Background: Opioid-induced respiratory depression (RD) is a potentially life-threatening adverse drug event. This study used the Japanese Adverse Drug Event Report (JADER) database to investigate the profile of opioid-related RD in non-cancer patients.
Methods: We analyzed data recorded in the JADER database between April 2004 and February 2020, which were downloaded from the Pharmaceutical and Medical Devices Agency website. Reporting odds ratios for RD were calculated for the 20 opioids approved in Japan, and daily dose and onset time were further analyzed for opioids used in chronic non-cancer pain (CNCP).
Results: Among the opioids, RD adverse event signals were detected for 22 combinations of opioids and administration routes in non-cancer patients. Of these combinations, transdermal buprenorphine and oral tramadol/acetaminophen were approved for CNCP and tended to be reported more frequently in elderly patients. The median daily doses of transdermal buprenorphine and oral tramadol/acetaminophen were 10.0 and 22.5 mg of daily oral morphine equivalent doses, respectively, which are within the standard range for starting dosage. The median time-to-onset of transdermal buprenorphine and oral tramadol/acetaminophen was 6.5 and 4.0 days, respectively, and 75% of cases were reported within 20 to 40 days after the start of treatment. The hazard type for both opioids was classified as early failure.
Conclusions: Our findings suggest that elderly CNCP patients should be closely monitored after the start of opioid treatment, especially during the first week and, if possible, for 1 month, even if starting doses are within ranges recommended by the manufacturer and guidelines.
Keywords: Japanese Adverse Drug Event Report database; non-cancer patients; opioid; respiratory depression; time-to-onset analysis.