Pirmenol in the long-term treatment of chronic ventricular arrhythmias: a placebo-controlled study

Pirmenol, a new class I antiarrhythmic drug, was given for the treatment of frequent premature ventricular complexes (PVCs) over a 6-month period. Ten patients who had their arrhythmia effectively suppressed by pirmenol in a dose-ranging study were treated with the lowest effective doses in an open investigation. The mean daily doses were 315 mg at the beginning and 340 mg at the end of 6 months. The mean reduction in the frequency of PVC/h remained between 85.5 and 88.6% during 24-h ambulatory electrocardiogram recordings at 1, 3, 5, and 6 months of therapy. With adjustment of the dosage, the predetermined efficacy criteria were fulfilled by eight to 10 patients at each of the four assessments. The PVC/h or repetitive PVC/h frequencies of the patient group did not decline spontaneously within 6 months of treatment, as shown in a placebo control phase. No aggravation of arrhythmias was observed. Side effects in two patients did not prevent prolonged use.