Cholestyramine is a prescription medication that is primarily given to reduce cholesterol levels in the blood. It is supplied as a powder that is dissolved in liquid and taken orally. The medication is a resin that binds bile acids in the intestine and carries these acids out of the body. Bile acids, which are necessary for digestion, are made from cholesterol that is produced by the liver. If bile acids are depleted from the intestines, more cholesterol must be converted to bile acids, thereby depleting cholesterol from the bloodstream.
Patients with elevated cholesterol levels are at risk of developing atherosclerosis, which is an accumulation of plaque along the walls of the arteries. Atherosclerosis can increase the risk of heart disease or stroke. Cholesterol is an essential fat that functions to allow nutrients to pass through the cell membrane. It is both ingested during meals and manufactured by the liver. If blood cholesterol levels are elevated, patients may be advised to adopt a low cholesterol diet or begin taking cholesterol lowering medication.
Cholesterol must be bound to proteins that can carry it through the bloodstream. Known as lipoproteins, these molecules are made in either a low-density or a high-density form. Low-density lipoproteins transport cholesterol to the cell, and these contribute to the buildup of cholesterol in the arteries. Maintaining normal levels of low-density lipoproteins is generally considered important in reducing the risk of atherosclerosis. Low-density lipoproteins are the target of the medication cholestyramine.
Cholestyramine acts by binding to bile acids in the intestine and trapping them so they are then excreted in the feces. This medication does not enter the bloodstream and should not interact with other systemic medications. Bile acids are produced from cholesterol in the liver and are transported to the gall bladder. They are stored in the gall bladder until they are needed for digestion.
When cholestyramine reaches the intestine it binds to the bile acids and removes them. This causes the liver to convert more of the low-density lipoproteins to bile acids, thereby lowering levels of low-density lipoproteins that are circulating in the bloodstream. Patients suffering from liver diseases that lead to a build-up of bile may also benefit from treatment with cholestyramine.
Cholestyramine is supplied as an off-white powder in either pouches or canisters. The recommended dose of powder must be dissolved in a liquid and ingested orally. Accepted liquids to mix with cholestyramine are water, fruit juice or even soup. Side effects of taking this medication include constipation and bloating.