Cholestyramine is a bile acid sequestrant used to treat certain gastrointestinal and lipid disorders. It works by binding bile acids in the gut, preventing their reabsorption, and promoting their excretion.
Indication
- Treatment of primary hypercholesterolemia
- Cholestyramine can be used in patients with bile-acid diarrhea or choleretic enteropathy due to limited ileal disease or resection
- Pruritus can occur in patients with cholestatic disease and incomplete biliary obstruction. Cholestyramine, in doses of 4 grams, one to three times daily, is effective in 80% of the cases
Mechanism
- Bile acids, metabolites of cholesterol, are normally efficiently reabsorbed in the jejunum and ileum. Excretion is increased up to tenfold when cholestyramine is given, resulting in the enhanced conversion of cholesterol to bile acids in the liver via 7a-hydroxylation, which is normally controlled by negative feedback by bile acids.