The three bile acid sequestrants, cholestyramine (Questran, Questran Light), colesevelam (Welchol), and colestipol (Colestid), all lower LDL cholesterol levels. They do this by preventing the intestinal absorption of substances called bile acids, which lowers blood cholesterol by increasing the conversion of cholesterol to bile acids in the liver. Bile acid sequestrants are available as powders or pills. They are typically prescribed in individuals who have elevated LDL cholesterol levels but normal triglyceride levels, because they can modestly raise triglycerides.
Benefits of Bile Acid Sequestrants
Bile acid sequestrants typically reduce LDL cholesterol by 15 to 30%. They are usually taken in combination with a statin or niacin. Research shows that these drug combinations slow the progression—and may even cause modest shrinkage—of plaques.
Side effects of Bile Acid Sequestrants
Side effects of bile acid sequestrants can include constipation, upset stomach, and gas. Intestinal obstruction is a rare but serious side effect. Call your doctor immediately if you experience severe abdominal pain. Taking a bile acid sequestrant at the proper times is important to avoid interfering with the absorption of other drugs such as beta-blockers, warfarin (Coumadin, Jantoven), and thiazide diuretics. So carefully follow your doctor’s instructions on when to take these medications.