Antibiotic-associated adverse drug events at a Japanese academic hospital

Introduction: To promote antimicrobial stewardship activity, an understanding of the incidence of antibiotic-associated adverse drug events (ADEs) is essential. In this study, we aimed to describe the occurrence of antibiotic-associated ADEs at our hospital. Methods: We retrospectively searched the ADE registration system in Osaka University Hospital between 2010 and 2017. Registrations of ADEs were dependent on the patients' drug history and clinical course after hospitalization. We classified the data according to types of ADEs (gastrointestinal, hepatobiliary, renal, cardiac, respiratory, hematologic, neurologic, dermatologic, and musculoskeletal) and antibiotic class. Results: During the study period, we found 707 cases of antibiotic-associated ADEs, accounting for 22.3% of all the cases. Beta-lactam antibiotics constitute more than half of the cases (51.3%). The most common ADE was dermatologic abnormalities (53.4%), followed by liver dysfunction (9.7%) and gastrointestinal symptoms (8.9%). Among all antibiotics, oral third-generation cephalosporins were frequently reported as offending drugs (107 cases), accounting for 29.5% of beta-lactam ADEs and 46.3% of cephem ADEs. Conclusion: Antibiotic-associated ADEs covered approximately 20% of all the ADEs at our hospital. We believe that the data would be helpful in ensuring patient safety by promoting antimicrobial stewardship in hospitals.