A twelve-week comparison of salmeterol and salbutamol in the treatment of mild-to-moderate asthma: a Canadian multicenter study.

Background: A long-acting inhaled bronchodilator that is both well tolerated and effective could allow for improved control of both daytime and nighttime symptoms in patients with asthma who use frequent as-needed short-acting bronchodilators despite antiinflammatory treatment.
Objective and Methods: We compared the efficacy and safety of inhaled salmeterol, 50 micrograms twice daily, with inhaled salbutamol, 200 micrograms four times daily, delivered through a metered-dose inhaler for 3 months in a multicenter, randomized, double-blind, parallel-group study of 228 patients (aged 12 to 76 years) with mild-to-moderate asthma.
Results: A single morning dose of salmeterol produced improvement in FEV1 that was significantly greater (p < or = 0.012) than that produced by two doses of salbutamol (taken 6 hours apart) when patients were assessed 3 to 6 hours and 10 to 12 hours after the dose. This greater bronchodilation was present on day 1 of the study and after 4, 8, and 12 weeks of regular treatment. Over the 12 weeks, compared with salbutamol, salmeterol treatment was associated with a greater mean improvement in morning peak expiratory flow (35 L/min vs -3 L/min, p < 0.001), a higher percentage of days with no symptoms (29% vs 15%; p = 0.012), and a higher percentage of nights with no awakenings (14% vs -1%; p < 0.001). Adverse events were similar for both treatments.
Conclusions: In this study salmeterol, 50 micrograms twice daily, was well tolerated and more effective than salbutamol, 200 micrograms four times daily, in improving symptoms and lung function in patients with mild-to-moderate asthma.