About sulfasalazine

Sulfasalazine is used to treat ulcerative colitis and Crohn's disease, and other types of inflammatory bowel disease.

It can also be used to treat rheumatoid arthritis.

It belongs to a group of medicines called aminosalicylates. These medicines help to reduce redness and swelling (inflammation) and can help with healing.

Some people take sulfasalazine together with steroids.

Sulfasalazine is available on prescription only.

It comes as tablets or a liquid that your swallow. It also comes as suppositories (a medicine that you push into your bottom).

Key facts

Who can and cannot take sulfasalazine

Adults and children aged 2 years and older can take sulfasalazine.

Sulfasalazine is not suitable for some people. To make sure it's safe for you, tell your doctor before starting the medicine if you:

How and when to take sulfasalazine

Dosage and strength

Always follow your doctor's advice and the instructions that come with your medicine.

The tablets and suppositories contain 500mg of sulfasalazine. The liquid contains 250mg per 5ml.

Doses will vary. Your dose and how often you take it depends on why you need sulfasalazine and how severe your symptoms are.

For inflammatory bowel disease the usual dose is either:

For rheumatoid arthritis, when you start treatment you'll usually take one 500mg tablet a day. This will increase by 1 tablet a day each week until you reach a dose of 1 tablet 4 times a day, or 2 tablets 3 times a day, depending on how you respond to it.

Children's doses are often lower. The doctor will use your child's weight to calculate the right dose for them.

How to take sulfasalazine tablets

Swallow the tablets whole, with a drink of water. Do not break, chew or crush them. This is because some tablets have a special coating to protect the medicine from the acids in your stomach.

You can take sulfasalazine tablets with or without food.

Try to space the doses evenly throughout the day and night, with a gap of no more than 8 hours between your bedtime and morning dose.

Drink plenty of fluids when taking this medicine to help prevent possible kidney problems.

How to take sulfasalazine liquid

Take the liquid with food. You'll usually take the same amount 4 times a day.

How to use sulfasalazine suppositories

Sulfasalazine suppositories are used to treat inflammatory bowel disease.

You will generally use the suppositories twice a day, in the morning and at bedtime. Use them after you do a poo.

  1. Wash your hands before and after using the suppository. Also clean around your bottom (anus) with mild soap and water, rinse and pat dry.
  2. Unwrap the suppository.
  3. Gently push the suppository into your anus with the pointed end first. It needs to go in about 3 centimetres (1 inch).
  4. Sit or lie still for about 15 minutes. The suppository will melt inside your bottom. This is normal.
  5. Try not to empty your bowels for at least an hour after inserting the suppository so it will work better.

Will my dose go up or down?

Once your symptoms start to get better, your doctor may reduce your dose to a maintenance dose. This is a lower dose of sulfasalazine that helps keep your symptoms under control.

If your symptoms flare up again, your doctor may want to put your dose back up.

What if I forget to take it?

If you miss a dose of sulfasalazine, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take your next one at the usual time.

Do not take a double dose to make up for a forgotten dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember your medicine.

What if I take too much?

Taking too much sulfasalazine is unlikely to cause you any problems.

However, speak to your doctor or a pharmacist if you take more than double your usual dose and you feel unwell. They may need to monitor you for side effects.

Side effects

Common side effects

Like all medicines, sulfasalazine can cause side effects, but many people have no side effects or only minor ones.

You're more likely to have side effects if you're taking a high dose of sulfasalazine. Sulfasalazine can turn your pee orange. This is harmless and nothing to worry about.

It's unusual, but sulfasalazine can also stain certain types of soft contact lenses. Single-use daily contact lenses are not affected.

Sulfasalazine side effects can vary depending on whether you are taking it as a tablet, suppository or liquid.

Keep taking the medicine, but tell your doctor if these side effects bother you or do not go away.

Common side effects which may affect more than 1 in 100 people include:

Serious side effects

Serious side effects are very rare, affecting less than 1 in 10,000 people.

Call a doctor straight away if you get:

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to sulfasalazine.

These are not all the side effects of sulfasalazine. For a full list see the leaflet inside your medicines packet.

How to cope with side effects of sulfasalazine

What to do about:

Pregnancy and breastfeeding

Sulfasalazine and pregnancy

There are no concerns that taking sulfasalazine in pregnancy can harm your baby.

Sulfasalazine can affect your folic acid levels. To help with this, take high dose folic acid (5mg a day), particularly in the 3 months before you start trying to get pregnant and during the first 12 weeks of pregnancy.

You can continue taking folic acid throughout your pregnancy.

Talk to your doctor or midwife if you're trying to get pregnant, or as soon as you become pregnant, so that high dose folic acid can be prescribed.

Sulfasalazine and breastfeeding

You may be able to take sulfasalazine while breastfeeding. Talk to your doctor, a pharmacist or your health visitor if you want to breastfeed.

Small amounts of sulfasalazine pass into breast milk and are unlikely to cause any side effects in your baby, although there have been some rare cases of diarrhoea.

Tell your midwife, health visitor or doctor as soon as possible if you notice your baby is not feeding as well as usual, has diarrhoea, or if you have any other concerns about your baby.

For more information about how sulfasalazine can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPs) website.

Cautions with other medicines

Mixing sulfasalazine with herbal remedies or supplements

There are some medicines that can affect the way sulfasalazine works.

Tell your doctor or pharmacist if you're taking:

There's very little information about taking herbal remedies and supplements with sulfasalazine. They are not tested in the same way as other medicines.

Common questions about sulfasalazine

How does sulfasalazine work? How long does it take to work? How long will I take it for? Is it safe to take for a long time? Can I stop taking sulfasalazine? Can I take sulfasalazine before surgery or dental treatment? Can I take painkillers with sulfasalazine? Can I drink alcohol with sulfasalazine? Is there any food or drink I need to avoid? Will sulfasalazine affect my fertility? Will sulfasalazine affect my contraception? Can I drive or ride a bike? Are there other treatments for Crohn's disease and ulcerative colitis? Are there other treatments for rheumatoid arthritis?