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Drugs used in IBD

Why do some drugs have several names?

Generic and brand names

Every drug has an approved generic or medical name, decided on by an expert committee. Many drugs are also known by a brand or trade name chosen by the pharmaceutical company making and selling that drug as a medicine. So, for example, the drug mesalazine (generic name) is also known as Octasa (brand name).Some drugs are sold in a generic form as well as in a branded form. If several companies market a drug, it will have several different brand names.

Does it matter which I have?

Medicines usually contain inactive ingredients as well as the main active ingredient, the generic drug. These help to formulate the medicine, that is, to make it into its tablet, cream or liquid form. They can also be used, for example, to give tablets a particular colour or affect how long the tablets take to dissolve in the gut.Usually, for most prescription medicines, such small differences are unlikely to create any problems. Whether you are prescribed the branded medicine or a generic version of a drug, provided your dose contains the same amount of active ingredient your medicine should have the same therapeutic effect.However, for a very small number of drugs, the differences in formulation may be more significant. For example, some of the different brands of mesalazine work in a slightly different way. For this reason your doctor may decide to prescribe a particular brand rather than the generic version. 

Why do drugs come in different forms?

This is so that they can be taken in the way that helps them to work most effectively. This is usually orally (by mouth) but may be topically (applied directly) or by injection. Which way is best will depend partly on the area of the gut affected by your IBD and partly on the nature of the drug itself.

Oral Drugs

Most of the drugs used for IBD have a tablet, capsule or granule form, so can be taken by mouth. Many people with IBD find this a convenient way to take their medication and it is easy for a doctor to change dosage levels if necessary. However, anything taken by mouth will start to dissolve very quickly, so many of the tablets and capsules have a special ’gastro-resistant’ coating. This makes sure the drug is released in the right part of the digestive system – usually the small intestine (small bowel) or large intestine (colon). This is why it can be important to swallow tablets or capsules whole and not to break or crush them.

Topical treatment

Taking a drug topically means applying it directly to the affected part of the body. This can mean that the drug works more efficiently. Another advantage can be that other parts of the body are not so readily affected by the drug, and this can reduce possible side effects.In IBD, topical treatment is usually most appropriate when the inflammation is in the rectum (a condition often known as proctitis) or near the end of the colon. 

One way of delivering topical treatment to inflammation in these areas is to use a suppository. This is a small bullet-shaped capsule of the drug in a waxy like substance that will dissolve at body temperature. The suppository is inserted directly through the anus (back passage) into the rectum. As it dissolves, it releases the drugs in exactly the right area. 

Another way of getting a drug directly into the rectum and colon is to take it as an enema – in a liquid or foam form, put into the rectum through the anus using a specially designed applicator. Foam enemas are often easier to retain than liquid enemas so can be particularly useful at the beginning of a flare-up, when the gut is most sensitive. Liquid enemas can usually travel further along the colon, so will reach more of the inflammation, especially if taken just before lying down. Both steroids and mesalazine are sometimes given topically, using a suppository or enema.

Injections and infusions

Some drugs are injected subcutaneously (under the skin) or intravenously (into a vein). Intravenous injections are often given through a drip using an infusion (a dilute form of the drug). Biologics such as infliximab and adalimumab cannot be taken orally so are always given by infusion or injection. Steroids may be also be given intravenously to get a quick response in someone having a severe flare-up.

Drugs used in IBD

Anti-inflammatory Drugs - Aminosalicylates (5-ASAs)

Aminosalicylic acids are also known as 5-ASAs. They are chemically related to aspirin, and work by damping down the inflammatory process, so allowing damaged tissue to heal.

There are several types of 5-ASA drugs:

  • Sulphasalazine (brand name Salazopyrin)
  • Mesalazine (Asacol, Ipocol, Octasa, Pentasa, Salofalk and Mezavant). This 5-ASA comes in different formulations which target slightly different parts of the digestive system. Asacol, Ipocol, Octasa and Salofalk tablets and granules have a special coating that dissolves at a certain pH (acidity) in the gut. This means that they work best in the last part of the small intestine and the beginning of the colon. Pentasa tablets and granules work throughout the gut. Mezavant tablets release their mesalazine as they pass through the large intestine (colon).
  • Olsalazine (Dipentum) and Balsalazide (Colazide). These 5-ASAs also work best in the large intestine (colon).

How are these 5-ASAs used in IBD?

