title: Dose-dependent inhibitory effect of inhaled beclomethasone on late asthmatic reactions and increased responsiveness to methacholine induced by toluene diisocyanate in sensitised subjects.
abstract: To determine whether inhaled beclomethasone, both at low and at high doses, inhibits late asthmatic reactions and the associated increase in airway responsiveness induced by toluene diisocyanate (TDI), we studied 9 sensitised subjects. Low dose beclomethasone (200 micrograms bid), high dose beclomethasone aerosol (1000 micrograms bid), and placebo were administered for 7 days before TDI inhalation challenge to each subject, according to a double-blind, crossover study design. The washout period between the treatments was at least 1 week. When the subjects were treated with placebo, forced expiratory volume in 1 sec (FEV1) markedly decreased after exposure to TDI. By contrast, high dose beclomethasone prevented the late asthmatic reaction and the low dose partially inhibited the reaction. With placebo the mean (+/- SE) value of FEV1 4 h after exposure to TDI was 2.6 +/- 0.17 L, which went to 3.3 +/- 0.12 after low dose beclomethasone, and to 3.5 +/- 0.15 L after high dose of beclomethasone (significant difference in the decrease of FEV1 in the 8 h after exposure to TDI, between treatments: F = 9.87, (P less than 0.001), After treatment with placebo or with low dose beclomethasone, airway responsiveness to methacholine increased 8 h after exposure to TDI. With placebo, the PD20 decreased from 0.66 mg (Geometric Standard Error of the Mean [GSEM], 1.38) to 0.18 mg (GSEM, 1.46); with low dose inhaled beclomethasone, the PD20 decreased from 0.93 mg (GSEM, 1.42) to 0.36 mg (GSEM, 1.63).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Institute of Occupational Medicine, University of Padova, Italy.
authors.forename: N
authors.initials: N
authors.lastname: De Marzo
authors.forename: L M
authors.initials: LM
authors.lastname: Fabbri
authors.forename: S
authors.initials: S
authors.lastname: Crescioli
authors.forename: M
authors.initials: M
authors.lastname: Plebani
authors.forename: R
authors.initials: R
authors.lastname: Testi
authors.forename: C E
authors.initials: CE
authors.lastname: Mapp
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001507:Beclomethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008688:Methacholine Compounds / Q000494:pharmacology*; D008875:Middle Aged; D014051:Toluene 2,4-Diisocyanate / Q000494:pharmacology*
chemical_list: D008688:Methacholine Compounds; D014051:Toluene 2,4-Diisocyanate; D001507:Beclomethasone