Efficacy and tolerance of the new class IB antiarrhythmic barucainide: An intravenous dose-finding study

Abstract

Barucainide is a new class IB antiarrhythmic agent that was studied for efficacy and safety after intravenous administration in patients with severe ventricular arrhythmias. All patients received 80 mg/hr barucainide intravenously for 7 hours or until ventricular arrhythmias were suppressed by greater than 90%. In responders a maintenance dose was given for 24 hours, aimed to achieve steady-state conditions. At baseline and during the treatment and washout periods 24-hour Holter recordings were performed. In addition, electrocardiogram, blood pressure, and plasma concentration of barucainide were measured. In 9 of 12 patients dose titration was effective (mean dose, 185 mg). In six of nine patients arrhythmia suppression persisted during maintenance therapy (mean dose, 18 mg/hr). Plasma concentrations correlated with given doses, rather than with antiarrhythmic efficacy. During the washout period, five patients required more than 12 hours for recurrence of arrhythmias. Treatment was stopped in one patient because of proarrhythmia; one patient had moderate heat sensations. Thus barucainide is a potent class IB agent, with a favorable side effect profile.