title: Changes in bronchial hyperreactivity induced by 4 weeks of treatment with antiasthmatic drugs in patients with allergic asthma: a comparison between budesonide and terbutaline.
abstract: We performed a double-blind crossover study to compare the effects of long-term treatment of inhaled budesonide and terbutaline on bronchial hyperreactivity in 17 patients with allergic asthma. Both drugs were administered for 4 weeks with a placebo-treatment period before and after each active-treatment period. To assess bronchial hyperreactivity, standardized inhalation provocation tests with histamine and propranolol were performed every 2 weeks. Before each inhalation provocation the drugs were withheld for at least 12 hours. Before the budesonide treatment the FEV1 value (percent predicted) was 85.3 +/- 4.1% (mean +/- SEM). After 2 and 4 weeks of treatment with this drug, the value increased significantly to 89.4 +/- 4.1% and 96.2 +/- 3.8%, respectively (p less than 0.05 and p less than 0.005). The histamine provocation concentrations causing a decrease in FEV1 of 20% (PC20) on the same days were 4.0, 7.2, and 9.5 mg/ml, respectively (both p less than 0.001). The PC20 values for propranolol, which were measured 1 hour after the histamine provocation, were 11.7, 13.3, and 14.0 mg/ml (ns). The FEV1 values before and after 2 and 4 weeks of treatment with terbutaline were 86.2 +/- 4.0%, 84.8 +/- 4.1%, and 87.0 +/- 4.6%, respectively. The histamine PC20 values on the same days were 4.7, 3.1 (p less than 0.05), and 3.8 mg/ml, respectively. The propranolol PC20 values were 14.2, 8.7, and 10.1 mg/ml (p less than 0.001 and p less than 0.05, respectively. We conclude that budesonide improves bronchial hyperreactivity, possibly by a dampening of late allergic reactions, whereas treatment with terbutaline may lead to a temporary increase of bronchial hyperreactivity, possibly as a result of beta-receptor desensitization.
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D019819:Budesonide; D004311:Double-Blind Method; D004804:Eosinophils; D005260:Female; D005541:Forced Expiratory Volume; D006632:Histamine; D006801:Humans; D008297:Male; D010366:Peak Expiratory Flow Rate; D010919:Placebos; D011282:Pregnenediones / Q000627:therapeutic use*; D011433:Propranolol; D011897:Random Allocation; D013726:Terbutaline / Q000627:therapeutic use*
chemical_list: D010919:Placebos; D011282:Pregnenediones; D019819:Budesonide; D006632:Histamine; D011433:Propranolol; D013726:Terbutaline