In addition to treatment with the statins, hypercholesterolemia is sometimes treated
with the use of nonabsorbable anion-exchange resins like cholestyramine (5.13) and
colestipol, which sequester bile acid in the intestine, excrete them, and thus increase their
synthesis in the liver by a feedback mechanism. Increased bile acid synthesis increases
cholesterol metabolism and also decreases LDL concentrations. Unfortunately, these resins
interfere with the absorption of other fats and fat-soluble vitamins (A, D, E, and K). They
HORMONES AND THEIR RECEPTORS 319