Long-Term Cannabis Oil Therapy Was Linked to Fewer Patients Using Opioids for Chronic Pain | Research

The takeaway

Among chronic pain patients in Italy who used cannabis-based oils long-term, the proportion not using opioids rose from 32% to 55%, though no change was seen in other pain medication classes.

Pain medicine clinicians; researchers studying opioid-sparing strategies; policymakers considering medical cannabis programs.

Opioid non-users: 32.1% before vs 55.4% after cannabis oil therapy

What the researchers found

After long-term cannabis-based oil therapy, opioid non-users increased significantly from 32.1% to 55.4% (p=0.0023). No significant changes were found in anticonvulsant, antidepressant, or benzodiazepine prescribing patterns.

Why it matters

The opioid-sparing potential of cannabis is one of the most debated topics in pain medicine. This real-world Italian data adds to the growing observational evidence that some patients reduce opioid use after starting cannabis, though causation remains uncertain.

The numbers in context

Opioid non-users increased from 32.1% to 55.4% (p=0.0023). No significant changes for anticonvulsants, antidepressants, or benzodiazepines. High benzodiazepine use prevalence was noted. In patients over 65, antidepressant users decreased from 93.7% to 56.2% (p=0.0313).

How the study worked

Retrospective observational study of patients treated with medical cannabis-based oils at a Pain Medicine Unit in Northern Italy from June 2016 to July 2019. Compared pain medication prescriptions before and after cannabis treatment using the McNemar test. Subgroup analyses by sex, age, comorbidity, and treatment duration.

What this study cannot tell us

Observational and retrospective design cannot establish causation. Patients choosing cannabis may have been more motivated to reduce opioids regardless. No control group for comparison. Single-center study in the Italian healthcare system.

How to read the evidence

Moderate: real-world clinical data with significant results, but limited by retrospective, single-center, uncontrolled design.

When this study was published

Published in 2022, covering data from 2016-2019.

The bigger picture

This study is consistent with other observational data showing opioid reduction among cannabis users, but it contrasts with randomized trials that generally have not found opioid-sparing effects. The specific finding about antidepressant reduction in older patients is intriguing but needs replication.

Questions still open

Would a randomized trial in Italian chronic pain patients confirm the opioid reduction finding? Why was the antidepressant reduction seen only in patients over 65? Does the Italian prescribing context differ meaningfully from other countries?

Common questions

Did cannabis oil replace opioids for these patients?

More patients stopped using opioids after starting cannabis oil (32% to 55%), but the study cannot determine whether cannabis directly caused the reduction or whether other factors were involved.

What type of cannabis oil was used?

The study used cannabis-based oils prescribed through the Italian medical system. Specific formulations and THC/CBD ratios were not detailed in the abstract.

Read the original research

Long-term Cannabis-based oil therapy and pain medications prescribing patterns: an Italian observational study.

European review for medical and pharmacological sciences, 26(4), 1224-1234

View on PubMed ↗Publisher’s paper ↗

Citation

Nunnari, P; Ladiana, N; Ceccarelli, G; Notaro, P. (2022). Long-term Cannabis-based oil therapy and pain medications prescribing patterns: an Italian observational study.. European review for medical and pharmacological sciences, 26(4), 1224-1234. https://doi.org/10.26355/eurrev_202202_28114