title: Budesonide reduces sensitivity and reactivity to inhaled mannitol in asthmatic subjects.
abstract: OBJECTIVE
  The aim of the study was to investigate whether treatment using inhaled corticosteroids decreases airway responsiveness to inhaled mannitol in asthmatic subjects.
  
  
  METHODS
  Before treatment or a change in treatment with inhaled corticosteroids, 18 asthmatic subjects had measurements of lung function and airway sensitivity to mannitol taken and they completed a self-administered questionnaire on asthma symptoms. The procedure was repeated 6-9 weeks after taking 800-2400 microg/day of budesonide.
  
  
  RESULTS
  There were significant reductions in airway sensitivity (provoking dose to induce a 15% fall in FEV1 (PD15)) and airway reactivity measured by the response dose ratio (RDR; final percentage fall FEV1/total dose of mannitol administered). The PD15 (Gmean (95%CI)) increased from 78 mg (51, 117) before treatment to 289 mg (202, 414) following treatment (P < 0.001). All subjects had a significant increase beyond the repeatability of 0.9 doubling doses with seven subjects becoming unresponsive. There was a 4.2 (3.4, 4.9)-fold improvement in the RDR with the value before the treatment period 0.18 (0.12, 0.28) decreasing to 0.04 (0.03, 0.08) following treatment (P < 0.001). These improvements were associated with significant improvements in lung function and symptom severity.
  
  
  CONCLUSIONS
  Treatment with the inhaled corticosteroid budesonide caused a decrease in airway sensitivity and reactivity to inhaled mannitol and this was associated with expected improvements in lung function and symptoms.
authors.affiliation: Department of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
authors.forename: John D
authors.initials: JD
authors.lastname: Brannan
authors.forename: Heikki
authors.initials: H
authors.lastname: Koskela
authors.forename: Sandra D
authors.initials: SD
authors.lastname: Anderson
authors.forename: H Kim
authors.initials: HK
authors.lastname: Chan
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000188:drug therapy* / Q000209:etiology; D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D019819:Budesonide / Q000008:administration & dosage* / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008353:Mannitol / Q000009:adverse effects; D008875:Middle Aged; D010865:Pilot Projects; D013997:Time Factors
chemical_list: D001993:Bronchodilator Agents; D008353:Mannitol; D019819:Budesonide