Cannabis Use Linked to Lower Early Opioid Prescription Use After Neck Fusion

A 2023 study found that patients with a documented history of cannabis use were less likely to fill an opioid prescription shortly after single-level anterior cervical discectomy and fusion (ACDF) surgery. The findings suggest a possible association between cannabis use and lower early opioid use, but they do not show that cannabis prevents opioid dependence or improves postoperative pain control.

The study, published in the North American Spine Society Journal, examined patients undergoing ACDF, a procedure that removes a damaged disc in the neck and fuses the neighboring vertebrae. The operation is commonly performed to relieve pressure on the spinal cord or nerves and may improve symptoms such as neck or arm pain, weakness, numbness, and tingling. MedlinePlus provides additional background on cervical diskectomy and fusion.

Researchers used the PearlDiver insurance-claims database to conduct a retrospective case-control study. They identified adults who underwent single-level ACDF between January 2010 and October 2020 and had a prior diagnosis code for cannabis use, dependence, or abuse. Patients who had filled an opioid prescription during the three months before surgery were excluded. Each of the 1,339 patients in the cannabis group was matched with a patient in a control group based on age, sex, and Charlson Comorbidity Index.

The clearest difference appeared during the first three days after surgery. About 2.7% of patients in the cannabis group filled an initial opioid prescription, compared with approximately 7.5% of patients in the control group. At 30 and 60 days, however, the groups did not differ significantly in the proportion of patients filling prescriptions.

The researchers also compared opioid doses using morphine milligram equivalents (MME), a standardized way to express the strength of opioid prescriptions. At 60 days after surgery, the average daily amount prescribed was 48.5 MME in the cannabis group and 59.4 MME in the control group. The study did not show that patients took these amounts, only that the prescriptions were dispensed at those doses.

Prescription patterns later in recovery were less straightforward. Across the full study population, 1.8% of cannabis users and 3.1% of controls filled additional opioid prescriptions. Among only the patients who filled an initial prescription, the cannabis group actually had a numerically higher rate of additional prescriptions at 30 days—about 34% versus 24%—although the difference was not statistically significant. There were no significant differences between groups at 60 or 90 days.

These results therefore indicate an association with lower early prescription fulfillment and a lower average prescribed dose at one later time point—not proof that cannabis reduced pain, replaced opioids, or lowered the risk of opioid use disorder. The authors called for further research into whether cannabis has a meaningful role in postoperative pain management.

The study has several important limitations. Because it was observational and based on insurance claims, it cannot establish cause and effect. A diagnosis code does not reveal how often a person used cannabis, the dose or method of consumption, or whether the product contained THC, CBD, or both. The database also could not capture pain scores, medication taken from a prescription, nonprescription cannabis use, or other factors that might influence opioid prescribing and recovery.

The study’s findings should also be interpreted alongside other research rather than treated as settled evidence. For example, a separate retrospective study of ACDF patients reported that preoperative marijuana use was associated with a higher risk of reoperation, while finding no significant reduction in postoperative opioid use. These differing results illustrate why cannabis should not be assumed to be either beneficial or harmful for every patient undergoing spine surgery.

The study also compared the cannabis group’s prescriptions with the 50-MME level used in opioid-prescribing guidance as a point at which clinicians should reassess benefits and risks. The CDC’s opioid prescribing guideline emphasizes that 50 MME per day is a clinical guidepost, not a risk-free threshold: overdose risk increases with dosage, and no dose completely eliminates risk.

Patients recovering from ACDF should discuss cannabis, opioids, and other medications with their surgeon or prescribing clinician. Cannabis products can vary widely and may interact with prescription drugs or affect alertness, coordination, and decision-making. For now, the evidence supports continued study—not the conclusion that cannabis is a proven way to prevent opioid dependence after neck fusion surgery.