Name: Propranolol (Inderal)
Class: Nonselective b-Blocking Agent
Mechanism: Competitive blockade of b1 and b2 receptors. No a effect. Decreases conversion of T4 to T3 by inhibiting hepatic monodeiodinase.
Absorption: Good oral (>90%). But low bioavailability ~30%. Plasma levels vary 20x btwn. patients.
Dist.:93% bound to protein. Enters CNS. Metabolism.: Hepatic Excret., t½: Short t½ (3.5-6 hr).
Toxicity/S.E.s: CV—hypotension, bradycardia, c/i for CHF or AV block. Resp—c/i in asthmatics, COPD, bronchitis, allergic rhinitis. Metabolism—caution w/diabetics (masks sign of hypoglycemia: tachycardia). CNS—weakness, fatigue, nightmares, depression. GI—n/v (uncommon). Hypersens—rash, hematologic disorders (rare).
Special Features: Abrupt w/drawal may trigger MI.