Fluoroquinolones Flashcards
What are the fluoroquinolones used today?
Ciprofloxacin, Levofloxacin, Moxifloxacin
Fluoroquinolones have _____ spectrum of activity and _____ half lives.
Broad spectrum
Long half lives
What is the general mechanism of action for fluoroquinolones?
Inhibiting DNA synthesis.
In Gram Negative bacteria, inhibit topoisomerase II (DNA gyrase).
In Gram Positive bacteria, inhibit topoisomerase IV.
Resistance mechanisms against fluoroquinolones
- Chromosomal mutations in DNA Gyrase of Topoisomerase IV
- Efflux pumps
- Altered permeability
Fluoroquinolones’ spectrum of activity for Gram Positive Aerobes
Levo, Moxi, or Gemi
Fluoroquinolones’ spectrum of activity for Gram Negative Aerobes
Cipro = Levo > Moxi
Fluoroquinolones’ spectrum of activity for Pseudomonas aeruginosa
Cipro > Levo
Never use Moxi or Gemi
Fluoroquinolones’ spectrum of activity for Anaerobes
Moxi
Fluoroquinolones’ spectrum of activity for atypical bacteria
Use any fluoroquinolone for atypical infection
Fluoroquinolones’ Clinical Uses
Respiratory Tract Infections - Community acquired and Nosocomial
CAP – Levo, Moxi, Gemi
Nosocomial – Cipro, Levo
Fluoroquinolones’ Clinical Uses
UTIs
Cipro, Levo
Fluoroquinolones’ Clinical Uses
Sinusitis, Bronchitis
All FQs
Adverse Effects of Fluoroquinolones
GI - nausea, vomiting, diarrhea
CNS- headache, irritability, insomnia, dizziness
Hepatotoxicity- Moxi only
Cardiac - Prolonged QT Syndrome
Tendonitis and tendon rupture
Contraindicated in Pediatrics and Pregnant Women
Phototoxicity (rare)
Fluoroquinolones Drug Interactions
Divalent and Trivalent Cations
Decrease absorption of all FQs, leading to decreased clinical efficacy
Fluoroquinolones Drug Interactions
Theophylline and Cyclosporin
Decrease metabolism of ciprofloxacin, leading to increased serum levels and toxicity
