Basic pharmacology of esmolol.

Preclinical studies show that esmolol is an ultrashortacting, cardioselective beta blocker that possesses minimal partial agonist action or membrane-depressant properties. The electrophysiologic and hemodynamic actions of esmolol are the result of beta blockade. No direct, beta receptor-independent cardiovascular actions have been identified with beta-blocking doses in laboratory experiments. Because esmolol slows atrioventricular conduction, increases atrioventricular refractoriness and decreases the determinants of myocardial oxygen demand, it should have use in the treatment of supraventricular tachycardias and acute myocardial ischemia. Esmolol, because of its ultrashort duration of action, should be safe for the induction of beta blockade in patients who are critically ill and is ideally suited for rapidly changing levels of beta blockade in this clinical situation.