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If you’ve been prescribed sulfasalazine for your Crohn’s disease or ulcerative colitis and you want to find out more, this is the article for you.
Sulfasalazine (also known as sulphasalazine) belongs to a group of medicines called aminosalicylates (5-ASAs), which are medicines commonly used to treat ulcerative colitis and Crohn’s disease. 5-ASA medicines are chemically related to aspirin, and work by reducing inflammation in your gut.
5-ASAs are not immunosuppressants.
There are several other types of 5-ASA medicines regularly used to treat inflammatory bowel disease (IBD) including:
It is not known exactly how sulfasalazine (and all types of 5-ASA medicine) works in treating IBD, but it is thought to slow down your body's production of prostaglandins, chemicals that have a key role in causing inflammation.
Each type of 5-ASA is formulated slightly differently, and works best in certain parts of your gut. Sulfasalazine treats your terminal ileum (the end of your small intestine) and your colon (large bowel).
Sulfasalazine v mesalazine
You might be wondering what the difference is between sulfasalazine and mesalazine, another commonly prescribed 5-ASA, is.
Sulfasalazine was the first widely prescribed 5-ASA medicine, and it contains a sulfonamide - an antibacterial medicine. Some people cannot tolerate the sulfonamides in sulfasalazine. Quite often, these people can take mesalazine instead, as mesalazine doesn’t contain any sulfonamides. Mesalazine is also available in different formulations which control its release to target specific areas of your bowels1.
Sulfasalazine and ulcerative colitis
Sulfasalazine is a common first treatment for mild to moderate flare ups of ulcerative colitis, and around seven in 10 people find it works well for them.
Sulfasalazine is also used as a maintenance treatment for ulcerative colitis, to keep you well once your UC is in remission.
Sulfasalazine and Crohn’s disease
Sulfasalazine is occasionally used as a first treatment option in mild Crohn’s disease. It can also be used to help manage Crohn’s disease symptoms post surgery.
There is little evidence to support the use of sulfasalazine to treat or maintain remission in moderate to severe Crohn’s disease. (2)
Sulfasalazine, sometimes called sulphasalazine, is often just referred to under its name - sulfasalazine (known as the generic name). However, there are also a couple of brands of sulfasalazine used in ulcerative colitis and Crohn’s disease which you may be prescribed. These include:
Your doctor will give you detailed information about the dosage and method of application of sulfasalazine for your IBD. This will depend on the severity and location of the inflammation in your gut. You can also read the patient information leaflet included in every medicine packet.
You will usually be prescribed a higher dose of sulfasalazine to treat a flare up, then a lower dose to maintain remission (keep you well) once your inflammation and symptoms are under control.
Sulfasalazine is available as:
Tablets can be swallowed with water. Tablets with an enteric coating (this is a special coating that allows the medicine to be released in the right part of your gut) must not be crushed or chewed, or taken at the same time as indigestion remedies, as this will affect how they work.
If you feel nauseous taking sulfasalazine, it can help to split your dose up throughout the day. Ask your IBD team about this.
Sulfasalazine suppositories and enemas are used to treat the lower part of your colon and your rectum. Sulfasalazine suppositories are small bullet shaped capsules inserted into your anus using a finger, where they dissolve. Liquid enemas come in a container with a specially designed applicator, which you insert into your anus and squeeze the liquid inside your body.
People are often worried about taking rectal medicines at first. To help make it easier you could:
If you forget to take a dose of your sulfasalazine at the right time, take it as soon as you remember, then carry on as normal. If it is almost time to take your next dose, skip the missed dose then carry on as normal.
It can take several weeks for sulphasalazine to start working for you. You should keep taking your prescribed dose even when you feel better.
Sulfasalazine is also a maintenance treatment which, if it works for you, you will probably take long term, for years or even indefinitely, in order to keep your disease under control and reduce the risk of flare ups.
Before you start taking sulfasalazine, you will have a blood test to check your kidney function. Sulfasalazine is cleared from your body through your kidneys. If your kidneys aren’t working well, they won’t be able to get rid of the medicine. This will increase your risk of side effects
You shouldn’t take sulfasalazine if you are sensitive to sulfonamides or salicylates.
It is generally considered safe to take sulfasalazine whilst you are pregnant or breastfeeding. However, sulfasalazine can cause folate deficiency so you may need to take a daily folic acid supplement. Speak to your IBD team if you are hoping to become pregnant.
Sulfasalazine can affect male fertility by reducing sperm count. This usually resolves within a couple of months of stopping treatment. If you are trying for a baby, you may need to be switched to a different type of 5-ASA medicine.
You can drink alcohol in moderation whilst taking sulfasalazine, although it can sometimes aggravate nausea.
You will usually have regular blood tests to monitor your kidney and liver function, your blood count, and to check for any unwanted side effects. These tests are likely to be every three months for the first year, then once every six months or every year after that.
It is less likely you will have side effects with sulfasalazine than with other IBD medicines, and around eight in 10 people don’t have any at all. If you experience any of these side effects, contact your IBD team straight away.
Common side effects include:
Less common side effects include:
Sulfasalazine is yellow/orange coloured, and you may notice your urine, tears and sweat develops a yellow tinge. This is nothing to worry about, but it can sometimes stain clothing and contact lenses.
Sulfasalazine is often prescribed alongside other medicines for your IBD, such as steroids or azathioprine. This is called combination therapy and is used to help treatment work more quickly or more effectively.
Folic acid is often prescribed alongside sulfasalazine.
Most other medicines, including over-the-counter, herbal and complementary medicines can be taken alongside sulfasalazine, but you should always check with your IBD team or pharmacist first.
It is considered safe to have vaccinations while taking sulfasalazine, although you should check with your IBD team beforehand, especially if you are taking other medicines for IBD.
Having inflammatory bowel disease does not increase your risk of contracting COVID-19. However, if you are having a flare, have underlying health conditions, or if you are taking certain medicines, you can be at increased risk of developing complications if you contract the virus.
Sulfasalazine does not increase your risk of severe symptoms or complications if you contract COVID-19. You should continue to take your sulfasalazine as normal. You can contact your IBD team if you have any questions or concerns.
Like everyone else, you should take precautions to avoid infection through good personal hygiene and avoiding unnecessary close contact with other people, especially if they are unwell.