Esmolol hydrochloride: an ultrashort-acting, beta-adrenergic blocking agent

The chemistry, pharmacology, pharmacokinetics, hemodynamic and electrophysiologic effects, clinical efficacy, adverse effects, drug interactions, compatibility and stability, dosage, and administration of esmolol hydrochloride are reviewed. Esmolol produces competitive blockade of beta receptors in both animals and humans. It does not possess membrane-stabilizing, intrinsic sympathomimetic, or alpha-adrenergic blocking activity. The relative cardioselectivity of esmolol is similar to that of metoprolol. Esterase metabolism accounts for the rapid total body clearance of 285 mL/kg/min and elimination half-life of 9.2 minutes. Its rapid metabolism following continuous intravenous infusion results in the rapid offset of pharmacologic effect after drug administration is discontinued. In patients with supraventricular tachyarrhythmias, esmolol produces rapid control of heart rate in an average effective dosage range from 97.2 to 115.0 micrograms/kg/min and effects that are similar to propranolol. Esmolol is effective and safe in managing tachycardia and hypertension during surgical stress and may be useful in postoperative hypertension or elevated heart rates during myocardial ischemia. Esmolol does not appear to interact with digoxin, morphine, warfarin, or succinylcholine to any clinically important extent. The most frequent adverse effects associated with esmolol infusion are hypotension and phlebitis. Hypotension can be avoided by careful titration, and if encountered, it can be rapidly resolved by dosage adjustment or discontinuation of the infusion. The ultrashort half-life and duration of action of esmolol may allow safer application of beta blockade in critically ill patients.