Short- and long-term therapy with tocainide for malignant ventricular tachyarrhythmias.

Tocainide was administered to 228 patients referred for treatment of recurrent ventricular tachyarrhythmias that were refractory to therapy with conventional antiarrhythmic drugs. After baseline studies, 1200 to 2400 mg tocainide/day was given for 4 days. Tocainide was effective in 49% of 180 patients evaluated with monitoring and exercise testing and in 35% of 48 patients undergoing electrophysiologic testing. No clinical parameter predicted the response to tocainide, although there was a correlation with the effect of lidocaine. Tocainide was selected for long-term treatment in 73 patients who were followed for an average of 26.4 months (range 1 to 92 months). The incidence of sudden death was 4.3% per year and two patients had nonfatal recurrence of arrhythmia. It is concluded that tocainide is effective and well tolerated during long-term use if therapy is evaluated carefully and is individualized.