Objective: To evaluate the effectiveness and onset of action of formoterol delivered by dry-powder inhaler in reversing methacholine-induced bronchoconstriction. Methods: Patients presenting a drop in forced expiratory volume in one second > 20% after methacholine inhalation were included. A total of 84 patients were evaluated. All of the participating patients presented respiratory symptoms of unknown origin, which were being investigated. The patients were randomized to receive 200 µg of spray fenoterol (n = 41) or 12 µg of dry-powder inhaler formoterol (n = 43), both administered in order to achieve immediate reversal of methacholine-induced bronchoconstriction. We evaluated the decrease in forced expiratory volume in one second (in relation to the baseline value) after methacholine challenge and the dose of methacholine required to provoke a drop of 20% in forced expiratory volume in one second, as well as the increase in forced expiratory volume in one second (in relation to the baseline value) at five and ten minutes after bronchodilator use. Results: There were no significant differences related to gender, age, weight, height or dose of methacholine required to provoke a drop of 20% in forced expiratory volume in one second. Nor were there any significant differences in terms of baseline or post-methacholine forced expiratory volume in one second. In the fenoterol group, the mean postbronchodilator increase in forced expiratory volume in one second increase was 34% (at five minutes) and 50.1% (at ten minutes), compared with 46.5% (at five minutes) and 53.2% (at ten minutes) in the formoterol group. Conclusion: The bronchodilator effect of formoterol at five and ten minutes after methacholine-induced bronchoconstriction was similar to that of fenoterol. Despite being a long-acting bronchodilator, formoterol also has a rapid onset of action, which suggests that it could be employed as a relief medication in cases of bronchoconstriction occurring during asthma attacks.

Keywords: Asthma; Formoterol; Fenoterol; Inhalation therapy; Bronchodilation, Methacoline

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.

Objective: To evaluate the pharmaceutical equivalence of a test formulation (fixed-dose combination of budesonide and formoterol fumarate in a single capsule dispensed in an Aerocaps® inhaler) in relation to a reference formulation (budesonide and formoterol fumarate in two separate capsules dispensed in an Aerolizer® inhaler). Methods: This was an in vitro study in which we performed the identification/quantification of the active ingredients by HPLC and determined dose uniformity and aerodynamic particle size distribution in the test and reference formulations. Results: In the test formulation, the content of budesonide and formoterol was 111.0% and 103.8%, respectively, compared with 110.5% and 104.5%, respectively, in the reference formulation. In the test formulation, dose uniformity regarding budesonide and formoterol was 293.2 µg and 10.2 µg, respectively, whereas it was 353.0 µg and 11.1 µg in the reference formulation. These values are within the recommended range for this type of formulation (75-125% of the labeled dose). The fine particle fraction (< 5 µm) for budesonide and formoterol was 45% and 56%, respectively, in the test formulation and 54% and 52%, respectively, in the reference formulation. Conclusions: For both of the formulations tested, the levels of active ingredients, dose uniformity, and aerodynamic diameters were suitable for use with the respective dry powder inhalers.

Keywords: : Asthma; Budesonide; Bronchodilator agents; Drug therapy, combination.