title: Modulation of efficacies and pharmacokinetics of antibiotics by granulocyte colony-stimulating factor in neutropenic mice with multidrug-resistant Enterococcus faecalis infection.
abstract: It has been demonstrated previously that, in non-neutropenic animals, interferon-gamma markedly enhances the efficacies of gentamicin and vancomycin against Enterococcus faecalis resistant to these antibiotics. The aim of our study was to determining whether granulocyte colony-stimulating factor (G-CSF) can be beneficial as an adjunct to gentamicin and vancomycin in the treatment of the same infection in neutropenic mice. After induction of neutropenia by cyclophosphamide, mice were inoculated ip with the organism. The infected animals received sc administrations of G-CSF, antibiotic or a combination of both agents at determined dosing regimens. Infected animals treated with G-CSF alone showed a dose-dependent increase in survival. The inoculum size used in establishing infection affected the effectiveness of the cytokine. Survival was significantly (P: < 0.01) better in the infected animals given gentamicin and vancomycin plus G-CSF than in those given antibiotics or G-CSF alone. The possibility of pharmacokinetic interaction between G-CSF and each of the antibiotics was examined. The cytokine significantly increased the plasma clearance of gentamicin, with a resultant decrease in the area under the concentration-time curve (AUC), while the disposition of vancomycin was not affected. This study suggests that G-CSF may be a useful adjunct to gentamicin and vancomycin for the treatment of multidrug-resistant E. faecalis infection in neutropenic patients.
authors.affiliation: Department of Pharmacy Research, Division of Infectious Diseases and Office of Research Administration, Hartford Hospital, Hartford, CT 06102, USA.
authors.forename: C O
authors.initials: CO
authors.lastname: Onyeji
authors.forename: D P
authors.initials: DP
authors.lastname: Nicolau
authors.forename: C H
authors.initials: CH
authors.lastname: Nightingale
authors.forename: L
authors.initials: L
authors.lastname: Bow
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000627:therapeutic use*; D018432:Drug Resistance, Multiple; D004359:Drug Therapy, Combination; D013293:Enterococcus faecalis / Q000187:drug effects*; D005260:Female; D005839:Gentamicins / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D051379:Mice; D009503:Neutropenia / Q000139:chemically induced / Q000188:drug therapy; D014640:Vancomycin / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D016179:Granulocyte Colony-Stimulating Factor; D014640:Vancomycin