What is the recommended oral medication for Crohn's disease affecting the small bowel?

Oral Medications for Crohn's Disease Affecting the Small Bowel

For Crohn's disease affecting the small bowel, oral budesonide 9 mg/day is the recommended first-line therapy for mild to moderate disease, while azathioprine (1.5-2.5 mg/kg/day) or mercaptopurine (0.75-1.5 mg/kg/day) are recommended for maintenance therapy after remission is achieved. 1

Initial Treatment Based on Disease Severity

Mild to Moderate Small Bowel Crohn's Disease

1. First-line therapy: Oral budesonide 9 mg/day 1

   • Particularly effective for ileal and/or right colonic disease
   • Superior response rate compared to placebo with clinical remission rate nearly twice that of placebo 1
   • Evaluate response between 4-8 weeks to determine need for therapy modification 2, 1

2. Not recommended:

   • Oral 5-ASA (mesalamine) is not recommended for small bowel Crohn's disease despite some older evidence of efficacy 2, 1
   • Sulfasalazine should only be considered for mild disease limited to the colon (4-6 g/day), not for small bowel disease 2
   • Systemically absorbed antibiotics are not recommended 2, 1

Moderate to Severe Small Bowel Crohn's Disease

1. Corticosteroids:

   • Oral prednisone 40-60 mg/day is recommended for moderate to severe disease 2, 1
   • Evaluate response between 2-4 weeks 2, 1
   • For hospitalized patients with severe disease, IV methylprednisolone 40-60 mg/day is suggested 2, 1

2. Biological therapies:

   • Consider early for patients with extensive disease or poor prognostic factors 1
   • Options include:
     • Anti-TNF agents (infliximab, adalimumab, certolizumab)
     • Ustekinumab
     • Vedolizumab
   • Combination therapy with an immunomodulator may improve efficacy 1

Maintenance Therapy

1. First-line maintenance options:

   • Azathioprine (1.5-2.5 mg/kg/day) or mercaptopurine (0.75-1.5 mg/kg/day) 2, 1
   • Particularly important for patients with adverse prognostic factors 1

2. Alternative maintenance options:

   • Methotrexate (15-25 mg weekly, preferably parenteral) for patients who cannot tolerate thiopurines 2, 1
   • Continue the same biologic that induced remission 1

3. Not recommended for maintenance:

   • Budesonide is not recommended for maintenance therapy 2, 1
   • Corticosteroids should not be used for maintenance due to significant side effects 1
   • Mesalamine has limited benefit for maintenance in small bowel Crohn's disease 2

Special Considerations

Stricturing Disease

• Endoscopic balloon dilation for short (<5 cm) strictures 1
• Surgical intervention for strictures >5 cm or when balloon dilation fails 1

Important Monitoring and Lifestyle Factors

• Smoking cessation is strongly recommended as it worsens Crohn's disease 1
• Monitor for complications of both disease and treatments:
  • Infection risk with biologics and immunosuppressants
  • Malignancy risk
  • Osteoporosis with corticosteroid use

Common Pitfalls to Avoid

1. Using 5-ASA preparations for small bowel disease

   • Despite older studies showing some benefit 3, current guidelines recommend against using oral 5-ASA for Crohn's disease of any severity 2, 1

2. Prolonged corticosteroid use

   • Plan taper of corticosteroids over 8-12 weeks 1
   • Initiate maintenance therapy early to prevent relapse and steroid dependence

3. Inadequate dosing of immunomodulators

   • Ensure adequate dosing of azathioprine (1.5-2.5 mg/kg/day) or mercaptopurine (0.75-1.5 mg/kg/day) 2
   • Allow sufficient time for these medications to take effect (may take 2-3 months)

4. Delaying biological therapy in high-risk patients

   • Consider early biological therapy for patients with risk factors for complicated disease 1