Papers of the Week

Despite a rapid expansion of cannabis use for pain management, how cannabis and prescription opioids are co-used and whether co-use improves analgesia and promotes reduction of opioid use in the daily lives of individuals with chronic pain is poorly understood. Based upon ecological momentary assessment (EMA), the present study examined (1) how pain and use of opioids and/or cannabis in the previous moment is associated with individuals' choice of opioids and/or cannabis in the next moment, (2) the effects of co-use on pain severity and pain relief, and (3) whether daily total opioid consumption differs on days when people only used opioids vs. co-used. Adults with chronic pain (N=46) using both opioids and cannabis who were recruited online completed a 30-day EMA. Elevated pain did not increase the likelihood of co-use in subsequent momentary assessments. Switching from sole use of either opioids and cannabis to co-use was common. Neither co-use nor sole use of either cannabis or opioids were associated with reductions in pain in the next moment. However, participants reported the highest daily perceived pain relief from co-use compared to cannabis and opioid use only. Post-hoc analysis suggested recall bias as a potential source of this discrepant findings between momentary vs. retrospective assessment. Lastly, there was no evidence of an opioid-sparing effect of cannabis in this sample. The present study shows preliminary evidence on cannabis and opioid co-use patterns, as well as the effects of co-use on pain and opoid dose in the real-world setting.