Meta-Analysis: Cannabinoids Provide Small Pain Relief for Chronic Neuropathic Pain | Research

The takeaway

Across 11 randomized trials with 1,219 patients, selective cannabinoids provided a statistically significant but clinically small reduction in neuropathic pain scores, with improvements in quality of life and sleep.

Read this if you have chronic nerve pain and want to know what the best evidence says about cannabinoid treatments.

-0.65 point pain reduction on a 0-10 scale across 1,219 patients

What the researchers found

This systematic review and meta-analysis addressed the conflicting recommendations from pain societies about cannabinoids for neuropathic pain.

Across 11 RCTs including 1,219 patients, selective cannabinoids (dronabinol, nabilone, nabiximols) produced a statistically significant reduction in pain scores compared to placebo or conventional treatment: -0.65 points on a 0-10 scale. While statistically significant, this was considered clinically small.

Beyond pain scores, cannabinoid use was associated with improvements in quality of life and sleep, and no major adverse effects were reported. The evidence was graded as moderate quality with a weak recommendation using the GRADE approach.

The heterogeneity across studies was high (I-squared = 60%), reflecting variability in the etiology of neuropathic pain, types and doses of cannabinoids used, and study quality.

Why it matters

National and international pain societies have given contradictory recommendations about cannabinoids for neuropathic pain. This meta-analysis provides a quantitative answer: there is a real but small benefit, supporting cannabinoids as an option but not a first-line treatment.

The numbers in context

11 RCTs, 1,219 patients (614 cannabinoid, 605 comparator). Pain reduction: -0.65 points on 0-10 NRS (95% CI -1.06 to -0.23, p=0.002). I-squared: 60%. GRADE: weak recommendation, moderate-quality evidence.

How the study worked

Systematic review and meta-analysis of RCTs comparing selective cannabinoids (dronabinol, nabilone, nabiximols) with conventional treatments or placebo for chronic neuropathic pain. Searched MEDLINE, EMBASE, and other databases through March 2016. GRADE approach used for evidence certainty.

What this study cannot tell us

High heterogeneity across studies. The effect size is small and may not be clinically meaningful for all patients. Studies varied in cannabinoid type, dose, and neuropathic pain etiology. The search ended March 2016 and newer trials are not included.

How to read the evidence

Meta-analysis of 11 RCTs with GRADE assessment. Strong methodology with moderate-quality underlying evidence.

When this study was published

Published in 2017, searching through March 2016.

The bigger picture

A 0.65-point reduction on a 10-point pain scale may seem small, but for patients with treatment-resistant neuropathic pain who have failed conventional therapies, any reduction can be meaningful. Combined with improvements in sleep and quality of life, cannabinoids fill a niche for patients without other options.

Questions still open

Are specific cannabinoid formulations more effective for particular types of neuropathic pain? Would higher doses produce larger effects or only more side effects? Could cannabinoids be more effective as adjuncts to other pain medications rather than as standalone treatments?

Common questions

Do cannabinoids help with nerve pain?

This meta-analysis found a statistically significant but clinically small reduction in neuropathic pain scores with cannabinoids. The average reduction was 0.65 points on a 10-point scale, with additional benefits for sleep and quality of life.

Should cannabinoids be first-line treatment for nerve pain?

No. The GRADE assessment gave a "weak recommendation" based on moderate-quality evidence. Cannabinoids appear to be an option for patients who have not responded to conventional treatments, not a first-line therapy.

Read the original research

Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis.

Anesthesia and analgesia, 125(5), 1638-1652

View on PubMed ↗Publisher’s paper ↗

Citation

Meng, Howard; Johnston, Bradley; Englesakis, Marina; Moulin, Dwight E; Bhatia, Anuj. (2017). Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis.. Anesthesia and analgesia, 125(5), 1638-1652. https://doi.org/10.1213/ANE.0000000000002110