title: In vitro inhibition of neutrophil elastase activity by inhaled anti-Pseudomonas antibiotics used in cystic fibrosis patients.
abstract: BACKGROUND
  Inhaled antibiotics are commonly used in the treatment of cystic fibrosis lung disease. A previous study suggested neutrophil elastase activation by colistin in vitro. Here, we investigated direct effects of the commonly used antibiotics colistin and tobramycin on neutrophil elastase activity.
  
  
  METHODS
  Neutrophil elastase was measured spectrophotometrically. The antibiotics colistin and tobramycin were added in different concentrations with or without the addition of albumin.
  
  
  RESULTS
  Generally, neutrophil elastase activity was lower in the absence of albumin compared to its presence. Both antibiotics, colistin and tobramycin, had inhibitory effects on neutrophil elastase activity except for high concentrations of colistin when albumin was absent.
  
  
  CONCLUSIONS
  Our results suggest inhibitory effects of colistin and tobramycin in vitro. There was a clear dependency of neutrophil elastase measurements on the presence of albumin. Clinical studies are needed to investigate potential direct effects of inhaled antibiotics on neutrophil elastase activity in cystic fibrosis airways.
authors.affiliation: Pediatric Pulmonology, Children's Hospital, University of Munich, 80337 Munich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hector
authors.forename: Matthias
authors.initials: M
authors.lastname: Kappler
authors.forename: Matthias
authors.initials: M
authors.lastname: Griese
mesh_terms: D000280:Administration, Inhalation; D000418:Albumins / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D003091:Colistin / Q000494:pharmacology / Q000627:therapeutic use; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000201:enzymology / Q000382:microbiology; D006801:Humans; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors*; D008826:Microbial Sensitivity Tests; D011549:Pseudomonas / Q000187:drug effects*; D011552:Pseudomonas Infections / Q000188:drug therapy*; D014031:Tobramycin / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000418:Albumins; D000900:Anti-Bacterial Agents; D019272:Leukocyte Elastase; D014031:Tobramycin; D003091:Colistin