Reducing carbon footprint by switching to reusable soft-mist inhalers

Objective Inhalation therapy is the cornerstone of COPD, together with non-pharmacological treatments. Long-acting muscarinic antagonists (LAMAs), alone or in combination with long-acting β-agonists (LABAs), are commonly used. Pressurised metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) and soft-mist inhalers (SMIs) are used, each with different carbon footprints. This study aimed to assess the carbon footprint of hypothetically replacing LAMA or LAMA/LABA inhalers with an SMI, Respimat Reusable, within the same therapeutic class. Methods An environmental impact model was established to assess the change in carbon footprint of replacing pMDIs/DPIs with Respimat Reusable within the same therapeutic class (LAMA or LAMA/LABA) across 12 European countries and the USA over 5 years. Inhaler use for country and disease-specific populations was derived from international prescribing data and the associated carbon footprint (CO2 equivalents (CO2e)) was identified from published sources. Results Over 5 years and across all countries, replacing LAMA inhalers with Spiriva Respimat Reusable reduced CO2e emissions by 13.3–50.9%, saving 93–6228 tonnes of CO2e in the different countries studied. Replacing LAMA/LABA inhalers with Spiolto Respimat Reusable reduced CO2e emissions by 9.5–92.6%, saving 31–50 843 tonnes of CO2e. In scenario analyses, which included total replacement of DPIs/pMDIs, consistent CO2e savings were estimated. Sensitivity analyses showed that results were sensitive to changes in several parameters including varying assumptions around reusability of inhalers and potential CO2e impact. Conclusion Replacement of pMDIs and DPIs with Respimat Reusable within the same therapeutic class would result in substantial reductions in CO2e emissions