Antiarrhythmic plasma concentrations of pirmenol on canine ventricular arrhythmias

Using two-stage coronary ligation-, digitalis- and adrenaline-induced canine ventricular arrhythmias, antiarrhythmic effects of pirmenol were examined, and the minimum effective plasma concentration for each arrhythmia model was determined. Pirmenol suppressed all the arrhythmias, and the minimum effective plasma concentrations for arrhythmias induced by 24 hr coronary ligation, 48 hr coronary ligation, digitalis and adrenaline were 1.1 +/- 0.3 (by 3 mg/kg, i.v.), 1.1 +/- 0.3 (by 3 mg/kg, i.v.), 1.1 +/- 0.2 (by 3 mg/kg, i.v.) and 2.5 +/- 1.5 (by 3 mg/kg, i.v.) microgram/ml, respectively (mean +/- S.D.M., n = 6-7). The concentration for adrenaline-induced arrhythmia was significantly higher than those for the other types of arrhythmias. This pharmacological profile is similar to those of mexiletine, tocainide and cibenzoline. Since pirmenol had no deleterious effects on the blood pressure and sinus node activity, its clinical usefulness is expected.