The mode of action of Sulfasalazine is still under investigation, but may be related to the anti inflammatory and/or immunomodulatory properties that have been observed in animal and in vitro models, to its affinity for connective tissue, and/or to the relatively high concentration it reaches in serous fluids, the liver and intestinal walls, as demonstrated in autoradiographic studies in animals. In ulcerative colitis, clinical studies utilizing rectal administration of Sulfasalazine, Sulfapyridine and 5-Aminosalyclic Acid have indicated that the major therapeutic action may reside in the 5-Aminosalyclic Acid moiety. The relative contribution of the parent drug and the major metabolites in rheumatoid arthritis is unknown.

Sulfasalazine is indicated in:

• Rheumatoid arthritis & Juvenile arthritis: In the treatment of patients with rheumatoid arthritis and pediatiric patients with polyarticular-course juvenile rheumatoid arthritis, who have responded inadequately to salicylates or other non-steroidal anti-inflammatory drugs (NSAIDs).
• Ulcerative colitis and Crohn's Disease: As adjunct in the treatment of ulcerative colitis with the usual supportive and dietary measures. In the treatment of active Crohn's disease, especially in patients with colonic involvement.

The dosage of Sulfasalazine tablets should be individually adjusted according to the patient's tolerance and response to the treatment and taken in evenly divided doses preferably after meals.

Adult dose for crohn’s disease: 500 mg orally 2 to 4 times a day with food.

Pediatric use (6 years or older) for Ulcerative Colitis: The initial dose 40 to 60 mg/kg/day orally divided into 3 to 6 doses. 

Adult dose for rheumatoid arthritis: 2 g daily in two evenly divided doses. It is advisable to initiate therapy with a lower dosage e.g. 0.5 to 1.0 g daily, to reduce possible gastrointestinal intolerance. A suggested dosing schedule is given bellow:

• First week: One tablet in the evening
• Second week: One tablet in the morning & One tablet in the evening
• Third week: One tablet in the morning & two tablet in the evening
• Fourth week: Two tablet in the morning & two tablet in the evening

In case of rheumatoid arthritis 6 years or older: initial dose 10 mg/kg/day orally in 2 equally divided doses.

Juvenile rheumatoid arthritis-polyarticular course: Children 6 years of age and older: 30 to 50 mg/kg/day in two evenly divided doses. Typically the maximum dose is 2 g per day.

For other indications:

Initial therapy:

• Adults: 3 to 4 g daily in divided doses with dosage intervals not exceeding eight hours. It may be advisable to initiate therapy with a lower dosage e.g. 1 to 2 g daily to reduce possible gastrointestinal intolerance.
• Children 6 years of age and older: 40 to 60 mg/kg/day in to 3 to 6 divided doses.

Maintenance therapy:

• Adults: 2 g daily.
• Children 6 years of age and older: 30 mg/kg/day in 4 divided doses.

Hypersensitivity to Sulfasalazine, its metabolites, sulfonamides or salicylates, patients with intestinal or urinary obstruction and porphyria.

The common adverse reactions are anorexia, headache, nausea, vomiting, gastric distress, dyspepsia, abdominal pain, dizziness, apparently reversible oligospermia etc.

Hepatic/renal impairment, G6PD deficiency, allergic bronchial asthma, lactation.

Pregnancy & Lactation

Use in pregnancy: Pregnancy category B. This drug should be used during pregnancy only if clearly needed.

Use in lactation: Caution should be exercised when sulfasalazine is administered to a nursing mother.