Cholestyramine

A resin that works inside the gut

Cholestyramine, spelled colestyramine on UK labels, is a resin that is never absorbed into the blood. It passes through the intestines and binds bile acids — the substances the liver makes from cholesterol to digest fat in food. Locked onto the resin, they leave the body in stool instead of being taken back up. The liver then pulls cholesterol out of the blood to build more bile acids, and blood cholesterol falls.

That is how it lowers cholesterol in hypercholesterolaemia (high cholesterol in the blood) when diet and other measures have not done enough, and how it eases itching caused by partial blockage of the bile ducts or by primary biliary cirrhosis (a long-term liver condition). It is also used for diarrhoea after part of the small bowel has been removed, or in Crohn's disease, where bile acids are not reabsorbed as they should be. When the bile ducts are completely blocked there are no bile acids for the resin to bind, so it is not used then.

The cholestyramine on sale here

Questran is the cholestyramine sold here: 4g sachets of powder for oral suspension, one sachet per dose, mixed into a drink. It sits in the shop's cholesterol range.

Mixing and taking a sachet

Empty the powder into a glass of water, milk or fruit juice, stir, and drink it. The resin does not dissolve; it settles within seconds, so stir again as you go and rinse the glass with a splash more liquid to get the last of it. Swallowing the powder dry is not the way to take it. Most people have a sachet once or twice a day with a meal, and some take it up to four times a day.

Other medicines need spacing from it. Take them at least an hour before a sachet, or leave four to six hours after one — cholestyramine binds a long list of drugs in the gut, including thyroid tablets, warfarin, digoxin and some antibiotics, and stops them being absorbed properly.

Side effects

Constipation is the one most people run into, and it can be stubborn. Bloating, wind, nausea, heartburn, stomach pain and diarrhoea also get reported. Severe stomach pain with vomiting and no bowel movement may mean a blockage, and that needs urgent treatment. Unusual bruising or bleeding needs urgent attention, because the resin can lower how much vitamin K the body takes in.

Long use and storage

Cholestyramine is often taken for years, and blood tests are how the effect on cholesterol is tracked rather than how you feel. Keep the sachets in their box somewhere dry and out of the sun, and mix each dose fresh — a jug left standing will settle and cake.