Pharmacokinetic study of oral ursodeoxycholic acid tolerance test

In order to investigate the mechanism of oral ursodeoxycholic acid (UDCA) tolerance test for patients with hepatic diseases the concentration of UDCA in serum and bile, which were obtained from healthy subjects and patients with hepatic diseases after oral or intravenous administration of UDCA, was measured by radioimmunoassay, enzyme immunoassay, and mass fragmentography. Almost all UDCA administered to subject with normal liver function was recovered in bile within 3 hours. When UDCA (25-300mg) was orally administered to healthy subjects, a hepatic fractional clearance was constant in doses up to 300mg. When UDCA (50mg) was orally administered, area under curve (AUC) in patients with hepatic diseases was larger than that in healthy subjects, and the enhancement of AUC was parallel to the severity of hepatic diseases. It is concluded that AUC in oral UDCA tolerance test reflects changes in liver function occuring with hepatocellular damage.