Mexiletine. Use in control of chronic drug-resistant ventricular arrhythmia.

The antiarrhythmic efficacy of mexiletine hydrochloride was studied in ten selected patients with stable resistant ventricular ectopic activity in whom lidocaine, procainamide, and other antiarrhythmic agents were of no avail. Continuous Holter ECG tapes were analyzed before, during, and after mexiletine. Orally administered mexiletine was found to be very effective in treatment of drug-resistant ventricular arrhythmias, with total abolition of arrhythmia in six and satisfactory control in two additional patients. Long-term follow-up confirmed maintenance of antiarrhythmic efficacy, while biochemical and hematological screening demonstrated no abnormalities. The long therapeutic half-life of the drug allowed convenient dosage schedule and good compliance. Its efficacy, low frequency of side effects, and long half-life make it an agent of notable value in suppressing ventricular arrhythmias.