Disposition of intravenous pirmenol

Twelve patients having frequent premature ventricular complexes (PVCs) averaging more than 60 per hour received a single 150-mg intravenous dose of pirmenol. Plasma pirmenol concentration declined biexponentially following the infusion and was analyzed according to a two-compartment open model. Following an erratic distribution phase, the terminal elimination half-life ranged from 4.2 to 16.9 hours, with a geometric mean of 7.6 hours. Total body clearance averaged 164 +/- 58 ml/min, and the mean volume of distribution was 1.45 +/- 0.38 liter/kg. Renal clearance averaged 46.6 +/- 21.2 ml/min, representing 30 +/- 10 per cent of total body clearance. Excretion of unchanged drug in the urine averaged 31.8 +/- 8 per cent of the dose. Renal clearance and elimination half-life were correlated (r = -0.61, P less than 0.05). Eight of the 12 patients achieved greater than 95 per cent suppression of PVCs with a duration between 20 minutes and 23 hours. These favorable pharmacokinetics indicate that pirmenol may be a useful addition to the therapy of ventricular arrhythmias.