Alpha adrenergic blocking agents

Question 1

phenoxybenzamine

Answer 1

used primarily for urethral hypertonus and to control hypertension with pheochromocytoma; non selective alpha blocker (greater affinity for alpha 1); no effects on beta

may be contraindicated with:
hypotension, glaucoma, DM
Use with caution: cardiac disease, renal impairment, arteriosclerosis

AE: hypotension, rebound hypertension, miosis, increased IOP, tachycardia, inhibition of ejaculation, nasal congestion, weakness, ataxia, GI

Question 2

Prazosin

Answer 2

Alpha 1 blocker; dilatory effects on arterial and venous systems; questionable efficacy for UO; may be used as adjunctive treatment for systemic hypertension
use in caution with hypotensive patients
AE: hypotension, CNS effects, GI effects, nictitating membrane elevation, orthostatic hypotension syncope in humans