Inclusion Criteria:
1. Age 18-75 years.
2. Acute ischemic stroke patients underwent intravenous thrombolysis, treated with ateplase (0.9mg/kg)
3. mRS≤1 before stroke onset, NIHSS ≥ 5 and ≤ 15,la (NIHSS) level of consciousness \< 1
Exclusion Criteria:
1. Endovascular treatment
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. Fasting blood glucose lower than 3.9 mmol/L;
7. Patients with symptomatic intracranial hemorrhage confirmed by clinical signs and imaging before randomization;
8. Patients allergy to fluoroquinolones or other antibiotics;
9. Patients with a life expectancy less than 3 months or patients unable to complete the study for other reasons;
10. Not willing to be followed up or poor treatment compliance;
11. 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;
12. Other conditions not suitable for enrollment.