Alterations in the disposition of differently cleared drugs in patients with cirrhosis.

We have compared the disposition of antipyrine orally (15 mg/kg) and the new antiarrhythmic drug lorcainide intravenously (1.5 mg/kg) in 8 patients with alcoholic cirrhosis. Antipyrine (AP) serves as a model drug for drugs which are eliminated independently of liver blood flow and lorcainide (L) elimination as a model for drugs which depend on liver blood flow. Since in healthy subjects elimination half-life (t 1/2) of L increased with age (r = 0.68, p less than 0.01) due to parallel change in the volume of distribution (r = 0.52, p less than 0.05), its disposition had to be compared to age-matched controls. Elimination of both AP and L was impaired in cirrhotic patients, expressed either in terms (mean +/- SD) of t 1/2 (AP = 26.8 +/- 15.0 hr and 12.3 +/- 1.8; L = 12.5 +/- 4.5 hr and 7.7 +/- 2.2 hr, p = 0.002) or of clearance (Cl) (AP = 21.9 +/- 7.9 ml/min and 41.7 +/- 5.5 ml/min; L = 814 +/- 144 and 1002 +/- 304 ml/min, p = 0.06). While the alterations in plasma Cl were great for AP, they were smaller for L. This suggests that elimination of drugs in cirrhotic patients is associated with relatively more impairment of enzyme activity than of hepatic blood flow. The slightly decreased Cl of L in patients with alcoholic cirrhosis would suggest that L should be carefully handled in patients with dysfunction of the liver.