What is the recommended dosage of Intravenous (IV) Levofloxacin (levofloxacin) for various infections?

Intravenous Levofloxacin Dosing

For most bacterial infections in adults, IV levofloxacin should be dosed at 500 mg once daily for 7-14 days, with a high-dose regimen of 750 mg once daily for 5 days approved for community-acquired pneumonia, acute bacterial sinusitis, complicated urinary tract infections, and acute pyelonephritis. 1, 2

Standard Adult Dosing by Infection Type

Community-Acquired Pneumonia (CAP)

• Standard regimen: 500 mg IV once daily for 7-14 days 3
• High-dose short-course: 750 mg IV once daily for 5 days (noninferior to 10-day standard regimen) 2, 3
• Sequential IV to oral therapy is appropriate as oral bioavailability approaches 100% 4, 3

Nosocomial Pneumonia

• 750 mg IV once daily for 7-14 days, with option for sequential IV-to-oral switch 3
• This regimen demonstrated equivalent efficacy to imipenem/cilastatin followed by oral ciprofloxacin 3

Complicated Urinary Tract Infections and Acute Pyelonephritis

• 750 mg IV once daily for 5 days 1, 2
• This high-dose short-course is noninferior to ciprofloxacin 2
• For uncomplicated UTI: 250 mg once daily may be sufficient 3

Acute Bacterial Sinusitis

• 750 mg IV once daily for 5 days 2
• Oral formulation at 500 mg once daily for 10-14 days is an alternative 3

Complicated Skin and Skin Structure Infections

• 750 mg IV once daily for 7-14 days 5, 3
• May transition to oral therapy when clinically appropriate 3

Catheter-Related Bloodstream Infections

• 500 mg IV twice daily for 7-14 days when used in combination with metronidazole for polymicrobial coverage 5

Renal Dose Adjustments

Dosage reduction is mandatory for creatinine clearance <50 mL/min due to predominantly renal elimination (80% excreted unchanged in urine) 1, 4:

• Levofloxacin clearance correlates directly with creatinine clearance 4
• Failure to adjust dosing risks drug accumulation and toxicity 1
• Specific adjustment protocols should follow manufacturer guidelines based on calculated creatinine clearance 4

Pediatric Considerations

Levofloxacin is generally not recommended for pediatric patients due to concerns about effects on bone and cartilage growth 1. However, for specific indications like tuberculosis where benefits outweigh risks, dosing guidelines exist 5.

Administration Considerations

IV-to-Oral Transition

• Seamless transition is appropriate as oral levofloxacin is bioequivalent to IV formulation 2, 3
• Oral absorption is rapid and complete, with peak concentrations reached within 1-2 hours 4
• Food does not significantly affect absorption 4

Drug Interactions

• Separate administration from aluminum/magnesium antacids and ferrous sulfate by at least 2 hours to avoid significantly decreased absorption 4
• Cimetidine and probenecid decrease renal clearance but interactions are not clinically significant 4
• Monitor patients on theophylline, warfarin, or cyclosporin closely for enhanced effects 4

Important Clinical Caveats

Resistance Considerations

• Reserve levofloxacin for appropriate indications to minimize resistance development 6
• S. pneumoniae resistance to levofloxacin remains <1% in the US, but judicious use is essential 3
• The high-dose regimen (750 mg) maximizes concentration-dependent killing and may reduce resistance emergence 2

Contraindications

• Avoid in pregnancy due to potential teratogenic effects 1
• Use caution in patients with seizure disorders or CNS conditions 6
• Monitor for tendonitis, QTc prolongation, and glucose disturbances 6

Tissue Penetration

• Excellent penetration into respiratory tissues, urinary tract, and skin 4, 2
• Poor CSF penetration (approximately 16% of plasma concentrations) 4
• Volume of distribution: 1.1 L/kg with 24-38% protein binding 4