Rheumatoid arthritis (RA) is an inflammatory disease of the joints characterized by pain, stiffness, and swelling, as well as an eventual loss of limb function. Rheumatoid arthritis affects about one percent of the population, primarily women.
Cannabinoids, including CBD, are acknowledged to possess anti-inflammatory, anti-arthritic, and anti-rheumatic properties,[1-4] and the endocannabinoid system has been proposed as modulator of RA.[5-6]
Nonetheless, few human studies are available assessing the use of either cannabis or cannabinoids in patients with RA. In one such trial, investigators reported that the administration of cannabis extracts over a five-week period produced statistically significant improvements in pain on movement, pain at rest, quality of sleep, inflammation, and intensity of pain compared to placebo.[7] Other human trials assessing the use of synthetic cannabinoid agents in patients with rheumatic diseases have yielded mixed results.[8] A review of the relevant literature, published in 2021 in the Journal of Clinical Rheumatology, identified 26 systematic review papers. Authors concluded: “Cannabis, cannabis-derived products and synthetic cannabinoids may slightly reduce disease activity in patients with RA.” They cautioned, however “Its use may result in little to no difference in pain reduction and may slightly increase nervous system adverse events. The evidence is very uncertain about the effect of cannabis, cannabis-derived products, and synthetic cannabinoids on serious adverse events risk.”[9] Additional human trials, such as an assessment of the use of CBD in patients with osteoarthritis are ongoing.[10]
Despite these limited results, patients with RA frequently report using cannabis therapeutically. For instance, in a 2005 anonymous questionnaire survey of medical cannabis patients in Australia, 25 percent reported using cannabinoids to treat RA.[11] A survey of British medical cannabis patients found that more than 20 percent of respondents reported using cannabis for symptoms of arthritis.[12] A review of state-registered medical cannabis pain patients reported that 27 percent used it to treat arthritis.[13] Most recently, survey data published in 2020 in the journal Rheumatology reported: “Nearly 20 percent of patients suffering from rheumatologic diseases actively consume cannabis, with an improvement in pain. … A favorable effect of cannabis on pain in our meta-analysis reinforces the idea that cannabis could be used for analgesic purposes.”[14]
REFERENCES
[1] Zaka et al. 2017. Comparative in silico analyses of Cannabis sativa, Prunella vulgaris and Withania somnifera compounds elucidating the medicinal properties against rheumatoid arthritis. Journal of Molecular Graphs & Modeling 74: 296-304.
[2] Malfait et al. 2000. The nonpsychoactive cannabis constituent cannabidiol is an oral anti-arthritic therapeutic in murine. Journal of the Proceedings of the National Academy of Sciences 97: 9561-9566.
[3] Lowin et al., 2020. Cannabidiol: A killer for inflammatory rheumatoid arthritis synovial fibroblasts. Cell Death & Disease 11 [E-pub ahead of print].
[4] Croxford and Yamamura. 2005. Cannabinoids and the immune system: potential for the treatment of inflammatory diseases. Journal of Neuroimmunology 166: 3-18.
[5] Gui et al. 2015. The endocannabinoid system and its therapeutic implications in rheumatoid arthritis. International Immunopharmacology 26: 86-91.
[6] Kaur et al. 2020. The endocannabinoid signaling pathway as an emerging target in pharmacotherapy, earmarking mitigation of destructive events in rheumatoid arthritis. Life Sciences 257 [E-pub ahead of print].
[7] Blake et al. 2006. Preliminary assessment of the efficacy, tolerability and safety of a cannabis medicine (Sativex) in the treatment of pain caused by rheumatoid arthritis. Rheumatology 45: 50-52.
[8] Fitzcharles et al. 2016. Efficacy, tolerability and safety of cannabinoids in chronic pain associated with rheumatic diseases: A systematic review of randomized controlled trials. Schmerz 30: 47-61.
[9] Schulze-Schiappacasse et al. 2021. Are cannabis, cannabis-derived products, and synthetic cannabinoids a therapeutic tool for rheumatoid arthritis? A friendly summary of the evidence. Journal of Clinical Rheumatology. [E-pub ahead of print].
[10] https://clinicaltrials.gov/ct2/show/NCT04195269.
[11] Swift et al. 2005. Survey of Australians using cannabis for medical purposes. Harm Reduction Journal 4: 2-18.
[12] Ware et al. 2005. The medicinal use of cannabis in the UK: results of a nationwide survey. International Journal of Clinical Practice 59: 291-295.
[13] Aggarwal et al. 2009. Characteristics of patients with chronic pain accessing treatment with medical cannabis in Washington state. Journal of Opioid Management 5: 257-286.
[14] Guillouard et al. 2020. Cannabis use assessment and its impact on pain in rheumatologic diseases: A systematic review and meta-analysis. Rheumatology 60: 549-556.