Switching inhalers could have good effects on the climate, but bad effects on health

Over the past few years, scientists have come to connect the use of metered dose inhalers, which are commonly prescribed to treat asthma and chronic obstructive pulmonary disease, with the production of greenhouse gases.

The good news is that patients have other options, specifically dry powder inhalers that don’t contain problematic propellants.

Recent research from Alexander Rabin, M.D., and Hallie Prescott, M.D., and their team at Michigan Medicine and the Veterans Affairs Ann Arbor Healthcare System, reveals a bit of bad news: a sample of patients who made the switch had more hospitalizations.

Their study, published in JAMA Internal Medicine, looked at two groups of patients treated for COPD and asthma from the Veterans Administration Health System who were switched through a formulary change from budesonide/formoterol (commonly known as Symbicort) to the dry powder inhaler fluticasone/salmeterol.

The change was associated with increased prednisone use, a steroid often prescribed to treat asthma flare-ups, and increased hospitalizations for pneumonia.

The authors note the change could be due to several factors, including the medication itself, the device or the change in routine and adherence.

Rabin notes that even as many health systems move toward lower-carbon inhaler options, transitions need to be carefully planned to protect patient outcomes.

Paper cited: “Budesonide-Formoterol Metered-Dose Inhaler vs. Fluticasone-Salmeterol Dray-Powder Inhaler,” JAMA Internal Medicine. DOI: 10.1001/jamainternmed.2025.2299

Fundings/disclosures: The study was funded by grant IIR 23-032 from the US Department of Veterans Affairs Office of Health Systems Research.