Benzodiazepine Use in Medical Cannabis Authorization Adult Patients from 2013-2021: Alberta, Canada

Background: Benzodiazepines are a class of medications that are being increasingly prescribed in Canada but carry significant risk of harm. There has been increasing clinical interest on the potential “sparing effects” of medical cannabis as one strategy to reduce benzodiazepine use. The objective of this study as to examine the association of medical cannabis authorization with benzodiazepine usage between 2013–2021 in Alberta, Canada. Methods A propensity score matched cohort study with patients on regular benzodiazepine treatment authorized to use medical cannabis compared to controls who do not have authorization for medical cannabis. A total of 9690 medically authorized cannabis patients were matched to controls. To assess the effect of medical cannabis use on daily average diazepam equivalence (DDE), interrupted time series (ITS) analysis was used to assess the change in the trend of diazepam equivalence in the 26 weeks (6 months) before and 52 weeks (1 year) after the authorization of medical cannabis. Results Over the 1-year follow-up period after medical cannabis authorization, there was no overall change in the DDE use in authorized medical cannabis patients compared to matched controls (-0.27 DDE, 95% CI: -0.62 to 0.08). With respect to prescription benzodiazepine discontinuation any time after the index date, similar rates of 51.5% (4986/9690) and 49.2% (4766/9690) of those authorized medical cannabis and controls, respectively, ceased using benzodiazepine during the follow-up (p < 0.001). Conclusions This short-term study found that medical cannabis authorization had minimal effects on benzodiazepine use. Our findings may contribute ongoing evidence for clinicians regarding the potential impact of medical cannabis to reduce benzodiazepine use.