How does tPA work?

IV tPA is a medication that is used for fighting stroke in the very early hours after your symptoms have begun. It's proven to be effective up to 4 1/2 hours after your symptoms start, in certain patient populations.  Typically, stroke doctors would administer this medication after evaluating the patient and concluding that they have had stroke symptoms and likely had an artery blocked by a clot. IV tPA is the medication that breaks up the clot. It's what some people call the clot busting drug. And we give it through an IV and it goes throughout the patient's body and looks for clot to dissolve. And it works very, very well but again, is limited in the fact that you have to meet certain criteria and you also have to arrive at the hospital very quickly after your symptoms begin. Otherwise the risk of giving you this clot busting drug is greater than the benefit it could bring to the patient.