What is the initial treatment regimen for Crohn's disease?

Initial Treatment Regimen for Crohn's Disease

The initial treatment for Crohn's disease should be tailored based on disease severity, location, and pattern, with budesonide 9 mg daily recommended as first-line therapy for mild to moderate ileal and/or right colonic disease, and systemic corticosteroids (prednisolone 40-60 mg daily) recommended for moderate to severe disease. 1

Disease Assessment and Classification

• Disease severity should be determined based on a combination of symptoms, objective measures of inflammation, and factors that predict increased risk of complications 1
• Disease location (ileal, colonic, ileocolonic) and behavior (inflammatory, stricturing, penetrating) significantly impact treatment selection 2
• Always rule out complications such as abscess, stricture, or infection that may require specific interventions before initiating treatment 2

Treatment Algorithm Based on Disease Location and Severity

Mild Disease

• For mild Crohn's disease limited to the ileum and/or right colon:

  • Oral budesonide 9 mg daily for 8 weeks is recommended as first-line therapy 1
  • Evaluate response between 4-8 weeks to determine need for treatment modification 1

• For mild Crohn's disease limited to the colon:

  • Sulfasalazine 4-6 g/day is suggested to induce remission 1
  • Evaluate response to sulfasalazine between 2-4 months 1
  • Note that other 5-ASA formulations are not recommended for Crohn's disease of any severity 1, 3

Moderate to Severe Disease

• For moderate Crohn's disease that has failed budesonide therapy:

  • Oral prednisone 40-60 mg/day is recommended to induce remission 1
  • Evaluate response between 2-4 weeks to determine need for treatment modification 1

• For moderate to severe Crohn's disease:

  • Oral prednisone 40-60 mg/day is strongly recommended as first-line therapy 1
  • For hospitalized patients with severe disease, IV methylprednisolone 40-60 mg/day is suggested 1
  • The American Gastroenterological Association suggests early introduction of biologic therapy with or without an immunomodulator rather than delaying their use until after failure of mesalamine and/or corticosteroids 1

Maintenance Therapy Following Remission

• Corticosteroids are not recommended for maintenance of remission in Crohn's disease of any severity 1
• For patients who achieved remission on corticosteroids, thiopurine monotherapy (azathioprine or 6-mercaptopurine) is suggested for maintaining remission 1
• For patients with high risk of relapse or complications, biologic therapy should be considered early 1, 2

Important Considerations and Cautions

• Antibiotics are not recommended for induction or maintenance of remission in Crohn's disease of any severity 1
• Oral 5-ASA formulations (except sulfasalazine for colonic disease) are not recommended for induction or maintenance of remission 1, 3
• Budesonide should not be used for maintenance therapy despite its effectiveness for induction 1
• Monitor for steroid-related adverse effects, including increased risk of abdominal/pelvic abscesses, Cushing syndrome, hypertension, diabetes, and osteoporosis 1

Biologic Therapy Options

• For moderate to severe Crohn's disease requiring biologic therapy:
  • Infliximab: Induction regimen of 5 mg/kg IV at weeks 0,2, and 6, followed by maintenance of 5 mg/kg every 8 weeks 4
  • Adalimumab: Initial dose of 160 mg (Day 1), followed by 80 mg two weeks later (Day 15), then 40 mg every other week starting on Day 29 5
  • For patients with primary non-response to TNF antagonists, ustekinumab is recommended; for secondary non-response, adalimumab or ustekinumab is recommended 1

Common Pitfalls to Avoid

• Avoid using mesalamine (except sulfasalazine for colonic disease) as it shows little benefit for Crohn's disease 3, 6
• Avoid prolonged corticosteroid use or rapid tapering, as this is associated with early relapse 1, 2
• Don't delay appropriate therapy with a step-up approach in high-risk patients, as this may result in disease progression 1
• Always consider alternative explanations for symptoms before determining treatment failure, such as infection, proximal constipation, or other complications 2