phenoxybenzamine hydrochloride /fēnok′sēben′zəmēn/ , an irreversible (noncompetitive) alpha1-adrenergic receptor blocker producing long-lasting blockade. ▪ INDICATIONS: It is prescribed in the control of pheochromocytoma and other instances of hypertensive crisis. If tachycardia is excessive, concomitant administration of propranolol may be necessary. ▪ CONTRAINDICATIONS: Hypotension or known hypersensitivity to this drug prohibits its use. ▪ ADVERSE EFFECTS: Among the more serious adverse effects are severe hypotension, tachycardia, and GI irritation.
