The aim of this study was to compare
bambuterol oral
solution (10 mg) administered once daily in the evening with
terbutaline oral
solution (0.075 mg/kg
body weight) administered three times daily in 2-5-year-old children and to compare
bambuterol tablets (10 mg or 20 mg) administered once daily in the evening with
terbutaline tablets (2.5 mg) administered three times daily in 6-12-year-old children with
asthma. The study was of an open, randomized, parallel-group design, and lasted 1 year. The primary objective was to evaluate safety (pulse rate, blood pressure, adverse events, hematology, and clinical chemistry). Plasma
terbutaline concentrations were also measured. Evaluation of efficacy (FEV(1)) was a secondary objective. A total of 141 patients (83 boys, 58 girls) were randomized and treated with the study drugs, i.e., 43 patients in the
terbutaline group (30 on oral
solution and 13 on
tablets) and 98 patients in the
bambuterol group (62 on oral
solution and 36 on
tablets). A total of 11 patients discontinued the study: 3 were on
terbutaline, and 8 were on
bambuterol. There were no clinically important differences between treatment groups regarding pulse rate, or systolic or diastolic blood pressure. There were no clinically important findings in the laboratory tests (hematology and clinical chemistry). Both
terbutaline and
bambuterol were well-tolerated, and the reported adverse events were mostly mild or moderate. Mean steady state plasma
terbutaline concentrations at the visits ranged between 8.0-11.5 nmol/L in the
bambuterol tablet group and between 10.6-15.2 nmol/L in the
terbutaline tablet group. The corresponding values in children on oral
solution were 10.3-11.3 nmol/L in the
bambuterol group and 7.5-9.7 nmol/L in the
terbutaline group. FEV(1) measured in the 6-12-year-old children increased by more than 0.2 L in both treatment groups during the year in the study. In conclusion,
bambuterol tablets or oral
solution once daily and
terbutaline tablets or oral
solution three times daily showed a comparable and favorable safety profile.