OBJECTIVES: Inhalation therapy is the cornerstone of chronic obstructive pulmonary disease and asthma management. Three therapeutic devices: pressurised metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), and soft-mist inhalers (SMIs) are commonly used. As pMDIs generate more carbon footprint than DPIs and SMIs, some national governments have introduced targets to reduce their use, as part of their efforts in the fight against global warming. Furthermore, the carbon footprint of SMIs is lower than pMDIs and DPIs. This study aimed to assess the carbon footprint of hypothetically replacing DPIs or pMDIs with reusable SMI device (Respimat®).

METHODS: A model was established to assess the carbon footprint of replacing pMDIs or DPIs with Respimat® reusable, across 12 European countries and the United States over 5 years. Inhaler use for country and disease-specific populations was derived from international prescribing data and the associated carbon footprint (CO₂ emissions) were identified from published sources.

RESULTS: Over 5 years, replacing DPI with SMI Respimat® reusable reduced CO₂ emissions by 59.4–69.2%, representing a saving of 2,206.9–66,333.9 tonnes across all countries. Replacing pMDIs with SMI (Respimat®) reusable reduced CO₂ emissions by 94.3–98.3%, saving 7,729.3–847,214.4 tonnes. Replacing both DPI and pMDI devices to SMI (Respimat®) reusable reduced CO₂ emissions by 75.9–94.5%, saving 13,126.4–913,548.3 tonnes, which is the equivalent of the annual carbon footprint of up to 136,351 EU citizens. Sensitivity analyses were performed and showed that the base case results were robust to changes in parameters including varying assumptions around re-usability of inhalers, potential CO₂ impact, market shares for devices, and the extent of inhaler replacement.

CONCLUSIONS: Hypothetical replacement of pMDIs and DPIs with SMI (Respimat®) reusable could result in substantial reductions in CO₂ emissions, supporting global environmental goals.