MONTREAL -- Researchers in Montreal are investigating whether a nasal inhaled steroid used for asthma can be an effective treatment to prevent mild COVID-19 cases from getting worse and requiring hospitalization.

A Research Institute of the McGill University Health Centre (RI-MUHC) team has begun a study that will test ciclesonide (a nasal inhaler used for asthma and nasal rhinitis) on a controlled group of patients who tested positive for COVID-19.

In a news release Wednesday, the MUHC said lab studies have shown ciclesonide can decrease SARS-Cov2 (the virus responsible for the disease) viral replication, and researchers hope the placebo-controlled randomized trial will confirm whether the nasal inhaler can reduce the severe respiratory symptoms associated with mild COVID-19 cases and avoid future need for hospitalization and oxygen.

“We know the COVID-19 virus starts by multiplying in the nose and progresses downwards to the lower parts of the airways and lungs," said Dr. Nicole Ezer, who is leading the study. "We hope that targeting the site of viral replication with inhaled and nasal ciclesonide will reduce early viral replication and decrease the severity of COVID-19 illness.”

The study comes on the heels of a New England Journal of Medicine article that showed that oral or intravenous use of the steroid dexamethasone was found effective in treating patients with severe COVID-19.

"In patients hospitalized with COVID-19, the use of dexamethasone resulted in lower 28-day mortality among those who were receiving either invasive mechanical ventilation or oxygen alone at randomization but not among those receiving no respiratory support," the article reads.

Researchers are hoping for similar results using ciclesonide for those with a mild case of COVID-19.

The drug was approved by Health Canada in 2008, and is administered locally without entering the bloodstream and has fewer side effects than dexamethasone.

“We believe that some individuals may benefit from a treatment option such as this one, which does not have significant side effects, does not interact with other medications and is used topically,” said Ezer.

The study is enrolling adults with a positive COVID-19 diagnosis within five days living in Quebec. Participants will not have to leave their homes and risk further infection, as the drug or placebo will be sent to their home address via courier seven days a week.

The trial requires 454 participants.

More information on the study can be found at or by emailing