Background: The effects of regular inhaled β-agonist treatment on lung function remain a controversial issue. In an earlier study, the administration of regular inhaled salbutamol resulted in negative changes in FEV1 not only in asthmatics, but also in nonasthmatic atopic subjects.
Objective: The aim of this study was to confirm these findings and also to examine whether regular inhaled salbutamol would increase bronchial hyperresponsiveness in atopic or normal individuals.
Design: The study was a randomized, double-blind, placebo-controlled, crossover investigation.
Participants: There were two groups: 10 normal healthy subjects (group A) and nine nonasthmatic atopic subjects (group B).
Interventions: Subjects received inhaled salbutamol or identical placebo for periods of 6 weeks, the dose being increased in stepwise fashion at 2-week intervals.
Measurements: Changes in lung function were assessed by measuring spirometric values, airways conductance, and changes in complete and partial expiratory flow volume curves. Changes in these parameters following a methacholine challenge were used to assess bronchial hyperresponsiveness.
Results: No statistically significant differences in lung function or bronchial hyperresponsiveness were noted to occur as the result of treatment in either group.
Conclusion: Our results do not support the view that regular inhaled salbutamol in normal or atopic subjects without asthma causes adverse changes in the airways.