Cholestyramine

From Wikipedia, the free encyclopedia

Cholestyramine (Questran®, Questran Light®, Cholybar®) is a bile acid sequestrant, which binds bile in the gastrointestinal tract to prevent its reabsorption. It increases removal of bile acids from body by forming insoluble complexes in intestine, which are then excreted in feces. When bile acids are excreted, plasma cholesterol is converted to bile acid to normalize bile acid levels. The conversion of cholesterol lowers plasma cholesterol concentrations. Bile acid sequestrants are primarily used to treat hypercholesterolemia, but can also be used to treat the pruritus, or itching, that often occurs during liver failure due to the liver's inability to eliminate bile.

Other drugs should be taken at least one hour before or four to six hours after cholestyramine to reduce possible interference with absorption.

It is also used post ileal (part of the small bowel) resection in Crohn's disease to prevent diarrhoea. This is due to the fact that the ileum is where the bile acids are reabsorbed. So when this is resected the bile acids pass into the large bowel and pull water into the bowel due to their osmotic effect thereby causing diarrhoea. Cholestyramine prevents this by making them insoluble and therefore not osmotically active.

[edit] Available forms

Cholestyramine is available as powder form, in 4 gram packets. In the United States, it can be purchased either as a generic medicine, or as Questran® or Questran Light® (Bristol-Myers Squibb).