Sotalol: a breakthrough antiarrhythmic?

OBJECTIVE

To review the pharmacology, pharmacokinetic, dosing, adverse effects, and therapeutic uses of sotalol.

DATA IDENTIFICATION

Articles were identified with an English-language literature computer search via Knowledge Finder, using the term sotalol, and with an extensive search of bibliographies of identified articles.

STUDY SELECTION

Relevant or representative animal studies, human trials, and case reports were selected for evaluation.

DATA EXTRACTION

The literature was assessed for quality, methodology, and outcome information.

DATA SYNTHESIS

Sotalol is a racemic compound with Class II (beta-blocking properties) and Class III (prolonged action potential) antiarrhythmic activity. It has been suggested that the plasma concentration associated with QTc prolongation (a measure of the Class III action) is much greater than that associated with beta-blockade. Therefore, sotalol is categorized as a Class III antiarrhythmic agent. The 1-isomer is responsible for the beta-blocking activity, whereas both isomers have Class III properties. After oral dosing in fasting patients with normal renal function, sotalol is > 90 percent absorbed, achieves peak serum concentrations in 2-4 h, is excreted unchanged 80-90 percent in the urine, has a volume of distribution of 1-2 L/kg, and has an elimination half-life of about 12 h. Sotalol is effective in patients with life-threatening ventricular arrhythmias that have been refractory to other conventional antiarrhythmic drugs. In general, sotalol appears to be well tolerated, with many of its adverse effects caused by beta-blocking activity. As with other antiarrhythmic agents, the possibility of proarrhythmia (frequently torsade de pointes) exists.

CONCLUSIONS

Racemic sotalol is an effective Class III antiarrhythmic agent approved by the Food and Drug Administration for the treatment of documented life-threatening ventricular arrhythmias. Investigations continue with racemic sotalol in the management of supraventricular arrhythmias. Trials with the d-isomer are also ongoing.