Esmolol toxicity

Esmolol is iv adrninistered. Maximal P-adrenoceptor blockade occurs in 1 min. Its elimination half-life is about 9 min. EuU recovery from P-adrenoceptor blockade is within 30 min after stopping the infusion. The therapeutic plasma concentrations are 0.4—1.2 lg/mL. It is metabolized by hydrolysis in whole blood by red blood cell esterases resulting in the formation of a primary acid metabohte and free methanol. The metabohte is pharmacologically inactive. The resulting methanol levels are not toxic. Esmolol is 55% bound to plasma protein, the acid metabohte only 10%. Less than 2% of parent dmg and the acid metabohte are excreted by the kidneys. Plasma levels may be elevated and elimination half-hves prolonged in patients with renal disease (41). 

Esmolol 3l > 2 Intravenous use half-life 10 min Rapid control of BP and arrhythmias, thyrotoxicosis and myocardial ischemia intraoperatively Parenteral only Toxicity Bradycardia hypotension... 

Ingestion is the most common route for both accidental and intentional exposures to the beta blockers. Esmolol, labetalol, metoprolol, and propranolol are all available for parenteral administration therefore, toxicity can occur via this route. Beta blockers are also administered as ocular medications and systemic toxicity can occur following administration by this route. 

B. Clinical Uses and Toxicities Esmolol, a very short-acting beta-blocker for intravenous administration, is used exclusively in acute arrhythmias. Propranolol, metoprolol. and timolol are commonly used as prophylactic drugs in patients who have had a myoeardial infarction. These drugs provide a protective effect for 2 years or longer after the infarct. 

Seneff M, Scott J,FreidmanB, Smith M Acute theophylline toxicity and the use of esmolol to reverse cardiovascular instability. Ann EmergMed( 990) 19,671-3. 

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