Detailed Drug Information:

DRUG CLASS AND MECHANISM: Cholestyramine is an oral medication that reduces the levels of cholesterol in the blood and improves the itching associated with liver disease.

Cholesterol that is ingested or manufactured in the body is eliminated primarily by conversion to bile acids in the liver and excretion in bile. The bile enters the intestine, and most of the bile acids are reabsorbed from the intestine. These reabsorbed bile acids are removed from the blood by the liver and excreted again into bile. Thus, bile acidsre-circulate in the body. Cholestyramine binds to bile acids in the intestine. This prevents their absorption, and the cholestyramine/bile acid complexes are eliminated in the stool.As a result, the body loses bile acids. To compensate for this loss, the liver increases the conversion of cholesterol to bile acids. The conversion of cholesterol to bileacids reduces the cholesterol in the body, and the levels of cholesterol drop in the blood.

One of the most troubling symptoms in patients with liver and biliary disease is itching. The itching is believed to be the result of accumulation of bile acids in the skin due to the inability of the liver or bile ducts to eliminate bile acids normally. By binding bile acids in the intestines and preventing their absorption, cholestyramine hastens the elimination of bile acids from the body and skin, and the itching improves.

Cholestyramine also binds some drugs in the intestine, preventing their absorption and hastening their elimination. Therefore, cholestyramine is useful in some situations in which there has been an overdose of drugs.

PREPARATIONS: Powder

STORAGE: Store at room temperature, 15-30°C (59-86°F)

PRESCRIBED FOR: Cholestyramine is used for reducing cholesterol levels in the blood, to relieve the itching of liver and biliary disease, and to treat overdoses of digoxin or thyroid hormone. Cholestyramine also is recommended for the rapid elimination of leflunomide (Arava).

DOSING: The usual dose is 4 to 8 grams once or twice a day.The maximum dose is 24 grams per day. Powder should be mixed with60 to 180 ml (2 to 6 fl oz) of water, noncarbonated beverage, pulpyfruits or soup.

DRUG INTERACTIONS: Cholestyramine decreases the absorption of warfarin (Coumadin), thyroid hormones (Synthroid, Levoxyl., Liotrix), digoxin (Lanoxin), And thiazide diuretics (Hydrodiuril, Oretic, Dyazide, Maxide). Therefore, these drugs should be administered 1 hour before or 4-6 hours after the administration of cholestyramine. Cholestyramine decreases the conversion of leflunomide (Arava) to its active form and reduces the absorption of vitamin A, D, E and K.

PREGNANCY: Use of cholestyramine in pregnant women has not been adequately evaluated. Since cholestyramine is not absorbed into the bloodstream, the risk of adverse effects on the fetus probably is low.

NURSING MOTHERS: Cholestyramine decreases the intestinal absorption ofvitamins A, D, E and K by the mother. This could lead to a decrease inthe concentration of these vitamins in the mother's milk and potentiallycause a vitamin deficiency in the infant.

SIDE EFFECTS: The most common side effects are constipation, abdominal pain, bloating, vomiting, diarrhea, weight loss, and excessive passage of gas (flatulence). Long-term use of cholestyramine may cause a deficiency of vitamin A, D, E, and K.