Effects of single-dose fluticasone on exercise-induced asthma in asthmaticchildren: A pilot study

A single high dose of inhaled corticosteroid (ICS) can increase airway cali ber in children with asthma attacks and laryngitis subglottica. Presumably the effect is due to the vasoconstrictive and antiedematous properties of t opical steroids. Enlarged vessels have been suggested to play a role in the pathophysiology of exercise-induced bronchial obstruction (EIB). To invest igate this, we evaluated the effect of a single high dose of fluticasone pr opionate (FP) on EIB in asthmatic children. Nine children aged 8-16 years w ith mild to moderate asthma were included. All children had a history of EI B, which was confirmed by an exercise test. None was taking ICS maintenance therapy. The children inhaled either a single dose of 1 mg FP or placebo o n 2 separate days within 7-14 days. After inhalation, airway caliber (FEV1) was assessed for 4 hr before exercise. Then an exercise challenge was perf ormed on a treadmill to assess EIB (% fall FEV1). A significant increase in FEV, was observed 1 hr after inhalation of FP com pared to placebo. Response to exercise was expressed as maximal % fall in F EV, from baseline (% fall) and as area under the curve (AUC) of the 30-min time/response curve. The % fall FEV, after exercise and the AUC were signif icantly reduced when FP was inhaled compared to placebo inhalation (% fall 9.7% vs. 19.2%, respectively, P = 0.038 and AUC 92.0%.min vs. 205.7%.min, r espectively, P = 0.03). There was considerable individual variability in re duction of EIB, with 5 out of 9 children having a clinically significant re sponse. We conclude that a single high dose of inhaled FP has an acute protective e ffect on the bronchial response to exercise in a substantial proportion of asthmatic children. (C) 2001 Wiley-Liss, Inc.