Cannabinoids, cannabis, and cannabis-based medicines (CBMs) are increasingly used to manage pain, with limited understanding of their efficacy and safety. We summarised efficacy and adverse events (AEs) of these types of drugs for treating pain using randomised controlled trials: in people of any age, with any type of pain, and for any treatment duration. Primary outcomes were 30% and 50% reduction in pain intensity, and AEs. We assessed risk of bias of included studies, and the overall quality of evidence using GRADE. Studies of <7 and >7 days treatment duration were analysed separately. We included 36 studies (7217 participants) delivering cannabinoids (8 studies), cannabis (6 studies), and CBM (22 studies); all had high and/or uncertain risk of bias. Evidence of benefit was found for cannabis <7 days (risk difference 0.33, 95% confidence interval 0.20-0.46; 2 trials, 231 patients, very low-quality evidence) and nabiximols >7 days (risk difference 0.06, 95% confidence interval 0.01-0.12; 6 trials, 1484 patients, very low-quality evidence). No other beneficial effects were found for other types of cannabinoids, cannabis, or CBM in our primary analyses; 81% of subgroup analyses were negative. Cannabis, nabiximols, and delta-9-tetrahydrocannabinol had more AEs than control. Studies in this field have unclear or high risk of bias, and outcomes had GRADE rating of low- or very low-quality evidence. We have little confidence in the estimates of effect. The evidence neither supports nor refutes claims of efficacy and safety for cannabinoids, cannabis, or CBM in the management of pain.
Well done systematic review that provides validation of what most providers in my field already know. Poor-quality evidence that fails to inform the question of these treatments for pain.
The article helps elucidate to what extent cannabis (or related products) help control pain. Their conclusion is that the analyzed studies were poor- or very poor-quality, thus we should not necessarily believe that the use of cannabis will lead to better pain control. The practical conclusions are we need properly done controlled studies, practitioners treating pain need to convey proper expectations when treating severe pain, and relying on a cannabis-related product as a main pain treatment may not be in the patient's best interest. I am not sure how well received this will be by the cannabis supporters, but the study says nothing about other potential benefits such as better control of nausea, appetite, or other QoL endpoints that could benefit.
"The evidence neither supports nor refutes claims of efficacy and safety for cannabinoids, cannabis, or CBM in the management of pain." Looks like we need decent studies.
This systematic review shows the paucity of evidence collected in using cannabinoids for multiple pain symptoms without definite benefits of use and low-quality evidence.
This systematic review of cannabis products for a variety of indications was very well done and methodical. They identified what many of us suspected: studies that are the underpinning this new medication class are of poor enough quality that little can be ascertained from them at this point. Besides making that point, there is little in this document that hospitalists need to know or could learn, other than the rigor of performing a systematic review.