title: In vitro synergy studies with ciprofloxacin and selected beta-lactam agents and aminoglycosides against multidrug-resistant Pseudomonas aeruginosa.
abstract: In order to determine the effect of combining ciprofloxacin with beta-lactam and aminoglycoside agents against multidrug-resistant P. aeruginosa, ciprofloxacin was tested in vitro with the checkerboard broth microdilution technique with various current beta-lactam and aminoglycoside agents. In both inhibitory and bactericidal testing, the combination of ciprofloxacin with a beta-lactam agent (ceftazidime, piperacillin, mezlocillin, azlocillin, or imipenem) was more likely to show a synergistic effect or additive effect and lack of antagonism (96.5% of all inhibitory and cidal tests) than was a combination of ciprofloxacin with an aminoglycoside [(amikacin, tobramycin, or gentamicin), 90% of all inhibitory and cidal tests]. Finding of antagonism in some testing, especially with aminoglycosides, indicates that results are unpredictable. These results may influence selection of agents for selection in clinical situations.
authors.affiliation: Department of Medicine, Cedars-Sinai Medical Center/UCLA School of Medicine.
authors.forename: R D
authors.initials: RD
authors.lastname: Meyer
authors.forename: S
authors.initials: S
authors.lastname: Liu
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D047090:beta-Lactams
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D002939:Ciprofloxacin