Taking Sulfasalazine (Azulfidine) for Arthritis

Azulfidine (sulfasalazine) is a prescription, oral, anti-inflammatory medication used to treat inflammatory conditions like rheumatoid arthritis (RA) and ulcerative colitis.

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Drug Class

Sulfasalazine belongs to a class of drugs referred to as sulfa drugs. It contains salicylate and the sulfa antibiotic.

Sulfasalazine treats the disease process, not just the symptoms of RA, and thus it is classified as a disease-modifying anti-rheumatic drug (DMARD).

Indications for Use of Sulfasalazine

Sulfasalazine is prescribed for treating RA, juvenile arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.

This medication helps reduce pain, swelling, and stiffness associated with arthritis. It is most effective for treating mild to moderate symptoms. Sulfasalazine also may prevent joint damage and decrease the risk of reduced joint function. Typically, symptom improvement is noticeable within 12 weeks of starting treatment.

Dosing Information and Availability

Sulfasalazine is available as a 500 milligram (mg) tablet. It is recommended that you take it with food and a full glass of water.

Treatment for rheumatoid arthritis typically starts at a low dose, which is then increased. For the first week, your healthcare provider may prescribe one or two sulfasalazine tablets per day. Your dose will likely be gradually increased to two tablets twice a day. The maximum dose is six tablets per day.

Enteric-coated tablets are available and may help prevent stomach upset.

Common Side Effects

The most common side effects of sulfasalazine are nausea or abdominal discomfort. Abdominal issues usually resolve over time, especially when the drug is started at a low dose.

Less common side effects may include skin rash, headache, mouth sores, itching, problems with liver function, and sun sensitivity.

Possible Severe Adverse Reactions

While severe adverse reactions are not considered common, they do tend to increase when the daily dose of sulfasalazine equals or exceeds 4 grams.

Adverse reactions associated with sulfonamides (sulfa drugs) that can occur with sulfasalazine include blood disorders, hypersensitivity reactions, central nervous system reactions, renal reactions, and urine and skin discoloration.

Severe adverse reactions affect about one-third of patients treated with sulfasalazine.

Severe reactions include:

  • Anorexia
  • Severe headache
  • Severe gastric distress
  • Vomiting
  • Low sperm count

The low sperm count may be reversible with discontinuation of the drug.

Adverse reactions that affect no more than 1 in 30 patients taking sulfasalazine include itching, hives, fever, Heinz body anemia, hemolytic anemia, and cyanosis (low oxygen and bluish discoloration).​​​​

Contraindications (Who Should Not Take the Drug)

Sulfasalazine is not an appropriate treatment option for patients with intestinal or urinary obstruction, porphyria, or in patients with known hypersensitivity to sulfasalazine, sulfonamides, or salicylates.

Warnings and Precautions

To minimize the risk of side effects or adverse reactions. you should be aware of the following warnings and precautions while taking sulfasalazine.

  • Prior to starting sulfasalazine, patients should be screened for deficiency of G6PD enzyme. Those patients who are deficient should avoid sulfasalazine due to an increased risk of life-threatening anemia.
  • Regular blood tests should be performed to monitor blood counts, kidney function, and liver function.
  • If you are planning to become pregnant, you should discuss your sulfasalazine usage with your healthcare provider.
  • Women who are breastfeeding should not take sulfasalazine.
  • Folic acid supplementation may be necessary if you are being treated with sulfasalazine.
  • Sulfasalazine can interact with Coumadin (warfarin), cyclosporine, and digoxin.
  • The drug may increase the risk of liver injury in patients who take isoniazid for tuberculosis.
  • Sulfasalazine may also increase the risk of low blood sugar among patients who take certain diabetes medications.
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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Sulfasalazine (Azulfidine). American College of Rheumatology. March 2015.

  • Rheumatoid Arthritis: Early Diagnosis and Treatment. Cush JJ M.D., Weinblatt ME M.D., Kavanaugh A M.D. Professional Communications, Inc. Third Edition. Copyright 2010.