Potent opioid analgesics are applicable for the treatment of severe pain, especially in cancer patients. Management of opioid-induced adverse effects is important to continue treatment with opioids because these drugs are associated with a variety of kinds of adverse effect, such as deliria and respiratory depression. However, information regarding these adverse effects in Japanese patients is limited. Therefore, we searched and analyzed a database for drug-induced adverse effects in Japan, the Japanese Adverse Drug Event Report database（JADER）, to acquire information related to the adverse effects induced by potent opioids such as morphine, fentanyl, and oxycodone. Cases with adverse effects associated with medications for palliative care were extracted from JADER, and types and frequencies of the events for each analgesic were analyzed. As a result, a lot of common adverse effects were found among the three opioids. However, the orders of their frequency differed among the analgesics. In principal component analysis, the property of morphine was intermediate between those of fentanyl and oxycodone. These findings may contribute to safe and effective pain control for patients receiving medical treatment with potent opioid analgesics.

　Recently, the amount of oxycodone used for palliative care in the medical setting has markedly increased in Japan. As the beneficial effects and pharmacokinetic profile of oxycodone are dependent on patient characteristics such as gender and age, it is important to understand the relationships between adverse effects and patient characteristics when administering oxycodone therapy to patients suffering from cancer-related pain. Therefore, we used the Japanese Adverse Drug Event Report Database administered by the Pharmaceuticals and Medical Devices Agency, Japan, to analyze the frequencies of adverse events associated with oxycodone therapy. Furthermore, the statistical significance of the associations between adverse effects and background parameters, such as age and gender, was determined using Fisher’s exact test and odds ratio. As a result, it was found that delirium, nausea, and vomiting are the most common adverse events seen after oxycodone administration. These symptoms are also caused by morphine and fentanyl. Nausea and diarrhea in female and interstitial lung disease in male reported more frequently. On the other hand, somnolence and delirium in elderly patients reported more often than in young patients. These findings might be helpful for managing the adverse effects of pain therapy on an individual basis.