title: Separate and combined effects of corticosteroids and bronchodilators on airflow obstruction and airway hyperresponsiveness in asthma.
abstract: We have investigated separate and interactive effects of corticosteroids and bronchodilators on airflow obstruction and airway hyperresponsiveness. Twelve allergic subjects with asthma were treated in a double-blind, crossover, randomized study with budesonide, 1.6 mg daily for 3 weeks, prednisone, 40 mg daily, for 8 days, and placebo. After each period, dose-response curves were measured on 4 study days with doubling doses of salbutamol, ipratropium, a combination of salbutamol and ipratropium, and placebo until a plateau in FEV1 was reached. A histamine challenge was then performed, and the provocation concentration causing a 20% fall in FEV1 (PC20) was calculated. The budesonide and prednisone regimens were equipotent. FEV1 was 81.2% of predicted after budesonide, 81.0% predicted after prednisone, and 67.5% predicted after placebo, bronchodilatation thus being 13.7% predicted (budesonide) and 13.5% predicted (prednisone). PC20 improved with 2.17 doubling concentrations (DCs) after budesonide, and 1.86 DCs after prednisone, compared with that of placebo. Salbutamol caused stronger bronchodilatation than ipratropium (26.2% versus 14.7% predicted) and a better protection against histamine challenge (3.95 versus 1.12 DC). The effects of corticosteroids and bronchodilators on FEV1 and PC20 were, in general, additive. This study emphasizes different modes of action on both airflow obstruction and airway hyperresponsiveness by corticosteroids and bronchodilators, and it demonstrates no enhancement of bronchodilator action by corticosteroids.
authors.affiliation: Department of Pulmonology, University Hospital Groningen, The Netherlands.
authors.forename: J B
authors.initials: JB
authors.lastname: Wempe
authors.forename: D S
authors.initials: DS
authors.lastname: Postma
authors.forename: N
authors.initials: N
authors.lastname: Breederveld
authors.forename: D
authors.initials: D
authors.lastname: Alting-Hebing
authors.forename: T W
authors.initials: TW
authors.lastname: van der Mark
authors.forename: G H
authors.initials: GH
authors.lastname: Koëter
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000402:Airway Obstruction / Q000188:drug therapy* / Q000503:physiopathology; D000403:Airway Resistance / Q000187:drug effects*; D000420:Albuterol / Q000008:administration & dosage; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000188:drug therapy* / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D019819:Budesonide; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage; D008297:Male; D011241:Prednisone / Q000008:administration & dosage; D011282:Pregnenediones / Q000008:administration & dosage
chemical_list: D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents; D011282:Pregnenediones; D019819:Budesonide; D009241:Ipratropium; D000420:Albuterol; D011241:Prednisone