Cholestyramine in type IIa hyperlipoproteinemia. Is low-dose treatment feasible?

The present study was undertaken to evaluate the possible lipid-lowering effects of low-dose cholestyramine medication in type IIa hyperlipoproteinemia. A total of 16 patients, 8 with heterozygous familial hypercholesterolemia and 8 with polygenic hypercholesterolemia, were investigated. After an initial 3-month period of dietary treatment, 8 of the patients were randomly selected for medication with 4 g of cholestyramine twice daily, and the other 8 received a dose of 8 g twice daily for 2 months. The regimens were then exchanged, and the patients followed for a further 2 months. Plasma lipids and lipoprotein cholesterol were determined at intervals of 4 weeks. Total plasma cholesterol was reduced by 17% during treatment with 8 g and somewhat more (26%) during treatment with 16 g of cholestyramine daily. The decrease in plasma LDL cholesterol did not differ during treatment with 8 g (27%) and 16 g (31%); no changes in plasma triglycerides, VLDL- or HDL-cholesterol were seen. Although plasma LDL-cholesterol was higher in patients with familial hypercholesterolemia, there was no obvious influence of the genetic origin of hypercholesterolemia on the response. It is concluded that low-dose treatment with cholestyramine lowers, and sometimes normalizes, LDL-cholesterol in hypercholesterolemia. Furthermore, the LDL-cholesterol level obtained during the 16-g dose could be predicted from the response seen during treatment with 8 g of cholestyramine daily.