Thiopental pharmacokinetics in patients with cirrhosis.
The effect of cirrhosis on the pharmacokinetics and plasma protein binding of thiopental was studied in eight patients with cirrhosis, aged (mean +/- SD) 42 +/- 11 yr, and nine patients with normal hepatic and renal function, aged 48 +/- 12 yr, undergoing elective abdominal or orthopedic surgery. The total apparent volume of distribution at steady state was of 2.3 +/- 0.5 1 X kg-1 in the controls and of 3.5 +/- 1.9 1 X kg-1 in the patients with cirrhosis. Thiopental plasma clearance based upon total drug concentrations was 3.9 +/- 1.2 ml X min-1 X kg-1 in the normal group and did not differ significantly in the patients with cirrhosis: 4.4 +/- 2.2 ml X min-1 X kg-1. The elimination half-life was of 529 +/- 97 min in the controls and of 714 +/- 252 min in the patients with cirrhosis. The thiopental free fraction was 14.5 +/- 3.4% in the controls and was increased significantly to 25.2 +/- 3.9% in the patients with cirrhosis. Thiopental intrinsic clearance was decreased insignificantly (P = 0.06) from 28.3 +/- 9.0 ml X min-1 X kg-1 in the controls to 18.2 +/- 10.5 ml X min-1 X kg-1 in those with cirrhosis, suggesting that these patients may have a decreased capacity for thiopental metabolism. These results suggest that the risk of a prolonged effect following thiopental administration appears unlikely in patients with cirrhosis.
D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008103:Liver Cirrhosis / Q000378:metabolism*; D008104:Liver Cirrhosis, Alcoholic / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D011485:Protein Binding; D013874:Thiopental / Q000097:blood / Q000378:metabolism*
D001798:Blood Proteins; D013874:Thiopental