Levofloxacin (Levaquin) Dosing for Adults
For adults with normal renal function (creatinine clearance ≥50 mL/min), levofloxacin is dosed at 250 mg, 500 mg, or 750 mg orally once every 24 hours, depending on the specific infection being treated. 1
Standard Dosing by Indication
The specific dose and duration depend on the type and severity of infection:
Respiratory Tract Infections
- Community-acquired pneumonia (CAP): 750 mg once daily for 5 days (high-dose short-course regimen) or 500 mg once daily for 7-14 days 2, 3, 1
- Acute bacterial sinusitis: 750 mg once daily for 5 days or 500 mg once daily for 10-14 days 3, 1
- Acute exacerbations of chronic bronchitis: 500 mg once daily for 7 days 3, 1
Urinary Tract Infections
- Complicated UTI and acute pyelonephritis: 750 mg once daily for 5 days or 250 mg once daily for 10 days 1, 4
- Uncomplicated UTI: 250 mg once daily for 3 days 1
Skin and Soft Tissue Infections
- Uncomplicated skin infections: 500 mg once daily for 7-10 days 1, 5
- Complicated skin and skin structure infections: 750 mg once daily for 7-14 days 2, 1
Drug-Resistant Tuberculosis
- MDR-TB (when first-line agents cannot be used): 750-1,000 mg once daily, with 1,000 mg/day representing the optimal balance between efficacy and tolerability 2, 3
Renal Dose Adjustments
Dose adjustment is mandatory for patients with creatinine clearance <50 mL/min to prevent drug accumulation, as levofloxacin is 80% renally eliminated. 3, 1, 6
- CrCl 20-49 mL/min: Initial dose of 500 mg, then 250 mg every 24 hours (or for 750 mg dosing: initial 750 mg, then 750 mg every 48 hours) 1
- CrCl 10-19 mL/min: Initial dose of 500 mg, then 250 mg every 48 hours 1
- Hemodialysis or peritoneal dialysis: Initial dose of 500 mg, then 250 mg every 48 hours; no supplemental doses needed after dialysis 3, 6
Administration Considerations
Timing with Other Medications
Levofloxacin must be administered at least 2 hours before or 2 hours after antacids containing magnesium or aluminum, sucralfate, iron supplements, or multivitamins with zinc, as these agents markedly decrease fluoroquinolone absorption. 3, 1, 6
Food and Hydration
- Levofloxacin can be taken without regard to food, as bioavailability approaches 100% and is minimally affected by food 1, 6
- Maintain adequate hydration to prevent crystalluria 1
High-Dose Short-Course Rationale
The 750 mg once-daily regimen for 5 days maximizes concentration-dependent bactericidal activity, optimizes peak drug plasma concentrations, and may reduce resistance development while improving compliance. 2, 4, 7 This regimen has been shown to be noninferior to the traditional 500 mg for 10 days in CAP and acute bacterial sinusitis 4, 5.
Special Population Warnings
- Pregnancy: Avoid use due to teratogenic effects 2, 3
- Pediatrics: Generally not recommended for routine use in children due to concerns about bone and cartilage growth effects, though may be considered for MDR-TB when benefits outweigh risks 2, 3
- Elderly: Obtain baseline renal function and adjust dose accordingly, as elderly patients commonly have reduced creatinine clearance 3
- Hepatic disease: No dose adjustment required 3
Common Pitfalls to Avoid
- Using 500 mg when 750 mg is indicated can lead to suboptimal peak concentrations and treatment failure, particularly given the concentration-dependent killing mechanism of fluoroquinolones 2
- Failure to adjust for renal impairment leads to drug accumulation and increased toxicity risk 2, 1
- Concurrent administration with divalent cations (antacids, iron, calcium) without proper spacing drastically reduces absorption 3, 1