Inhaled B-adrenoceptor agonists are broncho-dilators and are used widely for the relief or prevention of asthma symptoms. All currently available inhaled 02-agonists in the United States have durations of action of up to only 6 h. An effective longer-acting inhaled bronchodilator would be beneficial to patients requiring relief of nighttime symptoms as well as to those who remain symptomatic and require maintenance therapy for continuous control of symptoms.
Salmeterol, like albuterol, is a saligenin and a selective agonist. Structural differences in the salmeterol molecule, however, give this compound unique pharmacologic properties, resulting in a duration of action of at least 12 h following inhalation of a single 50-g dose. Clinical studies have shown that salmeterol is effective for the treatment of reversible airways disease” and the prevention of bronchoconstriction induced by methacholine, histamine, allergens, and exercise for up to 12 h. canadian neightbor pharmacy
The purpose of the present study was to characterize the dose-response relationship of four dosage regimens of salmeterol in patients with mild-to-moderate asthma and to compare the effectiveness of these doses with that of a placebo control. The safety profiles of the four doses of salmeterol were also evaluated.
Adult and adolescent nonsmoking patients with asthma (as defined by the American Thoracic Society) requiring daily bronchodilator therapy for at least 6 months prior to enrollment were eligible for this study. Each patient must have had a baseline (ie, medication-free) FEVi of 40 to 80 percent of their predicted value, with reversibility of bronchospasm documented by at least a 15 percent increase in baseline FEVi within 30 min following two inhalations (180 Mg) of albuterol.
This was a randomized, double-blind, placebo-controlled, parallel-group comparison study of four dosage regimens of salmeterol aerosol conducted at five study sites in the United States. Approvals for conduct of this study at these sites were granted by institutional review boards, and informed consent for participation was obtained from each patient enrolled in the study.