Colestipol Disease Interactions

The use of bile acid sequestrants is contraindicated in patients with complete biliary obstruction where bile is not secreted into the intestine. These agents adsorb and combine with bile acids in the intestine to form an insoluble complex that is excreted in the feces, resulting in partial removal of bile acids from the enterohepatic circulation. Bile acid sequestrants are ineffective if bile does not reach the intestine.

The use of bile acid sequestrants may produce or worsen preexisting constipation. Constipation associated with these agents may aggravate hemorrhoids. Therapy with bile acid sequestrants should be administered cautiously in patients with preexisting constipation, hemorrhoids, or symptomatic coronary artery disease. The dosage should be increased very gradually according to manufacturer guidelines to minimize the risk of fecal impaction, and patients should be encouraged to increase fluid and fiber intake. Occasional use of a stool softener may also be indicated. If constipation worsens or develops during therapy, or the desired therapeutic response is not achieved at the maximum recommended daily dosage, combination therapy or an alternative agent should be considered.

Bile acid sequestrants are chloride forms of anion exchange resins and may produce hyperchloremic acidosis with chronic use. Therapy with bile acid sequestrants should be administered cautiously in patients who may be particularly susceptible, including children or smaller patients and patients with renal impairment or volume depletion.

Questran Light and LoCholest Light (brands of cholestyramine) contain 16.8 mg and 22.4 mg of phenylalanine, respectively, per each dose. Flavored Colestid (brand of colestipol) contains 18.2 mg of phenylalanine per each 7.5-gram dose. WELCHOL (brand name of colesevelam) for Oral Suspension contains 13.5 mg phenylalanine per 1.875 gram dose and 27 mg phenylalanine per 3.75 gram dose. The phenylalanine content should be considered when these products are used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics). Regular Colestid, Questran and LoCholest do not contain phenylalanine.

Bile acid sequestrants may interfere with the absorption of folic acid and fat soluble vitamins such as A, D, and K. Chronic use of bile acid sequestrants may cause increased bleeding tendency due to hypoprothrombinemia associated with vitamin K deficiency. Anemia may also occur due to reduced serum or red blood cell folate. Supplementation with oral vitamins and/or folate should be considered during prolonged therapy with bile acid sequestrants, particularly in patients with preexisting vitamin and/or folate deficiencies, anemia, or a bleeding diathesis.