Pharmacokinetics of propofol ('Diprivan') as an induction agent

The disposition kinetics of propofol have been determined in 12 patients (6 female) receiving 2.5 mg/kg for induction of anaesthesia which was maintained using 1.5% halothane and 67% nitrous oxide in oxygen. Patients were premedicated with oral diazepam 10 mg and were undergoing body surface surgery. Peripheral venous samples were collected up to 8 h after injection of the drug. Whole blood propofol concentrations were determined by high pressure liquid chromatography using fluorescence detection. Data analysis indicates a 3 compartment model, with a terminal half-life of 286 (s.e.m. +/- 36) min, clearance of 1803 +/- 125 ml/min, and volume of distribution of 755 +/- 109 litres. These values are significantly different from those reported previously by Adam et al., (1983) for the Cremophor formulation of the drug. Seven of the patients showed significant secondary peaks of the blood concentration associated with recovery from anaesthesia.