5-ASAs are often used to treat mild to moderate flare-ups of UC. They may then be prescribed to maintain remission and help prevent flare-ups on a longer term basis.

The use of 5-ASAs for Crohn’s Disease is more controversial. Some 5-ASAs may help to control mild Crohn’s in the ileum and colon. However, there is little evidence that 5-ASAs are effective in maintaining remission, although they may help reduce the chance of Crohn’s reoccurring after surgery. 5-ASAs are not recommended for severe Crohn’s.

Some people with IBD have a slightly increased risk of developing colon cancer, and another possible benefit of using 5-ASAs long-term is that they may decrease this risk. So, if you have UC or Crohn’s Colitis your doctor may advise you to continue to take a 5-ASA indefinitely.

How do I take 5-ASAs?

As explained above, some 5-ASAs work best in certain parts of the gut, so you may be prescribed a particular type or brand depending on where you have the inflammation. Many specialists in IBD believe that if a particular brand or type of 5-ASA is working well; you should not be switched to another without a good clinical reason.

Oral mesalazine is often prescribed in two or three doses during the day. However, recent evidence suggests that taking these together in a single daily dose can be just as effective, and there are once-a-day brands available. If you feel this could be helpful for you, discuss this with your doctor.

Some 5-ASAs come as suppositories or enemas so may be useful if you have proctitis (inflammation of the rectum) or inflammation in the end of your colon.

Can 5-ASAs have side effects?

Like all drugs, 5-ASAs can have side effects, although not everyone will get them, and some are quite rare. They can include:

  • nausea, vomiting, and watery diarrhoea
  • headache and indigestion
  • mild allergic reactions with rash, itchiness and fever
  • less commonly, problems with the kidneys, liver, lungs and pancreas.

Sulphasalazine can cause male infertility by reducing the sperm count, but this usually resolves once the drug is stopped. Sulphasalazine can also reduce the body’s ability to absorb folates (B vitamins) which are essential for blood cell formation. Some people taking sulphasalazine may need a folic acid supplement.

It is usual to have regular blood tests while on 5-ASA treatment, especially when you first start taking the drug, to check for any unwanted side effects. You may have, for example, a blood test three months after you start taking it, then annually. If you are taking sulphasalazine you may need slightly more frequent blood tests.

As for all drugs and medicines, if you are concerned about side effects or any new symptoms you experience while on 5-ASAs, contact your doctor or your specialist IBD team.

Corticosteroids (Steroids)

Corticosteroids are often just called steroids. They are closely related to cortisol, a hormone produced naturally in the adrenal gland. They act on the immune system (the body’s protection system against harmful substances) and work by blocking the substances that trigger allergic and inflammatory responses. This means that they can reduce the redness, swelling and pain of the type of inflammation found in IBD.A range of corticosteroids are used in IBD. They include:

  • Prednisolone and Hydrocortisone. These are sometimes known as the ‘conventional corticosteroids’.
  • Budesonide (Entocort or Budenofalk). This is a newer type of steroid which has a local anti-inflammatory effect at the end of the small bowel (ileum).
  • Beclometasone Dipropionate(Clipper).

How are these steroids used in IBD?

Steroids such as prednisolone and hydrocortisone are used to treat acute attacks of UC or Crohn’s. They are generally very effective at bringing symptoms under control – as many as eight out of 10 people respond to treatment with steroids. People often notice an improvement in their symptoms within days of starting the drug.These steroids can be given by injection, as tablets, or topically. When injected or taken by mouth, they can reduce inflammation throughout the whole body. So they can be used to reduce inflammation in the eyes, skin and joints, if affected, as well as in the gut.While such a wide ranging effect can be very helpful, sometimes a more targeted approach is needed.

Budesonide is a new type  of steroid which is very active in the gut, but then broken down more quickly, so should affect the rest of the body less than the conventional corticosteroids. It is mainly used to treat Crohn’s disease of the ileum (the end of the small intestine) and the beginning of the large bowel. It can also be helpful for Collagenous Colitis (a slightly different form of inflammatory bowel disease).Beclometasone Dipropionate (also known as Clipper) is used only for UC. It is usually taken together with a 5-ASA (such as mesalazine) but for a shorter period of time. Like 5-ASAs, Clipper tablets have a special coating so the drug can reach the targeted area of inflammation without first dissolving in the stomach. This should mean less of the steroid enters the bloodstream to reach the rest of the body, and this can help reduce side effects.

