Cannabidiol (CBD) was not more effective than placebo at reducing pain intensity among patients with hand osteoarthritis (OA) or psoriatic arthritis (PsA), according to results of a study published in the journal Pain.
The NordCAN study was a single-center, double-blind, randomized, placebo-controlled trial conducted at Aalborg University Hospital in Denmark between 2018 and 2020. Patients with hand OA or PsA and 100-point visual analogue scale (VAS) pain scores of ≥30 mm were randomly assigned to receive 10 mg daily oral CBD which increased to twice daily after 2 weeks (n=70) or placebo (n=66) for a total of 12 weeks. Patients randomized to receive CBD who did not have pain reduction of ≤20 mm at 4 weeks increased their dose to 10 mg 3 times daily. The primary outcome was pain reduction.
Patients in the CBD and placebo cohorts were aged median 62.00 (interquartile range [IQR], 56.25-68.00) and 61.50 (IQR, 53.00-70.75) years, 60.0% and 70.0% were women, 56% and 58% had hand OA, and pain scores were 52.00 (IQR, 40.50-70.70) and 61.00 (IQR, 43.20-73.50) mm, respectively.
At 12 weeks, the mean difference (MD) in pain intensity between groups was 0.23 (95% CI, -9.41 to 9.90 mm; P =.96). Within both groups, both CBD (MD, 11.68; 95% CI, 5.33-18.0 mm; P <.001) and placebo (MD, 11.45; 95% CI, 0.51-1.78 mm; P =.001) recipients reported a significant reduction in pain.
Similarly, no group differences between CBD and placebo recipients were observed for the Hospital Anxiety and Depression Scale, the Health Assessment Questionnaire Disability Index, the Pain Catastrophizing Scale, or the Pittsburgh Sleep Quality Index.
No significant trends in pain intensity were observed when patients were stratified by hand OA and PsA.
A total of 2 patients in both treatment arms reported serious adverse events. No event was related with the study drug. For all adverse events, CBD recipients reported more ear-nose-throat (14% vs 0%) and dermal (5% vs 0%) events.
The major limitation of this study may have been the CBD dosage, as there has been a lack of trials evaluating optimal dosing needed to produce an effect. The 20-30 mg dosage may have been inadequate.
This study was the first large, randomized controlled trial of CBD for pain intensity in the context of chronic pain. “The current trial found neither clinically nor statistically significant effects of 20 to 30 mg/day CBD for 12 weeks on pain intensity in patients with Hand-OA and PsA when compared with placebo,” the investigators concluded. “In addition, no statistically significant effects were found on sleep quality, signs of depression, anxiety, or pain catastrophizing when comparing CBD with placebo. Studies investigating higher doses of CBD and assessing different pain disorders are needed.”
Vela J, Dreyer L, Petersen KK, Arendt-Nielsen L, Duch KS, Kristensen S. Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind, placebo-controlled trial. Pain. 2022;163(6):1206-1214. doi:10.1097/j.pain.0000000000002466