Antiarrhythmic efficacy of desipramine

The effect of desipramine on chronic ventricular ectopic depolarizations (VEDs) was studied in 10 patients with at least 30 VEDs per hour. A single-blind, placebo-controlled, dose-ranging protocol was followed. Efficacy was defined as a decrease in VED frequency of at least 75%, base on three 24 hour ambulatory ECGs obtained on each dose. Among seven patients with analyzable data, one responded to 75 mg daily, and three others responded to 150 mg daily. Six of the seven patients demonstrated decreases in VED frequency with increases in desipramine serum concentration. Among five patients with episodes of nonsustained ventricular tachycardia, desipramine completely abolished the episodes in two, and reduced the frequency of episodes by at least 90% in two others. Adverse reactions were common, and necessitated drug discontinuation or dose reduction in five patients. Desipramine has an antiarrhythmic effect in patients with chronic ventricular ectopy, but its clinical utility is limited by adverse effects.