®**chinese Name:** 左氧氟沙星氯化钠注射液  

**English Name:** Levofloxacin and Sodium Chloride Injection 

**Chinese Pinyin:** Zuoyangfushaxing Lühuana Zhusheye 

### **Composition** 

The main component of this product is levofloxacin. 

**Chemical Name:** (−)-(S)-3-Methyl-9-fluoro-2,3-dihydro-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid hemihydrate. 

**Molecular Formula:** C₁₈H₂₀FN₃O₄·½H₂O 

**Molecular Weight:** 370.38 

**Excipients:** Sodium chloride, dilute hydrochloric acid, and water for injection. 

### **Description** 

This product should be a clear, pale yellow to pale yellow-green liquid. 

### **Indications** 

To reduce the development of drug-resistant bacteria and maintain the effectiveness of levofloxacin and other antibacterial drugs, levofloxacin should be used only to treat or prevent infections proven or strongly suspected to be caused by susceptible bacteria. When selecting or modifying antibacterial therapy, bacterial culture and susceptibility testing should be considered. If such data are unavailable, empirical therapy should be based on local epidemiology and susceptibility patterns. 

Before initiating treatment, bacterial cultures and susceptibility tests should be performed to isolate and identify the causative organisms and determine their susceptibility to levofloxacin. Therapy may begin before obtaining these results, but treatment should be adjusted accordingly once available. 

As with other drugs in this class, some strains of *Pseudomonas aeruginosa* may rapidly develop resistance during treatment with levofloxacin. Periodic susceptibility testing is recommended during therapy to monitor for resistance. 

Levofloxacin oral and injectable formulations are indicated for adults (≥18 years) with mild, moderate, or severe infections caused by susceptible strains of the following microorganisms. The injectable form is preferred when intravenous administration offers a clinical advantage (e.g., intolerance to oral therapy). 

1. **Hospital-Acquired Pneumonia** 

   Caused by methicillin-susceptible *Staphylococcus aureus*, *Pseudomonas aeruginosa*, *Serratia marcescens*, *Escherichia coli*, *Klebsiella pneumoniae*, *Haemophilus influenzae*, or *Streptococcus pneumoniae*. Adjunctive therapies should be used as clinically indicated. If *P. aeruginosa* is confirmed or suspected, combination therapy with an anti-pseudomonal β-lactam is recommended. 

2. **Community-Acquired Pneumonia** 

   - **7–14 Day Regimen:** Caused by methicillin-susceptible *S. aureus*, *S. pneumoniae* (including multidrug-resistant strains [MDRSP*]), *H. influenzae*, *H. parainfluenzae*, *K. pneumoniae*, *Moraxella catarrhalis*, *Chlamydophila pneumoniae*, *Legionella pneumophila*, or *Mycoplasma pneumoniae*. 

   - **5-Day Regimen:** Caused by *S. pneumoniae*, *H. influenzae*, *H. parainfluenzae*, *M. pneumoniae*, or *C. pneumoniae*. 

   *MDRSP: Strains resistant to two or more of the following: penicillin (MIC ≥2 µg/mL), second-generation cephalosporins (e.g., cefuroxime), macrolides, tetracyclines, and trimethoprim/sulfamethoxazole.* 

3. **Acute Bacterial Sinusitis** 

   Due to reports of severe adverse reactions with fluoroquinolones (including levofloxacin) and the self-limiting nature of acute bacterial sinusitis in some patients, levofloxacin should be reserved for cases with no alternative treatment options. 

   - **5-Day Regimen:** Caused by *S. pneumoniae*, *H. influenzae*, or *M. catarrhalis*. 

   - **10–14 Day Regimen:** Caused by *S. pneumoniae*, *H. influenzae*, or *M. catarrhalis*. 

4. **Acute Bacterial Exacerbation of Chronic Bronchitis** 

   Caused by methicillin-susceptible *S. aureus*, *S. pneumoniae*, *H. influenzae*, *H. parainfluenzae*, or *M. catarrhalis*. 

