By IDSE NEWS Staff
An inhaled form of heparin might be effective in treating seriously ill patients with COVID-19, according to a new international study led by researchers at the Australian National University with King’s College London (eClinicalMedicine 2025 Sep 27. doi:10.1016/j.eclinm.2025.103339).
In a prospective, collaborative trial of six randomized clinical studies, adults who were hospitalized with COVID-19 but not intubated were randomly selected to inhaled nebulized heparin plus standard of care or standard of care alone. The researchers analyzed data from almost 500 patients hospitalized with COVID-19 across six countries between June 2020 and December 2022. The patients were enrolled from 10 hospitals in Argentina, Brazil, Egypt, Indonesia, Ireland, and the United States.
Patients who inhaled heparin were half as likely to require intubation and had a significantly lower risk for death compared with those receiving standard of care (odds ratio for intubation or death, 0.43 [95% CI, 0.26-0.73; P=0.001]). The dose of heparin and method for nebulizing the drug were specific to each study, the authors said (ClinicalTrials.gov Identifier: NCT04635241).
In addition, there were no reported cases of pulmonary or systemic bleeding among those who received nebulized heparin.
In addition to acting as an anticoagulant, heparin has anti-inflammatory and pan-antiviral properties, the researchers said. Earlier research results showed breathing and oxygen levels improved in COVID-19 patients after they inhaled a course of heparin.
“Inhaled heparin is antiviral, anti-inflammatory, and anticoagulant. There’s no other drug that has that unique combination,” said Clive Page, PhD, OBE, a professor emeritus of pharmacology at King’s College who co-led the international study.
The researchers believe the drug may be useful in fighting other serious respiratory infections, such as pneumonia.
Lead author Frank van Haren, MD, PhD, a professor and the director of the ICU at the St George Hospital, in Sydney, said the drug, if inhaled, appears to prevent the virus from infecting the lungs and damaging them.
“We’re aiming to conduct another trial in Europe to confirm its effectiveness in fighting other common respiratory infections such as influenza and RSV [respiratory syncytial virus]. And because it’s inexpensive, it’s much more accessible for those from low-income countries,” Dr. van Haren said.
While the findings highlight the potential of inhaled heparin, further development is required before the treatment can be adopted routinely, they said.
The researchers are now also developing an improved formulation of heparin, specifically designed to be given by inhalation.
