Thiopentone pharmacokinetics in patients with chronic alcoholism

The pharmacokinetics of thiopentone were compared in nine control patients and 10 patients with chronic alcoholism (without signs of cirrhosis or hepatitis) undergoing orthopaedic or abdominal surgery under general anaesthesia. The mean (+/- SD) alcohol intake was 92 +/- 14 litre of ethanol per year in the alcoholic patients and less than 10 litre yr-1 in the controls. Thiopentone plasma concentrations were measured by high pressure liquid chromatography after the administration of a single bolus dose (5-9 mg kg-1). The plasma clearance of thiopentone was significantly increased from 3.7 +/- 0.9 ml min-1 kg-1 in the controls to 5.4 +/- 2.2 ml min-1 kg-1 in the patients with chronic alcoholism. The volume of the central compartment and the total apparent volume of distribution were similar in both groups. The terminal elimination half-life was of 684 +/- 168 min in the alcoholics and did not differ significantly from the value found in the controls (750 +/- 212 min).