Antiarrhythmic effect of lorcainide during chronic treatment.

The effect of oral N-(4-chlorophenyl)-N-[1-(1-methylethyl)-4-piperidinyl]benzene acetamide (lorcainide) was studied in 12 patients with frequent and stable ventricular arrhythmias resistant to a number of other antiarrhythmic agents. Ambulatory electrocardiograms were obtained before and during treatment with lorcainide and in some patients after discontinuation of the drug. Lorcainide suppressed ventricular premature contractions by more than 90% in all but one patient. The daily doses were 200 mg (N = 8), 300 mg (N = 1), 400 mg (N = 1)and 600 mg (N = 2). Plasma concentrations of lorcainide and of the dealkylated metabolite ranged from 0.13 to 0.27 microgram/ml and 0.25 to 0.95 microgram/ml, respectively. Side effects such as insomnia and excessive perspiration were seen in 7 and 3 patients, respectively. Lorcainide is an effective antiarrhythmic agent against ventricular arrhythmias otherwise difficult to treat.