Low-dose chenodeoxycholic acid for gallstone dissolution: a randomized trial in poor operative risk patients.

Thirty-five patients, with minimally symptomatic radiolucent gallstones in well opacifying gallbladders who had an unusually high risk of operative mortality, were randomized, double blind, into three groups: group 1, placebo; group 2,250 mg chenodeoycholic acid (CDC)/day; group 3,375 mg CDC/day. Every six months, oral cholecystograms and duodenal bile were obtained. Serum was collected at 0, 1, 2, 3, and 6 months, then at 6-month intervals. After 6 months, all placebo patients were assigned to 375 mg CDC/day (group 3b). No changes occurred in group 1 (N = 15). Gallstones dissolution: group 2, 2/10; 1 complete (C), 1 partial (P); group 3, 4/10, 1C, 3P; group 3b, 2/12, 2C. Lowest dose with complete dissolution was 3 mg/k/day (actual body wt). Lithogenic index of bile only improved with 375 mg/day (1.27 +/- 0.13 vs 0.88 +/- 0.05; mean +/- SDM), P < 0.01. No diarrhea or serum biochemical changes occurred; however, three patients died of their other medical illness. Low fixed doses of CDC, although not optimal, dissolved stones without toxicity in very ill patients.