Comparison of ethmozine to propranolol and the combination for ventricular arrhythmias

A randomized, double-blind, crossover study was performed to evaluate the efficacy and tolerance of ethmozine, propranolol and a combination of ethmozine and propranolol for treatment of ventricular arrhythmias. Twenty-six patients received propranolol, 40 mg, or matching placebo 3 times daily, alone or in combination with ethmozine, 600 to 900 mg/day in 3 equally divided doses, for 1-week periods separated by matching placebo. As determined by 48-hour weekly Holter monitoring, the mean reduction in ventricular premature complex (VPC) frequency was significantly greater with ethmozine (86%) and with ethmozine plus propranolol (90%) than with propranolol (41%) (p less than 0.05). Seventy-five percent of patients had more than a 70% reduction in VPCs with ethmozine plus propranolol, although 70% of patients had an equal degree of suppression with ethmozine alone. Only 2 patients (10%) had the same degree of VPC suppression with propranolol. The results were similar for reductions in pairs of VPCs and VT runs. Two patients discontinued propranolol because of adverse effects, but no patient discontinued ethmozine or combination therapy. Adverse effects were not more frequent with combination therapy. Ventricular function as assessed by echocardiography during drug dosing showed no significant changes from placebo. Ethmozine alone or in combination with propranolol was effective in suppressing VPCs for as long as 1 year in patients who responded. It is concluded that ethmozine alone or in combination with propranolol is well tolerated. Propranolol does not appear to enhance the efficacy of ethmozine.