Phentolamine
REGITINE
What it isShort-acting reversible nonselective alpha-1/alpha-2 antagonist used for acute catecholamine excess and vasopressor extravasation.
Why this oneRapid IV alpha blockade can reverse a catecholamine-driven hypertensive crisis or local ischemia without prolonged postoperative hypotension.
What limits itMarked hypotension and reflex tachycardia can provoke myocardial or cerebral ischemia; avoid when coronary perfusion is tenuous.
FDA-approved for
- pheochromocytoma (~1952)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Reversal of pharmacologically-induced mydriasis | Adult & Pediatric >=12 yr | 1-2 drops per dilated eye after exam | ||
| Reversal of pharmacologically-induced mydriasis | Pediatric 3-11 yr | 1 drop per dilated eye after exam |
Renal Undefined
Hepatic Undefined
Second drop, if used, is given 5 minutes after the first.
Instructions
- Instill after completion of the ophthalmic exam/procedure
- If 2 drops used, give the second drop 5 minutes after the first
- Remove contact lenses before instillation; reinsert 10 minutes after dosing
- Discard single-patient-use vial immediately after use
Cautions
- Not recommended with active ocular inflammation (e.g., iritis) — risk of synechiae
- Avoid touching vial tip to the eye or other surfaces
Adverse reactions
- Instillation site discomfort (pain/stinging/burning) 16%
- Conjunctival hyperemia 12%
- Dysgeusia 6%
Pregnancy No human data; use only if benefit justifies potential fetal risk.
Lactation No data; weigh benefits of breastfeeding against clinical need.
NO BOXED WARNINGS
Principal riskmarked hypotension with reflex tachycardia and ischemia
Cost, est. cash$20–$1,500/dose or month
Generic entry1998
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Mechanism of action: Phentolamine ballicule
