Sulfasalazine (azulfidine, salazopyrin) belongs to a class of drugs called sulfa drugs. It’s a combination of salicilate (the main ingredient in aspirin) and a sulfa antibiotic. Sulfasalazine works by slowing the radiographic progression (damage to the joints) of rheumatoid arthritis, and reducing pain and swelling. It is one of the first line treatments for moderate to severe rheumatoid arthritis, along with methotrexate and leuflunomide (arava).
Its efficacy is similar to that of methotrexate, but the choice of sulfasalazine may be made if the patient is a heavy drinker, or may become pregnant.
It is sometimes prescribed by itself or maybe prescribed in combination with hydroxychloroquine (Plaquenil) or with methotrexate, it usually takes 6-12 weeks to start to feel the benefits.
How does Sulfasalazine work?
From ‘Australian Prescriber’ – the method of action is unclear but may involve the transcription factors which are increases in inflammation’. Confidence inspiring, no?
So no one is quite sure how it works. Just that, for a lot of people, it does work. It reduces inflammation and inhibits joint damage. Which is the aim!
Patients usually take 1 – 1.5 grams per day. Because Sulfasalazine can cause unpleasant gastric side effects, it is usually tapered up slowly, starting with 500 mg in the mornings for a week. Then 500 mg in the morning and night for a week. Gradually adding 500mg per week until the optimum dosage is reached. If side effects are severe, it can be tapered more slowly.
The most common side effect is stomach upset – nausea, vomiting, loss of appetite, and diarrhoea. Headache and dizziness are also common, as is depression.
Sulfasalazine can also cause liver problems, and a reduced white cell count. This leads to a higher chance of infections, and must be monitored closely with regular blood tests. Full blood count and liver function are tested month for the first for three months, then three monthly thereafter.
Sulfasalazine can also turn your tears or your urine orange. Even your skin! This is usually harmless and goes away once the medication is stopped.
For a complete list sulfasalazine side effects click here
Sulfasalazine should not be prescribed for patients who are hypersensitive to salicylates or sulfa drugs. It is also should be monitored carefully in patients with decreased kidney function, or decreased liver function.
Advice in pregnancy/breastfeeding
Sulfasalazine can be used in pregnancy. Very small amounts are found in breast milk, so it can be used cautiously by breastfeeding mothers.