Viper Extract Might Help Stroke Victims Recover
January 02, 2008
An extract from the Malayan pit viper might help people recover from the devastating effects of a stroke and could be a safer option than the only currently approved medicine for acute stroke.
Researchers reported that 42 percent of the people treated with the drug ANCROD within three hours of the onset a stroke recovered their physical and mental abilities. ANCROD is exciting because it represents new medicine that will become available. Whether the experimental ANCROD would prove a better choice than the only FDA-approved acute stroke treatment, known as tissue plasminogen activator (TPA), is uncertain because no studies have compared them. But ANCROD, which hasn't been approved by the Food and Drug Administration for stroke treatment, seems to be safer in terms of brain hemorrhage than TPA. And there may be an advantage over TPA in the way ANCROD is administered. ANCROD is given intravenously over three to five days in the hospital, providing physicians an extended time to monitor the patient's response and hemorrhage risks and intervene if necessary. TPA, on the other hand, is administered in a single-dose, hour-long injection.
Although the goal is the same for both drugs, the mechanism is entirely different, Sherman said. TPA dissolves clots causing the stroke and restores blood flow to the brain. The snake venom extract, and anticoagulant, lowers the body's level of fibrinogen - a natural clotting agent - and in doing so, improves blood flow to the stroke-damaged area, possibly reversing the effects of the initial stroke and protecting against recurrent stroke. It also may activate the body's natural clot-busting processes.
ANCROD was discovered coincidentally more than 20 years ago by a Malaysian physician who reported that his snake-bite patients didn't form clots and although the fibrinogen was gone for days, they didn't hemorrhage and die. Within several days, the clotting system returned to normal.
A snake farm in Germany is anticipating an increased demand and expanding its colony. Although it is not yet approved by the US Food and Drug Administration (FDA), ancrod (Viprinex) may offer a longer treatment window and have fewer risks than tissue plasminogen activator (tPA), the clot-busting drug that must be given to stroke patients within three hours of the onset of stroke symptoms.
COMMENT: This is the drug that I want for my patients if they ever get a stroke. It seems much better, and certainly more natural, than TPA or the prourokinase discussed in the above story. I hope that it is approved quickly. It is important to recognize, though, that the sooner these drugs are administered the better they work. There is a very narrow window for effectiveness. If you or someone you know is at risk for stroke (high blood pressure and high cholesterol) and they develop a sudden loss of neurological ability (they can’t speak, or loss the ability to control their movements) they should be rushed IMMEDIATELY to the ER so they can be evaluated to determine if they have had a stroke.