Protective effect of antiasthma drugs on late asthmatic reactions and increased airway responsiveness induced by toluene diisocyanate in sensitized subjects.
To determine whether 4 drugs used in the treatment of asthma inhibit the late asthmatic reaction and the associated increase in airway responsiveness induced by toluene diisocyanate (TDI), we studied 24 sensitized subjects divided into 4 groups. Beclomethasone aerosol (1 mg bid), slow-release theophylline (6.5 mg/kg bid), slow-release verapamil (120 mg bid), and cromolyn (20 mg qid via spinhaler), were administered for 7 days, respectively, to 1 of the 4 groups, according to a double-blind, crossover, placebo-controlled study design. When the subjects were treated with placebo, verapamil, or cromolyn, FEV1 markedly decreased and airway responsiveness increased after exposure to TDI. By contrast, beclomethasone prevented the late asthmatic reaction and the associated increase in airway responsiveness to methacholine induced by TDI. Slow-release theophylline partially inhibited both the immediate and the late asthmatic reactions but had no effect on airway hyperresponsiveness to methacholine. These results suggest that only high-dose inhaled steroids can completely block TDI-induced late asthmatic reactions.
Mapp
C
C
Institute of Occupational Medicine, University of Padova, Italy.
Boschetto
P
P
dal Vecchio
L
L
Crescioli
S
S
de Marzo
N
N
Paleari
D
D
Fabbri
L M
LM
D001249:Asthma / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D001507:Beclomethasone / Q000008:administration & dosage; D001985:Bronchial Provocation Tests; D002986:Clinical Trials as Topic; D004205:Cromolyn Sodium / Q000008:administration & dosage; D003485:Cyanates / Q000009:adverse effects*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005541:Forced Expiratory Volume; D006801:Humans; D007114:Immunization; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D016210:Methacholine Chloride; D008688:Methacholine Compounds; D010919:Placebos; D011897:Random Allocation; D012137:Respiratory System / Q000187:drug effects; D013806:Theophylline / Q000008:administration & dosage; D013997:Time Factors; D014051:Toluene 2,4-Diisocyanate / Q000009:adverse effects*; D014700:Verapamil / Q000008:administration & dosage
D003485:Cyanates; D003692:Delayed-Action Preparations; D008688:Methacholine Compounds; D010919:Placebos; D016210:Methacholine Chloride; D014051:Toluene 2,4-Diisocyanate; D013806:Theophylline; D014700:Verapamil; D001507:Beclomethasone; D004205:Cromolyn Sodium