Influence of inhaled steroids on recovery from occupational asthma after cessation of exposure: an 18-month double-blind crossover study.
Occupational asthma (OA) is a useful model for the study of asthma in humans. The possibility that inhaled corticosteroids, in addition to withdrawal from the workplace, could improve clinical and functional recovery from OA can be hypothesized. We assessed clinical, functional, and behavioral characteristics of 32 subjects (22 male, 10 female), in all but one of whom OA was confirmed by specific inhalation challenges induced by either high- (n=13) or low-molecular-weight (n=19) agents within 3 mo after cessation of exposure. In this randomized, crossover, double-blind study, subjects (paired for baseline PC20 and duration of symptoms after exposure) received either placebo or 1,000 micrograms of inhaled beclomethasone daily for 1 yr, followed by the alternate medication for 6 mo. Various clinical, functional, and behavioral parameters were examined at each 3-mo visit. Significant improvement in clinical (nocturnal symptoms, cough), functional (morning and evening peak expiratory flow rates), and behavioral (quality of life) parameters were detected in the active-treatment period, although the magnitude of the improvement was relatively small. Side effects (oropharyngeal, reduced cortisol) were similar in the placebo and treatment groups. Distinguishing subjects who started with the active preparation from those who were given placebo first showed that most clinical and behavioral parameters improved in the former instance, whereas there was no significant difference in the latter. We conclude that inhaled corticosteroids induce a small but significant overall improvement of the asthmatic condition in subjects with occupational asthma caused by high- and low-molecular-weight agents after withdrawal from exposure. The beneficial effect is, however, more pronounced if inhaled steroids are given early after diagnosis.
Malo
J L
JL
Department of Chest Medicine, Hôpital du Sacré-Coéur, Montreal Canada.
Cartier
A
A
Côté
J
J
Milot
J
J
Leblanc
C
C
Paquette
L
L
Ghezzo
H
H
Boulet
L P
LP
D000280:Administration, Inhalation; D000328:Adult; D000485:Allergens / Q000009:adverse effects; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy*; D001507:Beclomethasone / Q000627:therapeutic use*; D016535:Bronchial Hyperreactivity / Q000188:drug therapy; D001985:Bronchial Provocation Tests; D002176:Candida albicans / Q000302:isolation & purification; D003371:Cough / Q000188:drug therapy; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009784:Occupational Diseases / Q000188:drug therapy*; D016273:Occupational Exposure; D009960:Oropharynx / Q000382:microbiology; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D011788:Quality of Life; D014797:Vital Capacity / Q000187:drug effects
D000485:Allergens; D018927:Anti-Asthmatic Agents; D005938:Glucocorticoids; D001507:Beclomethasone; D006854:Hydrocortisone