The information on this page is specific to the rheumatology indications for sulfasalazine and how it is used by Dr Suppiah in the New Zealand context

What is sulfasalazine?

Sulfasalazine is in a class of medications called Disease Modifying Anti Rheumatic Drugs (DMARDs). This class of medication reduces joint damage and therefore protects from future disability.  Sulfasalazine is used in the treatment of rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis.   It is a large yellow tablet that consists of a sulfur component and an anti-inflammatory component.

It normally takes about 3 months to notice the benefit from sulfasalazine.

Benefits of sulfasalazine

Sulfasalazine improves the symptoms and signs of inflammatory arthritis in about 30-70% of patients depending on which study and which indication you look at.  It reduces joint damage and long-term disability.  It is not as effective as methotrexate on its own for rheumatoid arthritis, but often added to methotrexate in combination therapy.  It is thought to be as good as methotrexate for ankylosing spondylitis and psoriatic arthritis.

How to take sulfasalazine

The dose range is 1000 - 3000 mg per day.  It is normally prescribed in an enteric coated formulation (Salazopyrin EN) which comes in 500mg tablets.  The typical dose is 2 tablets twice per day.  When starting sulfasalazine, it is normal to start with a lower dose and build up to the full prescribed dose over 1-2 weeks.

The tablets are large, but because they are coated to allow slow release they should not be broken, chewed or crushed.  They are best taken with, or immediately after meals.

Side effects

Most patients get no side effects.  If you do get side effects, they are usually mild but can include: loss of appetite, nausea, reflux, diarrhea, abdominal pain, dizziness, headache, ringing in the ears (tinnitus) and mood problems.   

Sulfasalazine often causes urine and sweat to have an orange colour.  This is normal and does not mean you reacting to the medication.

About 10% of people are allergic to 'sulfur' and can break out in a widespread rash, get mouth ulcers and develop a fever.  The medication should be stopped immediately in this setting.

It can reduce the sperm count in males and make them temporarily infertile.  This is reversible if the medication is stopped.

Other serious side effects are rare but you can get blood test abnormalities (and hence the need for regular blood tests). People with G6PD deficiency should not take sulfasalazine as it can cause severe blood test abnormalities.  


Alcohol can increase the liver toxicity of sulfasalazine.

If you have no underlying liver problems, you can drink a maximum of 14 units of alcohol per week.  You should drink no more than 3 units in any one day (which is equivalent to about 2 small glasses of wine).  Ideally have 2-3 alcohol free days per week.


Blood tests to check kidney function, liver function and full blood count are needed every month for the first few months.  If stable the frequency of testing can be extended to every 2-3 months.

Response to treatment is usually assessed every 2-3 months.  If there is inadequate benefit then other medications may be added to sulfasalazine.


Sulfasalazine is usually safe in pregnancy and breastfeeding. However, the underlying disease needs to be well controlled prior to getting pregnant, so this needs to be discussed with your specialist and family doctor prior to trying to conceive.


Our recommendations for vaccines if you are on sulfasalazine are:

1. Influenza vaccine (yearly)
2. Vaccination against pneumococcal disease (Prevenar 13 and Pneumovax 23 - every 5 years)
3. Vaccination against haemophilus influenza b (Hiberix)
4. Vaccination against meningococcal disease (Menectra)
5. Covid 19 (as per MoH recommendations)
6. Shingles (Shingrix vaccine only)

If using sulfasalazine alone with no other DMARDs or biological medications then all other vaccines including live vaccines (e.g.  MMR, yellow fever, oral typhoid) are fine to have.

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