We're Running Out of Antivenom

(Inside Science) -- It’s estimated that globally there are over 400,000 snakebites and at least 20,000 resulting deaths each year. But many snakebites go unreported, so the actual numbers could also be as high as 1.8 million bites and 95,000 deaths each year.

In the U.S., rattlesnakes and coral snakes are highly venomous. And sub-Saharan Africa has ten of the deadliest snakes in the world. 

Antivenom can save lives -- but, as of right now, we’ve run out of some types of antivenom, and not just here in the U.S., but around the world. It’s a global health concern that doesn’t seem to have a solution.

Dr. Richard Clark from UC San Diego Health is an expert in treating snake bite victims. He said, “I think the big deal about antivenoms and shortages in the world right now is that drug companies that make any kind of pharmaceutical product, only make it if it’s profitable. And the problem with antivenoms is they tend to be fairly expensive to produce.”

It’s expensive to produce and there is not enough demand -- so little in fact, that the pharmaceutical company that produced antivenom products stopped making them in 2003. The Food and Drug Administration stepped in and extended the expiration dates of the last remaining supplies to last until June 2016. Clark says it will likely last even longer.

“So, there’s still expired antivenom around that we know still works. One day that will be gone unless a company starts to make the coral snake antivenom again,” said Clark.

“So, in the United States if not many people are bitten by coral snakes every year, if the company can’t sell enough antivenom to at least break even, they’re not going to make the antivenom. So another company is not going to come in, out of the goodness of their heart and provide coral snake antivenom in the United Sates unless they can make a profit doing that,” said Clark.

Coral snake antivenom is not the only one running out. Another antidote called FAV-Afrique used by Doctors Without Borders to treat snakebites in Africa, is now no longer being produced by the pharmaceutical company Sanofi Pasteur.

“A lot of people get bitten by snakes in Africa, and they get bitten by very poisonous snakes, like cobras and mambas, and stuff that will kill you very rapidly. So it’s very much of a public health concern,” said Clark.

The African antivenom is especially useful because it can treat bites from ten different venomous snakes found in Africa.

There are cheaper antivenom alternatives, but they don’t always work well and aren’t specific to different snake bites.

“They’re riskier as far as side effects are concerned. They may not bind to the snake venom as well as the more well-made antivenom. But if it’s all you’ve got, it’s better, in some situations, than nothing,” remarked Clark.

Snake antivenoms are made by first milking venom from a snake. The venom is then diluted and injected into animals, usually horses -- they’re large, friendly and easy to work with. The horse will produce antibodies against the venom, which are taken from the horse’s blood and processed for humans in the form of antivenom.

It’s a process that companies no longer want to invest the money to do. So right now, only cheaper alternatives are available in places like sub-Saharan Africa.

“So from a public health perspective, and believe me there’s nobody that is more concerned about public health than I am, I definitely think that if I could have antivenoms available that they should be. And if the federal government is willing to take on that priority, even if people can’t pay for it, I think that would be great for them to do,” said Clark.

For U.S. snake bite patients, the chance of encountering a coral snake is so rare that for right now, there is antivenom and when it runs out completely, doctors still have effective treatments.

“As an example, in the United States if you were bitten by a rattlesnake and you came in and I didn’t have antivenom to treat you with, I could still treat you in an intensive care unit with things like blood products and supportive care that would likely keep you alive until the venom had run its course through your body,” said Clark.

But in places like sub-Saharan Africa, where finding a medical facility is hard enough -- and then to be told there is no antivenom left -- this means people will continue to die and lose limbs.