Overview
Moxifloxacin 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. The drug carries important safety warnings including risks of tendon rupture, peripheral neuropathy, and QT prolongation.
Mechanism of Action
Moxifloxacin is a fluoroquinolone antibiotic that inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV enzymes. These enzymes are essential for bacterial DNA replication, transcription, repair, and recombination. Inhibition leads to rapid bacterial cell death.
Indications
- Acute bacterial sinusitis
- Acute bacterial exacerbation of chronic bronchitis
- Community-acquired pneumonia
- Uncomplicated skin and skin structure infections
- Complicated intra-abdominal infections
Common Doses
- 400 mg
Dosage
The usual adult dosage is 400 mg orally once daily. Duration of therapy varies by indication: 5-14 days for respiratory infections, 7-21 days for skin infections, and 5-14 days for intra-abdominal infections. Should be taken with or without food, but antacids containing magnesium or aluminum should be avoided within 4 hours of administration.
Contraindications
- History of hypersensitivity to moxifloxacin or any quinolone antibiotic
Side Effects
- Nausea
- Diarrhea
- Dizziness
- Headache
- Abdominal pain
- Vomiting
- Dyspepsia
- Tendonitis/tendon rupture
- Peripheral neuropathy
- QT prolongation
- Hypersensitivity reactions
- C. difficile diarrhea
- Photosensitivity reactions
- Central nervous system effects (anxiety, confusion, insomnia)
Interactions
- Antacids containing magnesium/aluminum (reduce absorption)
- Sucralfate (reduce absorption)
- Multivitamins containing iron or zinc (reduce absorption)
- Drugs that prolong QT interval (antiarrhythmics, antipsychotics, antidepressants)
- Nonsteroidal anti-inflammatory drugs (may increase CNS stimulation and seizure risk)
- Warfarin (monitor INR due to potential interaction)
Counseling Points
- Take once daily with or without food, but avoid antacids within 4 hours
- Complete the full course of therapy even if symptoms improve
- Discontinue and contact healthcare provider immediately if tendon pain, swelling, or rupture occurs
- Report symptoms of peripheral neuropathy (pain, burning, tingling, numbness)
- Avoid excessive sunlight/UV exposure due to photosensitivity risk
- Stay well hydrated
- Report any signs of allergic reaction
- Inform provider of all medications being taken
- Monitor blood glucose if diabetic