Pressurized Pandora’s box: Characterization of dose waste, overuse and days of therapy lost in hospital-discarded inhalers

RATIONALE Inhalers are frequently discarded in hospital before their contents are fully used, creating medication waste, avoidable costs and greenhouse gas emissions.OBJECTIVES The objectives of this study were to characterize discarded inhalers from 2 distinct hospitals in the Fraser Health region of British Columbia, Canada and to estimate the environmental and financial impacts of unused doses, including a patient-centered translation using days of therapy wasted (DOT-W).METHODS Discarded inhalers were collected from Hospital site A and B over 6 and 12 months, respectively. For each device we recorded brand, device type and wasted doses. Carbon emissions were estimated for metered-dosed inhalers (MDIs) using per-actuation carbon dioxide (CO2)-equivalents; costs were calculated using community pricing.MEASUREMENTS AND MAIN RESULTS A total of 993 inhalers were collected. The proportion of wasted doses was 64.5% at site A and 47.3% at site B. MDIs accounted for most unused doses at site A (97.6%). At site B, salbutamol and ipratropium comprised 92.4% of wasted doses. Across both sites, 138 inhalers (13.9%) were completely unused at disposal. DOT-W from salbutamol and ipratropium equaled 6,461 days (∼18 years) at site A and 4500 days (∼12 years) at site B. In use-pattern analyses, wasteful or extremely wasteful use predominated for both medications at site A, and all ipratropium inhalers at site B were wasteful or extremely wasteful. The estimated financial value of unused doses was $16,091 CAD, and MDI-only carbon emissions from discarded doses were 3583 kilograms of carbon dioxide equivalent (kgCO2e).CONCLUSIONS Discarded inhalers contained substantial wasted doses—particularly MDIs—resulting in meaningful environmental and financial burdens.