Thoughtful prescription of inhaled medication has the potential to reduce inhaler-related greenhouse gas emissions by 85.

Both physicians and patients are increasingly aware of the environmental impacts of medication. The shift of treatment paradigm towards MART-treatment (Maintenance and Reliever Therapy) in asthma affects the treatment-related emissions. The carbon footprint of inhaled medication is also tied to the type of the device used. Today the most commonly used propellant-containing pressurised metered-dose inhalers (pMDIs) have a carbon footprint typically 20-40-fold higher than propellant-free dry powder inhalers (DPIs) and soft mist inhalers. We analysed the carbon footprint of inhaled medications in Europe using published life cycle analyses of marketed inhalers and comprehensive 2020 European sales data. In addition, we give an estimate on treatment-related emissions of different treatment regimens on Global Initiative for Asthma (GINA) step 2. There is potential to reduce the carbon footprint of inhaled medications by 85% if DPIs are preferred over pMDIs. Emissions from pMDIs in the EU were estimated to be 4.0 megatons of carbon dioxide equivalent (MT CO2e) and this could be reduced to 0.6 MT CO2e if DPIs were used instead. In the treatment of moderate asthma with DPI, an as-needed combination of inhaled corticosteroid and long-acting beta-agonist in a single inhaler had a substantially lower annual carbon footprint (0.8 kg CO2e) than the more traditional maintenance therapy with an inhaled corticosteroid alone with as-needed short-acting beta-agonist (2.9 kg CO2e). There has been an urgent call for healthcare to reduce its carbon footprint for appropriate patients with asthma and chronic obstructive pulmonary disease (COPD), changing to non-propellant inhalers can reduce the carbon footprint of their treatment by almost 20-fold.

Vartiainen V ，Woodcock AA ，Wilkinson A ，Janson C ，Björnsdóttir U ，Haahtela T ，Lehtimäki L ... -  《BMJ Open Respiratory Research》

Reducing carbon footprint of inhalers: analysis of climate and clinical implications of different scenarios in five European countries.

Inhaled therapies are key components of asthma and chronic obstructive pulmonary disease (COPD) treatments. Although the use of pressurised metered-dose inhalers (pMDIs) accounts for <0.1% of global greenhouse gas emissions, their contribution to global warming has been debated and efforts are underway to reduce the carbon footprint of pMDIs. Our aim was to establish the extent to which different scenarios led to reductions in greenhouse gas emissions associated with inhaler use, and their clinical implications. We conducted a series of scenario analyses using asthma and COPD inhaler usage data from 2019 to model carbon dioxide equivalent (CO2e) emissions reductions over a 10-year period (2020-2030) in the UK, Italy, France, Germany and Spain: switching propellant-driven pMDIs for propellant-free dry-powder inhalers (DPIs)/soft mist inhalers (SMIs); transitioning to low global warming potential (GWP) propellant (hydrofluoroalkane (HFA)-152a) pMDIs; reducing short-acting β2-agonist (SABA) use; and inhaler recycling. Transition to low-GWP pMDIs and forced switching to DPI/SMIs (excluding SABA inhalers) would reduce annual CO2e emissions by 68%-84% and 64%-71%, respectively, but with different clinical implications. Emission reductions would be greatest (82%-89%) with transition of both maintenance and SABA inhalers to low-GWP propellant. Only minimising SABA inhaler use would reduce CO2e emissions by 17%-48%. Although significant greenhouse gas emission reductions would be achieved with high rates of end-of-life recycling (81%-87% of the inhalers), transition to a low-GWP propellant would still result in greater reductions. While the absolute contribution of pMDIs to global warming is very small, substantial reductions in the carbon footprint of pMDIs can be achieved with transition to low-GWP propellant (HFA-152a) inhalers. This approach outperforms the substitution of pMDIs with DPI/SMIs while preserving patient access and choice, which are essential for optimising treatment and outcomes. These findings require confirmation in independent studies.

Pernigotti D ，Stonham C ，Panigone S ，Sandri F ，Ferri R ，Unal Y ，Roche N ... -  《BMJ Open Respiratory Research》

Costs of switching to low global warming potential inhalers. An economic and carbon footprint analysis of NHS prescription data in England.

