Sulfasalazine

Key points

• Sulfasalazine: 5-ASA + sulfapyridine conjugate, cleaved by colonic bacteria; active moiety in IBD is 5-ASA.
• Uses: ulcerative colitis, Crohn's, rheumatoid arthritis.
• Side effects: reversible oligospermia, orange discolouration of urine/contact lenses, folate deficiency, Heinz body anaemia in G6PD deficiency.
• Avoid in G6PD deficiency and in aspirin/sulfonamide allergy.