Diagnosis of acute ischemic stroke with onset between 3 and 24 hours prior to planned start of study drugs. Acute ischemic stroke is defined as a measurable neurological deficit of sudden onset, presumed secondary to focal cerebral ischemia, and not otherwise attributable to ICH or another disease process. Stroke onset will be defined as the time the patient was last known to be without the new clinical deficit. Patients whose deficits have worsened in the last 24 hours are not eligible if their first symptoms started more than 24 hours before. If the stroke started during sleep, stroke onset will be recorded as the time the patient was last known to be intact. A careful history is important to determine when the patient was last without the presenting deficits.