Mechanism of Action
Ciprofloxacin is a fluoroquinolone antimicrobial (see CLINICAL
PHARMACOLOGY, Microbiology).
Pharmacokinetics
The plasma concentrations of ciprofloxacin were not measured
following administration of 0.25 mL CETRAXAL (total dose: 0.5 mg
ciprofloxacin). However, the maximum plasma concentration of ciprofloxacin is
anticipated to be less than 5 ng/mL.
Microbiology
The bactericidal action of ciprofloxacin results from
interference with the enzyme DNA gyrase, which is needed for the synthesis of
bacterial DNA.
Bacterial resistance to quinolones can develop through
chromosomally- or plasmidmediated mechanisms.
The mechanism of action of fluoroquinolones, including
ciprofloxacin, is different from that of macrolides. Therefore, ciprofloxacin
may be active against pathogens that are resistant to these antibiotics, and
these antibiotics may be active against pathogens that are resistant to
ciprofloxacin. In vitro studies demonstrated cross-resistance between ciprofloxacin
and some fluoroquinolones.
Ciprofloxacin has been shown to be active against most isolates of the following
bacteria, both in vitro and in clinical infections of acute otitis externa
as described in INDICATIONS AND USAGE:
Staphylococcus aureus
Pseudomonas aeruginosa.
Clinical Studies
In a randomized, multi-center, evaluator-blinded study of
patients with acute otitis externa, patients were treated with either CETRAXAL (ciprofloxacin otic solution)
twice daily or neomycin and polymyxin B sulfates and hydrocortisone otic
solution (PNH) three times daily for 7 days.
In the per protocol population, clinical cure was achieved
at the end of a 7-day treatment in 70% (173/247) for the CETRAXAL (ciprofloxacin otic solution) treated group
versus 60% (147/243) for the control treated group.
Last reviewed on RxList: 5/26/2009
This monograph has been modified to include the generic and brand name in many instances.