Thursday, November 15, 2007

Quinolones

QUINOLONES
- nalidixic acid as prototype
- DNA gyrase inhibitor
- DNA gyrase - uncoil DNA to for replication
- nalidixic acid + flurinated group = fluoroquinolone - increases antibacterial spectrum

Antibacterial activity
  • g-ve aerobic bacteria and atypical cover (mycoplasma, chlamydia, legionella, mycobacteria)
  • limited g+ve (covers MSSA, not MRSA)
  • development of fluoroquinolone aims to cover more g+ve
  • cipro, lemo, levo, oflox, peflox = good g-ve, moderate to good against g+ve
  • cipro best for P. aeruginosa
  • gati, moxi, spar, trova (3rd group) - covers Strep pneumoniae
Resistance
  • Staph, pseudomonas, serratia
  • Cross resistance happens
Pharmacokinetics
  • IV = oral administration = hence give oral
Clinical
  • UTI - norfloxacin concentrated in urine
  • bacterial diarrhoea
SE
  • QTc prolongation
  • damage growing cartilage --> not recommended <18>
  • tendinitis

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