There are already numerous studies showing how cannabis use can curb opioid use in relation to a myriad of diseases and conditions. Now, a new study reveals major neck surgery, as well as cannabis consumers who end up using less opioids in recovery than non-consumers.
A team of researchers at the University of Connecticut School of Medicine conducted the study, Journal of the North American Spine Society.
Expanding Literature on Cannabis, Pain, and Orthopedics
This study specifically investigates anterior cervical discectomy and fusion (ACDF). This procedure removes all or part of a damaged disc in the spine, effectively relieving pressure on the spinal cord or nerve roots in the neck and reducing associated pain, weakness, numbness and tingling.
The study’s introduction nods to “growing evidence suggesting that cannabis use may have a positive impact on opioid intake.” It also notes the growing literature surrounding cannabis and its potential medical benefits, but notes that only a handful of publications have explored cannabis’ potential for orthopedic surgery.
Investigators utilized a retrospective case-control design to assess opioid use after ACDF surgery. The researchers used PearlDiver to examine a patient who underwent a single level of her ACDF between January 2020 and October 2020.
Patients with a “previous diagnosis of cannabis use, dependence, or abuse” were then included in the study group. Patients under the age of 18 years or those who filled an opioid prescription within 3 months after surgery. The researchers matched age, gender, and the Charlson Comorbidity Index (which predicts 10-year mortality in patients with a range of related conditions) to form a control group of “undiagnosed cannabis use.”
A total of 1,339 patients were included in each group.
Cannabis users tend to use less postoperative opioids
Overall, the cannabis group had fewer patients filling opioid prescriptions within 3 days after surgery, which is consistent with the current literature on cannabis use and need for opioid medication.
More than 7% of patients in the control group met their first opioid prescription within 3 days after surgery, compared with 2.7% in the cannabis use group. There was no difference in patients who submitted prescriptions 30 and 60 days after treatment, and no patients in the cannabis group filled out their first prescription after 90 days after treatment.
In discussing the study results, the authors also noted that the control group required higher doses of opioids than the cannabis group at 60 days.
“Daily MME” [morphine milliequivalent] Cannabis group doses were below 50 MME for prescriptions filled within 60 days postoperatively, while the control group had a 60 MME level at the same time point,” the authors state. “The 50 MME threshold is important because research suggests that opioid doses above 50 MME per day are significantly associated with increased risk of opioid-related death and/or hospitalization. This suggests that patients who use cannabis may be at lower risk of opioid dependence than nonusers.”
In total patients, approximately 3.1% of the control group prescribed an additional opioid prescription compared to 1.8% of the cannabis group. Looking only at patients who filled out their first prescription, the cannabis group scored higher, with about 34% in the cannabis group and 24% in the control group creating additional prescriptions, although the authors said this was not a statistically significant difference.
There was no difference in the number of prescriptions filled at both 60 and 90 days post-procedure.
Conclusion and future prospects
“In summary, patients known to be using cannabis completed fewer opioid prescriptions following the ACDF protocol and prescribed lower daily doses than controls, suggesting that cannabis use may reduce opioid requirements in this population.” However, future studies investigating the impact of cannabis use on postoperative pain control are clearly needed,” the study concludes.
The researchers acknowledge that there were inherent limitations given the use of large claims databases. First, the data are based solely on billable codes, which may lead to selection bias in cannabis groups that “question the accuracy of diagnostic codes for cannabis use.” According to the researchers, this means that cannabis use is likely underestimated in this study.
Also, the code was common to cannabis and did not distinguish between CBD and THC. This could also significantly change general health effects and need for opioids. Also, this database was not designed to show the amount of prescriptions used after the prescription was filled, only if the prescription was filled in the first place.
The researchers also noted the changing climate surrounding cannabis, noting that 15 states enacted laws partially or fully legalizing cannabis between 2010 and 2020, the period covered by the database.
“As marijuana use and awareness continue to develop, our ability to collect accurate data may improve as patients become more outspoken about their use of marijuana, have more access to both medical and recreational products, and are better educated about the benefits and risks of marijuana,” the authors write. “These ongoing changes will inevitably affect the reliability of data collection in this area.”