What is the recommended treatment regimen for a patient with Crohn's disease?

Treatment of Crohn's Disease

Treatment selection for Crohn's disease must be based on disease severity, location, and risk stratification, with biologics as first-line therapy for moderate-to-severe disease or high-risk features, and budesonide or sulfasalazine reserved only for truly mild, low-risk disease. 1, 2

Disease Severity Assessment

Before selecting therapy, determine disease severity using a combination of:

• Clinical symptoms (abdominal pain, diarrhea, weight loss) 1
• Objective inflammatory markers (CRP, fecal calprotectin) 2
• Endoscopic findings and extent of disease involvement 1
• Risk factors predicting poor prognosis 2

High-Risk Features Requiring Biologic Therapy

Start anti-TNF therapy immediately as first-line treatment if any of the following are present: 2, 3

• Stricturing or penetrating disease behavior 2, 3
• Perianal fistulas 2, 3
• Age under 40 years at diagnosis 2, 3
• Need for corticosteroids at presentation 2, 3
• Extensive disease involvement 3

Treatment Algorithm by Disease Severity

Mild Disease (Ileal or Right Colonic)

• First-line: Oral budesonide 9 mg/day 1, 2
• Evaluate response at 4-8 weeks 1
• Budesonide should NOT be used for maintenance therapy 1
• If inadequate response, escalate to prednisone or biologics 1, 2

Mild Disease (Colonic Only)

• Consider: Sulfasalazine 4-6 g/day 1
• Evaluate response at 2-4 months 1
• Do NOT use other oral 5-ASA preparations—they are ineffective 1

Moderate-to-Severe Disease Without High-Risk Features

• First-line: Oral prednisone 40-60 mg/day 1, 2
• Evaluate response at 2-4 weeks 1, 2
• Taper gradually over 8 weeks if response achieved 2
• If steroid-dependent or steroid-resistant, switch to biologics immediately 2

Moderate-to-Severe Disease With High-Risk Features

• First-line: Anti-TNF therapy (infliximab or adalimumab) 2, 3, 4
• Dosing for infliximab: 5 mg/kg IV at weeks 0,2, and 6, then every 8 weeks 4
• Consider combination therapy with thiopurine or methotrexate to reduce immunogenicity and improve outcomes, particularly in young patients 2, 3
• Evaluate response at 8-12 weeks 3
• Alternative biologics include vedolizumab (evaluate at 10-14 weeks) or ustekinumab (evaluate at 6-10 weeks) 2

Severe Disease Requiring Hospitalization

• IV methylprednisolone 40-60 mg/day (typically 40 mg every 8 hours) 1, 2
• Evaluate response within 1 week 1, 2
• If inadequate response, initiate biologic therapy 2
• Consider joint medical-surgical management 2

Maintenance Therapy

Corticosteroids (prednisone, budesonide, or IV methylprednisolone) must NEVER be used for maintenance therapy—they are completely ineffective and associated with significant toxicity. 1, 2

After Steroid-Induced Remission

• Azathioprine or mercaptopurine for maintenance in patients who achieved remission with steroids 1
• Consider thiopurines for patients with adverse prognostic factors even if not previously used 1
• Methotrexate only if patient needed it for induction, or cannot tolerate thiopurines 2

After Biologic-Induced Remission

• Continue the same biologic indefinitely 2, 5
• Infliximab 5 mg/kg every 8 weeks 4
• Do NOT routinely discontinue after 1 year of remission—this leads to relapse in approximately 33% of patients within 1-2 years 5
• Consider continuing combination therapy versus de-escalating to monotherapy based on individual infection/lymphoma risk 3

Critical Pitfalls to Avoid

• Never use oral 5-ASA (mesalamine) for Crohn's disease—it is ineffective for both induction and maintenance 1
• Never use antibiotics routinely for inducing or maintaining remission 1
• Never use corticosteroids for maintenance—this is a strong recommendation against their use 1, 2
• Do not delay biologics in high-risk patients—early intervention prevents complications 2, 3
• Do not switch biologics in patients doing well on current therapy 5
• Avoid long-term opioid use—associated with poor outcomes 2
• Do not use probiotics, omega-3 fatty acids, marijuana, or naltrexone—no evidence of benefit 2

Monitoring Requirements

• Regular monitoring with objective markers (endoscopy, CRP, calprotectin, imaging) is essential due to disconnect between symptoms and inflammation 2
• Monitor thiopurines and methotrexate according to BNF/BNFC guidelines, including monitoring for neutropenia even with normal TPMT activity 1
• Screen for tuberculosis before initiating biologics 4, 6

Special Considerations

• Up to 50% of patients require surgery within 10 years despite medical therapy 2
• Combination therapy with anti-TNF plus immunomodulator increases risk of hepatosplenic T-cell lymphoma, particularly in adolescent and young adult males 4
• For patients with pain and depression, tricyclic antidepressants may offer dual benefits 2