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Large Eastern brown snake in Tamban Forest, New South Wales, Australia. Rats whose feet were injected with Eastern brown snake venom took 50 percent longer to die if their hind limbs were treated with the ointment. (Peter Woodard/Wikimedia)
Researchers in Australia have patented a potentially lifesaving topical ointment that can be used as a first aid treatment for snakebite. The team’s findings were published in Nature on June 26.
Currently, the main first aid method for snakebite in Australia is to immobilize the area with a pressure bandage and prevent spreading of the toxin via the lymph system. This approach buys time for the victim to find professional help if a limb is bitten, but not for other parts of the body such as the chest or face.
The new cream contains glyceryl trinitrate, or nitroglycerin, which releases nitric oxide and causes lymphatic vessels to constrict.
"Our preliminary trials indicate topical application of the ointment slows lymphatic transport by some 350 percent with no obvious adverse effects," write the authors in the study abstract.
"The cream will be of particular use for bites to the torso where pressure bandaging is ineffective," they continue. "It may also be useful as a first aid treatment against bites from other venomous creatures."
Physiologist Dirk van Helden at Australia’s University of Newcastle and colleagues tested the product using a benign radioactive mixture that travels through the lymph system. They injected participants’ feet with the compound and observed that it took 13 minutes to travel to the top of the leg in people with no ointment compared with 54 minutes in those immediately treated with ointment to the injection site.
The scientists found that rats whose feet were injected with Eastern brown snake venom took 50 percent longer to die if their hind limbs were treated with the cream.
According to van Helden, the cream gives victims "time and a half to get help," and could be beneficial for people working and hiking in rural areas to carry. "I’d prefer that to just time," he told Science Magazine.
However, the ointment may not work for some types of snakebite, such as rattlesnakes in the United States, whose venom is hemolytic and destroys tissues rather than causing paralysis and death like the neurotoxins produced by most Australian snakes and other types, such as cobras and mambas."If this treatment pans out, it may revolutionize first aid for snakebite in parts of the world where venom causes paralysis," said medical toxicologist Eric Lavonas at the Rocky Mountain Poison and Drug Center in Denver, Colorado, according to Science Magazine.
