BMA Concise Guide to Medicine & Drugs

Colestyramine

Brand names Questran, Questran Light

Used in the following combined preparations None

QUICK REFERENCE

Drug group Lipid-lowering drug

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Colestyramine is a resin that binds bile acids in the intestine, preventing their reabsorption. Cholesterol in the body is normally converted to bile acids. Therefore, colestyramine reduces cholesterol levels in the blood. This action on the bile acids makes bowel movements bulkier, creating an antidiarrhoeal effect (hence its use in diarrhoea associated with, for example, Crohn’s disease, removal of part of the intestine, or radiotherapy). Colestyramine is used to treat hyperlipidaemia (high levels of fat in the blood) in people who have not responded to dietary changes. In liver disorders such as primary biliary cirrhosis, bile salts sometimes accumulate in the bloodstream, and colestyramine may be prescribed to alleviate any accompanying itching.

Taken in large doses, colestyramine often causes bloating, mild nausea, and constipation. It may also interfere with the body’s ability to absorb fat and certain fat-soluble vitamins, causing pale, bulky, foul-smelling faeces.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Powder mixed with water, juice, or soft food.

Frequency and timing of doses 1–6 x daily before meals and at bedtime.

Adult dosage range 4–36g daily.

Onset of effect May take several weeks to achieve full beneficial effects.

Duration of action 12–24 hours.

Diet advice A low-fat, low-calorie diet may be advised for patients who are overweight. Use of this drug may deplete levels of certain vitamins. Supplements may be advised.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember.

Stopping the drug Do not stop taking the drug without consulting your doctor.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Adverse effects are more likely in people over 60 who take large doses. Minor side effects, such as indigestion, abdominal discomfort, constipation, nausea, and vomiting, are rarely a cause for concern. High doses may cause diarrhoea. More serious adverse effects, such as bruising or increased bleeding, are usually the result of vitamin deficiency; if they occur, consult your doctor.

INTERACTIONS

General note Colestyramine reduces the body’s ability to absorb other drugs. If you are taking other medicines, you should tell either your doctor or pharmacist so that they can discuss with you the best way to take all your drugs. To avoid any problems, take other drugs at least 1 hour before, or 4–6 hours after, colestyramine. The dosage of other drugs may need to be adjusted.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have jaundice.

· You have a peptic ulcer.

· You have diabetes.

· You suffer from haemorrhoids.

· You are taking other medicines.

Pregnancy Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding Safety not established. The drug binds fat-soluble vitamins long term and may cause vitamin deficiency in the baby. Discuss with your doctor.

Infants and children Not recommended under 6 years. Reduced dose necessary in older children.

Over 60 Increased likelihood of adverse effects.

Driving and hazardous work No special problems.

Alcohol Although this drug does not interact with alcohol, your underlying condition may make it inadvisable to take alcohol.

PROLONGED USE

As this drug reduces vitamin absorption, supplements of vitamins A, D, and K and folic acid may be advised.

Monitoring Periodic blood checks are usually required to monitor the level of cholesterol in the blood.