Trends in inhaler use and associated carbon footprint: a sales data-based study in Europe

Background Physicians are being encouraged to favour dry powder inhalers (DPI) over pressurised metered dose inhalers (pMDI) on environmental grounds. The EU is reviewing the F-gas regulation to accelerate emission phase-down targets. Thoughtful use of inhalers can reduce emissions while promoting positive clinical outcomes. We aim to describe the trends of pMDI and DPI use and associated carbon footprint in Europe. Methods DPI and pMDI sales data between 2011 and 2021 were extracted from IQVIA MIDAS Quarterly 2022 as total sold doses in 10 European countries. Carbon footprint calculations were based on the Medical and Chemicals Technical Options Committee 2022 assessment report. Results Between 2011 and 2021, the carbon footprint of pMDI-based inhalation therapy increased from 3368 to 3891 kilotons (kt) CO 2 equivalents (CO 2 e) because of a 16% increase in the number of sold doses of pMDI. Replacing pMDIs with low-carbon inhalers such as DPIs over this period would have produced 92% lower CO 2 emissions. The UK was the largest source of pMDI-related emissions in 2021 with 1235 kt CO 2 e (31% of all emissions) in Europe. Short-acting beta-2 agonist (SABA) dose sales were associated with 1642 kt CO 2 e emissions in 2021, 94% from pMDIs. Conclusions The carbon footprint of inhaler therapy in Europe grew due to an increased use of pMDIs in many European countries. Greater focus on guideline-based controller therapy will potentially improve patient outcomes and decrease SABA over-reliance. Prioritising DPIs or soft mist inhalers when clinically appropriate can lower inhaler greenhouse gas emissions.