The approach to treating inflammatory forms of arthritis depends on several factors. These include the type of arthritis, the doctor’s experience, the patient’s age, potential confounding factors such as allergies, the length of time the patient has had arthritis, previous attempted medications and whether medications should be used one at a time or “layered” on top of each other.
For example, a disease such as rheumatoid arthritis requires aggressive treatment with a disease-modifying antirheumatic drug (DMARD) such as methotrexate. Methotrexate tends to work well to slow down the disease. However, the start of methotrexate is only the first step. This is quickly followed by the addition of a biological medicine or the addition of other DMARDs.
In contrast, a disease such as psoriatic arthritis may or may not respond to methotrexate. So a different disease that modifies the antirheumatic drug is needed. And that’s where a medicine like sulfasalazine is useful.
Sulfasalazine was originally produced by combining an antibiotic, sulfapyridine, with an anti-inflammatory drug 5-aminosalicylic acid. The latter, as the reader might imagine, is a form of aspirin.
This was done because rheumatoid arthritis was thought to be an infectious disease many years ago, so an antibiotic associated with an anti-inflammatory drug made sense as a useful drug for the treatment of rheumatoid arthritis. And, in numerous studies, it has been shown that it is effective in rheumatoid arthritis which acts as a DMARD. Its effects are relatively mild.
It is an oral drug taken daily. About a third of sulfasalazine is absorbed from the intestine. The rest is divided into its chemical components, sulfapyridine and 5-aminosalicylic acid. Sulfapyridine is absorbed from the gastrointestinal tract and 5-aminosalicyclic acid is excreted.
Sulfasalazine (trade name, azulfidine) has immunomodulatory effects on cells that propagate inflammation. Sulfasalazine is often combined with biological therapy or is sometimes combined with methotrexate and hydroxychloroquine (Plaquenil) or azathioprine (Imuran) in patients with rheumatoid arthritis. The exact use generally depends on the professional’s experience.
Where it appears to be most effective is in other inflammatory forms of arthritis such as psoriatic arthritis, ankylosing spondylitis and some forms of juvenile arthritis. Because this is, nobody knows.
Sulfasalazine has potential side effects including elevated liver function tests, bone marrow suppression, skin rashes and reduced white blood cell counts.
Since it is a sulfa-based drug, it should not be used in patients with sulfa allergy.