Onset of action following formoterol Turbuhaler and salbutamol pMDI in reversible chronic airway obstruction

Abstract

Short-acting beta(2)-agonists are currently recommended for symptom relief in asthma and the treatment of mild, acute exacerbations in COPD. However, formoterol has as fast an onset of action as salbutamol with the additional benefit of longer-lasting bronchodilation (approximately 12 h). Furthermore, systemic side effects observed with formoterol are of a similar duration but less pronounced than with short-acting beta(2)-agonists. In this double-blind, randomized, cross-over study, 20 adult patients with reversible chronic airway obstruction (intrinsic asthma or COPD) inhaled single doses of formoterol 9 microg or salbutamol 100 microg (group A) or formoterol 18 microg or salbutamol 200 microg (group B). FEV(1) was measured prior to and 5, 10, 15, 20, 25 and 30 min following inhalation of study drug. No significant differences in FEV(1) values were observed between group A (P=0.704) or group B (P=0.270) at baseline, or at 5 (Group A: P=0.340; Group B: P=0.559) and 15 min (Group A: P=0.526; Group B: P=0.818) post dose. No adverse events were reported during the study. Formoterol Turbuhaler has as rapid an onset of action as salbutamol pMDI when given at the recommended doses.