title: Antibacterial activity of achievable epithelial lining fluid exposures of Amikacin Inhale with or without meropenem.
abstract: OBJECTIVE
  While Amikacin Inhale (BAY41-6551), an integrated drug-device combination under development, achieves an estimated amikacin epithelial lining fluid (ELF) concentration of ∼ 5000 mg/L, its target site pharmacodynamics are unknown. We evaluated the pharmacodynamics of ELF exposure of inhaled amikacin ± meropenem.
  
  
  METHODS
  ELF exposures of inhaled amikacin (400 mg every 12 h), intravenous meropenem (2 g every 8 h) and a combination of both were studied in an in vitro pharmacodynamic model. Seven Klebsiella pneumoniae and 10 Pseudomonas aeruginosa with amikacin/meropenem MICs of 1 to 32,768/≤ 0.125 to >128 mg/L were included. Efficacy was assessed over 24-72 h.
  
  
  RESULTS
  The mean ± SD 0 h bacterial density was 6.5 ± 0.1 log10 cfu/mL. Controls grew to 8.0 ± 0.5 log10 cfu/mL by the end of the experiments. Simulation of inhaled amikacin monotherapy rapidly achieved and sustained bactericidal activity near the limit of detection over 24 h for all 13 isolates with amikacin MIC ≤ 256 mg/L except only ∼ 2 log10 cfu/mL reduction was observed in K. pneumoniae 375 (amikacin/meropenem MIC 64/32 mg/L) and P. aeruginosa 1544 (amikacin/meropenem MIC 64/128 mg/L). No activity was seen against the three isolates with amikacin MIC ≥ 2048 mg/L. Among the six isolates tested with meropenem monotherapy, five (meropenem MIC ≥ 16 mg/L) grew similarly to the controls while one (meropenem MIC 2 mg/L) achieved ∼ 2.5 log10 cfu/mL decrease. Among seven isolates tested in combination, four (amikacin/meropenem MIC ≤ 64/32 mg/L), including K. pneumoniae 375, maintained limit of detection until 72 h, whereas P. aeruginosa 1544 sustained a 1 log reduction. Combination therapy had no activity against the two isolates with amikacin MIC ≥ 2048 mg/L.
  
  
  CONCLUSIONS
  Inhaled amikacin monotherapy showed bactericidal activity against most isolates tested with amikacin MICs ≤ 256 mg/L. Adjunct inhaled amikacin plus meropenem sustained this activity for 72 h for the tested isolates with amikacin/meropenem MIC ≤ 64/32 mg/L.
authors.affiliation: Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA.
authors.forename: Wonhee
authors.initials: W
authors.lastname: So
authors.affiliation: Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA.
authors.forename: Jared L
authors.initials: JL
authors.lastname: Crandon
authors.affiliation: Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Hamada
authors.affiliation: Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA Division of Infectious Diseases, Hartford Hospital, Hartford, CT, USA david.nicolau@hhchealth.org.
authors.forename: David P
authors.initials: DP
authors.lastname: Nicolau
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000583:Amikacin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D001826:Body Fluids / Q000737:chemistry*; D005260:Female; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013845:Thienamycins / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D000583:Amikacin; D000077731:Meropenem