Why is budesonide (corticosteroid) used to treat microscopic colitis?

Budesonide for Microscopic Colitis: First-Line Treatment with Strong Evidence

Budesonide is the first-line treatment for microscopic colitis due to its highly favorable risk/benefit profile, with patients more than twice as likely to achieve clinical remission compared to no treatment. 1 The American Gastroenterological Association (AGA) provides a strong recommendation with high-quality evidence supporting budesonide over other treatments for induction of clinical remission in symptomatic microscopic colitis.

Efficacy of Budesonide

Budesonide demonstrates superior efficacy compared to other treatments:

• Patients treated with 9 mg of budesonide daily are 2.52 times more likely to achieve clinical remission over 7-13 days compared to no treatment (95% CI: 1.45-4.4) 1
• Recommended dosing is 9 mg daily for 8 weeks 2
• Budesonide improves both clinical symptoms and histological inflammation 1
• Quality of life improvements have been documented in patients treated with budesonide 2

Advantages of Budesonide Over Other Treatments

Budesonide offers several advantages that make it the preferred treatment:

• Low risk of serious adverse events 1
• Convenient once-daily dosing 1
• Superior efficacy compared to mesalamine (AGA strong recommendation, high-quality evidence) 1
• Effective for both induction and maintenance therapy 2
• Better targeted local anti-inflammatory effect in the intestine with minimal systemic absorption

Treatment Algorithm for Microscopic Colitis

1. First-line: Budesonide 9 mg daily for 8 weeks 1, 2
2. If budesonide not feasible (contraindications, cost, preference):
   • Mesalamine (conditional recommendation, moderate quality evidence) 1
   • Bismuth salicylate (conditional recommendation, low quality evidence) 1
   • Prednisolone/prednisone (conditional recommendation, very low quality evidence) 1
3. For budesonide-refractory cases:
   • Consider anti-TNF therapy (limited evidence from case series) 2, 3, 4

Important Clinical Considerations

• Medication review: Identify and discontinue medications associated with microscopic colitis when possible (NSAIDs, PPIs, SSRIs, statins) 2
• Screen for associated conditions: Celiac disease (present in 5-7% of patients) and bile acid malabsorption (present in 29-41% of cases) 2
• Monitor bone health: Essential for patients on long-term budesonide therapy 2
• High relapse rate: Symptom relapse occurs in 46-80% of patients within 6 months of treatment cessation 5

Common Pitfalls to Avoid

• Failing to obtain biopsies from multiple segments of the colon during diagnosis 2
• Overlooking associated conditions like celiac disease or bile acid malabsorption 2
• Not considering cost factors: While budesonide is the most effective treatment, it is expensive; alternative therapies may be considered if cost is prohibitive 1
• Neglecting bone health monitoring in patients on long-term budesonide therapy 2

Budesonide remains the cornerstone of microscopic colitis treatment due to its proven efficacy and favorable safety profile, making it the clear first choice for managing this condition.