Scorpion Venom Meets Its Match

Aug 4, 2011
Originally published on August 6, 2011 6:36 am

Spiders and snakes don't bother me much. But scorpions? Get them away!

If you haven't spent time in the Southwest, you might be surprised to learn how common the creatures are there. And Arizona bark scorpions, in particular, can really do some damage, especially to kids.

When these scorpions sting, they inject a potent neurotoxin, which can be life-threatening for young children and infants. Severe reactions to the stings are seen in more than 200 children each year in Arizona.

But the Food and Drug Administration has just approved the first antivenom to neutralize the poison. Called Anascorp, the treatment was developed in Mexico and is being manufactured by a company there.

The drug was tested against a placebo in 15 kids. The neurological symptoms of eight children who got the antivenom went away within four hours, while the same result was achieved in only one child among seven getting a placebo. Both groups of children were sedated, typical treatment for the stings. Those results were published two years ago in the New England Journal of Medicine in 2009.

In other studies, more than 1,500 people, ranging in age from under a month to 90, were treated the antivenom, generally with good results.

The most common side effects of the treatment are vomiting, fever and rash.

The drug, marketed by Rare Disease Therapeutics of Nashville, Tenn., isn't cheap. The wholesale price per vial of Anascorp will be $3,500, the company tells Shots. And the recommended dose is three vials per patient, so treatment will typically cost more than $10,000.

And one more thing. The antivenom is derived from the plasma of horses injected with scorpion venom. Want to know more? Listen to Sunday's All Things Considered, when Monica Ortiz Uribe from member station KRWG in Las Cruces, N.M., tells the story of how the drug came to be.

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