Bretylium (tosylate)

Bretylium is a class III antiarrhythmic agent and an inhibitor of the Na+/K+-ATPase (IC50 = 4.5 mM).{46824} Bretylium also has antiadrenergic activity, inhibiting auricular nerve stimulation-induced vasoconstriction in isolated rabbit ears and hypogastric nerve stimulation-induced contraction of isolated rabbit uterus.{46827} It inhibits neuroeffector calcium transients (NCTs), as well as increases action potential delay and the absolute refractory period, but does not inhibit field stimulus-induced CTs in isolated mouse vas deferens sympathetic nerve terminals.{46828} Bretylium prevents ventricular fibrillation in anesthetized dogs in a model of sudden coronary death when administered at a dose of 10 mg/kg.{46829} Formulations containing bretylium were previously used in the prevention and treatment of ventricular fibrillation.