What is sulfasalazine?

Why is sulfasalazine prescribed?

What are the possible side-effects?

What else should I know about sulfasalazine?

What is sulfasalazine?

Sulfasalazine is a type of drug known as a disease-modifying anti-rheumatic drug (DMARD). These drugs have the effect of dampening down the underlying disease process, rather than simply treating symptoms. Sulfasalazine is generally prescribed as Salazopyrin EN-Tabs. This is the brand name for sulfasalazine that is specially coated so that it does not dissolve quickly in your stomach.

What are the brand names of sulfasalazine?

The biosimilar version is Salazopyrin.

What type of drug is sulfasalazine?

Sulfasalazine is a disease-modifying anti-rheumatic drug (DMARD).

What does it do?

It dampens down the underlying disease process by suppressing human immune system, rather than simply treating symptoms.

What is it used for?

It is used to treat conditions such as rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis and arthritis associated with bowel inflammation.

How is it taken?

It’s usually taken in tablet form.

Are there any side-effects?

In some patients sulfasalazine can cause nausea (feeling sick), diarrhoea, stomach pain, dizziness, headache and skin rashes. It can sometimes affect your blood or liver.

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Why is sulfasalazine prescribed?

Sulfasalazine is used to treat conditions such as rheumatoid arthritis, psoriatic arthritis, and arthritis associated with bowel inflammation. It may reduce the inflammation in your joints and decrease pain, swelling and stiffness.

Is there any reason I will not be prescribed sulfasalazine?

You should not take sulfasalazine if you are known to have a sulphonamide allergy.

When and how do I take sulfasalazine?

Sulfasalazine is taken in tablet form. The tablets should be taken with a glass of water. They should be swallowed whole and not crushed or chewed.

Your doctor will advise you about the correct dose. Usually you will start on a low dose, and the dose may be adjusted according to the severity of your symptoms. 

How long does sulfasalazine take to work?

Sulfasalazine does not work immediately. It may be at least 12 weeks before you notice any benefit.

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What are the possible side-effects?

The most common side-effects of sulfasalazine are nausea (feeling sick), diarrhoea, stomach pain, dizziness, headache and skin rashes. These side-effects usually occur during the first three months of treatment. Taking sulfasalazine can affect the blood count (one of the effects is that fewer blood cells are made). It can also affect your liver resulting in abnormal liver function tests. You should tell your doctor or nurse specialist straight away if you develop any of the following after starting sulfasalazine:

  • a sore throat
  • a fever
  • any other symptom of infection
  • unexplained bruising
  • any other new symptoms or anything else that concerns you.

Your urine may change colour (to orange) with sulfasalazine but this is nothing to worry about. Sulfasalazine may also stain soft contact lenses (and tears) yellow.

Side-effects caused by sulfasalazine may clear up if the dose is reduced. Your doctor or rheumatology nurse specialist may suggest increasing the dose again at a later date if your tolerance has improved, especially if it is helping your symptoms.

You should always read the patient information leaflet included with your medicines package to keep you informed about any possible side effects of your prescribed medications.

Will it affect vaccinations?

You can have vaccinations while on sulfasalazine. 

Can I drink alcohol while on sulfasalazine?

There is no particular reason to avoid alcohol while on sulfasalazine but it is advisable to drink moderately as excessive alcohol intake can trigger sulfasalazine side effects.

Does sulfasalazine affect fertility or pregnancy?

Sulfasalazine can be taken whilst trying to conceive and for the duration of your pregnancy. However it must be taken with 5 milligrams of folic acid per day, which your doctor will prescribe. Continuing to use sulfasalazine throughout your pregnancy decreases the risk of flare-ups. Sulfasalazine may negative impact a man's fertility, but the outcome is reversed if treatment is stopped, however it is not recommended that males stop taking sulfasalazine unless you have been trying to father a child for over one year.

Does it affect breastfeeding?

Sulfasalazine is considered safe to use while you are breastfeeding unless the baby is premature or at risk of jaundice. Discuss your wish to breastfeed with your rheumatologist.

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What else should I know about sulfasalazine?

Are there any alternatives? 

A number of other drugs are used in the treatment of rheumatoid arthritis and related conditions. Your doctor will discuss these other options with you.

Will I need any special checks while on sulfasalazine?

Side-effects of sulfasalazine on the blood or liver may be picked up at an early stage by regular blood tests. Your doctor will arrange for you to have a blood test before you start treatment and then regular checks while on sulfasalazine. You may be asked to keep a record of your blood test results in a booklet, and you should take it with you when you visit your GP or the hospital.

You must not take sulfasalazine unless you are having regular blood tests and the results are being checked.

Can I take other medicines alongside sulfasalazine?

You should discuss any new medications with your doctor before starting them, and you should always tell any other doctor treating you that you are taking sulfasalazine. You should also be aware of the following points:

  • Sulfasalazine is not a painkiller. If you are already on a non-steroidal anti-inflammatory drug (NSAID) or painkillers you can carry on taking these as well as sulfasalazine, unless your doctor advises otherwise. If sulfasalazine works for you, you may be able to reduce your NSAIDs or painkillers after a time.

Do not take over-the-counter preparations or herbal remedies without discussing this first with your doctor, rheumatology nurse specialist or pharmacist.

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Page updated 13 May 2021