Therapy with salmeterol, a long-acting, selective, inhaled β2-adrenergic agonist, is effective and safe for patients with persistent asthma; however, few long-term studies comparing salmeterol with current combination treatment regimens have been reported.METHODS.
A multicenter, randomized, placebo-controlled, double-blind study was conducted in 386 patients over 41 to 46 weeks in 27 medical centers (two thirds of the investigators were primary care physicians). Patients were randomized to receive either salmeterol or placebo, and further randomized to weaning or nonweaning from current asthma therapies (except inhaled corticosteroids). Treatment groups were: salmeterol/weaning (S + W), placebo/weaning (P + W), salmeterol/no weaning (S + NW), and placebo/no weaning (P + NW). Attempts at active weaning were carried out at the discretion of the investigator for 2 to 6 weeks. Pulmonary function, albuterol use, and asthma symptoms were measured.RESULTS.
The clinical benefits of salmeterol occurred despite weaning off existing nonsteroidal asthma medications. The mean morning peak expiratory flow rate was significantly increased in the S + W group (32.3 L/min) compared with both the P + W (4.9 L/min) and P + NW (6.8 L/min) groups (P < .001). Compared with the P + W and P + NW groups, the S + W group experienced significant (P < .05) improvements in overall mean asthma symptom scores, mean number of puffs of supplemental albuterol, the percentage of days with no supplemental albuterol use, and the mean number of awakenings caused by asthma (except for the P + NW comparison, P=.090). No significant differences were noted between treatment groups in any safety evaluation, including 12-lead electrocardiograms.CONCLUSIONS.
The addition of salmeterol in the treatment of persistent asthma resulted in sustained improvement in pulmonary function and symptoms. The long-term use of salmeterol is safe and improves the clinical course and stability of asthma following reductions in nonsteroidal asthma therapy.