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What does it do?

Sulfasalazine is used to treat and prevent inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, and some rheumatic conditions such as rheumatoid arthritis.

Before you start

  • Tell your doctor if you have an allergy to ‘sulfa’ medicines, liver or kidney problems, trouble peeing, or G6PD deficiency.
  • Tell your doctor if you have asthma, or have had problems with aspirin.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Sulfasalazine can affect fertility in men. Discuss this with your doctor.

How should you take it?

Take sulfasalazine regularly as directed, with food and a glass of water.
Swallow the enteric coated (EC or EN) tablets whole.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Skin rash, skin peeling or blisters

Stop taking and see your doctor immediately

Symptoms of allergy including: skin rash, itching, swelling, trouble breathing

Reduced number of blood cells that fight infections or help your blood to clot - symptoms include: fever, chills, sore throat or generally feeling unwell, or easy or unusual bruising or bleeding

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Severe stomach pain, nausea

Chest pain

Short of breath, persistent dry cough

Tell your doctor immediately

Pain, sores, or redness in mouth or on lips

Nausea, vomiting

Tell your doctor

Dizziness, headache

More sensitive to sunlight (sunburn or rash)

Loss of appetite

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • You will need regular blood tests while taking sulfasalazine to check if it is causing problems with your liver, kidneys or blood.
  • Protect yourself from too much sunlight while being treated with sulfasalazine. Always cover up and apply a thick layer of broad spectrum sunscreen (at least SPF 30) when outside. Do not use sunbeds.
  • Sulfasalazine may make your tears, sweat and pee an orange-yellow colour – this is harmless. Avoid wearing soft contact lenses as they may become stained.
  • You may not notice the effects of sulfasalazine straight away – it can take several weeks before you start to feel better.

This leaflet contains important, but not all, information about this medicine.

Prepared by the MyMedicines Committee at Christchurch Hospital, Te Whatu Ora - Waitaha, New Zealand. March 2023

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at Te Whatu Ora – Waitaha. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed