Mexiletine is less effective in patients with recurrent refractory ventricular tachycardia and fibrillation, and extracardiac side effects may limit its long-term usefulness. Supraventricular arrhythmias are not controlled by mexiletine. Additional Information Mexiletine has no active metabolites. Toxic effects include dizziness, vomiting, confusion, tremor, bradycardia, and hypotension. Metabolism of mexiletine is accelerated by rifampin, phenobarbital and phenytoin and retarded by cimetidine and ketoconazole.
Acidic urine accelerates elimination.
American Medical Association, Winter 1993.