Bambuterol: clinical effects of different doses of a long-acting bronchodilator prodrug.

Sixty-eight asthmatics participated in a dose-finding study on bambuterol, a terbutaline prodrug, administered once every evening. Bambuterol administrations of 0.185, 0.270 and 0.400 mg/kg gave effective and long-lasting bronchodilation, for at least 24 h, with the two higher doses probably close to the maximal effect of the drug. Bambuterol 0.400 mg/kg was associated with more adverse effects than bambuterol 0.185 mg/kg. The side effects were those expected in oral beta 2-agonist treatment and mainly experienced by patients who had not been on oral beta 2-agonists before. The most favourable of the investigated doses was found to be 0.270 mg/kg. It can not be excluded, however, that a somewhat lower dose may still be as beneficial. This will be investigated in forthcoming studies.