TY - JOUR
T1 - Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain
T2 - A systematic review and meta-analysis of randomised clinical trials
AU - Wang, Li
AU - Hong, Patrick J.
AU - May, Curtis
AU - Rehman, Yasir
AU - Oparin, Yvgeniy
AU - Hong, Chris J.
AU - Hong, Brian Y.
AU - Aminilari, Mahmood
AU - Gallo, Lucas
AU - Kaushal, Alka
AU - Craigie, Samantha
AU - Couban, Rachel J.
AU - Kum, Elena
AU - Shanthanna, Harsha
AU - Price, Ira
AU - Upadhye, Suneel
AU - Ware, Mark A.
AU - Campbell, Fiona
AU - Buchbinder, Rachelle
AU - Agoritsas, Thomas
AU - Busse, Jason W.
N1 - Funding Information:
Funding: This study was supported by a grant from the Canadian Institutes of Health Research (CIHR) (FRN 147994, Co-PIs: JW Busse, MA Ware). RB is supported by an Australian National Health and Medical Research Council (NHMRC) Senior Principal Research Fellowship. The funding organisations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. Competing interests: All authors have completed the ICMJE uniform disclosure form www.icmje.org/disclosure-of-interest/ and declare: no financial support from any industry for the submitted work; IP and SU have received research funds from Northern Green Canada; IP has been a paid consultant for Northern Green Science, Northern Green Canada, Monk-E psychedelics, and Evergreen Pacific Insurance Corporation; SU and IP received honoraria from Spectrum Therapeutics and Tilray Inc. for educational presentations; MAW is the chief medical officer for Canopy Growth Corporation.
Publisher Copyright:
© Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/9/8
Y1 - 2021/9/8
N2 - Objective To determine the benefits and harms of medical cannabis and cannabinoids for chronic pain. Design Systematic review and meta-analysis. Data sources MEDLINE, EMBASE, AMED, PsycInfo, CENTRAL, CINAHL, PubMed, Web of Science, Cannabis-Med, Epistemonikos, and trial registries up to January 2021. Study selection Randomised clinical trials of medical cannabis or cannabinoids versus any non-cannabis control for chronic pain at ≥1 month follow-up. Data extraction and synthesis Paired reviewers independently assessed risk of bias and extracted data. We performed random-effects models meta-analyses and used GRADE to assess the certainty of evidence. Results A total of 32 trials with 5174 adult patients were included, 29 of which compared medical cannabis or cannabinoids with placebo. Medical cannabis was administered orally (n=30) or topically (n=2). Clinical populations included chronic non-cancer pain (n=28) and cancer related pain (n=4). Length of follow-up ranged from 1 to 5.5 months. Compared with placebo, non-inhaled medical cannabis probably results in a small increase in the proportion of patients experiencing at least the minimally important difference (MID) of 1 cm (on a 10 cm visual analogue scale (VAS)) in pain relief (modelled risk difference (RD) of 10% (95% confidence interval 5% to 15%), based on a weighted mean difference (WMD) of -0.50 cm (95% CI -0.75 to -0.25 cm, moderate certainty)). Medical cannabis taken orally results in a very small improvement in physical functioning (4% modelled RD (0.1% to 8%) for achieving at least the MID of 10 points on the 100-point SF-36 physical functioning scale, WMD of 1.67 points (0.03 to 3.31, high certainty)), and a small improvement in sleep quality (6% modelled RD (2% to 9%) for achieving at least the MID of 1 cm on a 10 cm VAS, WMD of -0.35 cm (-0.55 to -0.14 cm, high certainty)). Medical cannabis taken orally does not improve emotional, role, or social functioning (high certainty). Moderate certainty evidence shows that medical cannabis taken orally probably results in a small increased risk of transient cognitive impairment (RD 2% (0.1% to 6%)), vomiting (RD 3% (0.4% to 6%)), drowsiness (RD 5% (2% to 8%)), impaired attention (RD 3% (1% to 