Multicenter dose-ranging study of bitolterol mesylate solution for nebulization in children with asthma

This open-label, placebo-controlled study was undertaken to assess the safety and effectiveness of bitolterol mesylate in pediatric asthma patients. Bitolterol mesylate was administered in increasing doses of 0.5 to 3.5 mg by continuous-flow nebulization on separate days to children 4 to 12 years of age. Pulmonary function tests and vital signs were measured before and for up to eight hours after each treatment. Bronchodilation was defined as a > or = 15% increase in FEV1 over baseline. Onset, magnitude, and duration of bronchodilation all showed general dose-related improvements. Onset of bronchodilation occurred within five minutes in 66% to 82% of all treatments. The mean maximum percent increase in FEV1 ranged from 35% to 52% for all doses. Median durations of bronchodilation in responding patients ranged from four and one tenth to more than eight hours. Bitolterol was well-tolerated with all adverse effects being mild to moderate in severity and transient in nature. Although the incidence of cough, increased pulse rate, and tremor were relatively low, they did increase slightly with the 2.5- and 3.5-mg doses. No significant clinical laboratory or electrocardiographic findings were noted. We conclude that doses of 1.0 and 1.5 mg bitolterol mesylate administered by continuous-flow nebulization are safe, effective, and well-tolerated for the treatment of asthma in pediatric patients.