Colestyramine removes bile acids from the body by forming insoluble complexes with bile acids in the intestine, which are then excreted in the feces.[1] As a result of this loss of bile acids, more plasmacholesterol is converted to bile acids in the liver to normalise levels.[1] This conversion of cholesterol into bile acids lowers plasma cholesterol levels.[1]
Medical uses
Bile acid sequestrants such as colestyramine were first used to treat hypercholesterolemia, but since the introduction of statins, now have only a minor role for this indication. They can also be used to treat the pruritus, or itching, that often occurs during liver failure and other types of cholestasis where the ability to eliminate bile acids is reduced.[citation needed]
Colestyramine is commonly used to treat diarrhea resulting from bile acid malabsorption.[2] It was first used for this in Crohn's disease patients who had undergone ileal resection.[3] 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 cause diarrhea due to stimulation of chloride/fluid secretion by the colonocytes resulting in a secretory diarrhea. Colestyramine prevents this increase in water by making the bile acids insoluble and osmotically inactive.
Colestyramine is also used in the control of other types of bile acid diarrhea. The primary, idiopathic form of bile acid diarrhea is a common cause of chronic functional diarrhea, often misdiagnosed as diarrhea-predominant irritable bowel syndrome (IBS-D), and most of these patients respond to colestyramine.[4] It is beneficial in the treatment of postcholecystectomy syndrome chronic diarrhea.[5][6] Colestyramine is also useful in treating post-vagotomy diarrhea.[7][8]
Colestyramine can be helpful in the treatment of Clostridium difficile infections, to absorb toxins A and B, and reduce the diarrhea and the other symptoms these toxins cause. However, because it is not an anti-infective, it is used in concert with vancomycin.[9]
It is also used in the "wash out" procedure in patients taking leflunomide or teriflunomide to aid drug elimination in the case of drug discontinuation due to severe side effects caused by leflunomide or teriflunomide.[10]
Ointments containing colestyramine compounded with Aquaphor have been used in topical treatment of diaper rash in infants and toddlers.[12]
Cholestyramine also binds with oxalate in the GI tract, ultimately reducing urine oxalate and calcium oxalate stone formation.[13]
Available forms
Colestyramine is available as powder form, in 4-g 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).
Dosage
A typical dose is 4 to 8 g once or twice daily, with a maximum dose of 24 g/d.
Intestinal obstruction has been reported in patients with previous bowel surgery who should use colestyramine cautiously.[16][17] Cholestyramine-induced hyperchloremic metabolic acidosis has also been reported rarely.[18]
Patients with hypothyroidism, diabetes, nephrotic syndrome, dysproteinemia, obstructive liver disease, kidney disease, or alcoholism should consult their doctor before taking this medication.[14] Other drugs should be taken at least one hour before or four to six hours after colestyramine to reduce possible interference with absorption. Patients with phenylketonuria should consult with a physician before taking Questran Light because that product contains phenylalanine.
Drug interactions
Interactions with these drugs have been noted:[14]
Most interactions are due to the risk of decreased absorption of these drugs.[17] The duration of treatment is not limited, but the prescribing physician should reassess at regular intervals if continued treatment is still necessary. The principal overdose risk is blockage of intestine or stomach.
Colestyramine may interfere in the absorption of fat-soluble vitamins such as vitamins A, D, E, and K. No special considerations regarding alcohol consumption are made.[14]
Notes and references
The Merck Index (12ed.). p.2257.
1 2 3 "Cholestyramine". LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases. September 2017. PMID31643750. NBK548431. Retrieved 22 June 2016.
↑ Hofmann AF, Poley JR (August 1969). "Cholestyramine treatment of diarrhea associated with ileal resection". The New England Journal of Medicine. 281 (8): 397–402. doi:10.1056/NEJM196908212810801. PMID4894463.
↑ Sciarretta G, Furno A, Mazzoni M, Malaguti P (December 1992). "Post-cholecystectomy diarrhea: evidence of bile acid malabsorption assessed by SeHCAT test". The American Journal of Gastroenterology. 87 (12): 1852–1854. PMID1449156.
↑ Danley T, St Anna L (October 2011). "Clinical inquiry. Postcholecystectomy diarrhea: what relieves it?". The Journal of Family Practice. 60 (10): 632c–632d. PMID21977493.
↑ George JD, Magowan J (July 1971). "Diarrhea after total and selective vagotomy". The American Journal of Digestive Diseases. 16 (7): 635–640. doi:10.1007/BF02239223. PMID5563217. S2CID45276562.
↑ Gorbashko AI (March 1992). "[The pathogenesis, diagnosis and treatment of postvagotomy diarrhea]". Vestnik Khirurgii Imeni I. I. Grekova. 148 (3): 254–262. PMID8594740.
↑ Wong SP, Chu CM, Kan CH, Tsui HS, Ng WL (December 2009). "Successful treatment of leflunomide-induced acute pneumonitis with cholestyramine wash-out therapy". Journal of Clinical Rheumatology. 15 (8): 389–392. doi:10.1097/RHU.0b013e3181c3f87e. PMID19955995.
↑ White CM, Gailey RA, Lippe S (September 1996). "Cholestyramine ointment to treat buttocks rash and anal excoriation in an infant". The Annals of Pharmacotherapy. 30 (9): 954–956. doi:10.1177/106002809603000907. PMID8876854. S2CID19929362.
