title: Effect of two doses of inhaled diltiazem on exercise-induced asthma.
abstract: Seven asthmatic children with moderately to severely increased bronchial responsiveness to methacholine took part in a double-blind placebo-controlled study to assess the effect of a calcium channel blocker, diltiazem, on exercise-induced asthma (EIA), and its duration. On the control day, bronchial response to exercise was found to be highly reproducible when performed 2 h apart (intraclass correlation coefficient 0.92). Normal saline and diltiazem at concentrations of 1.75 and 3.50 mg/ml (estimated nebulized doses 5 and 10 mg, respectively) were given in random order before exercise on a bicycle ergometer. Exercise challenge was performed 20 min and 2 h after each treatment, and bronchial response was expressed as percent fall in the forced expiratory volume in 1 s. In the overall group, diltiazem did not significantly change resting bronchial tone and produced no significant (p = 0.18) attenuation of EIA. An almost complete protection was detected only in two subjects 20 min after diltiazem 10 mg. This limited effect waned 2 h after the administration.
authors.affiliation: Laboratorio di Fisiopatologia Respiratoria, Università Cattolica S. Cuore, Roma, Italia.
authors.forename: A
authors.initials: A
authors.lastname: Foresi
authors.forename: G M
authors.initials: GM
authors.lastname: Corbo
authors.forename: G
authors.initials: G
authors.lastname: Ciappi
authors.forename: S
authors.initials: S
authors.lastname: Valente
authors.forename: G
authors.initials: G
authors.lastname: Polidori
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D001249:Asthma / Q000188:drug therapy*; D001250:Asthma, Exercise-Induced / Q000188:drug therapy* / Q000503:physiopathology; D001986:Bronchial Spasm / Q000188:drug therapy / Q000503:physiopathology; D002648:Child; D002986:Clinical Trials as Topic; D004110:Diltiazem / Q000008:administration & dosage* / Q000627:therapeutic use; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D011897:Random Allocation
chemical_list: D004110:Diltiazem