Clinical Medicine Insights: Gastroenterology

Background: The incidence of microscopic colitis (MC) is increasing, but its etiology remains unknown. Case reports and limited controlled data suggest that commonly prescribed drugs may be triggers. The aim of this study was to evaluate the prevalence of selected medication use [Proton pump inhibitors (PPIs), HMG-CoA reductase inhibitors (statins), and Selective serotonin reuptake inhibitors (SSRIs)] in patients with MC compared to ‘random controls’ and ‘diarrhea controls.’

Methods: All patients were selected from primary care practices of a university health system during 2002 to 2007. Patients with biopsy proven lymphocytic or collagenous colitis were identified as cases. Diarrhea controls consisted of a 10:1 random sample of patients with chronic diarrhea and normal colon biopsies. Ten random controls were matched to each case on sex and index date (date of biopsy proven diagnosis). Drugs prescribed within the year prior to the index date were collected from the electronic medical record system.

Results: 26 cases (median age 68.9 yrs), 259 random, and 259 diarrhea controls were identified. The adjusted ORs for PPI, SSRI, and statin prescription within 12 months of diagnosis of MC between cases and diarrhea controls were 0.28 (0.07–1.07), 0.87 (0.28–2.64), 1.12 (0.34–3.71) respectively. Use of PPI and statins was less common in MC patients than in random controls (P < 0.05 for both comparisons).

Conclusions: While prior data suggest that PPIs, statins, and SSRIs may be etiologically related to MC, our study found no increased association with these drugs.