Efficacy, tolerability, and effect on asthma-related quality of life of formoterol bid via multidose dry powder inhaler and albuterol QID via metered dose inhaler in patients with persistent asthma: a multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel-group study.

BACKGROUND: Inhaled beta(2)-agonists are widely used in asthma treatment. The design limitations of pressurized metered dose inhalers (pMDIs) have prompted the development of dry powder inhalers (DPIs) for the delivery of asthma medications.

OBJECTIVE: The goal of this study was to evaluate the efficacy, tolerability, and effect on asthma-related quality of life (QOL) of a long-acting beta(2)-adrenoreceptor agonist, formoterol, delivered via multidose DPI, compared with albuterol delivered via pMDI or placebo in adolescents and adults with persistent asthma.

METHODS: This multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel-group study was conducted in outpatient clinics at 18 US centers. Adolescents and adults with persistent asthma received formoterol 10 pg BID via multidose DPI, albuterol 180 microg QID via pMDI, or placebo for 12 weeks. The primary efficacy variable was the 12-hour AUC of forced expiratory volume in 1 second (FEV(1)) after 12 weeks treatment. Secondary efficacy variables included asthma-related QOL, asthma symptom scores, rescue medication use, and other pulmonary function measures.

RESULTS: A total of 239 patients (147 females, 92 males; age range, 13-85 years) with persistent asthma were enrolled (formoterol, n = 80; albuterol, n = 79; placebo, n = 80). Formoterol delivered via the multidose DPI resulted in clinically relevant and statistically significant increases in 12-hour AUC of FEV(1) after 12 weeks of treatment compared with albuterol pMDI and placebo (P < 0.019 and P < 0.001, respectively). Asthma-related QOL (total score) was significantly improved with formoterol treatment compared with placebo (P < 0.015). Nocturnal asthma symptom scores significantly improved with formoterol compared with albuterol and placebo (P < 0.001 and P < 0.003, respectively) and rescue medication use was significantly less with formoterol compared with albuterol and placebo (P < 0.004 and P < 0.002, respectively). Treatment with formoterol was well tolerated.

CONCLUSIONS: In this study of adolescents and adults with persistent asthma, 12 weeks of treatment with formoterol 10 microg BID delivered via a multidose DPI provided significantly greater 24-hour bronchodilation compared with albuterol and placebo and resulted in significant improvements in asthma-related QOL compared with placebo. Formoterol was well tolerated in these patients.