title: Stroke treatment window widens, but a fast response is still crucial.  Research shows the clotbusting drug rt-PA can work if given after four and a half hours, but its more effective the sooner it is administered.
mesh_terms: D004334:Drug Administration Schedule; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007269:Injections, Intra-Arterial; D020521:Stroke / Q000188:drug therapy*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator