UK Medical Cannabis Registry: An Updated Analysis of Inflammatory Arthritis.

AIM: Cannabis-based medicinal products (CBMPs) are an emerging therapeutic option for pain in inflammatory arthritis, yet clinical evidence remains limited. This study aimed to evaluate changes in pain-specific and general health-related outcomes in patients with inflammatory arthritis treated with CBMPs and to characterize the safety profile by examining the incidence and nature of adverse events. METHODS: Patients treated with CBMPs for inflammatory arthritis-associated pain for ⩾24 months were identified from the UK Medical Cannabis Registry. Primary outcomes included changes in patient-reported measures: Brief Pain Inventory (BPI), Pain Visual Analogue Scale (Pain VAS), Short-Form McGill Pain Questionnaire 2 (SF-MPQ-2), EuroQol 5-dimension 5-level (EQ-5D-5L), Generalized Anxiety Disorder-7 (GAD-7), and Single-Item Sleep Quality Scale (SQS) at 1, 3, 6, 12, 18, and 24 months vs baseline. Adverse events were recorded and analysed. Statistical significance was set at P < .050. RESULTS: A total of 192 patients met inclusion criteria. The CBMP initiation was associated with improvements in BPI Interference, BPI Severity, Pain VAS, SF-MPQ-2, SQS, and EQ-5D-5L index values at all follow-up time points (P < .010) and in GAD-7 scores up to 3 months (P < .001). Twenty-seven patients (14.06%) reported 296 adverse events: 126 (42.57%) mild, 132 (44.59%) moderate, and 38 (12.84%) severe. No life-threatening events occurred. CONCLUSION: The CBMP therapy was associated with reductions in pain and improvements in health-related quality of life among individuals with inflammatory arthritis. Although causality cannot be inferred from this observational design, these findings support the need for randomized controlled trials to determine the efficacy of CBMPs for inflammatory arthritis-related pain.