Abstract
Adverse events associated with opioid use in palliative care have been extensively studied. However, predicting the occurrence of adverse events based on the specific opioid used remains difficult. This study aimed to comprehensively analyze the adverse events related to µ-opioid receptor stimulation of opioids approved in Japan and investigate the tendencies of adverse event occurrence among different opioids. We utilized the FDA Adverse Event Reporting System database to extract reported adverse events for opioids approved in Japan. Cluster analysis was performed on reporting odds ratios (RORs) of adverse event names among opioids to visualize relationships between opioids and adverse events, facilitating a comparative study of their classifications. We calculated the RORs of adverse events for the target opioids. Cluster analysis based on these RORs resulted in five broad clusters based on the reported adverse events: i.e., strong opioids, weak opioids, loperamide, tapentadol, and remifentanil. This study provides a comprehensive classification of the association between μ-opioid-receptor-stimulating opioids and adverse events.