Heparin, a blood-clotting drug, may help prevent snakebite victims from limb amputations

A commonly used blood-thinning drug could prevent hundreds of thousands of people bitten by cobras from having to have limbs amputated.

138,000 people die from snakebites each yearIt occurs mainly in sub-Saharan Africa, South Asia and Southeast Asia, and a further 400,000 people suffer complications including the death of body tissue and subsequent amputations.

Focusing on complications from cobra bites, Thien Du Researchers at the University of Sydney in Australia and their team found that the venom targets a molecule called heparan sulfate that coats the surface of cells at the site of the bite, and a natural substance called heparin produced by certain immune cells.

The researchers then exposed human skin and blood cells to the venom of two African cobra species: the red cobra (Naja Parida And the Black-necked Spitting Cobra (Naja NigricolisAdding heparin, a commonly administered blood-thinning drug, prevented the toxin from killing the cells.

Similar experiments in mice also reduced the risk of tissue death, in which heparin “was able to almost completely block localized damage at the bite site,” the researchers said. Greg Neely The same is true at the University of Sydney.

Scientists believe that while the treatment may be effective against bites from many different types of cobras, it probably won't work on other species, unless their venom uses a similar chemical pathway to destroy cells.

Unlike existing antitoxins, heparin is stable at room temperature, which could make it easier to access when quick treatment is needed, which could be done via an auto-injector such as an EpiPen, Du said.

Another advantage of heparin is that existing antitoxins cannot prevent necrosis, Du said. Jeff Isbister Researchers from the University of Newcastle in Australia say that's probably because medicine isn't always available immediately after a snakebite.

“The paper didn't compare it to antitoxin, because it's likely that antitoxin would be just as effective,” he says. The mice were given heparin immediately, which may have helped, Isbister says. “But would it have an effect an hour, four hours or more later? [the] Does it take 24 hours to get from a remote part of Tanzania to a person who has been bitten by a cobra?