Fluoroquinolones

• Fluoroquinolones inhibit an enzyme called DNA topoisomerases, such as topoisomerase IV and II (DNA gyrase).
• Common fluoroquinolones include ciprofloxacin, ofloxacin, balofloxacin, levofloxacin, gemifloxacin, and moxifloxacin.
• The suffix "-floxacin" is commonly used to indicate fluoroquinolones.
•  fluoroquinolones are broad spectrum bactericidal antibiotics
• fluoroquinolones are very effective against gram-negative bacteria like Enterobacteriaceae, Haemophilus, Legionella, Neisseria, Moraxella, and Pseudomonas species.
• fluoroquinolones are used for the treatment of tuberculosis. 
• older fluoroquinolones are less effective against Gram positive bacteria
• Most fluoroquinolones are not effective against MRSA.
• fluoroquinolones should not be taken perorally together with mineral supplements like iron, zinc, or calcium pills, causing chelation, preventing their absorption from the gut.
• fluoroquinolones are metabolized in the liver by cytochrome p450 but are also inhibitors of this enzyme.
• fluoroquinolones side effects

  • tendonitis in the Achilles tendon
  • CNS toxicity: insomnia, agitation, seizures, and peripheral neuropathy
  •  prolong the QT interval - > arrhythmias
  •  toxic epidermal necrolysis 
  • Stevens-Johnsons syndrome.