Nature has its own clot buster “drug” that could work on stroke patients without increasing their risk for brain damage: vampire bat venom.
The venom-derived drug desmoteplase, currently in research trials, targets and destroys fibrin, which is the clot structure that can eventually cause a person to suffer a stroke.
“When a vampire bat bites a cow, it spits a compound into the blood vessel of the cow to keep blood flowing so it can suck the blood,” explains Dr. Cathy Sila, a vascular cardiologist at Cleveland Clinic. “The compound prevents blood from clotting.”
Desmoteplase injected in the human bloodstream has the same effect; it isolates and clears out only blood vessels containing fibrin — the clot. Also, the drug, which shows promising results in trials, is stronger than the current FDA-approved clot buster on the market, called rt-PA (recombinant tissue plasminogen activator).
The current drug works like Drano, unclogging all blood vessels and, therefore, restoring blood flow to the brain. The problem: rt-PA must be administered intravenously within three hours of stroke onset, and only about 5 percent of stroke victims get to the hospital fast enough for this treatment. After three hours, patients’ risk of internal bleeding and brain damage increases.
“For so many reasons, three hours is just not going to cut it,” Sila says.
So far, reports from the first two phases of desmoteplase trials suggest the drug could be a safer option up to nine hours after stroke onset and has not been shown to affect brain cells.