A commonly used blood thinner can be used as an antidote to cobra venom, an international study has found. A Queensland expert called the research “really exciting”.
In the study, published Thursday in the Journal of Science Translational Medicine, Prof. Nicholas Casewell described snakebites as the “deadliest of the neglected tropical diseases, the burden of which falls overwhelmingly on rural communities in low- and middle-income countries”.
Cobra bites are usually treated with an intravenous antivenom, meaning the drug reaches the bloodstream rather than the tissue. Antivenom treatments are therefore not effective in treating necrosis, the irreversible death of body tissue, which can lead to amputation or loss of limb function. Treatment is also expensive, and it can take days for patients to reach the hospital.
The study’s lead author, Tian Du from the University of Sydney, said that if human trials are successful, heparin – a blood thinner that can directly reach infected tissue – could be used on the spot, likely in combination with other drugs.
Du said heparin, an essential medicine listed as an essential medicine by the World Health Organization, could be brought to market relatively quickly as a cheap, safe and effective drug for treating cobra bites after successful human trials.
While she said it is unclear at this point how much heparin will reduce tissue damage, she hopes it will reduce damage by 50-100%, depending on the dosage and how quickly the drug is administered.
The WHO has announced a target to halve the number of deaths and disabilities from snakebites by 2030, and has recognized snakebite as a priority among neglected tropical diseases. While the number of people bitten by cobras is unclear, cobra species are responsible for the majority of snakebites in parts of India and Africa.
The research team analyzed which genes are targeted by snake venom. They then identified these genes as those responsible for the production of heparan sulfate on the surface of cells, as well as heparin sulfate, which is released during an immune response. Heparin acts as a decoy antidote that binds to and neutralizes toxins in the venom that cause tissue damage.
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The researchers used the same method to find an antidote to jellyfish venom in 2019 and are now working to find similar antidotes for Australian black snakes and blue bottle stings.
Professor Bryan Fry, a poison expert at the University of Queensland who was not involved in the research, said the research was “really exciting”.
“Cobra venoms cause severe local tissue damage … it’s like you’ve injected the person with acid,” he said. “This is the first study of its kind with this specific class of toxin and the way it works.”