1 2 Jacobson TA, Armani A, McKenney JM, Guyton JR (March 2007). "Safety considerations with gastrointestinally active lipid-lowering drugs". The American Journal of Cardiology. 99 (6A): 47C–55C. doi:10.1016/j.amjcard.2006.11.022. PMID17368279.
Diarrhea, also spelled diarrhoea or diarrhœa, is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively breastfed, however, are normal.
A gallstone is a stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to the presence of migrated gallstones within bile ducts.
The bile acid sequestrants are a group of resins used to bind certain components of bile in the gastrointestinal tract. They disrupt the enterohepatic circulation of bile acids by combining with bile constituents and preventing their reabsorption from the gut. In general, they are classified as hypolipidemic agents, although they may be used for purposes other than lowering cholesterol. They are used in the treatment of chronic diarrhea due to bile acid malabsorption.
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety of anaemias.
Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, gallbladder, and pancreas.
Small intestinal bacterial overgrowth (SIBO), also termed bacterial overgrowth, or small bowel bacterial overgrowth syndrome (SBBOS), is a disorder of excessive bacterial growth in the small intestine. Unlike the colon, which is rich with bacteria, the small bowel usually has fewer than 100,000 organisms per millilitre. Patients with bacterial overgrowth typically develop symptoms which may include nausea, bloating, vomiting, diarrhea, malnutrition, weight loss and malabsorption, which is caused by a number of mechanisms.
Short bowel syndrome is a rare malabsorption disorder caused by a lack of functional small intestine. The primary symptom is diarrhea, which can result in dehydration, malnutrition, and weight loss. Other symptoms may include bloating, heartburn, feeling tired, lactose intolerance, and foul-smelling stool. Complications can include anemia and kidney stones.
Chenodeoxycholic acid is a bile acid. Salts of this carboxylic acid are called chenodeoxycholates. Chenodeoxycholic acid is one of the main bile acids. It was first isolated from the bile of the domestic goose, which gives it the "cheno" portion of its name.
Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts.
Fenofibrate, is an oral medication of the fibrate class used to treat abnormal blood lipid levels. It is less commonly used compared than statins because it treats a different type of cholesterol abnormality to statins. While statins have strong evidence for reducing heart disease and death, there is evidence to suggest that fenofibrate also reduces the risk of heart disease and death. However, this seems only to apply to specific populations of people with elevated triglyceride levels and reduced high-density lipoprotein (HDL) cholesterol. Its use is recommended together with dietary changes.
Rifaximin, is a non-absorbable, broad spectrum antibiotic mainly used to treat travelers' diarrhea. It is based on the rifamycin antibiotics family. Since its approval in Italy in 1987, it has been licensed in over more than 30 countries for the treatment of a variety of gastrointestinal diseases like irritable bowel syndrome, and hepatic encephalopathy. It acts by inhibiting RNA synthesis in susceptible bacteria by binding to the RNA polymerase enzyme. This binding blocks translocation, which stops transcription. It is marketed under the brand name Xifaxan by Salix Pharmaceuticals.
Progressive familial intrahepatic cholestasis (PFIC) is a group of familial cholestatic conditions caused by defects in biliary epithelial transporters. The clinical presentation usually occurs first in childhood with progressive cholestasis. This usually leads to failure to thrive, cirrhosis, and the need for liver transplantation.
Postcholecystectomy syndrome (PCS) describes the presence of abdominal symptoms after a cholecystectomy.
Radiation enteropathy is a syndrome that may develop following abdominal or pelvic radiation therapy for cancer. Many affected people are cancer survivors who had treatment for cervical cancer or prostate cancer; it has also been termed pelvic radiation disease with radiation proctitis being one of the principal features.
Colesevelam is a bile acid sequestrant administered orally. It was developed by GelTex Pharmaceuticals and later acquired by Genzyme. It is marketed in the U.S. by Daiichi Sankyo under the brand name Welchol and elsewhere by Genzyme as Cholestagel. In Canada, it is marketed by Valeant as Lodalis.
Colestipol is a bile acid sequestrant used to lower blood cholesterol, specifically low-density lipoprotein (LDL). It is also used to reduce stool volume and frequency, and in the treatment of chronic diarrhea.
Jejunoileal bypass (JIB) was a surgical weight-loss procedure performed for the relief of morbid obesity from the 1950s through the 1970s in which all but 30 cm (12 in) to 45 cm (18 in) of the small bowel were detached and set to the side.
SeHCAT is a drug used in a clinical test to diagnose bile acid malabsorption.
Bile acid malabsorption (BAM), known also as bile acid diarrhea, is a cause of several gut-related problems, the main one being chronic diarrhea. It has also been called bile acid-induced diarrhea, cholerheic or choleretic enteropathy, bile salt diarrhea or bile salt malabsorption. It can result from malabsorption secondary to gastrointestinal disease, or be a primary disorder, associated with excessive bile acid production. Treatment with bile acid sequestrants is often effective. It is recognised as a disability in the United Kingdom under the Equality Act 2010
7α-Hydroxy-4-cholesten-3-one is an intermediate in the biochemical synthesis of bile acids from cholesterol. Its precursor, 7α-hydroxycholesterol, is produced from cholesterol by hepatic cholesterol 7α-hydroxylase (CYP7A1).
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
(what is this?) (verify) 
