used orally , in double-blind cross-over controlled trials conducted on 73 patients , disopyramide , a newly developed antiarrhythmic agent , was found to be more effective than an inert placebo ( lactose ) , with a statistically significant difference , and to be as effective as quinidine sulfate in suppressing ventricular and supraventricular premature beats .
C0012702
disopyramide
C0003195
antiarrhythmic agent