A dose-finding study with the once-daily oral beta(2)-agonist bambuterol in Asian children with asthma

Objective: The primary objective was to compare the efficacy of two dosages of bambuterol, a once-daily oral bronchodilator, with placebo in Asian chi ldren with asthma. The secondary objective was to assess the tolerability o f bambuterol in this population. Design: This was a multicentre, randomised, double-blind, placebo-controlle d crossover study, with a run-in period of 2 weeks. The study consisted of three treatment periods of 2 weeks each, separated by washout periods of 2 weeks, with 7 clinic visits in total. Setting: Outpatients were recruited from 10 centres in Indonesia, Malaysia, The Philippines, Singapore and Thailand. Patients: Seventy Asian children aged 6 to 12 years (53 boys and 17 girls) with asthma for at least 6 months were randomised to treatment, and 62 pati ents completed the study. Interventions: During the three treatment periods, patients received either placebo or 5 or 10 mg bambuterol tablets once daily for 2 weeks. Morning p eak expiratory flow (PEF) was the primary efficacy variable. Secondary effi cacy variables were forced expiratory volume in 1 second (FEV (1)), forced vital capacity (FVC) and diary card data including evening PEF. Results: At baseline, FEV1 predicted was 82.9% and the reversibility was 22 .2%. The study results suggest that the change from baseline in both mornin g and evening PEF recorded on the diary cards on days 4 to 1 it of each tre atment period was dose dependent, but only the difference in morning PEF be tween bambuterol 10 mg and placebo was statistically significant (9.1 L/min ; 95% confidence interval 0.2 to 18.0 L/min). FEV1, FVC, asthma symptom sco res and the use of supplementary beta(2)-agonists did not differ significan tly between placebo and the two bambuterol treatments. Blood pressure and p ulse rate remained consistent throughout the study. The number of spontaneo usly reported adverse events was similar for the three treatment groups. Conclusions: Bambuterol 10 mg once daily is an effective bronchodilator in 6- to 12-year-old Asian children in terms of improvement in morning PEF.