5. **Complicated Skin and Skin Structure Infections** 

   Caused by methicillin-susceptible *S. aureus*, *Enterococcus faecalis*, *Streptococcus pyogenes*, or *Proteus mirabilis*. 

6. **Uncomplicated Skin and Skin Structure Infections** 

   Caused by methicillin-susceptible *S. aureus* or *S. pyogenes* (mild to moderate), including abscesses, cellulitis, furuncles, impetigo, pyoderma, and wound infections. 

7. **Chronic Bacterial Prostatitis** 

   Caused by *E. coli*, *E. faecalis*, or methicillin-susceptible *Staphylococcus epidermidis*. 

8. **Complicated Urinary Tract Infections** 

   - **5-Day Regimen:** Caused by *E. coli*, *K. pneumoniae*, or *P. mirabilis*. 

   - **10-Day Regimen:** Caused by *E. faecalis*, *Enterobacter cloacae*, *E. coli*, *K. pneumoniae*, *P. mirabilis*, or *P. aeruginosa* (mild to moderate). 

9. **Acute Pyelonephritis** 

   - **5-Day Regimen:** Caused by *E. coli*, including cases with bacteremia. 

   - **10-Day Regimen:** Caused by *E. coli*, including cases with bacteremia. 

10. **Uncomplicated Urinary Tract Infections** 

    Caused by *E. coli*, *K. pneumoniae*, or *Staphylococcus saprophyticus* (mild to moderate). 

11. **Inhalational Anthrax (Post-Exposure)** 

    Indicated to reduce the incidence or progression of disease following exposure to *Bacillus anthracis*. Efficacy is based on surrogate endpoints (plasma concentrations). The safety of levofloxacin beyond 28 days in adults has not been studied. Long-term therapy should only be used if benefits outweigh risks. 

### **Dosage Forms** 

(1) 50 mL: Levofloxacin (as C₁₈H₂₀FN₃O₄) 0.25 g and sodium chloride 0.45 g 

(2) 100 mL: Levofloxacin 0.5 g and sodium chloride 0.9 g 

(3) 150 mL: Levofloxacin 0.75 g and sodium chloride 1.35 g 

### **Warnings and Precautions** 

1. **Disabling and Potentially Irreversible Serious Adverse Reactions** 

   Including tendinitis, tendon rupture, peripheral neuropathy, and CNS effects (e.g., hallucinations, anxiety, depression, insomnia, severe headache, confusion). These may occur within hours to weeks after starting levofloxacin. 

2. **Tendinitis and Tendon Rupture** 

   Risk increases with age (>60), corticosteroid use, renal failure, or prior tendon disorders. Discontinue at first sign of tendon pain or inflammation. 

3. **Exacerbation of Myasthenia Gravis** 

   Fluoroquinolones may worsen muscle weakness. Avoid in patients with myasthenia gravis. 

4. **QT Prolongation** 

   Avoid in patients with known QT prolongation, hypokalemia, or those taking antiarrhythmics (Class IA/III). 

5. **Hypersensitivity Reactions** 

   Severe, sometimes fatal, allergic reactions may occur. Discontinue at first sign of rash or hypersensitivity. 

6. **Other Serious Adverse Reactions** 

   Including hepatotoxicity, CNS effects (e.g., seizures, increased intracranial pressure), peripheral neuropathy, *Clostridioides difficile*-associated diarrhea (CDAD), blood glucose disturbances, and phototoxicity. 

7. **Aortic Aneurysm and Dissection** 

   Increased risk reported within two months of fluoroquinolone use, particularly in elderly patients. Avoid in patients with aortic aneurysm or high risk. 

 **Use in Specific Populations** 

- **Pregnancy (Category C):** Contraindicated unless potential benefit justifies risk. 

- **Lactation:** Avoid breastfeeding due to potential serious infant adverse reactions. 

- **Pediatric Use:** Contraindicated in patients <18 years except for inhalational anthrax (post-exposure). 

 **Storage and Shelf Life** 

**Shelf Life:** 18 months. 

*(crNote: This translation is for informational purposes. For clinical use, always refer to the latest official presibing information.)*