Morbidity and mortality associated with prescription cannabinoid drug use in COPD

Introduction — Respiratory-related morbidity and mortality were evaluated in relation to incident prescription oral synthetic cannabinoid (nabilone, dronabinol) use among older adults with chronic obstructive pulmonary disease (COPD).

Methods — This was a retrospective, population-based, data-linkage cohort study, analysing health administrative data from Ontario, Canada, from 2006 to 2016. We identified individuals aged 66 years and older with COPD, using a highly specific, validated algorithm, excluding individuals with malignancy and those receiving palliative care (n=185 876 after exclusions). An equivalent number (2106 in each group) of new cannabinoid users (defined as individuals dispensed either nabilone or dronabinol, with no dispensing for either drug in the year previous) and controls (defined as new users of a non-cannabinoid drug) were matched on 36 relevant covariates, using propensity scoring methods. Cox proportional hazard regression was used.

Results — Rate of hospitalisation for COPD or pneumonia was not significantly different between new cannabinoid users and controls (HR 0.87; 95% CI 0.61–1.24). However, significantly higher rates of all-cause mortality occurred among new cannabinoid users compared with controls (HR 1.64; 95% CI 1.14–2.39). Individuals receiving higher-dose cannabinoids relative to controls were observed to experience both increased rates of hospitalisation for COPD and pneumonia (HR 2.78; 95% CI 1.17–7.09) and all-cause mortality (HR 3.31; 95% CI 1.30–9.51).

Conclusions — New cannabinoid use was associated with elevated rates of adverse outcomes among older adults with COPD. Although further research is needed to confirm these observations, our findings should be considered in decisions to use cannabinoids among older adults with COPD.