Overview
Levofloxacin is a broad-spectrum fluoroquinolone antibiotic used to treat various bacterial infections. It works by inhibiting bacterial DNA gyrase and topoisomerase IV enzymes, preventing DNA replication and transcription. It is effective against both Gram-positive and Gram-negative organisms.
Mechanism of Action
Levofloxacin is a fluoroquinolone antibiotic that inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV enzymes. This inhibition interferes with DNA replication, transcription, repair, and recombination, leading to bactericidal activity against susceptible organisms.
Indications
- Acute bacterial sinusitis
- Acute bacterial exacerbation of chronic bronchitis
- Community-acquired pneumonia
- Uncomplicated skin and skin structure infections
- Chronic bacterial prostatitis
- Complicated urinary tract infections
- Acute pyelonephritis
- Inhalational anthrax (post-exposure)
Common Doses
- 250 mg
- 500 mg
- 750 mg
Dosage
Dosage varies by indication, typically ranging from 250-750 mg orally once daily for 7-14 days depending on infection severity and type. Renal function adjustment is required for patients with creatinine clearance <50 mL/min.
Contraindications
- Known hypersensitivity to levofloxacin or other quinolone antibiotics
Side Effects
- Nausea
- Diarrhea
- Headache
- Dizziness
- Insomnia
- Constipation
- Abdominal pain
- Rash
- Tendonitis/tendon rupture
- Peripheral neuropathy
- QT prolongation
- Hepatotoxicity
- Hypersensitivity reactions
Interactions
- Antacids containing magnesium or aluminum
- Sucralfate
- Metal cations (iron, zinc)
- Warfarin (increased anticoagulant effect)
- NSAIDs (increased CNS stimulation risk)
- Theophylline (increased theophylline levels)
- QT-prolonging drugs (increased arrhythmia risk)
Counseling Points
- Take with plenty of water to prevent crystalluria
- Complete full course even if symptoms improve
- Avoid antacids, iron, or zinc supplements within 2 hours of dose
- Report tendon pain, swelling, or weakness immediately
- Avoid excessive sun exposure and use sunscreen
- Monitor for signs of peripheral neuropathy
- Report diarrhea, especially if bloody or persistent
- Inform healthcare provider of all medications being taken