Formoterol by Pressurized Metered-Dose Aerosol or Dry Powder on Airway Obstruction and Lung Hyperinflation in Partially Reversible COPD

Background: We compared the efficacy and safety of formoterol given by a pressurized metered-dose inhaler (pMDI) (Atimos(R), Chiesi Farmaceutici, Italy), using a chlorine-free hydrofluoroalkane (HFA-134a) propellant developed to provide stable and uniform dose delivery (Modulite(R), Chiesi Farmaceutici, Italy), with formoterol by dry powder inhaler (DPI) (Foradil(R) Aerolizer(R), Novartis Pharmaceuticals) and placebo, in reducing airflow obstruction and lung hyperinflation, in moderate-to-severe, partially reversible chronic obstructive pulmonary disease (COPD). Methods: Forty-eight patients were randomized to a 1-week, double-blind, double-dummy, three-period crossover study with 12 mu g b.i.d. of formoterol given by pMDI or DPI, or placebo. Spirometry, specific airway conductance, and lung volumes were measured at the beginning and at the end of each treatment period from predose to 4 h postdose. A 6-min walking test was carried out 4 h after the first and the last dose, with dyspnea assessed by Borg scale. Safety was assessed through adverse events monitoring electrocardiography and vital signs. Results: The two formulations of formoterol were significantly superior to placebo but not different from each other in increasing 1-sec forced expiratory volume, specific airway conductance, inspiratory capacity, and inspiratory-to-total lung capacity ratio. The two active treatments were also equivalent and superior to placebo in reducing dyspnea at rest and on exertion. No differences in terms of safety between the two active forms and placebo were detected. Conclusions: Formoterol given with chlorine-free pMDI was equivalent to DPI in reducing airway obstruction and lung hyperinflation in COPD patients. Both formoterol formulations confirmed the good safety profile similar to placebo.