Cannabidiol for chronic pain in rheumatoid arthritis and ankylosing spondylitis: a randomized, placebo-controlled trial with exploratory tetrahydrocannabinol add-on
Oliver Hendricks, 1,2,3 Tonny Elmose Andersen, 4 Afshin Ashouri Christiansen, 1,3 Ellen Margrethe Hauge, 5 Tina Ingrid Horsted, 1 Philip Rask Lage Hansen, 1,2 Anders Bo Bojesen, 1 Hafsah Nabi, 6 Anders Wieghorst, 4 Mikkel Østergaard, 6,7 Merete Lund Hetland, 6,7 Niels Steen Krogh, 6 Kirsten Kaya Roessler, 4 Kim Hørslev-Petersen, 1,
Affiliationer
Abstract
Background
Persistent chronic pain remains a major unmet need in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS), even when inflammatory disease activity is low. Evidence for cannabinoid-based treatment in inflammatory rheumatic disease is limited. We investigated the efficacy and safety of low-dose cannabidiol (CBD) for chronic pain in RA and AS and explored the effects of adjunctive tetrahydrocannabinol (THC) in non-responders.
Methods
In this multicentre, double-blind, randomized, placebo-controlled trial, 66 patients with RA or AS and persistent pain despite low inflammatory disease activity were randomized 1:1 to oral CBD or placebo for 12 weeks. The primary endpoint was a reduction of at least 20 points on the pain visual analogue scale (VAS) at week 12. After the blinded phase, non-responders entered a 12-week open-label phase: non-responders in the placebo group switched to CBD, while non-responders in the CBD group received add-on THC. Secondary outcomes included continuous pain VAS, sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI), cognitive performance assessed by the Trail Making Test (TMT) and Digit Symbol Substitution Test (DSST), disease activity measures, and safety.
Results
At week 12, the primary endpoint was achieved by 9/32 patients (28%) receiving placebo and 3/30 patients (10%) receiving low-dose CBD. Low-dose CBD did not demonstrate superior pain relief compared with placebo and was associated with poorer sleep quality, while no significant between-group differences were observed for cognitive outcomes or inflammatory markers. In the exploratory open-label phase, 9/23 patients (39%) receiving CBD plus THC achieved the predefined pain response criterion compared with 2/25 patients (8%) receiving CBD alone. The CBD + THC group also showed greater improvements in continuous pain VAS and sleep quality.
Conclusions
Low-dose CBD did not yield meaningful pain relief. The addition of low-dose THC was associated with improvements in pain and sleep quality. These findings should be regarded as hypothesis-generating and require confirmation in blinded randomized controlled trials.
Trial registration
European Union Clinical Trials Register, EudraCT 2017–004226-15, prospectively registered before enrolment of the first participant; Danish Medicines Agency 2018–010018.
