Background and Importance There are several types of devices for inhaled therapy, being the most used ones: pressurised metered-dose inhalers (pMDIs), dry-powder inhalers (DPIs) and soft mist inhalers (SMIs). All the types have some environmental impact due to their effect on CO₂ emissions, although very low compared to total CO₂ emissions, pMDIs have proven to exert higher CO₂ emissions than DPIs and SMIs.

Aim and Objectives The main objective is to estimate the impact of pMDIs, DPIs and SMIs, prescribed for any indication, on CO₂ emissions in our health care area during 1 year.

Material and Methods Number of inhalers consumed in our health care area with a population of 550086 inhabitants during 2022 was extracted from the Pharmacy Benefit Management Data.

The inhalers’ carbon footprint values were extracted from the publication Montoro et al. The estimated mean value of Kg CO₂-eq/year/pack was 16.69 for pMDIs, 1.02 for DPIs and 0.59 for SMIs.

Results Of the total amount of inhalers consumed during 2022, 39.21% were pMDIs, 54.47% were DPIs and only 6.33% were SMIs.

Considering the estimated correction value, the carbon footprint was 2297846 kg CO₂-eq for pMDIs (91.69% of the total carbon footprint of all the inhalers), 195104 kg CO₂-eq for DPIs (7.79%) and 13105 kg CO₂-eq for SMIs (0.52%).

Conclusion and Relevance The carbon footprint of the pMDIs represented more than 90% of the total carbon footprint of all the inhalers, even when consumption of pMDIs represented less than the 40%. This put in evidence the considerable higher environmental impact of pMDIs compared to DPIs.

However, this does not go in line with several societies and organisms which keep defending that efficacy, safety and patient suitability must continue to be the main factors when choosing a type of inhaler for each patient.

References and/or Acknowledgements 1. Montoro J, Antolín-Amérigo D, Izquierdo-Domínguez A, Zapata JJ, González G, Valero A. Impact of Asthma Inhalers on Global Climate: A Systematic Review of Their Carbon Footprint and Clinical Outcomes in Spain. J Investig Allergol Clin Immunol. 2023 Jul 27;33(4):250–262. doi: 10.18176/jiaci.0887. Epub 2023 Jan 4. PMID: 36648318.

The authors acknowledge the Pharmaceutical Benefit Management Service – SERGAS (Spain) for the data provided.

Conflict of Interest No conflict of interest.