What are the treatment options for colitis, specifically ulcerative colitis or Crohn's disease?

Treatment Options for Colitis

For ulcerative colitis, a combination of topical mesalamine (1g daily) with oral mesalamine (2-4g daily) is the first-line treatment for mild to moderate disease, with therapy tailored to match disease extent. 1

Ulcerative Colitis Treatment Algorithm

First-Line Treatment

• Mild to Moderate Disease:
  • Oral mesalamine 2-4g daily (once-daily dosing is as effective as divided doses) 1
  • Combined with topical therapy based on disease location:
    • Proctitis: Mesalamine suppositories 1g daily
    • Left-sided colitis: Mesalamine enemas 1g daily
  • Combination therapy is more effective than either treatment alone 1, 2

Treatment for Inadequate Response to 5-ASA

1. Optimize 5-ASA therapy:

   • Ensure adequate dosing (high-dose >3g/day shows better efficacy)
   • Add topical therapy if using only oral therapy 1

2. Add corticosteroids for flares:

   • Oral prednisone 40mg daily with gradual taper over 8 weeks
   • Alternatively, budesonide MMX for less systemic effects 1

3. Steroid-dependent disease:

   • Add immunomodulators: azathioprine (1.5-2.5 mg/kg/day) or mercaptopurine (0.75-1.5 mg/kg/day) 1
   • Monitor for potential side effects including bone marrow suppression and increased risk of malignancy 3

4. Steroid-refractory disease:

   • Biologics (e.g., infliximab) or cyclosporine 1
   • Note increased risk of lymphoma and other malignancies with TNF blockers, particularly when combined with immunosuppressants 4

Severe Acute Colitis

• Intravenous steroids (methylprednisolone 60 mg/day or hydrocortisone 100 mg four times daily)
• Early surgical consultation if not responding to medical therapy
• Consider subtotal colectomy with ileostomy for emergency cases 1

Crohn's Disease Treatment

The evidence for 5-ASA compounds in Crohn's disease is less robust compared to ulcerative colitis:

• Topical steroids such as budesonide are primarily used in mild Crohn's disease 2
• Most guidelines are critical of 5-ASA use in Crohn's disease, though there is some evidence for high-dose treatment 2, 5, 6
• Clear evidence exists for postoperative use of 5-ASA in cases of mild recurrence 2
• For moderate to severe disease, immunomodulators and biologics are typically required

Monitoring and Follow-up

• Evaluate symptomatic response within 4-8 weeks of initiating therapy 1
• Monitor disease activity using:
  • Fecal calprotectin (remission: <150 mg/g)
  • Complete blood count
  • Inflammatory markers (CRP or ESR)
  • Liver function tests 1
• For patients on 5-ASA medications, periodically monitor renal function 1
• For patients on immunosuppressants or biologics, monitor for infections and malignancies 4, 3

Important Considerations and Pitfalls

• TPMT/NUDT15 deficiency: Test before starting azathioprine to avoid severe myelotoxicity 3
• Hepatosplenic T-cell lymphoma risk: Particularly concerning in young males with IBD on combination therapy of azathioprine/6-MP with TNF blockers 4, 3
• Avoid opioids: They increase risk of dependence, infection, and gut dysmotility 1
• Avoid treatment delays: Promptly escalate therapy in non-responders 1
• Skin cancer risk: Regular skin examinations for patients on immunosuppressants 4, 3
• Infection risk: Screen for opportunistic infections before starting immunosuppressants 4

Special Populations

• Young males with ulcerative colitis: Use caution with combination therapy (azathioprine/6-MP plus TNF blockers) due to increased risk of hepatosplenic T-cell lymphoma 4, 3
• Pregnant patients: Avoid azathioprine unless benefits clearly outweigh risks 3
• Patients with history of malignancy: Carefully consider risk-benefit of immunosuppressants and biologics 4

The treatment approach should follow a step-up strategy, starting with 5-ASA compounds for ulcerative colitis and progressing to more potent immunosuppressants as needed, while carefully monitoring for disease activity and medication side effects.