Expansion
Aminosalicylates, steroids, immunomodulators and biologics
Expansion
Aminosalicylates (mesalazine, sulfasalazine)
- Topical anti-inflammatory action on colonic mucosa
- Effective for ulcerative colitis induction and maintenance; little benefit in Crohn
- Sulfasalazine causes reversible oligospermia and haemolysis in G6PD deficiency
Corticosteroids
- For induction only, never maintenance, because of cumulative toxicity
- Budesonide has high first pass metabolism, giving fewer systemic effects
Immunomodulators
- Azathioprine and mercaptopurine: steroid-sparing maintenance. Check TPMT first; never combine with allopurinol at full dose
- Methotrexate: for Crohn disease
Biologics
- Anti-TNF (infliximab, adalimumab): effective in both, and particularly for fistulating Crohn disease. Screen for tuberculosis and hepatitis B first
- Vedolizumab (gut-selective anti-integrin), ustekinumab (anti-IL-12/23)
The organising principle is induction (steroids or biologics) followed by maintenance (aminosalicylates, thiopurines or biologics), with the aim of steroid-free remission and mucosal healing rather than symptom control alone.