What is the recommended treatment approach for inflammatory colitis?

Treatment Approach for Inflammatory Colitis

The recommended first-line treatment for inflammatory colitis is a combination of oral and topical mesalazine (5-ASA), with oral mesalazine 2-4g daily plus topical mesalazine 1g daily for optimal efficacy in mild to moderate disease. 1, 2

Treatment Based on Disease Extent and Severity

Mild to Moderate Distal Colitis

• Topical mesalazine 1g daily combined with oral mesalazine 2-4g daily is the most effective first-line therapy 3, 1
• Topical mesalazine is more effective than topical corticosteroids and should be the preferred topical agent 1, 2
• Once-daily dosing with mesalazine is as effective as divided doses, which may improve adherence 4
• Choice of topical formulation should match disease extent:
  • Suppositories for disease limited to rectum
  • Foam or liquid enemas for more proximal disease 3, 2
• Topical corticosteroids should be reserved as second-line therapy for patients intolerant to topical mesalazine 3, 1

Mild to Moderate Extensive Colitis

• Oral mesalazine 2-4g daily or balsalazide 6.75g daily or olsalazine 1.5-3g daily 3, 5
• Combination of oral and topical therapy is more effective than either alone 1, 5
• Sulphasalazine 2-4g daily is effective but has more side effects than newer 5-ASA drugs; may be beneficial for patients with reactive arthropathy 3

Inadequate Response to First-Line Therapy

• If no improvement with combination therapy, initiate oral prednisolone 40mg daily 3, 1
• Topical agents may be used as adjunctive therapy with systemic corticosteroids 3, 2
• Prednisolone should be tapered gradually over 8 weeks according to patient response 3, 1

Severe Colitis

• Requires hospital admission for intensive intravenous therapy 3, 5
• Joint management by gastroenterologist and colorectal surgeon is essential 3, 1
• Monitoring should include:
  • Daily physical examination for abdominal tenderness
  • Vital signs four times daily
  • Stool chart recording frequency and character of bowel movements
  • Regular laboratory tests (CBC, CRP, electrolytes, albumin) every 24-48 hours
  • Abdominal radiography to assess for colonic dilatation 3, 5
• Supportive care includes:
  • Intravenous fluid and electrolyte replacement
  • Blood transfusion to maintain hemoglobin >10 g/dl
  • Subcutaneous heparin to reduce thromboembolism risk
  • Nutritional support if malnourished 3, 5

Mechanism of Action and Pharmacology

• Mesalamine works through topical anti-inflammatory effects on colonic epithelial cells 6
• It may diminish inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon 6
• Mesalamine is poorly absorbed from the colon and primarily excreted in feces 6
• The absorbed portion undergoes acetylation and is excreted in urine as N-acetyl-5-ASA metabolite 6

Maintenance Therapy

• Lifelong maintenance therapy is generally recommended, especially for left-sided or extensive disease 3, 1
• Aminosalicylates are effective and safe for maintenance therapy 1, 5
• For steroid-dependent disease, consider immunomodulators: Azathioprine 1.5-2.5 mg/kg/day or Mercaptopurine 0.75-1.5 mg/kg/day 1, 5

Special Considerations and Common Pitfalls

• Proximal constipation should be treated with stool bulking agents or laxatives 3, 2
• Antidiarrheal medications should be avoided as they can mask worsening symptoms while allowing underlying inflammation to progress 2, 5
• Monitor renal function in all patients prior to initiation and periodically during mesalamine therapy 6, 7
• Ensure adequate dosing of mesalazine (at least 2g daily for active disease) 1, 8
• Avoid delaying corticosteroid treatment if no response to optimized 5-ASA therapy 2, 9
• Long-term steroid use should be avoided due to significant side effects 1, 9
• In elderly patients (≥65 years), monitor complete blood cell counts and platelet counts during treatment with mesalamine 6, 5
• Consider the increased risk of adverse outcomes with severe disease in elderly patients 5, 9