We read with great interest Pramhas et al.’s randomized controlled trial (RCT) investigating the analgesic effect of oral, high-dose cannabidiol (CBD) in patients with painful knee osteoarthritis (OA).1 This is a well-designed RCT that addresses many of the shortcomings of previous RCTs testing the effect of cannabinoids on chronic pain. Previously, the only published, peer-reviewed RCT on the effect of oral cannabinoids for osteoarthritis pain was a 12-week trial of a low dose of synthetic CBD (20–30 mg/day) in patients with hand osteoarthritis or psoriatic arthritis that found no significant difference from placebo for pain, sleep quality, anxiety, or depression.2 While we applaud Pramhas et al. for their use of a higher CBD dose (600 mg/day), we have a concern about the use of a fixed high dose, as individual responses to cannabinoids depend on many factors (e.g., history of cannabis use, sex, concurrent medications, genetics) and consensus recommendations for cannabinoid dosing in chronic pain management are to “start-low go-slow”—particularly in older and/or multimorbid individuals—and to titrate cannabis products (to patients’ desired effects).3 Nevertheless, this study is welcome given the scarcity of high-quality data on the efficacy of cannabinoids for pain management in conjunction with the high rates of medical cannabis use among people with arthritic pain. Future research must also examine the effectiveness of THC for OA related pain management, as the majority of arthritic patients using medical cannabis consume some amount of THC4 and preclinical studies suggest promising effects.5
Contributors
All authors contributed to conceptualizing and drafting this letter.
Declaration of interests
H. Clarke and K. Ladha are funded by a Merit Awards from the Department of Anesthesiology and Pain Medicine at the University of Toronto.
M. Peer, S. Miles: no conflicts of interest exist.
References
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