title: Preliminary study on the effect of broxaterol on bronchial hyperresponsiveness in asthmatic children: influence of allergen exposure.
abstract: Increased bronchial hyperresponsiveness (BHR) has been reported in adult asthmatic patients after regular treatment with beta 2-agonists. In this study we evaluated the effect of a 4-weeks treatment period with broxaterol, a new beta 2-agonist, on BHR in asthmatic children living in two different environmental conditions. Two groups of patients, 24 domiciled at sea level, allergen exposed (group 1), and 24 resident at high altitude (Misurina, 1,756 m) in an allergen-free environment (group 2), have been tested. Children were randomly treated with broxaterol 400 micrograms q.i.d. or sodium chromoglycate 10 mg q.i.d. (as control treatment) by the metered dose inhaler for 4 weeks. Pulmonary function tests and methacholine challenge were performed at the beginning and at the end of the study. Throughout the study period a diary card was completed and peak expiratory flow rate (PEFR) was measured three times daily. Forty-two of the patients admitted concluded the study. No significant change was observed in the methacholine PC20 throughout the study period regardless of the type of treatment and/or environment. The amplitude percentage mean of diurnal changes in PEFR during the study period showed no statistically significant differences between treatments or centres, or in the interaction of treatment with centre, time with treatment, time with centre, time with centre and treatment (p > 0.05). Therefore in this pilot study regular treatment with broxaterol for 4 weeks did not cause an increase in BHR in asthmatic children both in conditions of allergen exposure and in an environment free of offending allergens.
authors.affiliation: Department of Pediatrics, University of Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Benedetti
authors.forename: E
authors.initials: E
authors.lastname: Spezia
authors.forename: A
authors.initials: A
authors.lastname: Comis
authors.forename: G
authors.initials: G
authors.lastname: Marcer
authors.forename: A L
authors.initials: AL
authors.lastname: Boner
mesh_terms: D000293:Adolescent; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D000485:Allergens; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000503:physiopathology; D002648:Child; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate / Q000187:drug effects; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D010865:Pilot Projects; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D000318:Adrenergic beta-Agonists; D000485:Allergens; D007555:Isoxazoles; C045916:broxaterol