Interaction of chenodeoxycholic acid and dietary cholesterol in the treatment of cholesterol gallstones.

Standard doses of chenodeoxycholic acid (15 mg/kg/day) fail to dissolve gallstones in 30 to 50 percent of patients with radiolucent gallstones in a functioning gallbladder. In humans, increasing dietary cholesterol produces increased biliary secretion of cholesterol. Restriction of dietary cholesterol reduces the minimum effective dose of chenodeoxycholic acid and speeds gallstone dissolution. In this study we investigated the interaction of dietary cholesterol and chenodeoxycholic acid in the prevention of gallstones in the prairie dog gallstone model. In animals fed a moderately lithogenic diet, standard doses of chenodeoxycholic acid failed to prevent gallstones. Reduction of the cholesterol stimulus or doubling the dose of chenodeoxycholic acid prevented the formation of gallstones. These findings support the hypothesis that the formation and dissolution of cholesterol gallstones are an expression of the relative strengths of saturating and desaturating stimuli. Therefore, rational therapy for cholesterol gallstone dissolution and prevention requires both reduction of lithogenic stimuli and optimal titration of chenodeoxycholic acid.