On July 29, ASA representative, Robert Hurley, M.D., Ph.D., a member of ASA’s Committee on Pain Medicine, presented comments at a Food and Drug Administration (FDA) public workshop on clinical development programs for opioid conversion. According to the FDA, the goal of this scientific workshop was to bring together academic experts “to identify gaps in existing knowledge regarding equianalgesic opioid conversion in clinical practice, to develop a research agenda to address these gaps, and to identify mechanisms for communicating safe opioid analgesic conversion strategies to prescribers.”
In his formal comments at the workshop, Dr. Hurley explained that medical education regarding opioid conversion is necessary for physicians. He also highlighted that opioid conversion recommendations must balance the risk of over-dosing with the risk of under-dosing. Dr. Hurley shared that opioid conversion tables are helpful, but their ratios vary among sources, are missing medications and are often overly simplistic. In addition, he observed that opioid conversion tables have been derived primarily from acute post-surgical pain, which differs from chronic pain conditions.
Dr. Hurley offered a staged approach for opioid conversion labeling:
- Labels should identify which conversions have sufficient evidence to make a conservative dose ratio recommendation for the initiation of a new opioid. The table should produce conversion ratios that are conservative enough that an additional automatic reduction in the calculated equianalgesic dose is not required and excludes opioids from standardized scales that have known significant variability such as buprenorphine or methadone. For those that do not, no ratio can be listed until appropriate relative potency studies are performed.
- Federal funding sources should be used to develop comparative potency research studies in the chronic pain population that are opioid naïve in sufficient numbers to determine age, sex and conversion directionality differences, at a minimum. The research studies should use a reference standard of oral morphine, report responses at peak effect and at stable state, and develop high, low and mean conversion ratios.
- Federal funding sources should be used to repeat these studies in opioid tolerant chronic pain patients to address the effects of prior opioid exposure.
Dr. Hurley recommended that the research findings and development of opioid conversion tables be communicated through peer-reviewed publications. In addition, opioid conversion tables should be available in print form and in electronic form, including web-based, tablet-based, and smartphone-based applications.
ASA will continue working with the FDA on this important issue. Visit our pain medicine advocacy webpage
to learn more about ASA’s advocacy on behalf of our members who practice pain medicine.