Coming off steroids

Although they are very effective at bringing symptoms under control, steroids cannot prevent flare-ups and often have rather strong side effects, so are not used for maintenance treatment.So, once you begin to feel well, your doctor will start to reduce your steroid dose. This has to be done gradually, especially if you have been on steroid treatment for more than a few weeks.This is because corticosteroids are very similar to the naturally occurring hormone, cortisol, and when you take steroids as medicine your adrenal glands reduce or stop cortisol production. This is known as adrenal suppression. If you suddenly stop your steroid treatment, it may take some time before the adrenal glands start producing cortisol normally again. This could leave you with much lower levels of cortisol in your body, which can mean that your body does not respond so well to stressful situations, causing nausea, fatigue and light-headedness.Unfortunately, sometimes the symptoms return when you reduce the dose. If this keeps happening, immunosuppressant drugs (see below) may be added to help you come off steroids completely.

What are the possible side effects of steroids?

Although steroids are naturally present in the body, the high doses needed to control inflammation can have unwanted side effects. Most people will experience at least some of these side effects, which can be off-putting. However, steroids can be very effective at controlling flare-ups and many of these side effects usually disappear when the dose is reduced or stopped.The challenge is to get the greatest possible benefit with the fewest side effects and it is best to discuss this carefully with your IBD specialist.Temporary side effects can include:

  • an increase in appetite which can lead to weight gain
  • rounding or ‘mooning’ of the face, growth of facial hair
  • development or worsening of acne
  • an increase in blood sugar level and salt retention – so legs may swell
  • mood changes and problems with sleeping and/or concentrating
  • a reduced ability to cope with infections
  • more rarely, pain in the chest or upper abdomen.

Longer term side effects may include:

  • thinning of the bones, muscles and skin
  • a tendency to bruise easily
  • diabetes due to increased blood sugar levels
  • after longstanding treatment with steroids, problems with natural cortisol    production
  • more rarely, glaucoma or cataracts.


As their name suggests, immunosuppressants suppress (reduce the effectiveness of) the immune system (the body’s protection system against harmful substances). They are helpful in IBD because, in doing so they also reduce levels of inflammation.The main immunosuppressants used in IBD include:

  • Azathioprine (Imuran) and Mercaptopurine or 6-MP (Puri-nethol)
  • Methotrexate
  • Mycophenolate 
  • Ciclosporin

How are these immunosuppressants used in IBD?

Immunosuppressants are mainly used when treatment with steroids and 5-ASAs has failed to control the inflammation, or when steroids cannot be withdrawn without causing a relapse.If someone who is dependent on their steroid treatment in this way starts taking an immunosuppressant as well, they can often gradually reduce or even stop taking the steroids without worsening the inflammation. This is why immunosuppressants are sometimes called ‘steroid-sparing’ drugs.

The various immunosuppressants work slightly differently. Your doctor will talk you through the benefits and possible side effects of the one they are recommending for you. Make sure they know about any previous illnesses and about any new symptoms you notice once you start your treatment.Regular monitoring is important for people taking immunosuppressants. At first you will need frequent blood tests, usually weekly or fortnightly. As you become used to the treatment you will probably move to having a blood test every two to three months, for as long as you are on the immunosuppressant.

Biologics (Anti-TNF Drugs)

Biologics are the newest group of drugs to be used in IBD.They are sometimes called ‘anti-TNF’ drugs because most of them work by targeting a protein in the body called TNF-alpha. Your body naturally produces TNF-alpha as part of its immune response, but it is thought that over-production of TNF-alpha is partly responsible for the chronic inflammation found in IBD. Anti-TNF drugs bind to TNF-alpha, helping to prevent inflammation and relieve the symptoms of IBD.The two most commonly used biologics in Crohn’s disease are:

  • Infliximab (Remcema)
  • Adalimumab (Humira).

The two most commonly used biologics in Ulcerative Colitis are:

  • Infliximab (Remcema)
  • Golimumab (Simponi)

Another biologic that may in time be used if the others fail is:

  • Vedolizumab (This is a slightly different type of biologic. It works by blocking white blood cells, rather than by binding to TNF-alpha cells).

How are biologics used in IBD?

