Cannabinoids for chronic pain
Level of evidence: C
Cannabinoids may have little to no impact on chronic pain.
A systematic review and meta-analysis measured the effectiveness and adverse effects of cannabinoids in patients with any type of pain. In a subgroup analysis of patients with chronic pain, at 2 months follow-up cannabinoids decreased pain by -0.43 points (95% CI -0.72 to -0.15, scale 0-10).
In addition to pain relief, cannabinoid use slightly improved quality of sleep (-0.42, 95% CI -0.65 to -0.20, scale 0-10).
Cannabinoids did not increase the risk of serious adverse effects (RR 1.18, 98% CI 0.95 to 1.45), but the risk of non-serious adverse effects was increased (RR 1.20, 95% CI 1.15 to 1.25). Specific adverse effects were not reported.
However, umbrella review suggested that cannabinoids increase risk of adverse events related to central nervous system (odds ratio[OR] 2.84, 95% CI 2.16 to 3.73), psychological effects (OR 3.07 95% CI 1.79 to 5.26), and vision (OR 3.00, 95% CI 1.79 to 5.03).
There evidence suggested no difference between cannabinoids versus placebo on all-cause mortality (RR 1.20, 98% CI 0.85 to 1.67).
The quality of evidence was downgraded due to high risk of bias and imprecision.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis | |||||
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | SR and MA | Patients with any type of pain, irrespective of age, sex and comorbidities. | Randomised clinical trials on any type of cannabinoid versus placebo or no intervention | All-cause mortality, pain intensity, serious adverse events, quality of life | High |
| Reference | Comments |
|---|---|
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | 44 trials on chronic pain, 9 trials on cancer pain, 10 trials on acute pain, 2 trials on fibromyalgia-related pain. In 24 studies cannabinoids were administered as oromucosal spray. Other routes of administration were oral capsules, smoking, inhaling via vaporizer or intramuscular. The longest follow-up time in the included trials was 16 weeks. Only 35 of the 65 trials could be included in the meta-analysis (30 cross-over trials, no data provided at the end of the first phase). 7017 patients in 65 studies, mean age 50.4 years, mean length of follow-up 7.3 weeks. |
Results
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (%) I | Absolute number of events (%) C | Risk difference (98% CI) |
|---|---|---|---|---|---|
| Level of evidence: low The quality of evidence is downgraded due to study limitations, and imprecision. I=intervention; C=comparison; CI=confidence interval | |||||
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | 7 studies 2073 participants | 2 months | 134 (11.4) | 80 (8.8) | RR 1.20 (0.90 to 1.59) |
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Mean (SD) I | Mean (SD) C | Mean difference (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: low The quality of evidence is downgraded due to study limitations, and imprecision We found errors in extraction of three trials (Selvarajah 2009, Wade 2004, and Vela 2021). However, after correction, the results were very similar (md -0,42, 95 % CI -0,84 to -0,16, random effects meta-analysis). I=intervention; C=comparison; CI=confidence interval; MID=minimal important difference | |||||
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | 16 trials 2030 participants | 2 months | NA | 4,83 | -0.43 (-0.72 to -0.15) relative decrease -9 % (-17 % to -3 %) |
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (%) I | Absolute number of events (%) C | Risk difference (98% CI) |
|---|---|---|---|---|---|
| Level of evidence: low The quality of evidence is downgraded due to study limitations, and imprecision. I=intervention; C=comparison; CI=confidence interval | |||||
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | 18 trials 3980 participants | 2 months | RR 1.18 (0.95 to 1.45) | ||
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Mean (SD) I | Mean (SD) C | Mean difference (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: very low The quality of evidence is downgraded three levels due to study limitations, and very serious imprecision. I=intervention; C=comparison; CI=confidence interval | |||||
| «Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 »1 | 4 trials 548 participants | 2 months | NA | NA | -1.38 (-11.8 to 9.04) |
References
- Barakji J, Korang SK, Feinberg J, et al. Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis. PLoS One 2023;18(1):e0267420 «PMID: 36716312»PubMed