Adding Cannabis to Oxycodone for Fibromyalgia Offered No Advantage and Was Poorly Tolerated
In a randomized trial of fibromyalgia patients, combining cannabis with oxycodone reduced opioid tablet intake by 35% but offered no advantage in pain relief or side effects, and one-third of cannabis users dropped out due to adverse effects.
Quick Facts
What This Study Found
The combination of cannabis and oxycodone reduced opioid tablet consumption by 35% (p=0.02) but did not reduce adverse effects or improve pain relief compared to either treatment alone. One-third (31%) of cannabis-treated patients withdrew within 2-3 weeks due to severity of adverse effects, compared to 13% in the oxycodone-only group. Only 50% of patients experienced any pain reduction, and only 20% had meaningful (2+ point) relief.
Key Numbers
81 patients randomized. Dropouts: 13% oxycodone, 31% cannabis groups. No difference in adverse event scores (p=0.70). Combination reduced opioid intake by 35% (p=0.02). 50% had any pain reduction. 20% had meaningful reduction. Cannabis: 6.3% THC, 8% CBD.
How They Did This
Open-label randomized trial of fibromyalgia patients: 23 received oxycodone alone (5mg tablets, max 4x/day), 29 received inhaled cannabis (150mg, 6.3% THC/8% CBD, max 3 sessions/day), and 29 received the combination, for 6 weeks. Primary endpoint was composite adverse event score.
Why This Research Matters
This is one of the first RCTs to directly test the popular belief that cannabis can reduce opioid use in chronic pain. While it did reduce pill consumption, the overall drug burden was higher in the combination group, and cannabis was poorly tolerated.
The Bigger Picture
The cannabis-opioid substitution narrative is popular but oversimplified. This trial suggests that while cannabis may reduce the amount of opioids taken, it does not reduce overall drug burden or side effects, and is itself poorly tolerated by a significant minority of pain patients.
What This Study Doesn't Tell Us
Open-label design introduces expectancy effects. Small sample sizes per group. Six-week duration may be too short for full adaptation. The specific cannabis formulation (higher CBD than THC) may have contributed to the tolerability issues.
Questions This Raises
- ?Would a different THC:CBD ratio be better tolerated?
- ?Is the 35% opioid reduction clinically meaningful if overall drug burden increases?
- ?Would longer treatment allow adaptation to cannabis side effects?
Trust & Context
- Key Stat:
- 31% of cannabis users dropped out due to adverse effects within 2-3 weeks
- Evidence Grade:
- Randomized trial with appropriate comparisons, but open-label design and small sample sizes limit conclusions.
- Study Age:
- 2024 study
- Original Title:
- Cannabis combined with oxycodone for pain relief in fibromyalgia pain: a randomized clinical self-titration trial with focus on adverse events.
- Published In:
- Frontiers in pain research (Lausanne, Switzerland), 5, 1497111 (2024)
- Authors:
- van Dam, Cornelis Jan(2), Kramers, Cornelis(2), Schellekens, Arnt(2), Bouvy, Marcel, van Dorp, Eveline, Kowal, Mikael A, Olofsen, Erik, Dahan, Albert, Niesters, Marieke, van Velzen, Monique
- Database ID:
- RTHC-05776
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Can cannabis replace opioids for fibromyalgia pain?
Not based on this trial. While combining cannabis with oxycodone reduced opioid pill consumption by 35%, it did not improve pain relief or reduce side effects, and one-third of cannabis users dropped out due to adverse effects.
Was cannabis well tolerated for fibromyalgia?
No. 31% of patients using cannabis (alone or combined) withdrew within 2-3 weeks due to severity of adverse effects, compared to only 13% in the opioid-only group.
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Cite This Study
https://rethinkthc.com/research/RTHC-05776APA
van Dam, Cornelis Jan; Kramers, Cornelis; Schellekens, Arnt; Bouvy, Marcel; van Dorp, Eveline; Kowal, Mikael A; Olofsen, Erik; Dahan, Albert; Niesters, Marieke; van Velzen, Monique. (2024). Cannabis combined with oxycodone for pain relief in fibromyalgia pain: a randomized clinical self-titration trial with focus on adverse events.. Frontiers in pain research (Lausanne, Switzerland), 5, 1497111. https://doi.org/10.3389/fpain.2024.1497111
MLA
van Dam, Cornelis Jan, et al. "Cannabis combined with oxycodone for pain relief in fibromyalgia pain: a randomized clinical self-titration trial with focus on adverse events.." Frontiers in pain research (Lausanne, 2024. https://doi.org/10.3389/fpain.2024.1497111
RethinkTHC
RethinkTHC Research Database. "Cannabis combined with oxycodone for pain relief in fibromya..." RTHC-05776. Retrieved from https://rethinkthc.com/research/van-2024-cannabis-combined-with-oxycodone
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.