Anticholinergic activity and pharmacokinetic parameters of agent SS-68 with properties of class iii antiarrhythmic drugs

Abstract

It was shown that the indole derivate SS-68 (50 and 250 µg/kg intravenous) in acute experiments on cats with neurogenic atrial fibrillation (AF) has a dose-dependent antiarrhythmic action which is associated with the neurotropic influence of this substance, since the suppression of the AF coincides with its anticholinergic effect observed for more than 2 hours, but cardiotropic action at this time was not observed. High antiarrhythmic activity of SS-68 to neurogenic AF may be due to the IKAch inhibition and blockade of M2-cholinergic receptors. SS-68 (50 µg/kg intravenous) in experiments on rabbits is characterized by the following pharmacokinetic parameters: Cmax = 14.5 ng/ml of blood plasma (duration of plasma exposure of SS-68 is 4 hours), T1/2 = 1,1 ± 0.06 hours, MRT(0 – t) = 1.6 ± 0.08 hours, AUC(0 – 1440) = 1006.1 ± 147.7 ng/ml×min, Vss = 4.8 ± 0.8 l/kg and CL = 0.051 l/h. Based on pharmacodynamic and pharmacokinetic parameters it was suggested that anticholinergic action of SS-68 in neurogenic AF will occur in a much lower dose than 50 mg/kg.