Antiarrhythmic effects of bisaramil in canine models of ventricular arrhythmia

The antiarrhythmic effects of bisaramil were examined in canine models of digitalis-, adrenaline- and two-stage coronary ligation- induced arrhythmia. Bisaramil (0.3-1.5 mg/kg i.v.) suppressed all the arrhythmias. The antiarrhythmic plasma concentration (IC50) for arrhythmias induced by digitalis, adrenaline, and 24 h two-stage coronary ligation were 0.11, 0.81, and 0.75 micrograms/ml, respectively. Bisaramil is a potent class I agent, judging from its low antiarrhythmic plasma concentrations. Oral bisaramil (10 mg/kg) also suppressed 24-h coronary ligation-induced arrhythmia. These results indicate that bisaramil may be a useful drug for the treatment of various clinical ventricular arrhythmias.