[Mexiletin for treatment of ventricular ectopic rhythm in patients with acute myocardial infarction (author's transl)].

In a controlled investigation on 84 patients with acute myocardial infarction, the effect of mexiletine on ectopic ventricular rhythms was tested with respect to mexiletine serum concentration. Malignant ventricular arrhythmias were observed 10 times in the control group and 5 times in the treated group. In the latter patients, mexiletine serum concentrations were below or at the lower therapeutical range (0.5 microgram/ml). During the second day of treatment, ventricular ectopic beats were significantly suppressed in the treated group with effective mexiletine serum concentration between 0.5 and 2.0 microgram/ml. As a side effect, vomiting was noticed in some patients in coincidence with an initial intravenous dosis of 2 mg per kg bodyweight; however, in no case it was necessary to interrupt treatment. There were no significant alterations in hemodynamical data, derived from Swan-Ganz catheter measurements, with mean maximal serum concentrations, on the second day, of approximately 1.15 microgram/ml.