Adverse event profiles of microscopic colitis in the Japanese Adverse Drug Event Report (JADER) database.

Microscopic colitis (MC) is a chronic inflammatory bowel disease that is characterized by nonbloody watery diarrhea. The epidemiology in Japan differs from that in Europe and the United States, but little information is available from epidemiological surveys of MC in Japan. This study aimed to provide a new hypothesis regarding the factors associated with MC by using the Japanese Adverse Drug Event Report (JADER) database. "Colitis microscopic" (preferred term code: 10056979) cases entered into the JADER database between 2004 and 2021 were analyzed. Of the 246,997 cases in the JADER database, 161 cases were observed to be associated with MC. A Weibull analysis revealed that the median onset duration of MC (interquartile range) was 72.5 (36.0‒125.5) days in lansoprazole users and 116.0 (60.3‒1089.0) days in aspirin users. A multiple logistic regression analysis revealed that MC was significantly associated with the female sex, as well as ages ≥ 60 years and drugs including lansoprazole, aspirin, and nicorandil. A subset analysis revealed that MC was positively associated with obesity in female cases. Our study cannot demonstrate a causal inference between MC and each drug; however, the findings suggest that MC was associated with nicorandil as well as with lansoprazole and aspirin.