Sometimes, old drugs find a new purpose. A widely available steroid called dexamethasone might hold the potential to save a lot of lives that otherwise would be lost to coronavirus.
Preliminary results released from a randomized and controlled clinical trial involving more than 6,000 patients found that administering dexamethasone significantly reduced deaths among those with severe COVID-19 illnesses. The study, which has not yet been published in a peer-reviewed journal, found that the drug reduced deaths by one-third among patients on mechanical ventilators, and by one-fifth among patients receiving other forms of supplemental oxygen. Although dexamethasone is a far cry from a coronavirus cure, it feels like the first good news to transpire since earlier this spring, when the antiviral drug remdesivir showed it could modestly improve survival among COVID-19 patients.
With vaccine development still underway, scientists are also working to identify treatments that are able to halt the deadly cytokine storms that develop in a small number of patients.
Dexamethasone, which has been around since the 1950s, is commonly used to treat asthma, allergies and autoimmune conditions such as lupus and rheumatoid arthritis.
Why Does Dexamethasone Work for Coronavirus?
The drug is a synthetic version of cortisol, a natural steroid hormone produced by our adrenal glands. Most people associate cortisol with the stress response, but one of its lesser-known abilities is suppressing the immune system. Dexamethasone appears to dial down inflammatory cytokine production, which can impair a person's ability to breathe and cause respiratory failure.
Cytokines are proteins that are normally released by immune system cells during illnesses. Essentially, cytokines help by rallying troops of immune system cells that are capable of defeating a pathogen.
When cytokine production spirals out of control, it attracts too many immune system cells to the lungs, doing more harm than good. This causes immune system cells to attack healthy cells in the lungs, resulting in significant inflammation, fluid buildup and tissue damage.
Although dexamethasone effectively treated many seriously ill patients that required respiratory support in the study, there was no benefit administering it to those with milder cases. Giving dexamethasone to someone who isn't very sick could impair their immune system from functioning properly, leaving them worse off. So, an anti-inflammatory, immunosuppressive drug like dexamethasone seems to only come in handy when cytokines start going rogue.
The news release from the researchers did not outline when full details of the study will be made available. It is also not known whether other cortisol-like drugs on the shelves would have a similar benefit as dexamethasone. Demand for the drug has soared in the U.S., but shortages do not appear to be a concern. The National Institutes of Health has already added dexamethasone to its COVID-19 treatment guidelines.