indication

For the treatment of Crohn's disease and rheumatoid arthritis as a second-line agent.

pharmacology

Sulfasalazine is an anti-inflammatory indicated for the treatment of ulcerative colitis and rheumatoid arthritis.

mechanism of action

The mode of action of Sulfasalazine or its metabolites, 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP), 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, SP and 5-ASA have indicated that the major therapeutic action may reside in the 5-ASA moiety. The relative contribution of the parent drug and the major metabolites in rheumatoid arthritis is unknown.

half life

5-10 hours

route of elimination

The majority of 5-ASA stays within the colonic lumen and is excreted as 5-ASA and acetyl-5-ASA with the feces.

drug interactions

Azathioprine: Sulfasalazine may increase the toxicity of thiopurine, azathioprine.

Chlorpropamide: Sulfonamide/sulfonylurea: possible hypoglycemia

Cyclosporine: The sulfonamide decreases the effect of cyclosporine

Digoxin: Sulfasalazine may decrease the effect of digoxin.

Mercaptopurine: Sulfasalazine may increase the toxicity of thiopurine, mercaptopurine.

Thioguanine: Sulfasalazine may increase the toxicity of thiopurine, thioguanine.