Intravenous atenolol for ventricular arrhythmias.

To determine the efficacy and safety of intravenous atenolol in patients with frequent and repetitive benign or potentially lethal ventricular arrhythmias, 40 patients received an open-label, single dose of 10 mg of intravenous atenolol, given in aliquots of 2.5 mg every 10 minutes. Twenty-four-hour Holter monitoring was performed on the day before, the day of, and the day after infusion of atenolol. A full 10-mg dose was given to 37 patients; asymptomatic bradycardia developed in 3 patients, and they were not included in the efficacy analysis. A single 10-mg dose of intravenous atenolol was effective rapidly in suppressing ventricular arrhythmias, with peak suppression occurring 1 to 2 hours after infusion and significant suppression lasting for 7 hours. Only 1 patient had symptoms (lightheadedness), plus hypotension lasting 45 minutes after the infusion was concluded. The mean plasma level of atenolol was 231 ng/ml 10 minutes after the infusion, with individual patient values of 148 to 457 ng/ml. Thus, a single intravenous dose of 10 mg of atenolol can significantly reduce the frequency of ventricular premature complexes and ventricular tachycardia within the first hour after infusion; suppression can last for 7 hours. Atenolol is well tolerated.