I have had the privilege of practicing primary care for over 20 years at a community health center in Chelsea, Mass. This vibrant city is the dignified home to a diverse and proud community. It is also home to a lower-income population, living in a historically red-lined zone with sweltering urban heat islands that routinely experience temperatures 6°F higher than the National Weather Service’s regional report. With overcrowded residential buildings sandwiched among numerous industrial factories, and subject to plane, highway, and shipping traffic, it is no surprise that Chelsea has one of the worst air quality metrics in the state. These factors surely contribute to Chelsea’s higher prevalence of and worse outcomes for asthma as compared to the state average.
Asthma is a disease with known disparities including more severe disease in both people of color and those with lower income status. Asthma also has clear associations with environmental triggers—air pollution, heat waves, thunderstorms, dust storms, and pollen season—many of which are increasing in frequency and intensity due to climate change.
While education about these environmental triggers goes a long way, asthma management for my patients relies on inhaler medications used as rescue therapy for acute asthma symptoms and as controller therapy for the prevention of asthma exacerbations.
As a physician, I look to evidence-based guidelines to buttress individualized asthma treatment plans. Clinical guidelines are typically created by a consensus of experts after reviewing high-quality scientific studies. For asthma, most clinicians in the United States will refer to the Global Initiative for Asthma guidelines, updated yearly, or the National Asthma Education and Prevention Program guidelines, last updated in 2020.
Both of these step-therapy asthma guidelines include an inhaled corticosteroid (ICS) to reduce airway inflammation used in combination with formoterol, a unique medication that has both quick onset and long duration of action. These medication properties lend ICS-formoterol to function as a rescue medication for acute symptoms, as well as a controller to prevent exacerbations.
Here lies a thorn in my side. Our current metered dose inhalers (MDIs) use propellants that are greenhouse gases (GHGs) with global warming potentials (GWP100) of 1,300-3,350. In the United States, the number of MDIs used in one year generates carbon equivalent emissions that outstrip those generated from driving 500,000 gas-powered vehicles for an entire year.
This means that the very medication I am prescribing to my patients to treat their asthma is also contributing to the climate crisis that leads to more intense environmental triggers for their disease and that is recognized by many as the greatest public health threat humans have ever faced.
As the world strives to reduce GHG emissions in alignment with the Paris Agreement, hospitals, health systems, and other health organizations have committed to reduce emissions and prepare for climate resilience, for example by signing the White House/HHS Health Sector Climate Pledge.
Transitioning to low-emission DPIs plays an important role in the health care sector’s pathway to net-zero emissions. This is because DPIs are inhaler devices that do not need propellants and thus do not contain GHGs, and they have a 20- to 30-fold lower emission footprint as compared to their MDI counterparts. In fact, The Joint Commission, the Agency for Healthcare Research and Quality, the American Medical Association, and the National Academy of Medicine all identify inhalers as a target for health care emissions reduction.
While some patients cannot use DPIs, like young children or patients with limited inspiratory force, the vast majority of patients can. Many other countries predominantly prescribe DPIs with similar if not better asthma outcomes. Other studies have demonstrated that patients, when taught how to use different inhaler devices, prefer multi-dose DPIs over MDIs.
While there are several medications available as DPIs in the United States, the two ICS-formoterol agents are only available as MDIs. Meanwhile, they are available as DPIs in many other places including the United Kingdom, continental Europe, China, and Canada. The reasons for this inequity in access are not clear to me, given the known efficacy of these agents in DPI formulations which were used in many of the clinical trials driving the asthma management guidelines and has long been in use in other countries.
Pharmaceutical companies will be seeking regulatory approval for novel propellants with lower GWP for MDIs. However, these novel propellants will surely come at a high cost to insurers and patients throughout the duration of new patent terms, as we experienced in the past with the transition from chlorofluorocarbon (CFC) to hydrofluoroalkane (HFA) propellants in 2008. And this venture should not come with the tradeoff of withholding DPIs from the U.S. market. Our patients and our nation deserve expeditious access to this proven and recommended asthma therapy via a device with low GHG emissions—that without doubt would be more affordable.
Cost aside, should these novel propellant-MDIs be approved, it is unlikely they will be associated with lower GHG emissions than the DPIs; prior studies demonstrate a lower manufacturing climate footprint of DPIs as compared to MDIs, even without the propellant.
The environmental impact of DPIs is even smaller compared to MDIs if we also take into consideration plastic spacers, which, while recommended for use with MDIs to improve the delivery of the medication to the lungs, are not needed for DPIs. Yet, another environmental concern is that the novel propellants may yield per- and polyfluoroalkyl substances (PFAS), also known as “forever chemicals” – toxic chemicals that we need to limit.
It is for these reasons that I, along with hundreds of health professionals and concerned citizens in addition to health and other organizations, appeal to pharmaceutical companies to make ICS-formoterol DPI available in the United States.
Learn more about the climate impact of inhalers: The cruel irony of inhalers that make climate change worse
Acknowledgments: The author would like to thank Dr. William Feldman, Dr. Gregg Furie, and staff at Health Care Without Harm for their constructive feedback, valuable suggestions, and insightful comments during the writing of this blog.
This article originally appeared in Health Care Without Harm on Sept. 25, 2024 and has been adapted for Perspectives in Primary Care. Health Care Without Harm seeks to transform health care worldwide so the sector reduces its environmental footprint and becomes a leader in the global movement for environmental health and justice.
|
Dr. Wynne Armand is an internal medicine physician at Massachusetts General Hospital, assistant professor at Harvard Medical School, associate director of Mass General’s Center for the Environment and Health, contributing editor at Harvard Health Publications, and is on the editorial advisory board of Perspectives in Primary Care. Her opinion does not necessarily reflect the position of Mass General Brigham or Harvard Medical School. She is on the board of directors for Greater Boston Physicians for Social Responsibility. |
*Feature photos obtained with standard licenses on Shutterstock.
Interested in other articles like this? Subscribe to our newsletter.
Interested in contributing to Perspectives in Primary Care? Review our submission guidelines.