Features and significance of the early bronchodilatation effect of the first dose of a long-acting bronchodilator alone and in fixed combination in the treatment of chronic obstructive pulmonary disease

The early bronchodilatory effects of the first dose of long-acting anticholinergics (glycopyrronium and tiotropium) were compared with those of a fixed double combination of long-acting bronchodilators of various classes (indacaterol/glycopyrronium) in patients with stable chronic obstructive pulmonary disease. The possibility of using the results of an early bronchodilatory response to predict their effectiveness in the basic therapy of chronic obstructive pulmonary disease is evaluated. A total of 176 patients with chronic obstructive pulmonary disease were examined. The patients were randomized into three groups. The first group (n = 66) took glycopyrronium, the second group (n = 60) received a combination of indacaterol/glycopyrronium, and the third group (n = 50, control) took tiotropium. Broncholytic tests with the listed drugs were evaluated. The early bronchodilatory effect of the first dose of 110/50 mcg indacaterol/glycopyrronium was manifested by significant bronchodilation (p < 0.001) from 30 min, reached its maximum value 60 min after drug intake, and persisted after a 28-day course of treatment. The combination of indacaterol/glycopyrronium provided rapid and prolonged bronchodilation in patients with stable chronic obstructive pulmonary disease, demonstrating advantages over the isolated use of glycopyrronium and tiotropium. Maximization of bronchodilation by the sequential use of glycopyrronium and salbutamol leads to an increase in the volume of forced exhalation in the first second on the 90^th min, comparable with the results of indacaterol/glycopyrronium on the 60^th min after drug intake, which indicates the clinical feasibility of maximizing bronchodilation with drugs both separately and in combination. Based on a direct positive correlation between the initial value of the forced expiratory volume in the first second and the value on day 28 of indacaterol/glycopyrronium therapy, an equation for predicting the individual effectiveness of the drug during treatment is derived.