Post-antibiotic and synergic effects of fluoroquinolones and ceftazidime in combination against Pseudomonas strains.
Infectious complications are still the leading cause of morbidity and mortality in seriously ill patients [1-3]. To combat the resistance of (mainly Gram-negative, non-fermentative) bacteria, e.g. Pseudomonas aeruginosa, to a wide spectrum of antibiotics, drug combination therapy has been widely adopted as standard clinical practice since the late 1990s. beta-Lactam combinations are not optimal and the potential of nephrotoxicity and ototoxicity from aminoglycosides has caused clinicians to evaluate new possibilities, such as combinations of fluoroquinolones and beta-lactams. We examine here the synergic and post-antibiotic effects (PAEs) of ciprofloxacin, ofloxacin and pefloxacin-ceftazidime combinations against 6 clinical Pseudomonas isolates. The fluoroquinolone-ceftazidime combinations were not only synergic against Comamonas (P.) testosteroni, but had double the PAEs of the two drugs alone. The ciprofloxacin-ceftazidime combination had a longer PAE against P. aeruginosa isolate 1 than ciprofloxacin alone. The combinations, however, did not have longer PAEs than those of the single drugs against the other 5 P. aeruginosa isolates.
Mayer
I
I
Institute of Clinical Microbiology, Faculty of Medicine, University of Szeged, Hungary.
Nagy
E
E
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D020604:Comamonas testosteroni / Q000187:drug effects; D004357:Drug Synergism; D006801:Humans; D008826:Microbial Sensitivity Tests; D011549:Pseudomonas / Q000187:drug effects*; D011552:Pseudomonas Infections / Q000382:microbiology
D000890:Anti-Infective Agents; D002511:Cephalosporins; D002939:Ciprofloxacin; D002442:Ceftazidime