Double-blind randomized comparison of intravenous tocainide versus lidocaine in the treatment of chronic ventricular arrhythmias

The efficacy and safety of intravenous tocainide were compared with intravenous lidocaine in patients with chronic ventricular arrhythmias in a double-blind, parallel study. Twenty-nine patients were randomized to a tocainide (n = 15) or lidocaine (n = 14) group. Antiarrhythmic efficacy was defined as a ≥50% reduction in single ventricular premature complex (VPC) frequency, ≥90% reduction in paired VPC frequency, and total abolition of ventricular tachycardia. Efficacy was observed in 40% (6 of 15) of patients in the tocainide group and in 36% (5 of 14) patients in the lidocaine group. A 75% or greater reduction in total VPCs occurred in 40% (6 of 15) of patients in the tocainide group and in 57% (8 of 14) of patients in the lidocaine group. Greater than 90% suppression of paired VPCs occurred in 9 of 13 (69%) patients taking tocainide and in 6 of 11 (54%) patients taking lidocaine. Total abolition of ventricular tachycardia was documented in 5 of 11 (45%) patients given tocainide and in two of six (33%) patients given lidocaine. A total of 17 adverse reactions affecting 86% (12 of 14) of patients taking lidocaine and 11 adverse reactions affecting 53% (8 of 15) of patients taking tocainide occurred. Four patients in each treatment group suffered dose-limiting adverse effects. This study suggests that the efficacy and safety of intravenous tocainide are similar to that of intravenous lidocaine in patients with chronic ventricular arrhythmias.