The fluoroquinolones: how long will their utility last?

Injudicious use of the fluoroquinolones may result in treatment failure, increased patient morbidity, increased health care cost, and possible patient fatality. Fluoroquinolone-resistant bacteria may also adversely impact the microbiological environment in the hospital, the local community and eventually large geographical regions. Fluoroquinolone resistance develops in a stepwise fashion, and current susceptibility testing methods and recommended MIC susceptible breakpoint values for the United States may fail to identify some bacteria that are resistant due to first step mutations at the fluoroquinolone target site gene sequences. C-8 methoxy- fluoroquinolone compounds are more active against resistant bacteria than the older compounds. Fluoroquinolone resistance relates directly to human and veterinary usage and emerging bacterial resistance poses the single greatest threat to the future survival of the fluoroquinolone drugs as an antibiotic class.