Which lipid-lowering agent works by binding bile acids in the intestine?

Cholestyramine is a bile acid sequestrant that functions by binding to bile acids in the intestine. This binding prevents the reabsorption of bile acids into the bloodstream, leading to a reduction in the overall bile acid pool. As a result, the liver is prompted to convert more cholesterol into bile acids to replenish the bile acid pool. This process decreases the levels of circulating LDL (low-density lipoprotein) cholesterol, thereby lowering overall cholesterol levels in the blood.

The mechanism of action of cholestyramine is distinct from other lipid-lowering agents. Atorvastatin is a statin that works primarily by inhibiting HMG-CoA reductase, thereby reducing cholesterol synthesis in the liver. Niacin primarily acts by inhibiting the mobilization of free fatty acids from adipose tissue, which decreases hepatic triglyceride synthesis and subsequently reduces LDL levels. Fenofibrate, a fibrate, activates peroxisome proliferator-activated receptors (PPARs), which enhances the oxidation of fatty acids and lowers triglyceride levels.

Due to its unique mechanism of action, cholestyramine effectively decreases LDL cholesterol through a different pathway compared to the other agents listed.