Lack of protective effect of high-dose ipratropium on bronchoconstriction following exercise with cold air breathing in patients with mild asthma.
To evaluate the preventive effect of inhaled ipratropium powder on low-grade bronchoconstriction elicited by breathing cold air during exercise, we subjected 10 adult patients with mild asthma to four identical treadmill exercise tests. The temperature of inhaled air during exercise was -9 +/- 1 degree C. Sixty minutes before exercise, the patients inhaled either placebo or 0.2, 1, or 2 mg of ipratropium powder according to a cross-over, double-blind arrangement. The mean post-exercise fall from the post-treatment pre-exercise values in the four treatment groups was 14, 14, 16 and 16% for FEV1, and 59, 52, 52 and 55% for SGaw, respectively. We concluded that doses of ipratropium up to 20-50 times higher than those known to have a marked effect on resting bronchomotor tone in clinically stable asthma did not blunt the bronchoconstriction response following exercise with cold air breathing in our patients with mild asthma.
D000293:Adolescent; D000328:Adult; D000403:Airway Resistance; D001249:Asthma / Q000517:prevention & control*; D001250:Asthma, Exercise-Induced / Q000517:prevention & control*; D001286:Atropine Derivatives / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D003080:Cold Temperature; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D011208:Powders; D011897:Random Allocation; D012138:Respiratory Therapy
D001286:Atropine Derivatives; D011208:Powders; D009241:Ipratropium