title: Pharmacokinetics and systemic effects of inhaled fluticasone propionate in healthy subjects.
abstract: OBJECTIVE
  The present study was undertaken to see whether the difference in plasma cortisol suppression between single and repeated dosing of fluticasone propionate (FP) can be explained by systemic accumulation.
  
  
  METHODS
  Twelve healthy subjects (six women) were given, in a crossover fashion, a single dose inhalation (1000 micrograms) of FP via Diskhaler and repeated inhalations (1000 micrograms twice daily) every 12 h during 7 days. There was a washout period of 2 weeks between the treatments. An intravenous dose of 20 micrograms FP was given as a reference. Plasma concentrations of FP for each treatment were determined by liquid chromatography plus tandem mass spectrometry. Plasma cortisol after the inhaled doses was determined using an immunoassay and was compared with baseline values.
  
  
  RESULTS
  The average plasma concentration of FP was about 1.7 times higher after multiple inhalations than after a single dose. Systemic availability, mainly attributable to pulmonary deposition, was 15.6 [13.6-18.0]% of the nominal dose. Daytime plasma cortisol suppression vs baseline was 47 [20-65]% and 95 [93-97]% for the single and repeated doses, respectivley.
  
  
  CONCLUSIONS
  To conclude, a slow elimination of FP leads to accumulation during repeated dosing. This accumulation may explain the marked decrease in plasma cortisol seen during treatment with fluticasone propionate within the clinical dose range.
authors.affiliation: Astra Draco AB, Lund, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Thorsson
authors.forename: K
authors.initials: K
authors.lastname: Dahlström
authors.forename: S
authors.initials: S
authors.lastname: Edsbäcker
authors.forename: A
authors.initials: A
authors.lastname: Källén
authors.forename: J
authors.initials: J
authors.lastname: Paulson
authors.forename: J E
authors.initials: JE
authors.lastname: Wirén
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000730:Androstadienes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018926:Anti-Allergic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D005260:Female; D000068298:Fluticasone; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D012016:Reference Values
chemical_list: D000730:Androstadienes; D018926:Anti-Allergic Agents; D018927:Anti-Asthmatic Agents; D000068298:Fluticasone; D006854:Hydrocortisone