II. Indications
III. Dosing: Adults
-
Hypertensive Crisis in Pheochromocytoma
- Give 5 mg IV/IM for one dose
- Results in profound Blood Pressure drop (e.g. 60/25 mmHg decrease in BP)
-
Vasopressor Extravasation (e.g. Norepinephrine) - Not FDA approved
- Prepare 5-10 mg in 10 ml Normal Saline
- Inject 1 ml SC around extravasation site within 12 hours of extravasation
- In adults may repeat dose up to a total of 5 ml injected around extravasation site
IV. Dosing: Children
-
Hypertensive Crisis in Pheochromocytoma
- Give 0.05 to 0.1 mg/kg (up to 5 mg) IV/IM for one dose
- Results in profound Blood Pressure drop (e.g. 60/25 mmHg decrease in BP)
-
Vasopressor Extravasation (e.g. Norepinephrine) - Not FDA approved
- Prepare 5 mg in 10 ml Normal Saline
- Inject 1 ml SC around extravasation site within 12 hours of extravasation
V. Mechanism
- Synthetic imidazoline acts as a competitive Alpha Adrenergic Antagonist at alpha-1 and alpha-2 receptors resulting in vasodilation
- May block 5-HT receptors
- May stimulate Histamine release from Mast Cells
VI. Adverse Effects
- Hypotension
- Generalized Weakness
VII. Safety
- Pregnancy Category C
- Unknown Safety in Lactation
VIII. Resources
- Phentolamine (DailyMed)
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Related Studies
Definition (NCI) | A synthetic imidazoline with alpha-adrenergic antagonist activity. As a competitive alpha-adrenergic antagonist, phentolamine binds to alpha-1 and alpha-2 receptors, resulting in a decrease in peripheral vascular resistance and vasodilatation. This agent also may block 5-hydroxytryptamine (5-HT) receptors and stimulate release of histamine from mast cells. |
Definition (MSH) | 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. |
Definition (CSP) | nonselective alpha-adrenergic antagonist. |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D010646 |
SnomedCT | 372863003, 82165003 |
English | Fentolamin, Phenol, 3-(((4,5-dihydro-1H-imidazol-2-yl)methyl)(4-methylphenyl)amino)-, 2-[N-p'-Tolyl-N-(m'-hydroxyphenyl)aminomethyl]imidazoline, phentolamine (medication), alpha blockers phentolamine, Phentolamine [Chemical/Ingredient], fentolamin, Phentolamine, PHENTOLAMINE, phentolamine, Phentolamine (product), Phentolamine (substance), PTM |
Swedish | Fentolamin |
Czech | fentolamin |
Finnish | Fentolamiini |
Russian | FENTOLAMIN, ФЕНТОЛАМИН |
Japanese | メシル酸フェントラミン, レギチーン, フェントラミンメシル酸塩, フェントラミンシアル酸塩, フェントールアミン, フェントラミン, レギチン, ロギチン, 塩酸フェントラミン, フェントラミン塩酸塩, シアル酸フェントラミン |
Croatian | FENTOLAMIN |
Polish | Fentolamina, Regityna |
Spanish | fentolamina (producto), fentolamina (sustancia), fentolamina, Fentolamina |
French | Phentolamine |
German | Fentolamin, Phentolamin |
Italian | Fentolamina |
Portuguese | Fentolamina |