Also indexed as: Cholestyramine, Prevalite, Questran
Cholestyramine (Questran®) and colestipol (Colestid®) are bile acid sequestrants—a class of drugs that binds bile acids, prevents their reabsorption from the digestive system, and reduces cholesterol levels. Cholestyramine and colestipol are two of many drugs used to lower cholesterol levels in people with high cholesterol.
Bile acids are produced in the liver from cholesterol and secreted into the small intestine to help with the absorption of dietary fat and cholesterol. Bile acid sequestrants bind bile acids in the small intestine and carry them out of the body. This causes the body to use more cholesterol to make more bile acids, which are secreted into the small intestine, bound to bile acid sequestrants, and carried out of the body. The end result is lower cholesterol levels. Bile acid sequestrants also prevent absorption of some dietary cholesterol.
The information in this article pertains to bile acid sequestrants in general. The interactions reported here may not apply to all the Also Indexed As terms. Talk to your doctor or pharmacist if you are taking any of these drugs.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May Be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
Beta-carotene and other carotenoids Calcium* Folic acid Vitamin A Vitamin D Vitamin E Vitamin K Zinc* |
| Side effect reduction/prevention |
None known |
| Supportive interaction |
None known |
| Reduced drug absorption/bioavailability |
None known |
| Adverse interaction |
None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Vitamins and Minerals
Bile acid sequestrants may prevent absorption of
folic acid and the fat-soluble vitamins A,
D, E, and
K.1 2 Other medications and vitamin supplements should be taken one
hour before or four to six hours after bile acid sequestrants for optimal
absorption.3 Animal studies suggest
calcium and zinc may also be depleted by
taking cholestyramine.4
Carotenoids
Use of colestipol for six months has been shown to significantly lower blood levels of
carotenoids including
beta-carotene.5
Interactions with Foods and Other Compounds
Food
Bile acid sequestrants should be taken with plenty of water before meals.6
1. Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997, 221–2 [review].
2. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i–l.
3. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i–l.
4. Watkins DW, Cassidy MM, Khalafi R, Vahouny GV. Calcium and zinc balances in rats chronically fed the bile salt-sequestrant cholestyramine (Questran). Fed Proc 1983;42:819.
5. Probstfield JL, Lin T, Peters J, Hunninghake DB. Carotenoids and vitamin A: The effect of hypocholesterolemic agents on serum levels. Metabolism 1985;34:88–91.
6. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, Bile Acid Sequestrants. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1997, 171i–l.