Snakebite Treatment in Works at University of Arizona "Buys Time" for Hikers and Other Victims

Hikers and people working outdoors could be better protected against venomous snakes in the future by packing along a bite-treatment product now under development at the University of Arizona. 

While still a long way from store shelves, the treatment's already showing signs that it could be a life-saving breakthrough.

The treatment involves introducing tiny amounts of iron and carbon monoxide into the bloodstream, which combine to turn a key protein in the body's blood-clotting process into "stealth" mode, says the researcher who came up with the idea, Dr. Vance Nielsen, a professor and vice chair for research in the UA College of Medicine's Department of Anesthesiology.

One of Nielsen's areas of research is in how iron and carbon monoxide affect fibrinogen, a protein that helps form a sticky "mesh" important in blood clotting. He might not have ever connected the dots between that and a treatment for snakebites until he met Dr. Leslie Boyer, founding director of the U of A's VIPER institute, which researches anti-venom treatments for scorpions and snakes.

Many venomous snakes, including Arizona rattlesnakes, rely on a fibrinogen-destroying enzyme designed to make their prey bleed out quicker. This way, a snake doesn't need to slither around as much find the bitten prey.

Humans bitten by a snake trying to defend itself also succumb to the effects of plummeting levels of fibrinogen. Internal bleeding in victims sometimes leads to a loss of a limb or even death, Nielsen says.

By the time some victims arrive at a hospital, where snake antivenom can be administered, the fibrinogen level has dropped to almost zero, and even when the patient is given a blood transfusion, the snake enzyme continues to "chew up the [fibrinogen] like a chainsaw" and cause the patient to keep bleeding.

One day, "it just came to me" that fibrinogen could be made to "twist" so that the snake enzyme couldn't find its structural vulnerabilities, he says. Dr. Boyer looked at him "as if I was from Mars." But then the pair used snake venom to prove that Nielsen's iron-and-carbon-monoxide concoction really worked. The treatment causes the venom to be fooled into leaving the fibrinogen alone, allowing it to keep working at clotting blood.

Although carbon monoxide typically is thought of as killer gas, the molecule is used by cells for a myriad of purposes, and research over the last few years shows that it may have a wide range of medicinal uses. So far, animals tested with the compound don't seem to be harmed, Nielsen says.

Since Nielsen's discovery, he and other UA scientists have worked with the university's Tech Launch Arizona program, which "commercializes inventions stemming from university research" and helps put them in the marketplace, according to a U of A news release. About 8,000 Americans are bitten by venomous snakes each year, and of those, about five or six victims die.

Often with snakebites, "you may not die, but you may wish you were dead," Nielsen says. Bites can involve up to two weeks in the hospital, with limbs swelling up to several times their normal size.

Details haven't been fully worked out yet, but Nielsen envisions a product that people would take outdoors with them. In the event of a snakebite, the product could be applied with a patch or injection, "like an EpiPen, and you won't have these complications."

The concept would be similar to CPR, he says. The treatment "buys time" for the patient until antivenom can be applied. (Antivenom, it should be pointed out, can't be used in the field; it has dangerous side effects and must be administered by medical professionals.) It'll be particularly useful in the Third World, he says, where snakebite victims sometimes die because they can't get to a hospital for two or three days.

If it's successful, Nielsen would receive some small cut of the potential profit from the treatment.

Avoiding the snakebite in the first place is best, naturally. Accidents happen, but statistics show that up to 70 percent of Arizona victims were provoking the snake.