title: Acute effects of salmeterol and fluticasone propionate alone and in combination on airway blood flow in patients with asthma.
abstract: BACKGROUND
  The airway contains airway smooth muscle and airway vascular smooth muscle. The acute effects of inhaled long-acting β(2)-adrenergic agonists (LABAs) alone, or in combination with an inhaled glucocorticoid (ICS), on airway smooth muscle tone in asthma are known; however, to the best of our knowledge, their effect on airway vascular smooth muscle tone has not been investigated previously. The objective of this study was to investigate the immediate effects of a LABA and an ICS alone and in combination on airway blood flow (Qaw) as an index of airway vascular smooth muscle tone in patients with stable asthma.
  
  
  METHODS
  Fourteen subjects with moderate asthma inhaled single doses of salmeterol (50 μg), fluticasone propionate (250 μg), salmeterol/fluticasone propionate (50/250 μg), or placebo; Qaw was measured before and serially for 240 min after drug administration.
  
  
  RESULTS
  Mean Qaw increased after salmeterol and salmeterol/fluticasone propionate, with peaks at 60 min of 34% and 40%, respectively, and returned to baseline by 240 min after inhalation. Fluticasone propionate alone caused a transient decrease in mean Qaw. The maximal changes in Qaw, which occurred at different times, were 60% for salmeterol, 67% for salmeterol/fluticasone propionate, and -19% for fluticasone propionate (P < .05 vs placebo for all).
  
  
  CONCLUSIONS
  The LABA salmeterol has an acute vasodilator action on the airway of subjects with stable asthma. The addition of fluticasone propionate, which by itself causes vasoconstriction, does not attenuate the salmeterol-induced vasodilation, suggesting that fluticasone propionate potentiates the vasodilator effect of salmeterol. The vasodilation could be of clinical benefit by promoting the vascular clearance of inflammatory mediators including spasmogens from the airway.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT01231230; URL: www.clinicaltrials.gov.
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL. Electronic address: emendes@med.miami.edu.
authors: Eliana S
authors: ES
authors: Mendes
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL.
authors: Patricia
authors: P
authors: Rebolledo
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL.
authors: Adam
authors: A
authors: Wanner
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000403:Airway Resistance / Q000187:drug effects*; D000420:Albuterol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000730:Androstadienes / Q000627:therapeutic use*; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy*; D001783:Blood Flow Velocity / Q000187:drug effects; D001980:Bronchi / Q000098:blood supply*; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D000068298:Fluticasone; D000068297:Fluticasone-Salmeterol Drug Combination; D005541:Forced Expiratory Volume / Q000187:drug effects; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D000068299:Salmeterol Xinafoate; D014664:Vasodilation / Q000187:drug effects*; D014797:Vital Capacity / Q000187:drug effects; D055815:Young Adult
chemical_list: D000730:Androstadienes; D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D000068297:Fluticasone-Salmeterol Drug Combination; D005938:Glucocorticoids; D000068299:Salmeterol Xinafoate; D000068298:Fluticasone; D000420:Albuterol