disopyramide

Disopyramide

Disopyramide, sold under the brand name Norpace among others, is an antiarrhythmic medication used in the treatment of ventricular tachycardia. It is a sodium channel blocker and is classified as a Class 1a antiarrhythmic agent. Disopyramide has a negative inotropic effect on the ventricular myocardium, significantly decreasing the contractility. Disopyramide also has general anticholinergic effects which contribute to unwanted adverse effects. Disopyramide is available in both oral and intravenous forms. In 1972, when it was one of the few alternatives to quinidine, it was praised for being more potent and somewhat less toxic. However, a 2012 review of antiarrhythmic drugs noted that disopyramide is among the most toxic agents, with a high burden of side effects and increased mortality (compared to placebo) when used to treat atrial fibrillation.