Metered-dose inhalers for CF meds are bad for environment: Study
Devices use greenhouse gases to propel medicines into patients' lungs
Metered-dose inhalers that use potent greenhouse gases to propel medicines into the lungs of people with cystic fibrosis (CF) have the worst environmental impact across all types of inhalers, according to a new study from researchers in Spain.
The team noted that propellants in metered-dose inhalers are hydrofluorocarbons, potent greenhouse gases that trap heat and raise the Earth’s surface temperature. Greenhouse gases generated by human activity are major drivers of climate change, the researchers noted, in recommending more environmentally friendly treatment strategies.
“[These] results highlight the need to develop sustainable strategies to reduce the environmental impact of inhalers,” the researchers wrote.
Their study, “Environmental impact of inhaled therapies in a cystic fibrosis unit: Strategies for sustainability” was published in the journal Farmacia Hospitalaria.
Investigating different inhaler types used for CF meds
A genetic disorder, CF is characterized by the buildup of thick, sticky mucus in various organs, particularly the lungs. Such mucus accumulation makes it harder for patients to breathe and boosts the risk of repeated lung infections.
Many people with CF use inhalation devices to deliver medications directly to the lungs, which can help alleviate the disease’s symptoms. Among the inhaled medications for CF are mucolytics to thin mucus, bronchodilators to widen airways, and corticosteroids to reduce inflammation. Antibiotics are commonly used to fight infections.
The researchers noted that common types of inhalation devices are pressurized metered-dose inhalers, dry powder inhalers, and soft mist inhalers.
Metered-dose inhalers use pressurized canisters to propel a specific dose of medicine into the lungs. Dry powder inhalers don’t use propellants and deliver medication to the lungs by having users take in a deep, fast breath. Soft mist inhalers, or nebulizers, use compressed air to turn medicine into a mist.
To assess the environmental impact of these different type of inhalers, a research team from Barcelona conducted a retrospective study using data from 2018 to 2023. The team examined the use of inhalers by 395 people with CF.
For each medication and type of device, the environmental impact was measured by its carbon footprint, defined as the total amount of greenhouse gas emitted during its life cycle. This value uses carbon dioxide (CO2), the most common greenhouse gas, as a reference, with the unit of measurement being tons of CO2-equivalent, or tCO2eq.
Metered-dose inhalers had highest carbon footprint by far
Over the study period, slightly more than half of the CF patients used metered-dose inhalers, with a median of 1.529 inhalers dispensed per year. The most commonly used metered-dose inhaler was salbutamol Aldo-Union EFG at 41%, followed by Atroaldo (ipratropium) at 8%.
Metered-dose inhalers had the highest carbon footprint, with a tCO2eq of 38.3 per year, and accounted for nearly all (98%) of the inhalers’ greenhouse gases, per the researchers. Salbutamol Aldo-Union EFG was the highest emitter, at 32 tCO2eq (84%), followed by Atroaldo at 3.2 tCO2eq (8.35%).
We found that [metered-dose inhalers] were the most commonly used inhalation devices and generated the greatest [carbon footprint].
Dry powder inhalers were used by less than half (42%) of CF patients, with a median of 1.055 dispensed annually. The most common of these are Relvar Ellipta (fluticasone/vilanterol) at 17%, Symbicort Turbuhaler (budesonide/formoterol) at 9%, and Spiriva (tiotropium) at 6%.
The carbon footprint of dry powder inhalers was markedly lower, representing 2.04% of greenhouse gas emissions, with a 0.8 tCO2eq per year. Among these, Relvar Ellipta had a carbon footprint of 0.37 tCO2eq per year (45.5%), followed by Symbicort Turbuhaler at 0.13 tCO2eq (17%) and Spiriva at 0.04 tCO2eq (9%).
Soft mist inhalers were the least-used inhalers (1.7%). Though the use of these inhalers increased significantly from 2018 to 2023 (0.6% vs. 3.9%), they still had the lowest carbon footprint, making up 0.1% of greenhouse gases, with a tCO2eq of 0.02 per year.
“We found that [metered-dose inhalers] were the most commonly used inhalation devices and generated the greatest [carbon footprint],” the researchers wrote.
The researchers noted “the essential use of inhaled therapy in cystic fibrosis,” but said more could be done to “inform and raise awareness among healthcare professionals about the environmental impact of inhalers.”
The team is working with their hospital pharmacy service on “proposed potential strategic measures to be developed in the CFU [cystic fibrosis unit].” Their tips include ensuring correct administration techniques, providing information on recycling the inhalers after use, and encouraging the use of rechargeable devices.
About the Author
