Pirmenol is a class I antiarrhythmic agent.^1,2,3It lengthens the final repolarization of action potentials in isolated rabbit ventricular myocytes and inhibits tachyarrhythmias induced by prolonged afterdepolarizations in isolated guinea pig papillary muscles when used at a concentration of 5 µM.¹Pirmenol (2.5 and 5 mg/kg) suppresses ouabain- or epinephrine-induced ventricular arrhythmias and aconitine-induced atrial arrhythmias in dogs.^2,3

1.Sawanobori, T., Adaniya, H., Yamashita, S., et al.Electrophysiologic and antiarrhythmic actions of pirmenol on rabbit and guinea pig cardiac preparationsJ. Cardiovasc. Pharmacol.16(6)975-983(1990) 2.Kaplan, H.R., Mertz, T.E., and Steffe, T.J.Preclinical pharmacology of pirmenolAm. J. Cardiol.59(16)2H-9H(1987) 3.Steffe, T.J., Mertz, T.E., Hastings, S.G., et al.CL-845 (pirmenol hydrochloride): A new orally effective long-acting antiarrhythmic agentJ. Pharmacol. Exp. Ther.214(1)50-57(1980)