AFD-21 (maleate)
AFD-21 maleate is a dr_ug with antiarrhythmic activity. AFD-21 maleate inhibits sodium channels by binding to sodium channels in an inactive state, with both use-dependent and voltage-dependent effects. The unbinding rate of AFD-21 maleate is similar to that of Class I antiarrhythmic dr_ugs with moderate kinetics. AFD-21 maleate can cause a slight prolongation of the action potential duration and significantly reduce the maximum rise rate of the action potential at certain concentrations. AFD-21 maleate also showed use-dependent blocking effects as stimulation frequency increased.