COMPARATIVE EFFECTS OF LEVOFLOXACIN AND OFLOXACIN ON THE NORMAL ORAL AND INTESTINAL MICROFLORA

The aim of the study was to study the ecological effects of Levofloxac in, compared to that of ofloxacin, on the oral and intestinal human mi croflora, 10 healthy volunteers received levofloxacin (500 mg) and 10 subjects were given ofloxacin (400 mg) perorally, once daily for 7 day s, Saliva and stool samples were obtained prior to drug administration , during administration (days 2, 4 and 7), and after withdrawal of the agents (days 9, 11, 14 and 21). The concentrations of levofloxacin an d ofloxacin in the saliva and faecal samples, respectively, were assay ed, and quantitative and qualitative microbiological analyses were per formed, Oral administration of levofloxacin and ofloxacin led to low d rug concentrations in the saliva, which corresponded with mild disturb ances in the oral microflora, High drug levels were obtained in the in testinal tract, and both agents caused a selective reduction in the no rmal microflora, mainly directed towards aerobic cram-negative bacteri a. There was no significant difference between levofloxacin and ofloxa cin, regarding ecological effects on the normal oral and intestinal mi croflora, From an ecological point of view, these agents acted favoura bly, since no major selection of resistant strains occurred in the nor mal microflora during administration.