For the rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter in perioperative, postoperative, or other emergent circumstances where short term control of ventricular rate with a short-acting agent is desirable. Also used in noncompensatory sinus tachycardia where the rapid heart rate requires specific intervention.
Similar to other beta-blockers, esmolol blocks the agonistic effect of the sympathetic neurotransmitters by competing for receptor binding sites. Because it predominantly blocks the beta-1 receptors in cardiac tissue, it is said to be cardioselective. In general, so-called cardioselective beta-blockers are relatively cardioselective; at lower doses they block beta-1 receptors only but begin to block beta-2 receptors as the dose increases. At therapeutic dosages, esmolol does not have intrinsic sympathomimetic activity (ISA) or membrane-stabilizing (quinidine-like) activity. Antiarrhythmic activity is due to blockade of adrenergic stimulation of cardiac pacemaker potentials. In the Vaughan Williams classification of antiarrhythmics, beta-blockers are considered to be class II agents.
Symptoms of overdose include cardiac arrest, bradycardia, hypotension, electromechanical dissociation and loss of consciousness.
Rapidly absorbed, steady-state blood levels for dosages from 50-300 µg/kg/min (0.05-0.3 mg/kg/mm) are obtained within five minutes.
Rapid distribution half-life of about 2 minutes and an elimination half-life of about 9 minutes. The acid metabolite has an elimination half-life of about 3.7 hours.
Consistent with the high rate of blood-based metabolism of esmolol hydrochloride, less than 2% of the drug is excreted unchanged in the urine. The acid metabolite has an elimination half-life of about 3.7 hours and is excreted in the urine with a clearance approximately equivalent to the glomerular filtration rate. Excretion of the acid metabolite is significantly decreased in patients with renal disease, with the elimination half-life increased to about ten-fold that of normals, and plasma levels considerably elevated.
* 20 L/kg/hr [Men]