Background:

As the literature grows on opioid use, the impact of simultaneous cannabis use has hitherto been mostly unexplored. In this study, we assessed the effects of cannabis use on postoperative opioid utilization in opioid-naive patients undergoing single level fusions of the lumbar spine.

Methods:

Using an all-payer claims database, the medical records of 91 million patients were analyzed to identify patients who had undergone single level lumbar fusions between January 2010 and October 2020. Rates of opioid utilization at 6 months following index procedure (morphine milligram equivalents/day), the development of opioid use disorder, and the rates of opioid overuse were assessed.

Results:

Following examination of 87,958 patient records, 454 patients were matched and distributed equally into cannabis user and non-cannabis user cohorts. At six months following index procedure, cannabis users were equal to non-users in their rates of prescribed opioid utilization (49.78%, p>.99). Cannabis users used smaller daily dosages compared to non-users (51.1±35.05 vs. 59.72±41, p=.003). On the other hand, the proportion of patients diagnosed with opioid use disorder was found to be significantly higher among patients using cannabis (18.94% vs. 3.96%, p<.0001).

Conclusion:

Compared to non-cannabis users, opioid-naive patients who are cannabis users undergoing lumbar spinal fusions are at a higher risk of developing opioid dependence following surgery, despite having decreased daily dosages of opioids overall. Further studies should explore the factors associated with the development of opioid use disorder and the details of concurrent marijuana use to effectively treat pain while limiting the potential for abuse.