Biliary lipids, lithogenic index and biliary drug concentrations during etofibrate and bezafibrate treatment

Hypolipidemic drugs like etofibrate and bezafibrate may induce lithogenic bile and increase the risk of gallstone formation. In this study, biliary lipids, lithogenic index and biliary drug concentrations were investigated in 6 hyperlipidemic patients after cholecystectomy. Patients were treated once daily for 5 days with either 500 mg/day etofibrate or 400 mg/day bezafibrate. Hepatic bile was collected for 6 days via T-drainage in 4 hourly aliquots. In the patients treated with etofibrate, the range of the lithogenic index remained stable with 0.89-1.69 before and 0.78-1.51 after 5 day drug therapy. In the bezafibrate group, the range of the lithogenic index rose from 0.81-1.40 to 1.26-1.66 mainly as a result of an increase of biliary cholesterol concentrations. Biliary drug concentrations were substantially higher under bezafibrate treatment than under etofibrate treatment. In conclusion, the fibrate drugs, etofibrate and bezafibrate, are different with regard to lithogenicity of bile and extent of biliary excretion. The safety profile of etofibrate may be preferably compared to other fibrate drugs.