title: Observed Antagonistic Effect of Linezolid on Daptomycin or Vancomycin Activity against Biofilm-Forming Methicillin-Resistant Staphylococcus aureus in an In Vitro Pharmacodynamic Model.
abstract: Pharmacodynamic activity in antibiotic combinations of daptomycin, vancomycin, and linezolid was investigated in a 48-h in vitro pharmacodynamic model. Using human-simulated free drug concentrations, activity against clinical biofilm-forming methicillin-resistant Staphylococcus aureus isolates was evaluated. Linezolid antagonized vancomycin activity at 24 and 48 h. Linezolid antagonized daptomycin at 24 and 48 h depending on dose and strain. Adding daptomycin increased vancomycin activity at 48 h (P < 0.03). These results may be strain dependent and require further clinical investigation.
authors.affiliation: Rhode Island Infectious Diseases (RIID) Research Program, Veterans Affairs Medical Center, Providence, Rhode Island, USA Department of Pharmacy Practice, University of Rhode Island, Kingston, Rhode Island, USA.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Luther
authors.affiliation: Rhode Island Infectious Diseases (RIID) Research Program, Veterans Affairs Medical Center, Providence, Rhode Island, USA Department of Pharmacy Practice, University of Rhode Island, Kingston, Rhode Island, USA Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA kerrylaplante@uri.edu.
authors.forename: Kerry L
authors.initials: KL
authors.lastname: LaPlante
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D015169:Colony Count, Microbial; D017576:Daptomycin / Q000493:pharmacokinetics / Q000494:pharmacology*; D006801:Humans; D000069349:Linezolid / Q000493:pharmacokinetics / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D011500:Protein Synthesis Inhibitors / Q000493:pharmacokinetics / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D011500:Protein Synthesis Inhibitors; D014640:Vancomycin; D000069349:Linezolid; D017576:Daptomycin