Cholestyramine is used with diet changes (restriction of cholesterol and fat intake) to reduce the amount of cholesterol and certain fatty substances in your blood. Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats may help to prevent heart disease, angina (chest pain), strokes, and heart attacks.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

Cholestyramine comes in a chewable bar and in a powder that must be mixed with fluids or food. It usually is taken two to four times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take cholestyramine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Take this medication before a meal and/or at bedtime, and try to take any other medications at least 1 hour before or 4 hours after you take cholestyramine because cholestyramine can interfere with their absorption.

Continue to take cholestyramine even if you feel well. Do not stop taking cholestyramine without talking to your doctor. This precaution is especially important if you also take other drugs; changing your cholestyramine dose may change their effects.

Do not take the powder alone. To take the powder, follow these steps:

1. Stir the powder into a glass of water, milk, heavy or pulpy fruit juices such as orange juice, or other beverage. If you use a carbonated beverage, mix the powder slowly in a large glass to avoid excessive foaming.
2. Drink the mixture slowly.
3. Rinse the drinking glass with more of the beverage and drink it to be sure that you get all of the powder.

The powder also may be mixed with applesauce, crushed pineapple, pureed fruit, and soup. Although the powder may be mixed in hot foods, do not heat the powder. To improve the taste and for convenience, you can prepare doses for an entire day on the previous evening and refrigerate them.

To take the chewable bars, chew each bite thoroughly before swallowing.

Drink plenty of liquids while you are taking this medication.

Before taking cholestyramine,

• tell your doctor and pharmacist if you are allergic to cholestyramine or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amiodarone (Cordarone), antibiotics, anticoagulants ('blood thinners') such as warfarin (Coumadin), digitoxin, digoxin (Lanoxin), diuretics ('water pills'), iron, loperamide (Imodium), mycophenolate (Cellcept), oral diabetes medications, phenobarbital, phenylbutazone, propranolol (Inderal), thyroid medications, and vitamins.
• tell your doctor if you have or have ever had heart disease, especially angina (heart pain); stomach, intestinal, or gallbladder disease; or phenylketonuria.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cholestyramine, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking cholestyramine.

Cholestyramine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• constipation
• bloating
• stomach pain
• gas
• upset stomach
• vomiting
• diarrhea
• loss of appetite
• heartburn
• indigestion

If you experience the following symptom, call your doctor immediately:

• unusual bleeding (such as bleeding from the gums or rectum)