The purpose of this study is to determine the efficacy and safety of levofloxacin in treating acute ischemic stroke.

Acute ischemic stroke is a leading cause of disability and mortality. The investigators' previous studies suggested levofloxacin to be a newly identified neuro-protective agent, which could reduce infarct volume and improve neurologic function in animal models. To evaluate the efficacy and safety of levofloxacin in treating acute ischemic stroke patients, the prospective, multicenter and randomized controlled trial was designed.

Inclusion Criteria:

1. Age 18-75 years.
2. The patients were clinically diagnosed with acute ischemic stroke with NIHSS score ≥5 points and ≤15 points,and NHISS score 1a level of consciousness < 1 point.
3. mRS≤1 before stroke onset.
4. Signed and dated informed consent is obtained.

Exclusion Criteria:

1. Patients with transient ischemic attack and those undergoing emergency reperfusion therapy, including intravenous thrombolysis and emergency thrombectomy.
2. Patients using glucocorticoids, antiarrhythmic drugs (class I and class III antiarrhythmic drugs: quinidine, procaine amine, lidocaine, phenytoin sodium, verapamil, etc.), and quinolones within 14 days.
3. Patients with other diseases that may aggravate adverse drug reactions, such as ventricular arrhythmias, prolonged QT interval (male: QTc>430ms, female: QTc>450ms), severe cardiac insufficiency (NYHA functional grade ≥ III), myasthenia gravis, peripheral neuropathy, seizures, tendon-related diseases, severe immune system-related diseases, hematological diseases, active hepatitis or cirrhosis, serious respiratory diseases.
4. Abnormal liver and kidney function: glutamic oxaloacetic transaminase or glutamic pyruvic transaminase exceeds 3 times the upper limit of normal; Direct bilirubin or indirect bilirubin more than 3 times the normal upper limit; Blood creatinine exceeds 1.1 times the upper limit of normal; Creatinine clearance rate≤50ml/min; Urea nitrogen≥ 20mg/dL.
5. Concurrent infection.
6. Blood glucose lower than 3.9 mmol/L.
7. Patients allergy to fluoroquinolones or other antibiotics.
8. Patients with a life expectancy less than 3 months or patients unable to complete the study for other reasons.
9. Not willing to be followed up or poor treatment compliance.
10. Patients who are participating in other clinical studies, or have participated in other clinical studies within 3 months before enrollment, or have participated in this study.
11. Other conditions not suitable for enrollment.