Abstract
<title>Abstract</title> <p> <bold>Background:</bold> The growing complexity of perioperative drug therapy, driven by an aging population, technological advancements, and an increasing number of surgical procedures, has led to an increase in drug-related incident reports. However, whether comprehensive pharmacist-led management can mitigate these incidents remains unclear. In this study, we aimed to investigate the effects of perioperative cross-sectional pharmacological management on medical safety. <bold>Methods:</bold> This retrospective observational study evaluated medication-related incidents at Kameda Medical Center between 2013 and 2023 before and after implementation of a cross-sectional pharmacist-led perioperative care system. Incident severity and pharmacist interventions based on World Health Organization (WHO) Safe Surgery goals were analyzed. Statistical analyses were performed using the chi-square and Mann–Whitney U tests. <bold>Results:</bold> During Phase I (2013–2018), pharmacists at Kameda Medical Center primarily managed postoperative pain and ward-based medication oversight. In Phase II (2018–2023), a cross-sectional pharmaceutical management system encompassing preoperative outpatient clinics, operating rooms, and wards was introduced. The rate of medication-related incidents remained unchanged despite a 16% increase in surgical procedures. However, pharmacist interventions increased markedly, from an annual average of 149.6 cases in Phase I to 892.4 cases in Phase II. Level 0 and Level 1 incidents, representing near-misses and minor events, increased significantly, suggesting that proactive pharmacist involvement prevented more severe incidents. Interventions aligned with the Safe Surgery goals included pain management, prevention of anesthesia-related adverse events, mitigation of bleeding risks, allergy management, and optimization of antimicrobial prophylaxis. Standardized training and evidence-based checklists during Phase II likely improved the consistency and quality of care. Furthermore, integration of perioperative pharmaceutical records into the electronic medical systems enhanced interdisciplinary communication. <bold>Conclusions:</bold> These findings indicate that cross-functional, team-based pharmaceutical care contributes to improved perioperative safety and may serve as a model for future systems. This study provides a basis for evaluating scalability and cost-effectiveness across diverse healthcare settings. </p>