A multicenter dose-response study of pirmenol hydrochloride in patients with ventricular premature contractions

The efficacy of pirmenol in suppressing ventricular premature complexes (VPCs) was assessed in 196 patients in a placebo-controlled, double-blind, multicenter study. At a daily dosage of 200 to 400 mg, pirmenol was effective in suppressing VPCs. In the double-blind phase of the trial, 60% of patients had at least a 70% reduction in VPC frequency and at least 70% of those patients who entered the open-label phase of the study continued to show at least a 70% reduction in VPC rate. Pirmenol was well tolerated by most patients; 66% of the patients treated with pirmenol in the double-blind phase had no adverse experiences. Of those who did have an adverse experience, the most common complaint was unusual taste. Serious adverse reactions were rare and only 2% of the patients had what may have been a proarrhythmic response. The same pattern of tolerance was seen in the open-label phase of the study when 151 patients were treated for an extended length of time with pirmenol. Pirmenol shows considerable promise for patients in whom the reduction of VPC frequency is desirable. Currently available antiarrhythmic drugs may have limited efficacy, cause serious or intolerable side effects or require frequent administration. Pirmenol has a convenient twice-daily dosing regimen, dependable antiarrhythmic action and a good safety record. This study demonstrated the effectiveness and safety of pirmenol in the control of VPCs.