II. Indications
-
Hypertensive Crisis of Pheochromocytoma
- Not indicated in routine benign Hypertension
III. Mechanism
- Synthetic dibenzamine Alpha Adrenergic Antagonist at post-synaptic Adrenergic Receptors (alpha-1 and alpha-2)
- Binding results in non-selective, irreversible alkylation of the Alpha Adrenergic Receptor
- Causes Smooth Muscle relaxation, blocking Vasoconstriction and vasospasm
IV. Dosing: Adults
- Start 10 mg orally twice daily
- Titrate to typical dose 20 to 40 mg orally twice daily
- Maximum total daily dose: 120 mg/day
V. Dosing: Children (Not FDA approved)
- Start 0.2 mg/kg/day (up to 20 mg/day or 10 mg/dose) divided twice daily orally
- May titrate 0.4 to 1.2 mg/kg/day up to 20 to 40 mg orally twice daily
VI. Adverse Effects
- Symptomatic Hypotension
- Observe after dosing
- Reflex Tachycardia
- Possibly carcinogenic
VII. Safety
- Pregnancy Category C
- Unknown Safety in Lactation
VIII. Resources
- Phenoxybenzamine Capsule (DailyMed)