Name: Esmolol (Breviblock)
Class: Cardioselective b1-Blocking Agent
Mechanism: Selective blockade of b1 (heart, kidney) w/rel. sparing of b2. No a effect.
Absorption: IV
Dist.:
Metabolism.: RBC esterases Excretion, t½: Ultrashort (10 min.).
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 signs of hypoglycemia: tachycardia). CNS—weakness, fatigue, nightmares, depression. GI—n/v (uncommon). Hypersens—rash, hematologic disorders (rare).
Utility: Acute cardiac arrhythmias (esp. supravent. tachyarrhythmias)—general anesthetics, thyrotoxicosis, digitalis toxicity. Perioperative hypertension. Acute MI (reduction of infarct size and failure).
Special Features: Ultrashort t½. Cardioselectivity not great.