Cholestyramine Clinical data Trade names Questran AHFS/Drugs.com MedlinePlus Pregnancy cat. C(US) Legal status ? Routes gastrointestinal Pharmacokinetic data Metabolism bile acids Half-life .1 hr Excretion feces Identifiers CAS number ATC code C10 DrugBank UNII KEGG ChEMBL Chemical data Formula ? Mol. mass Average MW exceeds 106 Daltons (what is this?)
Cholestyramine or colestyramine (Questran, Questran Light, Cholybar) is a bile acid sequestrant, which binds bile in the gastrointestinal tract to prevent its reabsorption. It is a strong ion exchange resin, which means that it can exchange its chloride anions with anionic bile acids in the gastrointestinal tract and bind them strongly in the resin matrix. The functional group of the anion exchange resin is a quaternary ammonium group attached to an inert styrene-divinylbenzene copolymer.
Cholestyramine removes bile acids from the body by forming insoluble complexes with bile acids in the intestine, which are then excreted in the feces. When bile acids are excreted, plasma cholesterol is converted to bile acid to normalize bile acid levels. This conversion of cholesterol into bile acids lowers plasma cholesterol concentrations.
Bile acid sequestrants such as cholestyramine are primarily used to treat hypercholesterolemia, but can also be used to treat the pruritus, or itching, that often occurs during liver failure, due to the liver's inability to eliminate bile.
Cholestyramine is also used to prevent diarrhea in Crohn's disease patients who have undergone ileal resection. The terminal portion of the small bowel (ileum) is where bile acids are reabsorbed. When this section is removed, the bile acids pass into the large bowel and attract water due to their osmotic effect, causing diarrhea. Cholestyramine prevents this increase in water by making the bile acids insoluble and osmotically inactive. Post-ileal resection patients should use this medication cautiously, however, because bowel surgery heightens the occurrence of small-bowel obstructions, and there are several reports in the medical literature of Cholestyramine causing bowel obstructions. Cholestyramine can also be used in the treatment of Clostridium difficile infections, in order to absorb toxins A and B, and reduce the diarrhea and other symptoms that these toxins cause, however, because it is not an anti-infective it is used in concert with vancomycin.
It is also used in the "wash out" procedure in patients taking leflunomide to aid drug elimination in the case of severe side effects caused by leflunomide.
Cholestyramine is available as powder form, in 4 gram packets, or in larger canisters. In the United States, it can be purchased either as a generic medicine, or as Questran or Questran Light (Bristol-Myers Squibb).p;;ii;,u
4 to 8 grams once or twice daily, maximum dose 24 grams a day.
The following side effects have been noted.
- Most frequent: Constipation
- Seldom: tooth discoloration, tooth enamel erosion, and premature tooth decay, all from prolonged oral exposure to the suspension
- Increased risk for gallstones due to increased cholesterol concentration of bile.
Patients with hypothyroidism, diabetes, nephrotic syndrome, dysproteinemia, obstructive liver disease, kidney disease, or alcoholism should consult their doctor before taking this medication. Other drugs should be taken at least one hour before or four to six hours after cholestyramine to reduce possible interference with absorption.
The following interactions have been noted.
- Estrogens and progestins
- Oral diabetes drugs
- Penicillin G
- Thiazide-type diuretic pills
- Thyroid medication
Most interactions are due to the risk of decreased absorption of these drugs.
Duration of treatment
The duration of treatment is not limited, but the prescribing physician should reassess at regular intervals if continued treatment is still necessary.
Principal overdose risk is blockage of intestine or stomach.
Cholestyramine also bonds to mold fungi in the human body, and is taken by some mold remediation workers.
A 5% compound with Aquaphor can be applied as a topical diaper rash ointment for infants and toddlers.
Cholestyramine is used by Complementary and Alternative medical physicians to treat "sick building syndrome" mold exposure. (Shoemaker, Ritchie C. Mold Warriors)
- The Merck Index (12 ed.). p. 2257.
- The Merck Index (12 ed.). p. 2257.
Lipid modifying agents (C10) GI tractEzetimibe • SCH-48461 Liver Blood vesselsCETP inhibitors (HDL) Combinations Other
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