Phentolamine
- Atc Codes:C04AB01#V03AB36
- CAS Codes:65-28-1#50-60-2
- PHARMGKB ID:65-28-1#50-60-2
Table of contents
- Brand Names
- Chemistry
- Pharmacologic Category
- Mechanism of Action
- Therapeutic Use
- Unlabeled Use
- Pregnancy and Lactation Implications
- Contraindications
- Warnings and Precautions
- Adverse Reactions
- Genes that may be involved
- Drug Interactions
- Nutrition/Nutraceutical Interactions
- Dosage
- Pharmacokinetics and Pharmacodynamics
- Special Considerations
Brand Names
Europe
Greece: Regitine, Rogitine; Hungary: Regitine; Luxembourg: Regitine; Netherlands: Regitine; UK: Rogitine.
North America
Canada: Phentolamine, Rogitine. USA: Oraverse, Phentolamine, Regitine.
Latin America
Argentina: Regitina; Brazil: Herivyl, Vigamed.
Asia
Japan: Regitine.
Drug combinations
Chemistry
Phentolamine Mesylate: C~17~H~19~N~3~O CH~4~O~3~S. Mw: 377.46. (1) Phenol, 3-[[(4,5-dihydro-1H-imidazol-2-yl)methyl](4-methylphenyl)amino]-, monomethanesulfonate; (2) m-[N-(2-Imidazolin-2-ylmethyl)-p-toluidino]phenol monomethanesulfonate. CAS-65-28-1; CAS-50-60-2 (phentolamine).

Pharmacologic Category
Non-selective α-Adrenergic Blocking Agents. (ATC-Code: C04AB01; V03AB36).
Mechanism of action
Competitively blocks α-adrenergic receptors to produce brief antagonism of circulating epinephrine and norepinephrine to reduce hypertension caused by α-effects of these catecholamines. Also has positive inotropic and chronotropic effect on heart. Causes vasodilation and increased blood flow in injection area via α-adrenergic blockade to accelerate reversal of soft tissue anesthetic.
Therapeutic use
Diagnosis of pheochromocytoma and treatment of hypertension associated with pheochromocytoma or other forms of hypertension caused by excess sympathomimetic amines. Treatment of dermal necrosis after extravasation of drugs with α-adrenergic effects (norepinephrine, dopamine, epinephrine). Reversal of soft tissue anesthesia and associated functional deficits resulting from local dental anesthetic containing vasoconstrictor.
Pregnancy and lactiation implications
Use with caution during pregnancy or lactation.
Unlabeled use
Treatment of pralidoxime-induced hypertension.
Contraindications
Hypersensitivity to phentolamine or any component of the formulation. Renal impairment. Coronary or cerebral arteriosclerosis. Concurrent use with phosphodiesterase-5 inhibitors including sildenafil (>25 mg), tadalafil, or vardenafil.
Warnings and precautions
Angina might occur or worsen. Following administration, myocardial infarction, cerebrovascular spasm and cerebrovascular occlusion occurred. Use with caution in tachycardia or history of cardiac arrhythmias, and in gastritis or peptic ulcer disease.