By contrast, dry powder and soft mist inhalers don’t use propellants.
The former rely on a patient’s breath to release medicine, and the latter turn liquid into a fine spray – making both far less harmful to the planet.
“Five hundred and thirty thousand cars on the road each year is a lot, and I think this is a really important topic because it’s fixable — there are easy ways to reduce emissions,” lead author William Feldman, a pulmonologist and researcher at UCLA, told AFP.
Medically, only a small fraction of patients require metered-dose inhalers.
Very young children need spacers – valved chambers that help deliver medicine to the lungs – and these only work with metered-dose devices.
Frail older adults with weak lungs may also need puffers because they can’t generate enough inhalation force.
“But the vast majority of people could use dry powder or soft mist inhalers,” Feldman said, noting that countries such as Sweden and Japan use alternative inhalers without any loss in health outcomes.
Insurance barriers
The slower US uptake of greener inhalers, he added, stems from insurance and market barriers.
A dry-powder version of albuterol, the most commonly used inhaler drug, exists but is often not covered by insurance, making it more expensive.
Another drug, budesonide-formoterol, is widely sold in dry-powder form in Europe, which is not available in the US.
Feldman emphasised that the goal of the research is not to blame patients but to highlight the need for policy and pricing reform.
“We absolutely do not want to stigmatise patients with asthma and COPD,” he said.
“I think it’s incumbent upon us as a society to get those medications to the patients in a sustainable way, and that ultimately falls to the highest levels.”
A related JAMA commentary authored by Alexander Rabin of the University of Michigan and others echoed that insurers and policymakers must ensure lower-emission inhalers are affordable and accessible for all.
They warned that several new low-global-warming metered-dose inhalers are expected to launch in the US as high-priced brand-name products, “raising the risk that patients without robust insurance coverage … could be left behind”.
-Agence France-Presse