Suppression of the oropharyngeal and gastrointestinal microflora by ciprofloxacin: microbiological and clinical consequences.

The impact of ciprofloxacin on the human oropharyngeal and gastrointestinal microflora has been studied by several authors during the last years. The use of ciprofloxacin for selective decontamination in immunocompromised patients has also been investigated. This review article summarizes the published data concerning these studies. The results show that the impact on the oropharyngeal microflora is minor. Administration of ciprofloxacin leads to a rapid elimination of the major components of the aerobic Gram-negative intestinal microflora. The aerobic Gram-positive flora is partly affected, while the impact on the anaerobic microorganism is minor. Oral ciprofloxacin given prophylactically to immunocompromised patients during severe granulocytopenia prevented colonization with potentially pathogenic aerobic Gram-negative rods, and reduced the incidence of infections caused by these microorganisms. There was no effect on the incidence of aerobic Gram-positive or fungal infections. Administration of ciprofloxacin seems not to predispose to the development of resistant microorganisms.