OVERNIGHT PROTECTION BY INHALED SALMETEROL ON EXERCISE-INDUCED ASTHMAIN CHILDREN

The main aim of the present study was to evaluate whether inhaled salm eterol given in the evening protected against exercise-induced asthma the next morning. Twenty three children (12 males and 11 females) with a mean age of 11 yrs and with exercise-induced asthma participated in a double-blind, randomized, placebo-controlled study, The children in haled salmeterol 25 mu g, salmeterol 50 mu g and placebo by Diskhaler( R) at 10 p,m, on 3 separate days, Next morning, half of the children r an on a motor-driven treadmill for 6 min at submaximal load at 8 a,m. and the remainder at 10 a,m, Lung function was measured by maximal exp iratory flow-volume loops before running, immediately after, and 3, 6, 10 and 15 min after running. The mean maximum reduction in forced exp iratory volume in one second (FEV1) after treadmill run was 34% before inclusion in the study. Mean maximum fall in FEV1 was significantly g reater after placebo: 30% (23-36) (95% confidence interval) than after salmeterol 25 mu g: 19% (12-23) or salmeterol 50 mu g: 18% (12-25), I n addition to the reduced postexercise bronchoconstriction, pre-exerci se lung function (FEV1) was significantly higher both after salmeterol 25 mu g: 2.4 L . s(-1) (2.1-2.7) and salmeterol 50 mu g: 2.5 L.. s(-1 ) (2.2-2.8) than after placebo: 22 L . s(-1) (1.9-2.5), No significant differences in pre- and postexercise lung function were found between children tested at 8 or 10 a,m,, or in relation to salmeterol dosage. Thus, inhaled salmeterol 25 and 50 mu g offered similar overnight pro tection against exercise-induced asthma and improved baseline lung fun ction in the morning as compared to placebo.