SB-237376 (free base) is a potassium and calcium channel blocker. SB-237376 (free base) can inhibit the rapidly activating delayed rectifier potassium current I (Kr) (IC50 is 0.42 μM), and at high concentrations, it blocks the L-type calcium current I (Ca, L) . In the rabbit ventricular model, SB-237376 (free base) can induce early afterdepolarizations (EADs) at a concentration of 3 µM. Compared to other IKr inhibitors such as dl-sotalol, SB-237376 has a lower proarrhythmic risk. SB-237376 (free base) holds potential for research in the field of arrhythmia-related diseases[1].