By and large, cannabis products have little to no effect on chronic pain, found a new systematic review published in the Annals of Internal Medicine.
“It’s complicated because cannabis products are complicated,” said lead author of the study, Roger Chou, M.D., senior adviser for the Pacific Northwest Evidence-based Practice Center at Oregon Health & Science University, in a press release.
“It’s not like taking a standardized dose of ibuprofen, for example. Cannabis is derived from a plant and has multiple chemicals in addition to THC and CBD that may have additional properties depending on where it’s grown, how it’s cultivated, and ultimately prepared for sale.”
Whether cannabinoids are beneficial or harmful for chronic pain remains uncertain. While the American College of Physicians recently declined to recommend inhaled cannabis for non-cancer pain, in 2021, an expert panel issued a soft recommendation for inhaled cannabis for chronic cancer or non-cancer pain when standard treatments failed to work. In the current study, researchers set out to update the evidence on cannabinoids for chronic pain.
To do so, they analyzed 25 short-term randomized controlled trials involving over 2300 participants, of whom 64% had neuropathic pain. Ultimately, they found that cannabis products with high levels of THC may provide short-term improvements in pain and function. The same products, however, also lead to moderate-to-large increases in adverse symptoms, including dizziness, sedation, and nausea.
Both dronabinol and nabilone are made of 100% THC or its analogue. The review found that nabilone, but not dronabinol, moderately reduced pain severity. Products containing mainly or only CBD demonstrate almost no improvement in managing pain.
“This may be surprising to people,” said Chou, “Conventional wisdom was that CBD was promising because it doesn’t have euphoric effects like THC, and it was thought to have medicinal properties. But, at least in our analysis, it didn’t have an effect on pain.”
Sources: EurekAlert, Annals of Internal Medicine
