Cholestyramine or colestyramine is a bile acid sequestrant. Bile acid sequestrants are polymeric compounds which serve as ion exchange resins. Cholestyramine resin is quite hydrophilic, but insoluble in water. (en)
Indicated as adjunctive therapy to diet for the reduction of elevated serum cholesterol in patients with primary hypercholesterolemia (elevated low density lipoprotein [LDL] cholesterol) who do not respond adequately to diet. Also for the relief of pruritus associated with partial biliary obstruction. (en)
Cholestyramine binds bile in the gastrointestinal tract to prevent its reabsorption. The resin is a strong anion exchange resin, which means that it can exchange its chloride anions with anionic bile acids in the gastrointestinal tract and bind them strongly in the resin matrix. The functional group of the anion exchange resin is a quaternary ammonium group attached to an inert styrene-divinylbenzene copolymer. (en)