Hemodynamic effects of mexiletine

A review of studies of mexiletine, a class I antiarrhythmic drug, supports its use in patients with ventricular arrhythmias or in sinus rhythm. Studies include patients likely to receive the drug in clinical use--patients with and without coronary disease and patients who have suffered acute myocardial infarction. Some studies are open and others are controlled to compare mexiletine to placebo or to lidocaine. Mexiletine in therapeutic ranges was shown not to affect arterial pressure; to prolong aortic ball travel time, indicating depression of myocardial contractility; and not to adversely affect cardiac function. Adverse effects occurred as often in patients taking placebo as in mexiletine-treated patients, even in those with impaired cardiac function. Studies bear out early reports of mexiletine as an effective antiarrhythmic drug nearly devoid of adverse hemodynamic effects when administered intravenously or orally in a dosage to maintain a therapeutic plasma concentration.