Budesonide reduces sensitivity and reactivity to inhaled mannitol in asthmatic subjects.
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.
Brannan
John D
JD
Department of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
Koskela
Heikki
H
Anderson
Sandra D
SD
Chan
H Kim
HK
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
D001993:Bronchodilator Agents; D008353:Mannitol; D019819:Budesonide