Sotalol hydrochloride is a potent and non-selective antagonist of β-adrenergic receptor. Sotalol is also an inhibitor of potassinm channels with the IC50 value of ~1.2mM in HEK cell lines [1].
As a class III antiarrhythmic drug, Sotalol hydrochloride has been reported to increase the functional refractory period without reducing conduction velocity, using an in vitro experimental rabbit heart model of reentrant tachycardia. In vivo, Sotalol hydrochloride has shown to lengthen atrial and ventricular monophasic action potential duration in the intact dog heart during constant atrial pacing [2].Besides, Sotalol is a β-adrenergic receptor blocker commonly used in rhythm-control treatment of AF (Atrial fibrillation) [3].
References:
[1] Vormberge T1, Hoffmann M, Himmel H. Safety pharmacology assessment of drug-induced QT-prolongation in dogs with reduced repolarization reserve. J Pharmacol Toxicol Methods. 2006 Sep-Oct;54(2):130-40. Epub 2006 Apr 25.
[2] Claudel JP1, Touboul P. Sotalol: from "just another beta blocker" to "the prototype of class III antidysrhythmic compound".Pacing Clin Electrophysiol. 1995 Mar;18(3 Pt 1):451-67.
[3] Sicouri S1, Pourrier M, Gibson JK, Lynch JJ, Antzelevitch C. Comparison of electrophysiological and antiarrhythmic effects of vernakalant, ranolazine, and sotalol in canine pulmonary vein sleeve preparations. Heart Rhythm. 2012 Mar;9(3):422-9.