What is the primary mechanism of action for bile acid sequestrants?

Bile acid sequestrants primarily work by preventing the reabsorption of bile acids in the intestines. When these agents bind to bile acids in the gastrointestinal tract, they create an insoluble complex that is not reabsorbed. Consequently, since bile acids are derived from cholesterol, this binding leads to a reduction in the enterohepatic circulation of bile acids, forcing the liver to convert more cholesterol into bile acids to replace those lost. As a result, there is a decrease in the overall levels of cholesterol in the bloodstream.

This action distinctively contributes to lowering low-density lipoprotein (LDL) cholesterol levels, making bile acid sequestrants effective in cholesterol management. Other mechanisms of lipid-lowering agents do not apply to bile acid sequestrants, as they do not directly inhibit cholesterol absorption, increase lipoprotein lipase activity, or inhibit HMG-CoA reductase, which are mechanisms attributed to different classes of lipid-lowering drugs. Therefore, the mechanism of bile acid sequestrants is specifically linked to their ability to prevent the reabsorption of bile acids.