UK Medical Cannabis Registry: A Clinical Analysis of Patients with Substance Use Disorder

With a global rise in opioid-related mortality, there comes a need to address this with novel therapies. Cannabinoid receptors are highly expressed and co-localised with opiate receptors of the mesolimbic system. Cannabis-based medicinal products (CBMPs) have been suggested as a measure to reduce harm as maintenance therapy for substance use disorder (SUD). This aim of this study was to assess changes in patient-reported outcomes measures (PROMs) and opioid medications in individuals treated with CBMPs for SUD.

Data from patients with SUD from the UK Medical Cannabis Registry were analysed. Outcomes included changes at 1, 3, and 6 months from baseline of the EQ-5D-DL, single-item sleep quality scale (SQS), and Generalised Anxiety Disorder-7 (GAD-7) questionnaire. Change in opioid medications was assessed as change in oral morphine equivalent (OME).

34 patients were included. Twenty-seven (79.41%) participants were male. Twenty-nine (85.29%) participants were illicit cannabis consumers at baseline. The most common SUD was opioid use disorder (n = 18; 52.94%). Four (11.76%), 14 (41.18%), and 16 (47.05%) patients were prescribed oils, dried flower, or a combination of dried flower and oils, respectively. Improvements in GAD-7, SQS, and EQ-5D-5L at 1, 3, and 6 months from baseline were observed (p < 0.050). Median OME consumption at baseline was 274.95 (79.50-441.80) mg/day. This was reduced at 6 months (204.45 [61.88-354.85] mg/day; p = 0.043), there was no significant difference at 1 or 3 months (p > 0.050). Three (8.81%) participants reported 17 (50.00%) adverse events.

There was an associated improvement in health-related quality of life PROMs and reduction in prescribed opioids in individuals with SUD treated with CBMPs. CBMPs were well tolerated by most individuals in this 6-month analysis. Further evaluation through randomised controlled trials is needed to determine causality.