In general, biologics are prescribed for severe IBD when standard treatments have not worked. However there is some evidence that earlier use of biologics or combined therapies (biologics plus immunosuppressants) may be helpful, especially in Crohn’s Disease. Research is continuing in these areas, and on the comparative effectiveness of the newer biologics.

Other Common Questions

How safe are IBD drugs?

Before drugs are licensed in the UK, they go through rigorous research and clinical trials on thousands of people. This process can take many years. Drugs are licensed by the Government’s Medicines and Healthcare products Regulatory Agency (MHRA). The MHRA is responsible for regulating all medicines and medical devices in the UK, ensuring they work and are acceptably safe. It gives permission and sets strict safety criteria for all clinical trials in the UK. It demands very high standards from medicines manufacturers, and will only issue a licence when it is satisfied that a medicine meets all its safety and quality requirements.The MHRA also continues to review the safety of drugs after licensing. As part of this process, it has introduced a Yellow Card scheme to encourage people to report any suspected side-effects from medicines. 

Can other medicines affect IBD drugs?

It is possible that other drugs or medicine might interact with your IBD medication – and that this interaction could make your treatment less (or more) effective, or perhaps alter its side effects.So it is very important to tell your doctor and specialist IBD team about any other medicines, treatments or therapies you are taking. This includes not only medication for other conditions but also any over-the-counter, herbal or complementary medicines. It may also be a good idea to carry a list of all your medicines, including dosages, to make sure you don’t forget to mention something.

Can IBD drugs affect fertility or pregnancy?

In general, the evidence suggests that active Crohn’s or UC may do more harm to the growing baby than most IBD medicines, so most women with IBD are advised to continue taking their IBD medication during pregnancy. However, a small number of the drugs used for IBD should not be taken when trying to conceive a baby or by women once they are pregnant. Male fertility can also be affected. So if you are planning to have a baby or especially if you are already pregnant, it is important to check with your IBD team whether you need to change your drug treatment.

Does it matter if I don’t take my drugs?

When you are first prescribed medication for your IBD you will probably find it easy to remember to take it exactly as instructed, especially if it has an immediate effect on your symptoms. Once you feel better, you may be less focused on taking your tablets or applying your topical medicines, and start to forget the odd dose. Or you may be tempted to stop taking it altogether, now you don’t feel so ill, thinking you don’t need it. A lot of people get fed up with having to take pills every day, maybe even several times a day – or just feel they would rather do without such a regular reminder of their IBD.

These are understandable feelings, but many studies have shown that maintenance therapy (continuing to take medication even when you are well) is important and does reduce the chance of a flare-up. It can also mean that you are less likely to need to move on to taking additional or stronger drugs. There is also some evidence that some IBD drugs may help reduce the chances of developing another condition. For example, 5-ASA drugs may reduce the slightly increased risk of bowel cancer for some people with IBD.If you do miss taking a dose, don’t panic – the Patient Information Leaflet that comes with your medication should tell you what to do. If you can’t find this, check with your doctor or nurse.If you are prone to forgetting things like taking tablets, try and make taking them part of your daily routine, like brushing your teeth or setting an alarm on your phone.

Can I alter the dose myself?

It is usually important to take the full dose to get the full effect. Some medicines must also be taken in particular ways – for example, at particular times of day, on an empty stomach, or with or after food. If your lifestyle makes it difficult to for you to do this, try discussing it with your doctor. It may be that some compromise or alteration in the dose is possible. For example,if you are taking 5-ASAs you may be able to change to taking the full dose just once a day, which some people find easier.It is also worth talking to your doctor and/or your IBD nurse about any other worries you have about the amount of medicine you are taking, or concerns about side effects. It may be that they can reassure you, or again, suggest changes that you find helpful.

There may be other options such as different size doses as mentioned. Or it may be that a change in brand or form of drug would suit you better. With some drugs just taking them at a different time of day can make a difference, for example, taking steroids before 11am can help reduce side effects because this follows the natural rhythm of steroids in the body.  It is important however that you do not alter the dose of your immunosuppressant as this could cause you to be over-supressing your immune system.

You may be feeling that as someone who has lived with an on-going medical condition for some time, perhaps years, you are now quite an expert on what works for you. And, as a result, you may feel you would like to take a more active part in your treatment and be able to adjust your own medication when your symptoms begin to get worse or better. If so, discuss this with your doctor or IBD specialists. You may find that they are happy to include this idea in a plan around what to do in the event of a flare-up.

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