One month treatment with the once daily oral beta 2-agonist bambuterol in asthmatic patients.

Bambuterol is a new long-acting oral bronchodilator for once daily use in patients with asthma. It is a prodrug of terbutaline, designed to be slowly metabolized to terbutaline. Results from comparative studies have shown that it has similar clinical efficacy to other oral bronchodilators, but less side-effects. The present study was aimed at verifying the 24 h effect duration of bambuterol, 10 and 20 mg in comparison with placebo during a one month treatment period. The study was conducted as a double-blind, randomized, parallel group placebo-controlled, multicentre trial. It started with a one week run-in period with placebo, when oral bronchodilators were withdrawn. At the end of this reference period, the patients were randomized to one of three treatments: placebo, bambuterol 10 mg, or bambuterol 20 mg, once daily in the evening. The treatment period lasted for 4 weeks. Four hundred and eighty seven patients with a mean age of 45 yrs were included. Mean baseline forced expiratory volume in one second (FEV1) and FEV1% of predicted were 2.05 l and 62%, respectively. Administration of 10 mg bambuterol resulted in a significant 24 h effect duration, expressed as an increase in mean daily morning and evening peak expiratory flow (PEF) (+11 l.min-1, adjusted means) throughout the study, as compared with placebo. Bambuterol, 20 mg, gave a significant 24 h effect duration in both FEV1 and morning and evening PEF as compared with placebo. Furthermore, the adverse events observed during the study were relatively few and mild.(ABSTRACT TRUNCATED AT 250 WORDS)