Can statins (HMG-CoA reductase inhibitors) exacerbate microscopic colitis?

Statins and Microscopic Colitis: Association and Management

Statins are well-established triggers of microscopic colitis and should be discontinued in patients with this condition when possible. 1

Evidence for Statin Association with Microscopic Colitis

The relationship between statins and microscopic colitis has been documented in several studies with varying levels of evidence:

• The most recent and comprehensive evidence from Praxis Medical Insights (2025) identifies statins as one of the well-established triggers of microscopic colitis, along with NSAIDs, PPIs, and SSRIs 1

• Earlier research from 2007 found that statin use was associated with a 4.6-fold increased risk of lymphocytic colitis compared to controls (OR 4.6,1.04-20) 2

• A 2016 study investigating drug-induced microscopic colitis focused primarily on NSAIDs and PPIs but also noted statins as a potential contributing medication 3

However, more recent evidence presents some contradictions:

• A 2024 retrospective study found no increased risk of clinical relapse requiring budesonide treatment in microscopic colitis patients using statins (OR: 0.83,95% CI: 0.35-1.99) 4

• A nationwide Swedish study from 2025 examining older adults found minimal evidence for a causal relationship between statins and microscopic colitis risk 5

Management Algorithm for Patients with Microscopic Colitis and Statin Use

1. Medication Review and Discontinuation

   • Conduct a thorough medication review focusing on potential triggers including statins 1
   • Consider discontinuation of statins in patients with microscopic colitis when clinically appropriate 1
   • Weigh cardiovascular benefits against gastrointestinal symptoms

2. First-line Treatment

   • If statin discontinuation is not possible or symptoms persist:
     • Initiate budesonide 9 mg daily for 8 weeks (strong recommendation based on moderate quality evidence) 1
     • Monitor for symptom improvement

3. Second-line Options

   • If symptoms persist despite statin discontinuation and budesonide:
     • Consider mesalamine (conditional recommendation, moderate quality evidence) 1
     • Bismuth salicylate is a third-line option (conditional recommendation, low quality evidence) 1

4. Screening for Associated Conditions

   • Screen for bile acid malabsorption (present in 41% of collagenous colitis and 29% of lymphocytic colitis) 1
   • Consider celiac disease screening (present in 5-7% of microscopic colitis patients) 1

Important Clinical Considerations

• The American Gastroenterological Association recommends identifying and discontinuing medications associated with microscopic colitis, including statins 6, 1

• When patients have ongoing symptoms despite medical therapy, consider coexisting causes of chronic diarrhea such as celiac disease or bile acid malabsorption 6

• Bone health monitoring is essential for patients on long-term budesonide therapy 1

Common Pitfalls to Avoid

• Failing to identify and discontinue potential medication triggers, including statins 1
• Not obtaining biopsies from multiple segments of the colon during diagnosis 6
• Overlooking associated conditions like celiac disease or bile acid malabsorption 1
• Neglecting bone health monitoring in patients on long-term budesonide therapy 1

The evidence suggests that while statins may contribute to microscopic colitis in susceptible individuals, the relationship may be complex and potentially influenced by other factors. Nevertheless, medication review and consideration of statin discontinuation remain important components of microscopic colitis management.