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

Treatment Options for Colitis

The treatment of colitis depends on the type (ulcerative colitis vs. Crohn's disease), disease location, and severity, with 5-aminosalicylates (5-ASA) being the first-line therapy for mild to moderate ulcerative colitis, while corticosteroids, immunomodulators, and biologics are reserved for more severe disease or those who fail initial therapy. 1, 2

Ulcerative Colitis Treatment

Mild to Moderate Disease

Proctitis (Rectal Involvement Only)

• First-line: 1g 5-ASA suppository once daily 2
• If incomplete response:
  • Add oral 5-ASA 2-3g daily
  • If still inadequate, add or switch to corticosteroid suppository (e.g., 5mg prednisolone)
  • Optimize oral 5-ASA dose to 4-4.8g daily

Left-sided or Extensive Colitis

• First-line: Oral 5-ASA 2-4g daily, preferably combined with topical 5-ASA for left-sided disease 2, 3
• If no response within 2-4 weeks:
  • Add oral prednisolone 40mg daily with 6-8 week taper 2

Moderate to Severe Disease

1. Oral prednisolone 40mg daily (combined with 5-ASA) 2
2. If no response within 2 weeks:
   • Initiate advanced therapy (biologics or small molecules) 2
   • Options include:
     • Anti-TNF agents (e.g., infliximab)
     • JAK inhibitors
     • S1P agonists
     • Vedolizumab

Maintenance Therapy

• Continue with the agent that induced remission, except corticosteroids 2
• 5-ASA is effective for maintaining remission in ulcerative colitis 4
• For those requiring immunosuppression, options include:
  • Thiopurines (azathioprine, mercaptopurine)
  • Biologics (continue the inducing agent)
  • JAK inhibitors
  • S1P agonists

Crohn's Disease Treatment

Mild to Moderate Disease

• Topical steroids such as budesonide are primarily used 5
• 5-ASA has limited effectiveness in Crohn's disease but may be considered for colonic involvement at sufficiently high doses 5, 4
• Clear evidence supports 5-ASA for postoperative prevention of mild recurrence 5

Moderate to Severe Disease

• Corticosteroids for induction of remission
• For maintenance or steroid-dependent disease:
  • Immunomodulators (azathioprine, mercaptopurine, methotrexate)
  • Biologics (anti-TNF agents, vedolizumab, ustekinumab)
  • Small molecules (JAK inhibitors)

Important Safety Considerations

5-ASA Therapy

• Generally safe with favorable risk-benefit profile 3
• May be continued when adding biologics, though evidence is mixed 3

Immunomodulators (Azathioprine)

• Increased risk of malignancy, particularly skin cancer and lymphoma 6
• Risk of hepatosplenic T-cell lymphoma, especially in young males with IBD 6
• Bone marrow suppression requiring regular blood count monitoring 6
• TPMT/NUDT15 deficiency increases risk of myelotoxicity 6

Biologics (Infliximab)

• Increased risk of serious infections 7
• Risk of lymphoma and other malignancies 7
• Hepatosplenic T-cell lymphoma risk, particularly when combined with azathioprine/6-mercaptopurine 7
• Increased risk of skin cancers requiring periodic skin examinations 7

Treatment Algorithm

1. Assess disease type, location, and severity
2. For ulcerative colitis:
   • Mild-moderate: Start with 5-ASA (oral and/or topical based on disease extent)
   • Moderate-severe: Start with corticosteroids + 5-ASA
   • Steroid-dependent/refractory: Advance to biologics or small molecules
3. For Crohn's disease:
   • Mild: Consider budesonide or high-dose 5-ASA (limited efficacy)
   • Moderate-severe: Corticosteroids followed by immunomodulators or biologics

Special Considerations

• Vaccination status should be assessed before starting immunosuppressive therapy 2
• Thromboprophylaxis is essential during hospitalization for severe colitis 1
• Regular monitoring for malignancy is required for patients on long-term immunosuppression 7, 6
• Combination therapy with anti-TNF agents and immunomodulators increases efficacy but also increases risk of complications, particularly infections and certain malignancies 7

The treatment landscape for colitis continues to evolve with new therapies, but the fundamental approach remains tailored to disease type, location, and severity, with escalation of therapy for those who fail to respond to initial treatments.