Aprindine hydrochloride is a class I-b anti-arrhythmic agent and a hERG channel blocker with an IC50 of 0.23 μM. Aprindine hydrochloride has inhibitory effects on Na+/Ca2+ exchanger currents, which is partly responsible for their antiarrhythmic and cardioprotective effects. Aprindine hydrochloride is widely used for trial and ventricular tachyarrhythmias research research.