They are designed to keep asthma attacks in check but a group of Australian researchers believe inhalers could also be used to treat COVID-19.
A trial by Queensland University of Technology and Oxford University researchers is looking at whether inhalers can stop coronavirus infection becoming a full-blown respiratory illness.
They are focused on its potential impact early in the infection and if using an inhaler could lead to fewer emergency department presentations and hospital admissions.
Dan Nicolau, an associate professor at QUT, noticed only small numbers of asthmatics and people with the chronic lung disease, COPD, among the seriously ill in the early stages of the pandemic.
He thought it was odd, because their lung problems should mean they were at greater risk of infection.
"One explanation for the low numbers was that something these people were doing regularly was protecting them and that, logically, was that they routinely used inhalers for their chronic lung problems," Associate Professor Nicolau explained.
"Ideally it may be that the corticosteroid therapy would be given to anyone with a new, dry cough, and while they are awaiting their COVID test results."
Modelling by the research team indicates the earlier people are given the inhaler, the less likely they are to become sick, Prof Nicolau added.
About 500 people are needed for the trial and recruitment is already underway at the Churchill Hospital in the city of Oxford, England.
Some patients will be given an inexpensive, widely-prescribed inhaler medication used by people with asthma to prevent and control symptoms.
Others will be given a placebo.
Australian Associated Press