Pharmacology Mnemonics - Flash Cards

Name: Prazosin (Minipress)

Class: a-Blocking Agent

Mechanism: Blocks a1 receptors in vasculature ® ¯ phospholipase C activation, ¯ IP₃ formation, ¯ Ca²⁺ released from intracellular stores ® arteriolar & venous vasodilation.

Absorption: Oral. 50% bioavailability

Dist.:

Metabolism.:

Excretion, t½: 3 hr.

Toxicity/S.E.s: 1st dose syncope (1%), dizziness, headaches, weakness.

Utility: Treat periph. vasc. disease (Raynaud’s Disease), hypertension (lowers BP w/o producing sig. tachycardia), pheochromocytoma (phenoxybenz. is best), benign prostatic hyperplasia (relieves obstruction symptoms).

Special Features: Prazosin-type a blockers are the only clinically useful anti-hypertensive a-receptor antagonists. Produce less tachycardia than do direct vasodilators. Readily combined w/other drugs.

Name: Terazosin (Hytrin)

Class: a-Blocking Agent (Prazosin-type)

Mechanism: Blocks a1 receptors in vasculature.

Absorption: Oral. High bioavailability.

Dist.:

Metabolism.:

Excretion, t½: 9-12 hr.

Toxicity/S.E.s: 1st dose syncope (1%).

Utility: Treat periph. vasc. disease (Raynaud’s Disease), hypertension, pheochromocytoma (phenoxybenz. is best), benign prostatic hyperplasia (relieves obstruction symptoms).

Special Features: Prazosin-type a blockers are the only clinically useful anti-hypertensive a-receptor antagonists. Lower BP w/o producing sig. tachycardia. Readily combined w/other drugs.

Name: Prazosin (Minipress)

Class: a-Blocking Agent

Mechanism: Blocks a1 receptors in vasculature ® arteriolar & venous vasodilation.

Absorption: Oral. 50% bioavailability

Dist.:

Metabolism.:

Excretion, t½: 3 hr.

Toxicity/S.E.s: 1st dose syncope (1%), dizziness, headaches, weakness.

Utility: Treat periph. vasc. disease (Raynaud’s Disease), hypertension (lowers BP w/o producing sig. tachycardia), pheochromocytoma (phenoxybenz. is best), benign prostatic hyperplasia (relieves obstruction symptoms).

Special Features: Prazosin-type a blockers are the only clinically useful anti-hypertensive a-receptor antagonists. Produces less tachycardia than do direct vasodilators. Readily combined w/other drugs.

Name: Phenoxybenzamine (Dibenzyline)

Class: a-Blocking Agent

Mechanism: Blocks a-receptors. No effect on b-receptors. Forms irreversible (i.e., covalent) bond w/receptors. Vasc— ¯ BP. Reduces compensatory reflexes (orthostatic hypotens.). Blocks pressor response to symp. (EPI reversal). Myocard.—No direct effect. Reflex tachycard. due to ¯ BP. Eye—Miosis. GI—No effect. CNS—High doses ® stimulation and depression.

Absorption: Oral, but poor bioavailability.

Dist.:

Metabolism.:

Excretion, t½: Effect lasts 3-4 days.

Toxicity/S.E.s: Orthostatic hypotension, tachycardia, inhib. of ejaculation.

Utility: Reduce effects of pheochromocytoma.

Special Features: Discovered at the U. of U.