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 (FEV 1 ). All patients were classified as having stage II, III, or IV COPD (Brazilian Thoracic Society/Global Initiative for Chronic Obstructive Lung Disease) and presented FEV 1 ≤ 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 FEV 1 , 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.
ResumoObjetivo: Avaliar, por meio de provas de função pulmonar, a eficácia broncodilatadora do formoterol após 30 min de sua administração em portadores de doença pulmonar obstrutiva crônica (DPOC) com pouca reversibilidade. Métodos: Estudo prospectivo incluindo 40 pacientes portadores de DPOC com resposta negativa ao broncodilatador de curta duração utilizado no teste espirométrico-variação menor que 200 mL e 7% do previsto do volume expiratório forçado no primeiro segundo (VEF 1 ). Os pacientes encontravam-se nos estágios II, III ou IV da DPOC (Sociedade Brasileira de Pneumologia e Tisiologia/Global Initiative for Chronic Obstructive Lung Disease) e apresentavam VEF 1 ≤ 70% do previsto. Foram randomizados em dois grupos de 20, com características clínicas semelhantes, e cada grupo recebeu formoterol ou placebo por meio de inalador de pó seco. As provas de função pulmonar (por pletismografia) foram repetidas após 30 min da administração de formoterol ou placebo. Resultados: Observaram-se aumento significativo de VEF 1 (p = 0,00065), capacidade inspiratória (p = 0,05) e capacidade vital forçada (p = 0,017) e redução significativa da resistência das vias aéreas (p = 0,010) no grupo formotero...