title: Roflumilast, a phosphodiesterase 4 inhibitor, reduces airway hyperresponsiveness after allergen challenge.
abstract: BACKGROUND
  Roflumilast, an oral, once-daily phosphodiesterase 4 inhibitor, is currently in clinical development for the treatment of asthma.
  
  
  OBJECTIVE
  This pilot study examined the effect of roflumilast on allergen-induced airway hyperresponsiveness (AHR) to histamine challenge and asthmatic response to allergen challenge.
  
  
  METHODS
  In a randomized, double-blind, 2-period, crossover trial, 13 patients with mild allergic asthma [mean forced expiratory volume in 1 s (FEV(1)) % predicted = 86%] received a single dose of oral roflumilast 1,000 microg or placebo. Patients were administered roflumilast 60 min before allergen challenge, and asthmatic responses were assessed via change in FEV(1) <or=9 h after allergen challenge. AHR to histamine provocation was measured before and repeated 24 h after allergen provocation. Patients inhaled histamine in doubling concentrations until attaining a decrease in FEV(1) of <or=20% (PC(20)FEV(1)).
  
  
  RESULTS
  Roflumilast had no detectable bronchodilator activity 60 min after administration. Roflumilast significantly attenuated AHR compared with placebo, with a mean change in pre- to postallergen challenge PC(20)FEV(1) ratio of 1.23 +/- 2.75 and 2.51 +/- 2.95 for roflumilast and placebo, respectively (p = 0.002). During the late asthmatic response, roflumilast reduced the mean maximum decrease in FEV(1) from 2 to 9 h after allergen challenge compared with placebo (p = 0.005). Additionally, FEV(1) at 9 h after challenge was significantly higher in patients treated with roflumilast (p = 0.03). Early asthmatic responses to allergen challenge were not significantly reduced by the single dose of roflumilast.
  
  
  CONCLUSIONS
  Roflumilast attenuated allergen-induced AHR in patients with mild asthma. These results support further investigation of roflumilast as an anti-inflammatory treatment of asthma.
authors.affiliation: Internal Medicine, Lung and Allergy Unit, University of Stellenbosch, School of Medicine, Cape Town, South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Louw
authors.forename: Z
authors.initials: Z
authors.lastname: Williams
authors.forename: L
authors.initials: L
authors.lastname: Venter
authors.forename: S
authors.initials: S
authors.lastname: Leichtl
authors.forename: C
authors.initials: C
authors.lastname: Schmid-Wirlitsch
authors.forename: D
authors.initials: D
authors.lastname: Bredenbroker
authors.forename: P G
authors.initials: PG
authors.lastname: Bardin
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D000631:Aminopyridines / Q000008:administration & dosage / Q000627:therapeutic use*; D001549:Benzamides / Q000008:administration & dosage / Q000627:therapeutic use*; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000009:adverse effects; D018592:Cross-Over Studies; D003521:Cyclopropanes / Q000008:administration & dosage / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D010865:Pilot Projects; D016896:Treatment Outcome
chemical_list: D000485:Allergens; D000631:Aminopyridines; D001549:Benzamides; D003521:Cyclopropanes; D010726:Phosphodiesterase Inhibitors; C424423:Roflumilast