Does cholestyramine reduce the efficacy of ursodeoxycholic acid in primary biliary cirrhosis?

Abstract

Background Ursodeoxycholic acid (UDCA) has been accepted for its efficacy in the treatment of primary biliary cirrhosis. It is not clear whether such benefit is compromised in patients who use cholestyramine for pruritus. Aims and methods To study serum bile acid levels, liver function tests, and the degree of pruritus in eight patients with primary biliary cirrhosis with histological stages I-III. The study was divided into four consecutive phases each lasting 2 weeks: (1) cholestyramine alone; (2) wash-out period; (3) UDCA alone, and (4) both agents taken 5 h apart. Results UDCA with or without cholestyramine significantly reduced alkaline phosphatase and gamma-glutamyl transpeptidase activities. The median visual analogue score of pruritus rose from 16 mm at the end of cholestyramine alone to 31 mm in the wash-out period, 25mm on UDCA alone, and 24mm on combined treatment. The median serum level of glycoursodeoxycholic acid was 22 £mol/l during UDCA therapy compared with 6 £/mol/l during cholestyramine therapy (P=0.02), 7 £mol/l during the washout phase (P=0.02), and 19 £mol/l during combined treatment (P=0.04). The increase in the levels and proportions of UDCA conjugates was accompanied by a relative fall in the proportions of the primary bile acids when UDCA was taken with or without cholestyramine. Conclusion The beneficial activities of UDCA (improving liver function tests, reducing pruritus, and increasing UDCA conjugates) could still be preserved in primary biliary cirrhosis patients who use cholestyramine, at least in the short-term when the two agents are taken at least 5 h apart.