Which drug binds bile acids in the intestine and prevents their return to the liver?

Cholestyramine is a bile acid sequestrant that works by binding to bile acids in the intestine. This binding prevents the reabsorption of bile acids into the bloodstream, which would normally return them to the liver. As a result, cholestyramine promotes the increased excretion of bile acids in the stool. The liver then compensates for the reduced bile acids by synthesizing more from cholesterol, which ultimately lowers the levels of cholesterol in the blood.

This mechanism of action is particularly useful in treating cholesterol-related conditions, as it not only helps lower LDL cholesterol levels but also improves overall lipid profiles. By effectively interrupting the enterohepatic circulation of bile acids, cholestyramine plays a critical role in managing hyperlipidemia.

The other options, while important drugs in their own right, operate via different mechanisms. Niacin and fenofibrate also help manage cholesterol levels but do so through methods like reducing liver triglyceride production or increasing HDL cholesterol levels, rather than directly binding bile acids. Fluvastatin, a statin, primarily works by inhibiting HMG-CoA reductase, which is a key enzyme in cholesterol synthesis, but it does not interact with bile acids in the way that cholestyramine does