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 p atients. Bitolterol mesylate was administered in increasing doses of 0 .5 to 3.5 mg by continuous-flow nebulization on separate days to child ren 4 to 12 years of age. Pulmonary function tests and vital signs wer e measured before and for up to eight hours after each treatment. Bron chodilation was defined as a greater than or equal to 15% increase in FEV(1) over baseline. Onset, magnitude, and duration of bronchodilatio n all showed general dose-related improvements. Onset of bronchodilati on occurred within five minutes in 66% to 82% of all treatments. The m ean maximum percent increase in FEV(1) ranged from 35% to 52% for all doses. Median durations of bronchodilation in responding patients rang ed from four and one tenth to more than eight hours. Bitolterol was we ll-tolerated with all adverse effects being mild to moderate in severi ty and transient in nature. Although the incidence of cough, increased pulse rate, and tremor were relatively low, they did increase slightl y with the 2.5- and 3.5-mg doses. No significant clinical laboratory o r electrocardiographic findings were noted. We conclude that doses of 1.0 and 1.5 mg bitolterol mesylate administered by continuous-flow neb ulization are safe, effective, and well-tolerated for the treatment of asthma in pediatric patients.