Prolonged Q-T interval and severe tachyarrhythmias, common features of sotalol intoxication.

The findings in six patients admitted to hospital 0.5-4.5 h after the ingestion of an overdose of 2.4-8 g sotalol are described. In addition to bradycardia and hypotension, all patients had a considerably prolonged corrected Q-T interval, up to 172 +/- 8% of normal. Severe ventricular tachyarrhythmias occurred in five of the six patients, the risk was greatest up to 20 h after the ingestion of sotalol. The long Q-T interval returned to normal over 3 to 4 days, which is consistent with the long half-life of sotalol. In addition to its beta-blocking action, sotalol has marked electrophysiological properties of a Class III antiarrhythmic drugs, which are likely to be able to account for its observed effects. Special attention should be paid to the risk of severe ventricular arrhythmias in sotalol intoxications.