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Medicines for inflammatory bowel disease (IBD) have two jobs: to settle the inflammation when the disease is active (inducing remission) and to keep it quiet afterwards (maintaining remission). Some medicines do one job, some do both. Your IBD team will choose a treatment according to which part of the gut is affected, how severe the disease is, how you have responded to treatment in the past, and your own preferences.
For many people with Crohn's disease (CD), diet is an effective alternative or addition to medicines. See Should I go for drugs or diet? and Nutritional Therapy.
Aminosalicylates (5-ASAs)
Mesalazine (Asacol, Octasa, Pentasa, Salofalk and others) and the older sulfasalazine are the first-line treatment for mild to moderate ulcerative colitis (UC). They come as tablets or granules, and as suppositories, liquid or foam enemas for disease in the rectum and lower colon. They are taken long term to keep UC in remission and they also reduce the long-term risk of bowel cancer. They are less useful in CD.
Steroids
Steroids such as prednisolone, budesonide and hydrocortisone are used to settle a flare-up quickly. They are given as a course, usually over about 8 weeks with the dose gradually reduced, and are not used to keep IBD in remission because of their side effects with long-term use, which include thinning of the bones, weight gain, raised blood sugar and mood changes. Budesonide acts mainly in the gut and causes fewer side effects. If you need more than one course of steroids a year, your IBD team will usually suggest a longer-term treatment.
Immunosuppressants
Azathioprine, mercaptopurine and methotrexate damp down the immune response. They take two to three months to work, so they are used to keep IBD in remission and to reduce the need for steroids rather than to treat a sudden flare-up. They need regular blood tests. They are sometimes given together with a biologic medicine to make it work better and for longer.
Biologic medicines
Biologics are proteins made in the laboratory that block a particular part of the inflammation process. They are given by drip (infusion) in hospital or by injection at home.
- Anti-TNF medicines: infliximab and adalimumab, used for both CD and UC, and golimumab for UC. Most are now prescribed as biosimilars, which are equally effective, lower-cost versions of the original medicine.
- Vedolizumab: acts only on the gut, so it has little effect on the immune system elsewhere in the body.
- Ustekinumab and the newer risankizumab, mirikizumab and guselkumab: block chemical messengers called interleukins.
Before starting a biologic you will be checked for infections such as tuberculosis and hepatitis.
Tablet treatments (small molecules)
Newer medicines taken by mouth include the JAK inhibitors (tofacitinib, filgotinib and upadacitinib) and ozanimod and etrasimod. Most are used for UC, and upadacitinib is also used for CD. They work quickly and are usually offered when other treatments have not worked or are not suitable.
Other medicines
- Antibiotics, such as metronidazole and ciprofloxacin, for perianal Crohn's disease, abscesses and pouchitis.
- Anti-diarrhoeal medicines, such as loperamide, for diarrhoea when the disease is not active.
- Bile acid binders, such as colestyramine, for diarrhoea after part of the small intestine has been removed.
- Iron, vitamin B12, calcium and vitamin D to correct deficiencies.
A–Z of medicines
Individual medicines, including their doses, precautions and side effects, are listed in our Drug Treatment A–Z. We are adding a full page for each of the main medicines, starting with azathioprine.
Important
Never stop or change a medicine without talking to your IBD team first, even if you feel well. Stopping suddenly can cause a flare-up, and steroids in particular must be reduced gradually. If you think you are having side effects, contact your IBD nurse or GP.