Ancrod: A Venomous New Treatment for Stroke

The Malaysian pit viper has a killer bite. But its venom could actually help stroke patients, and the FDA is also considering approving a form of the venom to prevent brain damage.

When 66 year-old Steven Gaul suffered a stroke, he thought his world was coming to an end. Steven could hardly imagine that venom from a snake might preserve his brain function.

As part of a study at Pennsylvania's Lehigh Valley Hospital, doctors gave Steve an experimental drug called Ancrod, made from the poison of the Malaysian pit viper. The venom is known to cause uncontrollable bleeding, but when purified and administered slowly, it can prevent brain damage.

Dr. Peter Barbour, from Lehigh Valley Hospital, explained, "They knew that it causes the blood to become thinned when the victim is bitten and they figured out how that thinning occurs and applied it to medical conditions."

Researchers see Ancrod as an alternative to TPA, the current clot-dissolving drug of choice. That's because TPA is more likely to cause hemorrhaging, because it is given one time for about an hour. Ancrod is given by IV over several days, allowing doctors to control its effect and reduce hemorrhaging.

"Its major effect is to make the blood less sticky, less viscous, so that it can flow more easily, so that it improves circulation to the area that needs circulation improved," maintains Barbour.

In a study of 500 stroke patients nationwide, 42% of those treated with the venom recovered physical and mental function compared to 34% treated with a placebo.

It worked for Steve, but he had to learn to read, write, and speak all over again. Getting treatment fast is the key. Both Ancrod and TPA must be given within 3 hours of the stroke to be effective.

Ancrod, the stroke venom, is now awaiting FDA approval. It could come this year, but there is no guarantee. Doctors don't expect it to replace TPA for stroke, but it may offer one more option to prevent brain damage.

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