A low-cost, widely available drug may offer new hope for patients with severe COVID-19.
An international study led by the Australian National University (ANU) and King’s College London found that inhaled heparin can reduce the need for ventilators and lower the risk of death in seriously ill patients.
The study involved nearly 500 hospitalized patients across six countries.
Results showed that those who inhaled heparin were about half as likely to require mechanical ventilation compared with patients who received standard care.
They also had a significantly lower risk of dying from the virus.
Heparin has long been used as an injectable drug to treat blood clots, but this study tested it in a new way: as an inhaled treatment delivered directly into the lungs.
Researchers believe this targeted approach is key to its success.
Heparin’s benefits go beyond preventing clots—it also has anti-inflammatory and broad antiviral properties, which may help reduce lung damage caused by respiratory infections.
Earlier studies had already shown that inhaled heparin could improve breathing and oxygen levels in COVID-19 patients.
Professor Clive Page of King’s College London, who co-led the study with ANU’s Professor Frank van Haren, explained the drug’s unique potential. “Inhaled heparin is anti-viral, anti-inflammatory and anti-coagulant.
There’s no other drug with that combination,” he said. “We know another pandemic will come eventually, and even now, some patients with COVID-19 still get very sick. This is a great weapon to have up our sleeve.”
The findings also suggest that inhaled heparin could be useful for treating other serious respiratory illnesses, including pneumonia, influenza, and respiratory syncytial virus (RSV).
Because it works by preventing infections from spreading and damaging the lungs, the treatment may also benefit people with weakened immune systems, such as cancer patients.
“It doesn’t matter what kind of respiratory infection the patient is dealing with,” said Professor van Haren, who is also director of the intensive care unit at St George Hospital in Sydney.
“When inhaled, the drug stops the infection from taking hold and damaging the lungs.” He and his team plan to conduct further trials in Europe to confirm its effectiveness against other common infections.
Another advantage of heparin is its affordability. Because it is inexpensive and already widely available, it could be especially valuable for patients in low-income countries where access to advanced therapies is limited. Researchers are now working on improving the drug’s formulation so that it can be optimized for inhalation.
The study was published in eClinicalMedicine and presented at the European Respiratory Society International Congress in Amsterdam, the world’s leading annual conference for respiratory research.
While more trials are needed before inhaled heparin becomes part of standard treatment, the results so far point to a safe, accessible option that could transform care for patients facing severe respiratory infections.
