What is the dosage of levofloxacin (Levaquin) for community-acquired pneumonia?

Levofloxacin Dosing for Community-Acquired Pneumonia

For community-acquired pneumonia, use levofloxacin 750 mg once daily for 5 days or 500 mg once daily for 7-10 days, with the higher dose preferred for severe disease or hospitalized patients. 1, 2

Standard Dosing Regimens

Non-Severe CAP (Outpatient or Ward)

• Levofloxacin 500 mg once daily for 7-10 days is the standard regimen for mild to moderate community-acquired pneumonia 1, 2
• This dose provides adequate coverage for Streptococcus pneumoniae (including penicillin-resistant strains), atypical pathogens (Mycoplasma, Chlamydophila, Legionella), and other common respiratory pathogens 1, 3

Severe CAP (ICU or High-Risk Patients)

• Levofloxacin 750 mg once daily for 5 days is the preferred high-dose, short-course regimen 1, 2, 4
• Alternative dosing: 500 mg twice daily can be used for severe pneumococcal pneumonia, particularly in ICU patients 1, 5
• The 750 mg dose exploits concentration-dependent killing by maximizing the AUC/MIC and Cmax/MIC ratios 4

Route of Administration

• Oral and IV formulations are bioequivalent, allowing seamless transition between routes 6
• Start IV in hospitalized patients unable to take oral medications, then switch to oral once clinically stable (afebrile for 24 hours, hemodynamically stable, able to take PO) 1, 2

Treatment Duration

• Do not exceed 8 days in responding patients 1, 2
• The 750 mg × 5 day regimen is as effective as 500 mg × 10 days, with faster symptom resolution 3, 7, 4
• Clinical response should be evident by day 3 (resolution of fever, improved respiratory symptoms) 7

Coverage Considerations

Monotherapy is Appropriate When:

• No risk factors for Pseudomonas aeruginosa 1
• No septic shock 1
• Mild to moderate severity pneumonia 1

Combination Therapy Required When:

• Risk factors for P. aeruginosa present: combine with antipseudomonal beta-lactam (cefepime, piperacillin-tazobactam, or meropenem) 1, 6
• Severe CAP with septic shock: add non-antipseudomonal cephalosporin III (ceftriaxone or cefotaxime) 1

Critical Pitfalls to Avoid

Recent Fluoroquinolone Exposure

• Do NOT use levofloxacin if patient received any fluoroquinolone within the past 90 days due to high risk of resistant organisms 8, 2
• In this scenario, use amoxicillin-clavulanate 1-2g every 12 hours PLUS azithromycin 500mg daily for 3-5 days instead 8

Inadequate Pathogen Coverage

• Ciprofloxacin is contraindicated for CAP due to inadequate pneumococcal coverage 1
• Levofloxacin does not cover MRSA—add vancomycin or linezolid if risk factors present (recent hospitalization, IV drug use, prior MRSA infection) 2

Dosing Errors

• The 750 mg dose is given once daily, not divided 1, 2
• Avoid administering within 2 hours of antacids or medications containing divalent cations (calcium, magnesium, aluminum, iron), which markedly decrease absorption 9

Efficacy Data

• Clinical success rates for levofloxacin in CAP range from 90-95% across multiple trials 3, 10, 4
• For atypical pathogens: 96% success for Mycoplasma and Chlamydophila, 70% for Legionella 3
• Effective against multidrug-resistant S. pneumoniae (95% success rate) 3
• The 750 mg × 5 day regimen achieves more rapid fever resolution by day 3 compared to standard dosing 7

Special Populations

Renal Impairment

• Dose adjustment required for CrCl <50 mL/min (levofloxacin is 80% renally cleared) 9
• No supplemental dose needed after hemodialysis 9

Hepatic Impairment

• No dose adjustment required 9