title: Fleroxacin combined with rifampin.
abstract: We determined the effect of the combination of rifampin and fleroxacin against Enterobacteriaceae and streptococcal species. None of the 65 isolates tested by checkerboard assay demonstrated synergy, 12% of isolates showed an additive effect; 86.7% were indifferent, and only 1 isolate showed antagonism. The mean FIC was 1.2. When using 2 and 8 micrograms/ml of rifampin, fleroxacin MICs of 285 isolates of Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae, staphylococci, streptococci, Bacteroides, and Clostridium were not increased, but synergy was not demonstrated. Time-kill studies against Escherichia coli, P. aeruginosa, Enterobacter cloacae, Staphylococcus aureus, and Enterococcus faecalis failed to show increased killing when the two agents were present at one-half the MBC. The fleroxacin-rifampin interaction is one of indifference but provides coverage for species not adequately inhibited by fleroxacin.
authors.affiliation: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York.
authors.forename: Y X
authors.initials: YX
authors.lastname: Zhang
authors.forename: H C
authors.initials: HC
authors.lastname: Neu
mesh_terms: D000150:Acinetobacter / Q000187:drug effects; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000494:pharmacology; D004336:Drug Antagonism; D004357:Drug Synergism; D004755:Enterobacteriaceae / Q000187:drug effects; D016576:Fleroxacin; D006801:Humans; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012293:Rifampin / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D016576:Fleroxacin; D012293:Rifampin