Ciprofloxacin

As a type example of a quinolone.

Uses: UTI, Gonorrhea, and other susceptible infections
Mechanism of action Inhibits DNA gyrase (aka topoisomerase I
Dose Uncomplicated gonorrhea: PO 500mg one off
UTI: 500mg BD 7 d
Pharmacokinetics Absorption PO
Distribution
Metabolism liver
Elimination
Time course of action max concentration in
Adverse effects Tendon
Important interactions NSAIDs - lowers seizure threshold
Warfarin - increases exposure to warfarin
Clozapine - ↑ exposure to clozapine
MTX - ↑ risk toxicity?

CNS effects of quinolones

  • due to competitive binding at GABA receptors (whyyyy)
  • lowers seizure threshold → monitor closely with phenytoin