Cholestyramine Health Dictionary

An excess of fat in the blood, characterising a group of metabolic disorders. The two most important fats circulating in the blood are CHOLESTEROL and TRIGLYCERIDE. Raised blood levels of cholesterol predispose to ATHEROMA and coronary artery disease (see HEART, DISEASES OF); raised triglycerides predispose to pancreatitis (see PANCREAS, DISORDERS OF). Six types of hyperlipidaemia have been identi?ed, and diagnosis of the di?erent types depends upon blood tests to discover lipid levels. Some of the hyperlipidaemias are familial, and some are secondary to other diseases such as hypothyroidism (see THYROID GLAND, DISEASES OF), DIABETES MELLITUS, nephrotic syndrome and alcoholism.

Treatment There is evidence that therapy which lowers the lipid concentration reduces the progression of premature atheroma, particularly in those who suffer from the familial disorder. Treatment should include appropriate diets, usually food that is low in cholesterol and saturated fats. There are a number of drugs available for lowering the lipid content of the plasma, but these should be reserved for patients in whom severe hyperlipidaemia is inadequately controlled by weight reduction. Anion-exchange resins – clo?brate, beza?brate and gem?brozil, for example – and statins such as atorvastatin and simvastatin, as well as nicotinic acid, all lower plasma cholesterol and plasma triglyceride concentration through their e?ect on reducing the hepatic production of lipoproteins. Cholestyramine and colestipol, both of which are anion-exchange resins, bind bile salts in the gut and so decrease the absorption of the cholesterol that these bile salts contain – hence lowering plasma cholesterol concentrations. Probucol lowers plasma cholesterol concentrations by increasing the metabolism of low-density lipoproteins.

The statins (atorvastatin, cerivastatin, ?uvastatin, pravastatin and simvastatin) inhibit an enzyme involved in synthesising cholesterol, especially in the liver. They are more e?ective than anion-exchange resins in lowering LDL (low-density lipoprotein) cholesterol – a form of low-density cholesterol carried in the bloodstream, high levels of which are believed to be the main cause of atheroma. Statins are, however, less e?ective than the clo?brate group in reducing triglycerides and raising HDL (highdensity lipoprotein) cholesterol (high-density cholesterol).... hyperlipidaemia

(cholestyramine) n. a drug that binds with bile salts so that they are excreted (see bile-acid sequestrant). It is used to relieve conditions due to irritant effects of bile salts (such as the itching that occurs in obstructive jaundice), to treat diarrhoea, and to lower the blood levels of cholesterol and other fats in patients with hyperlipidaemia. Common side-effects include constipation, heartburn, and nausea.... colestyramine