Almost five million people around the world are bitten by snakes each year, and as many as 125,000 of those bites are lethal. Many more cause serious injury and disability. Now, imagine if you could save some of those lives – not with expensive antivenoms, but with a common drug ... administered in a simple nasal spray.
A team of scientists from the California Academy of Sciences (CAS) and Trinity College Dublin is working on a snakebite treatment just like that. Their research could help save thousands of victims in poor developing nations around the world, where bites often claim more lives than common tropical diseases or hazards like landmines. "Ninety-eight percent of snakebite victims live in poverty, which is perhaps why funding and innovation are lacking," says the team's lead scientist Dr Matt Lewin, the Director of CAS's Center for Exploration and Travel Health.
In developing countries, snakes often strike in remote locations, meaning that most victims die before they even reach a hospital. And even for those lucky enough to get medical care, existing treatments come with a price tag people in impoverished locations can't afford, often forcing families to take out loans or sell valuables to cover the medical costs.
And then there's the antivenom itself. Currently the only antidote to snake venom, it comes with a set of problems. First off, a snake needs to be correctly identified so matching antivenom can be used (if one exists). And even then, antivenoms require a hospital setting: they need to be kept cool and administered (intravenously) by people who know what they're doing – far from ideal as a treatment for victims in remote, hard-to-reach places.
With all of these challenges in mind, Dr Lewin first began working on the idea of a nasal spray treatment for venomous snake bites last year, using an antiparalytic drug called neostigmine, which is routinely used after surgery to help reverse the effects of certain types of anesthesia. Dr Lewin hoped the drug would work in cases where snakebite victims are paralysed by neurotoxic venom, which often results in death by respiratory failure. Administering it in spray form, he reasoned, would mean it could be used quickly and easily, giving victims in rural locations precious time to get to hospital for further treatment.
Later in 2013, Dr Lewin teamed up with Dr Stephen Samuel from Trinity College Dublin to work on the neostigmine spray in India, where an estimated one million snakebites occur each year. There, the treatment was used on a patient who'd received antivenom for a krait bite, but still suffered from lingering facial paralysis. The nasal spray worked to relieve those lingering symptoms – in just 30 minutes.
Now, new results from the ongoing neostigmine research have been published in the Journal of Tropical Medicine. As part of this study, Dr Lewin and Dr Samuel, along with other researchers, treated mice that had been injected with Indian cobra (Naja Naja) venom. After otherwise-lethal shots of venom, mice dosed with neostigmine survived for much longer than their untreated counterparts – and the study suggests that in some cases, the treatment didn't just delay death, but might actually have allowed the mice to survive.
Although the scientists admit much more research is needed, they're very optimistic about the results so far. "This is the first promising step towards development of a universal antidote for snake bites. We urge global health leaders to accelerate the development of affordable, innovative treatments for snakebite," says Dr Samuel.
"The bottom line is that no one should die from a snakebite in the twenty-first century,” adds Dr Lewin.
Top header image: Leo, Flickr
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