Duration of preventive effect of inhaled salbutamol on early airway response to allergen in asthmatic subjects.
Salbutamol is known to effectively prevent early asthmatic response (EAR) after specific bronchial provocation test (sBPT) in asthmatic subjects, but the time-course of this protection is not known. In this study the effects of 200 micrograms salbutamol inhaled 2 h before sBPT were compared with 200 micrograms salbutamol inhaled 10 min before sBPT in eight asthmatic subjects sensitized to Phleum pratensis (PP) or Dermatophagoides pteronyssinus (DP). All subjects showed an EAR (% decrease in FEV1 from baseline value: 30.4 +/- 11%) in a preliminary sBPT performed with cumulated doses of extracts of PP or DP titrated in biological units (BU). Each subject performed, on two different days, in a random, double-blind, cross-over study, two puffs of placebo 2 h before sBPT and two puffs of salbutamol 10 min before sBPT (treatment A) or two puffs of salbutamol 2 h before sBPT and two puffs of placebo 10 min before sBPT (treatment B). Baseline FEV1 were similar in both tests. In treatment B, 10 min, 1 h and 2 h after salbutamol inhalation, FEV1 increased significantly with respect to placebo inhalation in treatment A. Ten minutes after salbutamol inhalation in treatment A, FEV1 became similar to that obtained 2 h after salbutamol inhalation and 10 min after placebo in treatment B. Allergen inhalation induced an EAR in only one out of eight subjects after treatment A, and five of the eight subjects after treatment B.(ABSTRACT TRUNCATED AT 250 WORDS)
Paggiaro
P L
PL
Second Institute of Internal Medicine, University of Pisa, Italy.
Dente
F L
FL
Vagaggini
B
B
Bancalari
L
L
Carrara
M
M
Di Franco
A
A
Giannini
D
D
Bacci
E
E
Testi
R
R
Giuntini
C
C
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage*; D000485:Allergens; D001249:Asthma / Q000188:drug therapy*; D016535:Bronchial Hyperreactivity / Q000517:prevention & control*; D001985:Bronchial Provocation Tests; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors
D000485:Allergens; D000420:Albuterol