Stroke victims who receive care at the University of Wisconsin Hospital and Clinics can now participate in an experimental drug trial inspired by vampire bats, officials announced Friday.

The drug, known as desmoteplase, mimics vampire bat saliva in that it prevents blood from clotting when administered, UW Hospital spokesperson Susan Lampert Smith said.

Blood clots are the key to tackling ischemic stroke because they prevent blood from circulating in the brain. This results in the death of brain tissue, a statement released by UW Health said.

Patients do have to fit certain criteria, however, with the key being time since the stroke occurred, Lampert Smith said.

The current drug of choice has only been shown to treat stroke up to four and a half hours after it happens. However, desmoteplase gives patients a nine hour window for treatment after the onset of a stroke, according to the statement.

The extra time is significant, Lampert Smith said, because many people who suffer an ischemic stroke do not realize it until several hours have passed.

“The problem with stroke is people have…these horrible symptoms and they lay down,” she said. “Then when the pain doesn’t go away, they seek medical treatment.”

As one of 32 clinics taking part in the worldwide trial according to the statement, UW Health’s Comprehensive Stroke Center has treated one patient so far using the drug.

This trial is the drug’s fourth round and previous results have been mixed.

“It’s shown a benefit in some people…they’re trying to refine which patients it will work for,” Lampert Smith said.

Through Magnetic Resonance Imaging and Computer Tomography scans, Lampert Smith said physicians will hopefully be able to determine when the drug will be effective.

Lampert Smith said she is not sure when the trial will end because the trial has a specific number of patients it needs to meet worldwide, so the length of the trial depends on how many patients the other clinics see.

If this round of trials shows the drug benefits patients more widely, Lampert Smith said it would be more widely used in the future. If the results do not show benefits, she said UW Hospitals and Clinics would be the drug’s final stop.