Long-term treatment of ventricular arrhythmias with oral mexiletine.

Twenty-four patients with ventricular arrhythmias were treated with oral mexiletine for periods of from one to 16 months (total 10.4 patient-years). In 19 patients arrhythmias were satisfactorily controlled and plasma levels previously shown to be within the therapeutic range were maintained on an 8 hourly regimen. The drug was well tolerated in most patients and regular hematological and biochemical screening revealed no problems of toxicity.