Biliary lipid composition during treatment with different hypolipidaemic drugs.

In an attempt to clarify the possible lithogenic effects of commonly used hypolipidaemic drugs, gallbladder bile was obtained from patients with primary hyperlipoproteinaemia before and during treatment with nicotinic acid (n = 13), cholestyramine (n = 19), clofibrate (n = 11), and a combination of cholestyramine and clofibrate (n = 11). Each treatment period was minimum 6 weeks, and standardized dietary conditions were obtained. Both nicotinic acid and clofibrate treatment caused an increase in biliary cholesterol concentration relative to biliary total lipids (bile acids, phospholipids, and cholesterol). During cholestyramine medication the relative cholesterol concentration fell. A combination of cholestyramine with clofibrate medication led to a decrease of bile saturation to pretreatment levels in nine of the eleven subjects. In the other two a further increase in the cholesterol saturation of the bile occurred. Treatment with nicotinic acid and clofibrate but not with cholestyramine is thus probably associated with an increased risk for development of cholesterol gallstones. It is suggested that addition of cholestyramine may be a possible way to prevent the lithogenic effect of clofibrate in patients with hyperlipoproteinaemia when not only hypocholesterolaemic but also hypotriglyceridaemic effects are wanted.