Older Chronic Pain Patients Starting Medical Cannabis Were More Likely to Later Start Opioids
Opioid-naive older adults prescribed medical cannabis were 54% more likely to initiate long-term opioids the following year.
Quick Facts
What This Study Found
Among 3,427 opioid-naive patients 66+ with cannabis prescriptions, 1.84/100 person-years initiated 90+ day opioids vs 1.19/100 in 12,006 controls. Adjusted RR: 1.54 (95% CI 1.07-2.23), driven by males (RR 1.82).
Key Numbers
3,427 vs 12,006 controls. Opioid initiation: 1.84 vs 1.19/100 person-years. RR: 1.54 (1.07-2.23). Males: RR 1.82. Females: RR 1.35 (NS).
How They Did This
Retrospective cohort using Ontario administrative data. 3,427 exposed patients vs 12,006 controls (2014-2019). Inverse probability of treatment weighting.
Why This Research Matters
This challenges the opioid-sparing narrative. For opioid-naive older adults, cannabis prescriptions were followed by higher opioid initiation rates.
The Bigger Picture
Most opioid-sparing studies look at people already on opioids. This study asks if cannabis prevents future opioid use in naive patients. The answer appears to be no.
What This Study Doesn't Tell Us
Observational. Cannabis patients may have more severe pain. Cannot capture OTC or black market cannabis use in controls.
Questions This Raises
- ?Does cannabis fail to control pain in older adults?
- ?Is the prescription simply a marker for more severe pain?
Trust & Context
- Key Stat:
- 54% higher risk of opioid initiation after cannabis prescription in older adults
- Evidence Grade:
- Large retrospective cohort with statistical adjustment, but observational design.
- Study Age:
- 2025 study
- Original Title:
- Opioid Initiation in Older Patients with Chronic Pain Who Received Authorized Cannabis Prescription.
- Published In:
- Substance use & misuse, 1-12 (2025)
- Authors:
- Fontaine, Emilie, El-Mourad, Jihane(4), Dubois, Cerina(6), Eurich, Dean T, Dyck, Jason R B, Hanlon, John G, Zongo, Arsene
- Database ID:
- RTHC-06476
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Doesn't medical cannabis reduce opioid use?
Some studies show it can for people already on opioids. This study found the opposite for opioid-naive older adults starting cannabis.
Why might cannabis users start opioids more often?
Cannabis may have been insufficient for their pain, or seeking cannabis reflects more severe pain that eventually requires opioids.
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Cite This Study
https://rethinkthc.com/research/RTHC-06476APA
Fontaine, Emilie; El-Mourad, Jihane; Dubois, Cerina; Eurich, Dean T; Dyck, Jason R B; Hanlon, John G; Zongo, Arsene. (2025). Opioid Initiation in Older Patients with Chronic Pain Who Received Authorized Cannabis Prescription.. Substance use & misuse, 1-12. https://doi.org/10.1080/10826084.2025.2586250
MLA
Fontaine, Emilie, et al. "Opioid Initiation in Older Patients with Chronic Pain Who Received Authorized Cannabis Prescription.." Substance use & misuse, 2025. https://doi.org/10.1080/10826084.2025.2586250
RethinkTHC
RethinkTHC Research Database. "Opioid Initiation in Older Patients with Chronic Pain Who Re..." RTHC-06476. Retrieved from https://rethinkthc.com/research/fontaine-2025-opioid-initiation-in-older
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.