Formoterol, a new long-acting selective beta 2-adrenergic receptor agonist: double-blind comparison with salbutamol and placebo in children with asthma

Abstract

We compared the protective effect and duration of action of inhaled formoterol, a new, long-acting, selective beta 2-agonist, to inhaled salbutamol and placebo in a double-blind, randomized, crossover study in 16 children with asthma with a mean age of 10.3 +/- 0.4 years. Mean baseline FEV1 was 96 +/- 3% predicted and mean provocative concentration of methacholine (milligrams per milliliter) required to decrease FEV1 by 20% (PC20) was 0.81 +/- 0.25 mg/ml of methacholine. On the 4 study days, baseline FEV1 was within 10% of the FEV1 on visit 1, and baseline PC20 was within one doubling dose of visit 1. Each day patients inhaled either placebo, salbutamol, 200 micrograms, formoterol, 12 micrograms, or formoterol, 24 micrograms. FEV1 and PC20 were measured repeatedly during 12 hours. After placebo inhalation, mean FEV1 did not change significantly during 12 hours. After salbutamol inhalation, the mean FEV1 was significantly increased for less than 3 hours, but after formoterol inhalation, 12 or 24 micrograms, the mean FEV1 was significantly increased for 12 hours. After placebo treatment, mean PC20 did not change significantly. After salbutamol inhalation, mean PC20 was significantly increased for only 3 hours, but after formoterol inhalation, 12 or 24 micrograms, mean PC20 was significantly increased for 12 hours. Protection by formoterol, 12 and 24 micrograms at 12 hours, was equivalent to protection by salbutamol at 3 hours. Inhaled formoterol is a potent, long-acting bronchodilator and provides significantly better antiasthma protection than inhaled salbutamol.