboximidamides / Carboxamidines
show 4 more
Substituents
Alkyldiarylamine / M-aminophenol / Aminophenol / Aminotoluene / Aniline or substituted anilines / 1-hydroxy-4-unsubstituted benzenoid / 1-hydroxy-2-unsubstituted benzenoid / Phenol / Toluene / Monocyclic benzene moiety
show 15 more
Molecular Framework
Aromatic heteromonocyclic compounds
External Descriptors
tertiary amino compound, substituted aniline, imidazoles, phenols (CHEBI:8081)

Targets

Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Antagonist
General Function
Thioesterase binding
Specific Function
Alpha-2 adrenergic receptors mediate the catecholamine-induced inhibition of adenylate cyclase through the action of G proteins. The rank order of potency for agonists of this receptor is oxymetazo...
Gene Name
ADRA2A
Uniprot ID
P08913
Uniprot Name
Alpha-2A adrenergic receptor
Molecular Weight
48956.275 Da
References
  1. Polak J, Moro C, Klimcakova E, Hejnova J, Majercik M, Viguerie N, Langin D, Lafontan M, Stich V, Berlan M: Dynamic strength training improves insulin sensitivity and functional balance between adrenergic alpha 2A and beta pathways in subcutaneous adipose tissue of obese subjects. Diabetologia. 2005 Dec;48(12):2631-40. Epub 2005 Nov 5. [PubMed:16273345]
  2. Molderings GJ, Bonisch H, Bruss M, Likungu J, Gothert M: Species-specific pharmacological properties of human alpha(2A)-adrenoceptors. Hypertension. 2000 Sep;36(3):405-10. [PubMed:10988273]
  3. Vonend O, Habbel S, Stegbauer J, Roth J, Hein L, Rump LC: Alpha(2A)-adrenoceptors regulate sympathetic transmitter release in mice kidneys. Br J Pharmacol. 2007 Jan;150(1):121-7. Epub 2006 Nov 20. [PubMed:17115069]
  4. Trendelenburg AU, Meyer A, Klebroff W, Guimaraes S, Starke K: Crosstalk between presynaptic angiotensin receptors, bradykinin receptors and alpha 2-autoreceptors in sympathetic neurons: a study in alpha 2-adrenoceptor-deficient mice. Br J Pharmacol. 2003 Apr;138(8):1389-402. [PubMed:12721093]
  5. Blandizzi C, Fornai M, Colucci R, Baschiera F, Barbara G, De Giorgio R, De Ponti F, Breschi MC, Del Tacca M: Altered prejunctional modulation of intestinal cholinergic and noradrenergic pathways by alpha2-adrenoceptors in the presence of experimental colitis. Br J Pharmacol. 2003 May;139(2):309-20. [PubMed:12770936]
  6. Giussani DA, Moore PJ, Bennet L, Spencer JA, Hanson MA: Alpha 1- and alpha 2-adrenoreceptor actions of phentolamine and prazosin on breathing movements in fetal sheep in utero. J Physiol. 1995 Jul 1;486 ( Pt 1):249-55. [PubMed:7562640]
  7. Bylund DB: Subtypes of alpha 1- and alpha 2-adrenergic receptors. FASEB J. 1992 Feb 1;6(3):832-9. [PubMed:1346768]
  8. Saeed M, Sommer O, Holtz J, Bassenge E: Alpha-adrenoceptor blockade by phentolamine causes beta-adrenergic vasodilation by increased catecholamine release due to presynaptic alpha-blockade. J Cardiovasc Pharmacol. 1982 Jan-Feb;4(1):44-52. [PubMed:6176798]
Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Antagonist
General Function
Protein heterodimerization activity
Specific Function
This alpha-adrenergic receptor mediates its action by association with G proteins that activate a phosphatidylinositol-calcium second messenger system. Its effect is mediated by G(q) and G(11) prot...
Gene Name
ADRA1A
Uniprot ID
P35348
Uniprot Name
Alpha-1A adrenergic receptor
Molecular Weight
51486.005 Da
References
  1. Giussani DA, Moore PJ, Bennet L, Spencer JA, Hanson MA: Alpha 1- and alpha 2-adrenoreceptor actions of phentolamine and prazosin on breathing movements in fetal sheep in utero. J Physiol. 1995 Jul 1;486 ( Pt 1):249-55. [PubMed:7562640]
  2. Bylund DB: Subtypes of alpha 1- and alpha 2-adrenergic receptors. FASEB J. 1992 Feb 1;6(3):832-9. [PubMed:1346768]
  3. Saeed M, Sommer O, Holtz J, Bassenge E: Alpha-adrenoceptor blockade by phentolamine causes beta-adrenergic vasodilation by increased catecholamine release due to presynaptic alpha-blockade. J Cardiovasc Pharmacol. 1982 Jan-Feb;4(1):44-52. [PubMed:6176798]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Antagonist
General Function
Protein heterodimerization activity
Specific Function
This alpha-adrenergic receptor mediates its action by association with G proteins that activate a phosphatidylinositol-calcium second messenger system. Its effect is mediated by G(q) and G(11) prot...
Gene Name
ADRA1B
Uniprot ID
P35368
Uniprot Name
Alpha-1B adrenergic receptor
Molecular Weight
56835.375 Da
References
  1. Koshimizu TA, Tsujimoto G, Hirasawa A, Kitagawa Y, Tanoue A: Carvedilol selectively inhibits oscillatory intracellular calcium changes evoked by human alpha1D- and alpha1B-adrenergic receptors. Cardiovasc Res. 2004 Sep 1;63(4):662-72. [PubMed:15306222]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Antagonist
General Function
Alpha1-adrenergic receptor activity
Specific Function
This alpha-adrenergic receptor mediates its effect through the influx of extracellular calcium.
Gene Name
ADRA1D
Uniprot ID
P25100
Uniprot Name
Alpha-1D adrenergic receptor
Molecular Weight
60462.205 Da
References
  1. Koshimizu TA, Tsujimoto G, Hirasawa A, Kitagawa Y, Tanoue A: Carvedilol selectively inhibits oscillatory intracellular calcium changes evoked by human alpha1D- and alpha1B-adrenergic receptors. Cardiovasc Res. 2004 Sep 1;63(4):662-72. [PubMed:15306222]
  2. Zhang D, Yuan B, Deng X, Yang G, He L, Zhang Y, Han Q: Chromatography studies on bio-affinity of nine ligands of alpha1-adrenoceptor to alpha1D subtypes overexpressed in cell membrane. Sci China C Life Sci. 2004 Aug;47(4):376-81. [PubMed:15493479]

Drug created on June 13, 2005 07:24 / Updated on August 15, 2018 09:43