The use of intravenous labetalol in the setting of rapid atrial fibrillation secondary to methamphetamine use.

The use of beta-adrenoceptor antagonists for treatment of tachydysrhythmias secondary to sympathomimetic agents is controversial due to concerns of "unopposed alpha receptor stimulation." Labetalol is a dual alpha 1 and beta1/beta 2 adrenoceptor antagonist. We report the case of a 33-year-old male who developed rapid atrial fibrillation with a ventricular rate of 151 beats per minute in the setting of methamphetamine use. He received intravenous labetalol 10 mg on five occasions over a 6.5 h period, which slowed his ventricular rate and eventually resulted in restoration of sinus rhythm. Administration of labetolol did not produce a clinically significant rise in blood pressure. Combination alpha and beta blockade using labetalol may be an effective and safe treatment option in patients with methamphetamine associated supraventricular tachydysrhythmias. [ABSTRACT FROM AUTHOR]