Formoterol and salbutamol metered aerosols: comparison of a new and an established beta-2-agonist for their bronchodilating efficacy in the treatment of childhood bronchial asthma.

In this placebo-controlled, double-blind, single-dose study the new beta-2-agonist formoterol (one puff, 12 micrograms) was intraindividually compared with salbutamol (one puff, 100 micrograms) for onset, magnitude, and duration of bronchodilating efficacy in 15 young asthmatics aged 5 to 14 years with mild to severe asthma. All but one had regular antiasthmatic medication before beginning the study, but none was oral steroid dependent. Both medications produced rapid bronchodilatation within 10 minutes, reflected by a decrease in specific airway resistance (sRaw) with maximum effects at 10 minutes (salbutamol, 51%) and 30 minutes (formoterol, 60%). Significant bronchodilation was present at 10 minutes to 2 hours after inhalation of salbutamol and at 30 minutes to 8 hours after formoterol. Mean percent improvement over baseline was higher for formoterol at all measured times from 30 minutes to 12 hours, when 55% mean decrease in sRaw was still present. The effect of salbutamol was a less than 10% mean decrease in sRaw after 6 hours. The differences in sRaw decrease between the two medications were statistically significant at 4 to 10 hours after inhalation. Neither medication administered as an aerosol caused cardiac side effects. Both had a rapid onset of action and a comparable maximal effect. However, at the doses studied, formoterol produced a larger decrease in sRaw from baseline for longer periods after inhalation than did salbutamol.