TOPICS > Health

Searching for the holy grail of snake bite antidotes

June 18, 2014 at 6:37 PM EDT
Although snake bites are rarely fatal in the United States, every year about 100,000 people die worldwide after being bitten by venomous snakes. A California doctor has developed a nasal spray treatment that may be able to help some snake bite victims halt paralysis before they reach a hospital. Special correspondent Spencer Michels has the story.

JUDY WOODRUFF: Snakebites, although they are rarely fatal here in the United States, every year, about 100,000 people die worldwide after being bitten by venomous snakes. A California doctor has come up with a way that might lower those numbers.

NewsHour special correspondent Spencer Michels has our report.

And a warning: It contains images that might be disturbing to some viewers.

MAN: Oh, my God. Did you see that?

SPENCER MICHELS: In India, children sometimes play with venomous snakes like cobras. This one in a YouTube video may have been defanged, but, playing aside, snakes these children encounter in the wild or in agricultural areas can be deadly.

In fact, venomous snakes attack more than two million people a year in rural parts of India, Asia, Africa, Central and South America. Most of the victims come from poor agricultural areas remote from hospitals. Without timely medical treatment, patients often die.

Matt Lewin, an emergency room physician and medical director of King American Ambulance in San Francisco, has used his experience in treating seizures and his training as a neuroscientist to develop a fast-acting treatment for poisonous snakebites.

Lewin does much of his research and his snakebite research here at the California Academy of Sciences in San Francisco’s Golden Gate Park. He serves as a physician on academy expeditions around the world where the health of scientists is often at risk, sometimes from snakebites.

In fact, in 2001, a 38-year-old academy researcher, Dr. Joseph Slowinski, died after being bitten by a small snake while doing field work in Myanmar. Venom from some snakes contains neurotoxins that paralyze the body, including the respiratory system, and Slowinski couldn’t get to a hospital before he stopped breathing.

DR. MATTHEW LEWIN, California Academy of Sciences: They were more than 24 hours from help. And they were breathing for this poor man, down a mountain, taking turns, and they just couldn’t sustain it.

He was bitten by krait, which is a highly venomous snake. It could fit in the palm of your hand.

SPENCER MICHELS: Treating snakebite victims in India is extremely expensive, often more than rural families can afford. To temporarily counteract the neurotoxins in some snake’s venom, doctors often rely on a drug called neostigmine, which is commonly used in surgery.

DR. MATTHEW LEWIN: It’s available everywhere in the world, heat stable, and it’s very inexpensive.

SPENCER MICHELS: But in the hands of inexperienced people, injecting it into a bite victim could induce heart problems.

DR. MATTHEW LEWIN: In the injectable form or I.V. form, it’s very toxic. It’s difficult to handle. So the idea is to develop a formulation that’s less toxic, less prone to complications. To get rid of the needle would be a great way to do this.

SPENCER MICHELS: Lewin says a nasal spray containing neostigmine drug could be used safely by almost anyone anywhere, unlike the injectable version.

He got the idea from his work in the ambulance and the emergency room.

DR. MATTHEW LEWIN: As one of our protocols, we were using nasal sprays to treat the seizures. And so the thoughts came together sort of out of the blue in a clear moment, and I thought, wow, wouldn’t it be cool if we could treat a snakebite with nasal spray?

SPENCER MICHELS: It would buy valuable time until the hospital could administer antivenoms that uses antibodies to treat and neutralize the snake poison.

DR. MATTHEW LEWIN: Seventy-five percent of the patients or more who die from snakebites never get treated in the hospital. If you make it to the hospital, you will probably do quite well.

SPENCER MICHELS: Without funding, Lewin and a group of his scientific friends decided they had to prove that nasal spray would actually counteract the neurotoxin-induced paralysis.

So Lewin became the guinea pig while a team of researchers at the University of California, San Francisco, including anesthesiologist Philip Bickler, conducted a full-hour, self-financed experiment.

DR. PHILIP BICKLER, University of California, San Francisco: It involved administering an infusion of curare-like drug to create a controlled and safe state of partial paralysis.

DR. MATTHEW LEWIN: I couldn’t see, couldn’t move, couldn’t talk. I was very weak.

DR. PHILIP BICKLER: So he developed some blurred vision, then difficulty swallowing, and at the level we were using it, some slight effects on breathing.

DR. MATTHEW LEWIN: Then Dr. Theiner administered the nasal spray, and a few minutes later, I was really quite close to normal.


MAN: It worked. It worked. It worked.

SPENCER MICHELS: But it hasn’t been proven in humans against actual snake venom.

DR. ROBERT NORRIS, Stanford University: No, you stay right where you are. I will move the snake around.

SPENCER MICHELS: And some scientists say its benefit is limited, because it won’t work on most North American snakes, especially not the most common ones in this country, which don’t inject neurotoxins in their victims.

At Stanford University, director of emergency medicine Robert Norris, is a snake enthusiast and a former colleague of Lewin’s. Here, he’s wrangling a venomous Northern Pacific rattlesnake named Jake. It’s a common North American snake.

DR. ROBERT NORRIS: Neostigmine would have no benefit for a rattlesnake bite. The venom from rattlesnakes is going to cause tissue damage, blood clotting problems, possibly shock, but very rarely any neurotoxicity at all, which is what neostigmine might help in some cases.

SPENCER MICHELS: In fact, Norris argues the venom from most snakes throughout the world are not affected by neostigmine.

DR. ROBERT NORRIS: Well, I think it’s a noble idea. Unfortunately, I don’t think it’s going to have a — would have a great impact. The percentage of snakebites that it would be applicable to are pretty — is pretty small, and whether or not it would even be effective in those types of snakes is still questionable as well.

SPENCER MICHELS: But Lewin and his colleague Bickler disagree and they add that the spray is just a first step towards solving a large problem.

DR. PHILIP BICKLER: Neostigmine specifically addresses the venom of snakes like cobras that paralyze the muscles. And that alone would have a major impact in terms of a number of victims worldwide who die from snakebite. The paralytic snakebites are the vast majority of the deaths that occur.

SPENCER MICHELS: Since statistics on snake deaths are spotty, it’s hard to tell who’s right. Lewin and others are working on that problem and on finding a drug or combination of drugs, a universal antidote that would counteract various kind of venom, either administered by nasal spray or by an EpiPen that is common for getting relief from allergies.

DR. ROBERT NORRIS: Well, that’s obviously the Holy Grail, but there’s nothing out there right now that looks like it would even potentially fit that definition.

SPENCER MICHELS: One thing Norris and Lewin do agree on is that because it is not a major problem in the U.S. and Europe, there is far too little attention or research going into snakebites and their treatment.

JUDY WOODRUFF: If you can take it, read more about the research to save lives affected by snakebites. Spencer details that in a blog on our Health page.