Dose duration of nebulized nedocromil sodium in exercise-induced asthma

The dose-duration effect of nebulized nedocromil sodium was studied in ten patients with exercise-induced asthma (7 males mean (SEM) age 30.1 (3.5) yrs and predicted forced expiratory volume in one second (FEV1) 102%). All of these patients showed > 40% protection of their exercise asthma with 4 mg of nedocromil sodium delivered via metered dose inhaler. Three concentrations of nedocromil sodium (0.5, 2.5 and 10 mg.ml-1) and placebo were administered in double-blind, randomized manner. One ml of each solution was nebulized via a Wright nebulizer. Effects were assessed from the mean maximal percentage fall in FEV1 after 6-8 min treadmill exercise at 15, 135 and 255 min following each treatment and expressed as percentage protection. The mean baseline FEV1 values before and after treatments were comparable on four days of testing. Nedocromil sodium inhibited exercise-induced fall in FEV1 at all concentrations (p < 0.001) and the inhibitory effect was still present at 255 min. No differences were observed between active treatments.