Almokalant is a class III antiarrhythmic drug, acts as a potassium channel blocker, and inhibits a specific component (Ikr) of the time-dependent delayed rectifier K⁺ current. IC50 & Target: Potassium channel^[1] In Vitro: Almokalant is a class III antiarrhythmic drug, acts as a potassium channel blocker, and inhibits a specific component (Ikr) of the time-dependent delayed rectifier K⁺ current^[1]. In Vivo: Almokalant (125 μmol/kg, p.o.) induces cardiovascular defects, orofacial clefts, and tail defects in pregnant rats, after administration on Day 11. Almokalant also causes in pregnant rats^[1].