Comparative effect of disopyramide and ethmozine in suppressing complex ventricular arrhythmias by use of a double-blind, placebo-controlled, longitudinal crossover design.
This placebo-controlled, double-blind, longitudinal crossover study compares the efficacy of disopyramide and ethmozine, a new investigational drug, in suppressing frequent (40 or more per hour) ventricular premature depolarizations (VPDs) in 27 patients completing a 37 day protocol. Although both drugs significantly reduced VPDs relative to placebo, ethmozine was a superior antiarrhythmic drug in ach9eving near-total abolition of VPDs (30% of patients), which was never observed during disopyramide dosing (p less than .05). At the 80% VPD reduction level, ethmozine was effective in 56% of all patients compared with an effectiveness in only 22% of patients during disopyramide therapy (p less than .05). The mean peak plasma level of ethmozine was 0.66 +/- 0.8 micrograms/ml, which significantly fell to a trough level of 0.1 +/- 0.08 micrograms/ml (p less than .001). Mean peak and trough plasma levels of disopyramide exhibited less fluctuation (2.6 +/- 0.9 micrograms/ml vs 2.2 +/- 0.9 micrograms/ml). Ethmozine had no effect on the QT interval, whereas disopyramide prolonged it significantly. Importantly, while disopyramide produced serious side effects in 30% of patients, ethmozine was well tolerated with no statistically significant side effects compared with placebo.
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004206:Disopyramide / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016293:Moricizine; D010640:Phenothiazines / Q000009:adverse effects / Q000627:therapeutic use*
D000889:Anti-Arrhythmia Agents; D010640:Phenothiazines; D016293:Moricizine; D004206:Disopyramide