A widely available and affordable drug, heparin, limits lung damage when inhaled by COVID-19 patients, according to world-first findings by researchers from The Australian National University (ANU).
The researchers are coordinating multiple studies tracking hospital patients infected with SARS-CoV-2 in 13 countries who were given doses of inhaled heparin.
ANU study lead Professor Frank van Haren said initial results indicate the drug could be "a promising treatment" and also "a possible preventative against the virus".
Breathing and oxygen levels improved in 70 per cent of the patients after they inhaled a course of heparin, and their symptoms improved according to the World Health Organization (WHO) COVID symptoms scale.
"There is still an urgent need for an effective treatment of COVID-19 and the early results of our trials show inhaled heparin is safe and effective," Professor van Haren said.
"This drug is already available in hospitals all over the world and it is a very inexpensive drug. If it is as effective as our early results suggest, it could have a major impact in our fight against COVID."
Heparin, which is normally administered via injection, is a blood thinner used to treat and prevent blood clots across the world and is said to be widely available.
Co-author Professor Clive Page, from King's College London, who is co-leading the global studies, said: "Inhaled heparin has antiviral properties which work by binding to the spike proteins the coronavirus uses to enter the cells of the body.
"Inhaled heparin effectively stops the virus infecting cells in the lungs and could also stop people from getting the virus from others.
"It also works as an anti-inflammatory drug - the medicine has the ability to calm everything down when the body is mounting an exaggerated response to the virus. We already know heparin can reduce lung damage caused by this inflammation and the immune response overdrive that we see in other lung diseases which could provide benefit to patients hospitalised with COVID-19.
"It's also a blood thinner. When COVID-19 patients get very sick they develop blood clots in the lungs and these can be lethal. Heparin stops these clots from forming. There is no other drug that has these three different effects - anti-viral, anti-inflammatory and anti-coagulant."
The researchers say because the drug has antiviral properties and calms the immune system down it could be used at different stages of treatment.
When inhaled, heparin also shows promise as a preventative and could be used to boost vaccination efforts.
"Most COVID experts agree that vaccination alone is not going to stop the pandemic. This could really assist in poorer countries where vaccination is challenging and we think it could help front line workers who could use it as a preventative measure," Professor van Haren said.
"Inhaled heparin is a promising new possibility to provide a low-cost, safe and effective treatment for COVID-19 that is available and affordable to low and middle-income countries around the globe."
Professor van Haren said the team was now collecting more evidence that inhaled heparin works as a treatment and prevention for COVID-19.
"Once we have this evidence, heparin via inhalation could be an option to treat COVID-19 patients, everywhere, within months," he said.
The findings from the first 98 patients in the studies are published in a new paper in the British Journal of Clinical Pharmacology.