cholestyramine (Questran)

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 into the intestine with 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 acids re-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 bile acids 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 in some cases 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. The FDA approved cholestyramine in August 1973.

Prevalite, Questran, Questran Light

GENERIC AVAILABLE: Yes

Yes

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 (Lanoxin), or thyroid hormone. Cholestyramine also is recommended for the rapid elimination of leflunomide (Arava).

The most common side effects of cholestyramine are:

• constipation,
• abdominal pain,
• bloating,
• vomiting,
• diarrhea,
• belching,
• gallstones,
• weight loss, and
• excessive passage of gas (flatulence).

Other side effects include:

• discolored tooth,
• gastric ulcer, and
• gastrointestinal bleeding.

Long-term use of cholestyramine may cause a deficiency of vitamin A, D, E, and K. Constipation can be an important side effect of cholestyramine, perhaps because the presence of free bile acids in the intestine helps determine the amount of water in stool, and cholestyramine binds the free bile acids. It is recommended that additional fluids be drunk when taking cholestyramine; however, it is not known for certain if this prevents constipation, and more aggressive treatment with fiber, stool softeners or even laxatives such as milk of magnesia may be necessary.

The usual dose for reducing cholesterol is 4 to 8 grams once or twice a day. The maximum dose is 24 grams per day. Powder should be mixed with 60 to 180 ml (2 to 6 fl oz) of water, noncarbonated beverage, pulpy fruits or soup.

Cholestyramine decreases the absorption of warfarin (Coumadin, Jantoven), thyroid hormones (levothyroxine sodium [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.

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.

Cholestyramine decreases the intestinal absorption of vitamins A, D, E and K by the mother. This could lead to a decrease in the concentration of these vitamins in the mother's milk and potentially cause vitamin deficiency in the infant.

What preparations of cholestyramine are available?

Powder (Resin): 4 grams (Packet or Scoopful)

How should I keep cholestyramine stored?

Cholestyramine should be stored at room temperature, 15 C - 30 C (59 F - 86 F)