Fixed airflow obstruction in asthma: a descriptive study of patient profiles and effect on treatment responses
BACKGROUND Inhaled corticosteroids (ICSs) are the preferred maintenance therapy for adults and children with mild, moderate and severe persistent asthma, with the addition of a long-acting beta(2)-adrenoceptor agonist to ICS therapy recommended for patients with moderate or severe persistent asthma. The efficacy and safety of the combination of budesonide and formoterol delivered via dry powder inhaler (DPI) is well documented. OBJECTIVE To compare the efficacy and safety of budesonide/formoterol pressurised metered-dose inhaler (budesonide/formoterol pMDI; Symbicort pMDI, AstraZeneca LP, Wilmington, DE, USA) with budesonide pMDI (Pulmicort pMDI, Astra [corrected] Zeneca, Lund, Sweden), formoterol DPI (Oxis Turbuhaler, AstraZeneca, Lund, Sweden), budesonide plus formoterol in separate inhalers (budesonide pMDI + formoterol DPI) and placebo. STUDY DESIGN This was a 12-week randomised, double-blind, double-dummy, placebo-controlled study. SETTING This multicentre study was conducted in the respiratory specialty clinical practice setting. PATIENTS The study included 596 patients > or =12 years of age with moderate to severe persistent asthma previously receiving ICSs. INTERVENTIONS After 2 weeks on budesonide pMDI 80 microg x two inhalations (160 microg) twice daily, patients received budesonide/formoterol pMDI 160 microg/4.5 microg x two inhalations (320 microg/9 microg); budesonide pMDI 160 microg x two inhalations (320 microg) + formoterol DPI 4.5 microg x two inhalations (9 microg); budesonide pMDI 160 microg x two inhalations (320 microg); formoterol DPI 4.5 microg x two inhalations (9 microg); or placebo twice daily. MAIN OUTCOME MEASURES There were two prespecified primary efficacy variables: mean change from baseline in morning predose forced expiratory volume in 1 second (FEV(1)), obtained approximately 12 hours after the most recent administration of study medication at home and immediately before the next administration of study medication at the clinic; and mean change from baseline in 12-hour FEV(1), assessed as the average change in FEV(1) from serial spirometry over the 12-hour period after administration of the morning dose of study medication at the clinic. RESULTS Mean changes from baseline in morning predose FEV(1) at end of treatment were greater (p < or = 0.049) with budesonide/formoterol pMDI (0.19L) versus budesonide pMDI (0.10L), formoterol DPI (-0.12L) and placebo (-0.17L). Mean changes from baseline in 12-hour FEV(1) were greater (p < or = 0.001) with budesonide/formoterol pMDI after 1 day (0.37L), 2 weeks (0.34L) and at end of treatment (0.37L) versus budesonide pMDI (0.11, 0.15 and 0.15L) and placebo (0.09, -0.03 and -0.03L), and after 2 weeks and at end of treatment versus formoterol DPI (0.19 and 0.17L). Fewer (p < or = 0.025) patients receiving budesonide/formoterol pMDI versus monoproducts or placebo met worsening asthma criteria. Results were similar in the budesonide/formoterol pMDI group and the budesonide pMDI + formoterol DPI group on all measures. All treatments were well tolerated with similar safety profiles. CONCLUSIONS In this population, twice-daily budesonide/formoterol pMDI provides asthma control significantly greater than the monocomponents or placebo and comparable with budesonide pMDI + formoterol DPI. Safety profiles were similar for all treatments.