title: Population pharmacokinetics of inhaled fluticasone furoate and vilanterol in adult and adolescent patients with asthma.
abstract: OBJECTIVE
  Population pharmacokinetic (PK) methods were used to characterize the PK of fluticasone furoate (FF) and vilanterol (VI) in patients with asthma following once daily inhaled FF/VI and FF and to identify significant covariates that impact the PK.
  
  
  METHODS
  Four of the five studies in the meta-analysis were conducted in patients with asthma (> 90%), the fifth in healthy subjects. FF data were described by a two-compartment model with first order absorption and elimination. VI data were described by a three-compartment model with zero-order absorption and first order elimination.
  
  
  RESULTS
  Race was a significant covariate on inhaled clearance (CL/F) of FF PK. AUC(0-24) for Asian patients was on average 33 - 53% higher than for non-Asians. Race was also a significant covariate on VI PK, with lower (81%) central volume of distribution (Vc/F) for Asian patients compared with non-Asians; VI C(max) was 220 - 287% higher in Asian patients. Treatment (combination or monotherapy), predicted percentage FEV(1), and other demographic variables did not influence the PK of FF or VI.
  
  
  CONCLUSIONS
  Combination of FF/VI does not appear to affect the PK of FF or VI. The effect of race on PK of FF or VI does not have impact on dosage adjustments for FF/VI in East Asian patients with asthma.
authors.forename: Ann
authors.initials: A
authors.lastname: Allen
authors.forename: Sarah
authors.initials: S
authors.lastname: Siederer
authors.forename: Shuying
authors.initials: S
authors.lastname: Yang
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000730:Androstadienes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001249:Asthma / Q000188:drug therapy*; D001592:Benzyl Alcohols / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002648:Child; D002722:Chlorobenzenes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological
chemical_list: D000730:Androstadienes; D001592:Benzyl Alcohols; D002722:Chlorobenzenes; C550468:vilanterol; C523187:fluticasone furoate