Indications
Cholestyramine (colestyramine) is a powder taken by mouth that is used to:
- Lower high LDL (“bad”) cholesterol, alongside diet, when other treatments are not suitable or need support
- Relieve itching caused by partial blockage of the bile ducts, such as in some liver diseases
- Treat diarrhoea caused by bile acids, for example after removal of part of the small intestine (ileum) or after gallbladder surgery
How It Works
Cholestyramine is a resin that is not absorbed into the body. In the gut it binds to bile acids and carries them out in the stool. The liver then uses cholesterol from the blood to make new bile acids, which lowers blood cholesterol. Removing bile acids also reduces the itching and diarrhoea they can cause.
Dosage and Administration
Each sachet usually contains 4 g of cholestyramine. For high cholesterol, adults usually start with 4 g once or twice daily, increasing gradually as advised by the doctor to a usual 12 to 24 g a day in divided doses. For itching or bile acid diarrhoea, 4 to 8 g a day is often enough. Never take the powder dry: mix each dose with at least 150 ml of water, fruit juice or a thin soup, stir well and drink straight away, rinsing the glass to take all of it. Children: only as directed by a doctor.
Interactions
Cholestyramine can bind to many medicines and stop them being absorbed. Take other medicines at least 1 hour before or 4 to 6 hours after cholestyramine. This is especially important for Warfarin, Digoxin, Levothyroxine, thiazide diuretics, Propranolol, oral contraceptives, Mycophenolate, Valproate, some antibiotics, and fat-soluble vitamins A, D, E and K. Your doctor may adjust other doses when starting or stopping it.
Contraindications
Do not take cholestyramine if you have complete blockage of the bile ducts (no bile reaching the gut), or are allergic to it. It is not suitable for people with phenylketonuria if the product contains aspartame; check the label.
Side Effects
Common side effects include:
- Constipation, which may be severe
- Bloating, wind, heartburn, nausea and stomach discomfort
- Diarrhoea in some people
Long-term use can lower levels of vitamins A, D, E, K and folic acid, which may lead to easy bleeding or weak bones. It may raise blood triglycerides. In children and people with kidney problems, it can make the blood too acidic.
Get urgent medical help if you have severe abdominal pain or swelling with no bowel movement, vomiting, black or bloody stools, unusual bleeding or bruising, or signs of a serious allergic reaction.
Pregnancy and Lactation
Cholestyramine is not absorbed into the body, but it may reduce absorption of vitamins the baby needs. It may be used in pregnancy and breastfeeding if the doctor advises, often with vitamin supplements.
Precautions and Warnings
Drink plenty of fluids and eat fibre to reduce constipation; tell your doctor if constipation is a problem, especially if you have haemorrhoids or heart disease. Your doctor may check cholesterol, triglycerides and vitamin levels. Some flavoured products contain sugar or sweeteners; tell your doctor if you have diabetes or phenylketonuria.
Overdose
Overdose is unlikely to be absorbed, but it may block the bowel. Seek medical help if a large amount is taken and abdominal pain, vomiting or inability to pass stools develops.
Therapeutic Class
Lipid-lowering agent; bile acid sequestrant.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Keep sachets sealed until use.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.