8%)), and nausea (RD 5% (2% to 8%)), but not diarrhoea; while high certainty evidence shows greater increased risk of dizziness (RD 9% (5% to 14%)) for trials with <3 months follow-up versus RD 28% (18% to 43%) for trials with ≥3 months follow-up; interaction test P=0.003; moderate credibility of subgroup effect). Conclusions Moderate to high certainty evidence shows that non-inhaled medical cannabis or cannabinoids results in a small to very small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared with placebo. The accompanying BMJ Rapid Recommendation provides contextualised guidance based on this body of evidence. Systematic review registration https://osf.io/3pwn2
AB - Objective To determine the benefits and harms of medical cannabis and cannabinoids for chronic pain. Design Systematic review and meta-analysis. Data sources MEDLINE, EMBASE, AMED, PsycInfo, CENTRAL, CINAHL, PubMed, Web of Science, Cannabis-Med, Epistemonikos, and trial registries up to January 2021. Study selection Randomised clinical trials of medical cannabis or cannabinoids versus any non-cannabis control for chronic pain at ≥1 month follow-up. Data extraction and synthesis Paired reviewers independently assessed risk of bias and extracted data. We performed random-effects models meta-analyses and used GRADE to assess the certainty of evidence. Results A total of 32 trials with 5174 adult patients were included, 29 of which compared medical cannabis or cannabinoids with placebo. Medical cannabis was administered orally (n=30) or topically (n=2). Clinical populations included chronic non-cancer pain (n=28) and cancer related pain (n=4). Length of follow-up ranged from 1 to 5.5 months. Compared with placebo, non-inhaled medical cannabis probably results in a small increase in the proportion of patients experiencing at least the minimally important difference (MID) of 1 cm (on a 10 cm visual analogue scale (VAS)) in pain relief (modelled risk difference (RD) of 10% (95% confidence interval 5% to 15%), based on a weighted mean difference (WMD) of -0.50 cm (95% CI -0.75 to -0.25 cm, moderate certainty)). Medical cannabis taken orally results in a very small improvement in physical functioning (4% modelled RD (0.1% to 8%) for achieving at least the MID of 10 points on the 100-point SF-36 physical functioning scale, WMD of 1.67 points (0.03 to 3.31, high certainty)), and a small improvement in sleep quality (6% modelled RD (2% to 9%) for achieving at least the MID of 1 cm on a 10 cm VAS, WMD of -0.35 cm (-0.55 to -0.14 cm, high certainty)). Medical cannabis taken orally does not improve emotional, role, or social functioning (high certainty). Moderate certainty evidence shows that medical cannabis taken orally probably results in a small increased risk of transient cognitive impairment (RD 2% (0.1% to 6%)), vomiting (RD 3% (0.4% to 6%)), drowsiness (RD 5% (2% to 8%)), impaired attention (RD 3% (1% to 8%)), and nausea (RD 5% (2% to 8%)), but not diarrhoea; while high certainty evidence shows greater increased risk of dizziness (RD 9% (5% to 14%)) for trials with <3 months follow-up versus RD 28% (18% to 43%) for trials with ≥3 months follow-up; interaction test P=0.003; moderate credibility of subgroup effect). Conclusions Moderate to high certainty evidence shows that non-inhaled medical cannabis or cannabinoids results in a small to very small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared with placebo. The accompanying BMJ Rapid Recommendation provides contextualised guidance based on this body of evidence. Systematic review registration https://osf.io/3pwn2
UR - http://www.scopus.com/inward/record.url?scp=85114771134&partnerID=8YFLogxK
U2 - 10.1136/bmj.n1034
DO - 10.1136/bmj.n1034
M3 - Review Article
C2 - 34497047
AN - SCOPUS:85114771134
SN - 0959-535X
VL - 374
JO - BMJ
JF - BMJ
M1 - n1034
ER -
