Prifuroline is a benzofuran derivative patented by French pharmaceutical company Laboratoires Jacques Logeais S. A. As an antiarrhythmic agent. After intravenous administration to pentobarbital-anesthetized dogs, Prifuroline produced a significant dose-related decrease in heart rate and in sinus node recovery time. Prifuroline dose-dependently antagonizes the arrhythmogenic action of aconitine in rats when administered either intravenously or intraduodenally. Prifuroline also diminishes ventricular susceptibility to electrical stimulation in open-chest rats; its effect is comparable to that of disopyramide and amiodarone at the same dose levels. Prifuroline was also able to restore sinus rhythm in guinea-pigs after intracardiac conduction blockade with acetylcholine, although being devoid of anticholinergic activity.