S435 Drug Exposure and Microscopic Colitis: Analysis of a Large Multi-Institutional Research Network

Introduction: Microscopic colitis (MC) is increasing in incidence worldwide. While its etiology remains unclear, an association with various medications has been suggested, though large-scale data are limited. We aimed to determine the risk of MC in patients exposed to specific drugs within a large, multi-institutional healthcare database. Methods: We conducted a retrospective cohort study using the TriNetX research network. Patients aged >18 years with no prior history of MC or inflammatory bowel disease undergoing colonoscopy with biopsy were included and divided into cohorts based on exposure to drugs of interest within 3 months prior to procedure. Control cohorts comprised patients with no prior exposure to the studied drug. After crude analysis, unexposed cohorts were propensity score-matched for age, gender, race, smoking status, and alcohol use for a propensity matched analysis. Primary outcome was diagnosis of MC following procedure. Results: A total of 1,234,310 patients undergoing colonoscopy with biopsy were analyzed across the cohorts. Among major drug classes, selective serotonin reuptake inhibitors (SSRIs; RR 1.40 [1.31-1.51]) and nonsteroidal anti-inflammatory drug (NSAIDs; RR 1.05 [1.01-1.11]) were noted to be significantly associated with increased risk of MC diagnosis. Highest risk among SSRIs was noted with sertraline (RR 1.58 [1.39-1.79]) while diclofenac was noted to have the highest risk among NSAIDs (RR 1.61 [1.41-1.84]). As a class, proton pump inhibitors were associated with a lower risk of MC diagnosis (RR 0.86 [0.80-0.91]), however dexlansoprazole showed an independent increase in risk (RR 2.62 [1.38-4.95]). H2 blocker use was noted to have no increased risk of MC diagnosis. Statins were noted to be associated with a decreased risk of MC diagnosis (RR 0.88 [0.84-0.93]). Among Parkinson’s disease drugs, the combination agent stalevo was noted to be associated with significant increase in risk. Conclusion: In this large cohort, we identified important associations between medication use and MC. SSRIs, particularly sertraline, and certain NSAIDs (diclofenac, celecoxib) were associated with highest increase in risk. Interestingly, overall use of statins, histamine H2-receptor antagonists, and proton pump inhibitorss showed no increase in risk, though specific drugs within these classes (e.g., dexlansoprazole) demonstrated an association. These findings add important data for identifying potential culprit agents in patients with MC and can help identify alternative medications from the same drug class if continued use is needed.