Adalberto Sperb Rubin, Fábio José Fabrício de Barros Souza,
Jorge Lima Hetzel, José da Silva Moreira
Objective: To evaluate, using pulmonary function tests, the effectiveness of formoterol as a bronchodilator at 30 min after its administration
in patients with poorly reversible COPD. Methods: A prospective study including 40 COPD patients not responding to the short-acting
bronchodilator used in the spirometric test-variation of less than 200 mL and less than 7% of predicted in forced expiratory volume in
one second (FEV1). All patients were classified as having stage II, III, or IV COPD (Brazilian Thoracic Society/Global Initiative for Chronic
Obstructive Lung Disease) and presented FEV1 ≤ 70% of predicted value. The patients were randomized into two groups of 20, with similar
clinical characteristics, receiving, via a dry powder inhaler, either formoterol or a placebo. The pulmonary function testing (plethysmography)
was repeated at 30 min after formoterol or placebo administration. Results: In the formoterol group, the mean values obtained for FEV1,
inspiratory capacity, and forced vital capacity were significantly greater than those obtained in the placebo group (p = 0.00065, p = 0.05,
and p = 0.017, respectively), whereas that obtained for airway resistance was significantly lower (p = 0.010). Less pronounced differences
were observed for residual volume, vital capacity and specific airway conductance, which were lower, higher and higher, respectively, in the
formoterol group. Conclusions: In COPD patients not responding to the short-acting bronchodilator used in the spirometric test, formoterol
promoted significant improvement in lung function at 30 min after of administration. Further studies are required to confirm whether
formoterol can also be used as a medication for immediate relief of symptoms in COPD.
Keywords: Chronic obstructive pulmonary disease; Respiratory function tests; Bronchodilator agents.