A comparison of cholestyramine and probucol in the treatment of familial hypercholesterolaemia.

Twelve patients with familial hypercholesterolaemia (FH) who had not achieved satisfactory cholesterol levels on dietary advice alone were treated with cholestyramine for 6 months and probucol for 6 months in a randomised cross-over study to compare the relative effectiveness of the two drugs. Over the 6-month period, mean total cholesterol fell by 16.4% on cholestyramine and 12.7% on probucol. Cholestyramine produced a 17.4% fall in low density lipoprotein (LDL) cholesterol, no significant changes in very low density lipoprotein (VLDL) cholesterol or high density lipoprotein (HDL) cholesterol, a 21.4% increase in HDL cholesterol subfraction HDL2 and a 24.1% increase in the HDL/LDL cholesterol ratio. Triglyceride levels rose by 29.6% but remained within the normal range. Probucol produced a 11.7% fall in LDL cholesterol, a 9.9% fall in VLDL cholesterol, a 10% fall in total HDL cholesterol, a 37% fall in HDL cholesterol subfraction HDL2 and no change in the HDL/LDL cholesterol ratio. Triglyceride levels fell by 14%. The mean corrected QT interval increased from 0.418 to 0.434 s (P less than 0.01) on probucol but did not change significantly on cholestyramine (from 0.405 to 0.41 s). The two drugs have different metabolic effects on FH. Cholestyramine has a more marked effect on LDL cholesterol, favourably influences the HDL/LDL cholesterol ratio and is therefore considered to be the drug of choice.