Emerging role of quinolones in the prevention of gram-negative bacteremia in neutropenic cancer patients and in the treatment of enteric infections.

The pharmacokinetic and antibacterial characteristics of the fluorinated carboxyquinolones make them attractive candidates for the treatment and prevention of infections arising from the alimentary canal. Norfloxacin and ciprofloxacin have been shown to suppress and eliminate the pool of potentially pathogenic aerobic gram-negative rods colonizing the alimentary canal of neutropenic patients with acute leukemia, thereby reducing infection-related morbidity and mortality due to gram-negative sepsis. Although norfloxacin appears to have limited efficacy in the prevention of gram-positive infections in neutropenic patients, other quinolones with improved in vitro activity against such organisms are being evaluated. Co-trimoxazole is considered a standard of therapy for many bacterial infectious diarrheal illnesses. However drug resistance, and the absence of coverage of Campylobacter jejuni are important deficiencies. Early trials suggest that the quinolones are safe and effective treatment of a wide variety of bacterial diarrheal illnesses. Despite these encouraging results, further controlled trials will be necessary to clarify how the quinolones should best be used.