Name: Labetalol (Trandate)
Class: Nonselective b and a1 Blocking Agent
Mechanism: Competitive blockade of b1, b2, and a receptors.
Absorption:
Dist.:
Metabolism.:
Excretion, t½:
Toxicity/S.E.s: CV—orthostatic hypotension, sexual dysfxn, 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). Also a effects.
Utility: Hypertension (¯ CO ® ¯ BP; blocks renin release). Angina pectoris (prophylactic ® exercise tolerance due to ¯ O2 demand). Cardiac arrhythmias (esp. supravent. tachyarrhyths). Acute MI (prophylaxis and reduction of infarct size and failure). Pheochromocytoma (in comb. w/alpha blocker). Essential tremor. Migraine headache (prophylaxis). Performance anxiety.
Features: Abrupt w/drawal may trigger MI. More a side effects. Widely used.