Background: An effective, long-acting bronchodilator could benefit patients with asthma who have symptoms not controlled by antiinflammatory drugs. We compared a new long-acting, inhaled beta 2-adrenoceptor agonist, salmeterol, with a short-acting beta 2-agonist, albuterol, in the treatment of mild-to-moderate asthma.
Methods: We randomly assigned 234 patients (150 male and 84 female patients 12 to 73 years old) to one of three treatment groups: one group received 42 micrograms of salmeterol twice daily, one received 180 micrograms of albuterol four times daily, and one received placebo. Treatment was assigned in a double-blind fashion, and all patients could use supplemental inhaled albuterol as needed during the 12-week treatment period.
Results: Measurements of the forced expiratory volume in one second, performed hourly for 12 consecutive hours, showed that a single dose of salmeterol produced a greater mean area under the curve than two doses of albuterol taken 6 hours apart (6.3 vs. 4.9 liter.hr, P < 0.05). The difference was significant on day 1 and at week 4 of the study, but not at week 8 or 12. Salmeterol was also more effective than albuterol or placebo (with albuterol taken as needed) in increasing the morning peak expiratory flow rate: salmeterol induced a mean increase of 24 liters per minute over the pretreatment values, as compared with a decrease of 6 liters per minute with albuterol (P < 0.001) and an increase of 1 liter per minute with placebo (P = 0.002). The mean overall symptom score was improved most by salmeterol treatment (P < 0.05), with the number of days with symptoms and of nights with awakenings decreasing by 22 percent and 52 percent, respectively; there were no differences in results between albuterol treatment and placebo administration. We found no evidence of tolerance to the bronchodilating effects of salmeterol, and adverse reactions to all the treatments were infrequent and mild.
Conclusions: For the management of mild-to-moderate asthma, salmeterol given twice daily is superior to albuterol given either four times daily or as needed.