Feasibility of low-dose and intermittent chenodeoxycholic acid therapy of gallstones

Efficacy of bile acid therapy for gallstone dissolution: a meta-analysis of randomized trials

To define better the efficacy of bile acid therapy for dissolution of radiolucent gallstones, we performed a meta-analysis of published trials from January 1966 to September 1992. Studies were identified using a MEDLINE computer search followed by an extensive manual search. The inclusion criteria used were: randomized trial, radiolucent gallstones in a visualizing gallbladder on oral cholecystography, and complete stone dissolution confirmed by oral cholecystography or ultrasound. Study results were pooled into 6 groups: placebo: high- and low-dose chenodeoxycholic acid (CDCA) (> or = 10 mg.kg/day and < 10 mg.kg/day); high- and low-dose ursodeoxycholic acid (UDCA) (> or = 7 mg.kg/day and < 7 mg.kg/day) and combined CDCA plus UDCA. Homogeneity calculations were performed and the percentage of complete stone dissolution calculated for each group with 95% confidence intervals. Of 66 trials identified, 23 comprising 1949 patients met the inclusion criteria. A total of 1062 patients were treated with CDCA, 819 with UDCA and 78 combination therapy. In studies > 6 months' duration, high-dose UDCA completely dissolved stones in 37.3% of patients (95% C.I. 33-42%), low-dose UDCA in 20.6%) and high-dose CDCA 18.2% (95% C.I. 15-21%). Based on only two studies, combination therapy achieved dissolution in 62.8% (95% C.I. 51-74%) of patients. Stones less than 10 mm dissolved significantly more frequently than stones larger than 10 mm. This analysis shows that UDCA in doses greater than 7 mg.kg/day taken for greater than 6 months will dissolve radiolucent gallstones in 38% of patients. The combination of UDCA and CDCA may be more efficacious but this observation is based upon only 78 patients and requires confirmation in further randomized trials.

Chenodeoxycholic acid administration monitored by serum bile acid profiles: a dose-response study

Serum bile acid analysis was used to monitor the bile acid composition of bile in 16 healthy male volunteers before and during the oral administration of different doses of the gallstone-dissolving bile acid, chenodeoxycholic acid. Daily chenodeoxycholic acid ingestion increased the percentage of this bile acid in bile to a new steady-state level after two to three weeks. Doses of 125, 250, 500, and 750 mg/day significantly increased the proportion of chenodeoxycholic acid in bile from 41% to 55, 61, 78, and 79%, respectively, during the fourth week of ingestion. The results indicate that useful information concerning chenodeoxycholic acid-induced changes in the bile acid composition of bile can be obtained solely by serum bile acid analysis, and bile collection by duodenal intubation can be avoided.

Chenodeoxycholic acid: a review of its pharmacological properties and therapeutic use

Chenodeoxycholic acid (chenic acid; CDCA) is 1 of the 3 major biliary bile acids in man. When administered in pharmacological doses it causes a decrease in cholesterol saturation of bile, which in turn may lead to gradual dissolution of cholesterol gallstones. The stone dissolution rate during CDCA therapy has varied considerably from about one-third of patients overall to 80 to 90% in a highly selected group of patients. Radiolucent gallstones in a functioning gallbladder are absolute requirements. CDCA is well tolerated; diarrhoea (sometimes requiring dosage reduction) is the only frequent side effect. Although hepatotoxicity has occurred in certain animal species, and slight hypertransaminasaemia has occurred in some patients, definite liver damage has not been observed in man. CDCA is considered contraindicated in pregnancy, and in those patients with the complications from gallstones which require immediate surgery. Care should be taken in patients with liver disease. The only other proven agent for dissolving gallstones is the 7 beta-epimer of CDCA, ursodeoxycholic acid (UDCA). Preliminary results show that UDCA is as effective as CDCA, but at one-half to two-thirds the dose, without causing diarrhoea. Further studies need to be done with both CDCA and UDCA to improve criteria for selection of patients most likely to respond, and to establish optimum schedules for dosage and duration of treatment.

Chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile in the dog

Six dogs were given chenodeoxycholic acid, 200 mg/day for 15 days; gallbladder and hepatic bile samples were taken and biliary bile acids, phospholipids and cholesterol were compared to those of fourteen control dogs. It was found that: (1) the cholesterol saturation index of gallbladder bile was higher in treated dogs (0.12 +/- 0.06; m +/- SD) than in controls (0.07 +/- 0.01; P less than 0.05); the proportion of chenodeoxycholic acid in gallbladder bile was higher in treated dogs (27.8 +/- 12.5%) than in controls (4.5 +/- 1.9%; P less than 0.01); (2) in hepatic bile, the saturation index and proportion of chenodeoxycholic acid were significantly higher in treated dogs (respectively 0.13 +/- 0.03 and 21.6 +/- 8.8%) than in control dogs (respectively 0.07 +/- 0.01; P less than 0.01 and 4.6 +/- 2.2%; P less than 0.01). In the dog, chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile. It is concluded that the difference of effect of chenodeoxycholic acid in man and in the dog is not related to the duration of administration, but to a species difference.

Gallstones. The present and future of medical dissolution

Adequate concentrations of bile acids and phospholipids are necessary to keep cholesterol in solution in bile. When the amount of cholesterol exceeds the capacity of bile acids and phospholipids to keep the cholesterol in micellar solution, bile becomes supersaturated; then, under appropriate conditions, cholesterol crystals form and gallstones may develop. Current dissolution therapy is aimed at desaturating the bile, thereby shifting the equilibrium of cholesterol from a crystalline phase back toward a micellar state, thus permitting gallstones to dissolve. Chenodeoxycholic acid is the drug being most extensively tested for efficacy in dissolution; at present, it is successful in about 60 per cent of cases. The primary mechanism of action appears to be suppression of biliary secretion of cholesterol. Further experience is needed to confirm the safety of chenodeoxycholic acid, to gain more precision in patient selection, and to determine ideal dose. The role of chenodeoxycholic acid in prophylaxis and in prevention of recurrence needs further study. Other potential agents for dissolution also deserve investigation.