The onset of action of formoterol, a new beta 2 adrenoceptor agonist.

Formoterol, a new long-acting beta 2-agonist, seems to be a step forward in the treatment of recurrent obstructive airway disease. Obstruction during the night and morning dip are less frequent and patient compliance is expected to be better than with the bronchodilators now in use. We studied the characteristics of the onset of action of formoterol by measuring sGAW (sGAW = specific airway conductance) to see if formoterol could be used as a rescue drug in cases of sudden attacks of obstruction. Our results show that one minute after inhalation of 12 micrograms formoterol MDI 14 patients out of 20 have a clinically relevant increase in sGAW after formoterol (+ 40% of the initial values) in comparison with 2 patients receiving placebo.