Metered-dose inhalers (MDIs) contain propellants which are potent greenhouse gases. Many agencies propose a switch to alternative, low global warming potential (GWP) inhalers, such as dry powder inhalers (DPIs). We aimed to analyse the impact on greenhouse gas emissions and drug costs of making this switch. We studied National Health Service prescription data from England in 2017 and collated carbon footprint data on inhalers commonly used in England. Inhalers were separated into different categories according to their mechanisms of action (eg, short-acting beta-agonist). Within each category we identified low and high GWP inhalers and calculated the cost and carbon impact of changing to low GWP inhalers. We modelled scenarios for swapping proportionally according to the current market share of each equivalent DPI (model 1) and switching to the lowest cost pharmaceutically equivalent DPI (model 2). We also reviewed available data on the carbon footprint of inhalers from scientific publications, independently certified reports and patents to provide more accurate carbon footprint information on different types of inhalers. If MDIs using HFA propellant are replaced with the cheapest equivalent DPI, then for every 10% of MDIs changed to DPIs, drug costs decrease by £8.2M annually. However if the brands of DPIs stay the same as 2017 prescribing patterns, for every 10% of MDIs changed to DPIs, drug costs increase by £12.7M annually. Most potential savings are due to less expensive long-acting beta-agonist (LABA)/inhaled corticosteroids (ICS) inhalers. Some reliever inhalers (eg, Ventolin) have a carbon footprint over 25 kg CO2e per inhaler, while others use far less 1,1,1,2-tetrafluoroethane (HFA134a) (eg, Salamol) with a carbon footprint of <10 kg CO2e per inhaler. 1,1,1,2,3,3,3-Heptafluoropropane (HFA227ea) LABA/ICS inhalers (eg, Flutiform) have a carbon footprint over 36 kg CO2e, compared with an equivalent HFA134a combination inhaler (eg, Fostair) at <20 kg CO2e. For every 10% of MDIs changed to DPIs, 58 kt CO2e could be saved annually in England. Switching to DPIs would result in large carbon savings and can be achieved alongside reduced drug costs by using less expensive brands. Substantial carbon savings can be made by using small volume HFA134a MDIs, in preference to large volume HFA134a MDIs, or those containing HFA227ea as a propellant.

Wilkinson AJK ，Braggins R ，Steinbach I ，Smith J ... -  《BMJ Open》

Greenhouse Gas Emissions from Respiratory Treatments: Results from the SABA CARBON International Study.

Healthcare systems are looking to reduce their carbon impact. Short-acting β2-agonist (SABA) overuse (≥ 3 canisters/year) is common in asthma and linked to poor outcomes; however, its environmental impact remains unknown. As part of the CARBON programme, this study retrospectively quantified the carbon footprint of SABA and controller inhalers across all respiratory indications and SABA overuse in asthma in lower-middle-income countries (LMICs), upper-middle-income countries and high-income countries across Africa, Asia Pacific, Latin America and the Middle East. Two data sources were utilised to evaluate the carbon contribution of inhalers to respiratory care. To quantify greenhouse gas (GHG) emissions associated with total inhaler use across all respiratory indications, inhaler sales data were obtained from IQVIA MIDAS® (Q4/2018-Q3/2019) and compared by dose to prevent confounding from differences in canister actuation counts. GHG emissions associated with SABA overuse in asthma were evaluated using prescription and self-reported over-the-counter purchase data from the SABA use IN Asthma (SABINA) III study (2019-2020). Inhaler-related GHG emissions were quantified using published data and product life cycle assessments. SABA accounted for > 50% of total inhaler use and inhaler-related emissions in most countries analysed. The total SABA-related emissions were estimated at 2.7 million tonnes carbon dioxide equivalents, accounting for 70% of total inhaler-related emissions. Among the countries, regions and economies analysed, per capita SABA use and associated emissions were higher in Australia, the Middle East and high-income countries. Most SABA prescriptions for asthma (> 90%) were given to patients already overusing SABA. Globally, SABA use/overuse is widespread and is the greatest contributor to the carbon footprint of respiratory treatment, regardless of the economic status of countries. Implementing evidence-based treatment recommendations, personalising treatment and reducing healthcare inequities, especially in LMICs, may improve disease control and patient outcomes, thereby reducing SABA overuse and associated carbon emissions beyond SABA use alone.

Alzaabi A ，Bell JP ，Montero-Arias F ，Price DB ，Jackson DJ ，Wang HC ，Budgen N ，Farouk H ，Maslova E ... -  《-》

Impact of choice of inhalers for asthma care on global carbon footprint and societal costs: a long-term economic evaluation.

Kponee-Shovein K ，Marvel J ，Ishikawa R ，Choubey A ，Kaur H ，Ngom K ，Fakih I ，Swartz N ，Schatzki T ，Signorovitch J ... -  《-》