In addition, Symbicort has provided a similar bronchodilatory response to albuterol. Bronchodilatory response is defined as the mean time to achieve improvement in lung function. In both studies, bronchodilatory response was measured by the mean improvements in forced expiratory volume in one second (FEV1), how much air a person can exhale during a forced breath in the first second of exhalation, which is a measure of airway function and can be reduced with airway obstruction.
In both studies, results showed that mean improvements in FEV1 at three minutes postdose were significantly greater with Symbicort and albuterol pressurized metered-dose inhaler (pMDI) compared to fluticasone propionate and salmeterol DPI (P<.001). At the same time, all active treatments resulted in significantly greater FEV1 at three minutes postdose compared to placebo (P less than or equal to .029). In addition, significantly (P<.001) more patients (combined studies) achieved greater than or equal to 15% and greater than or equal to 12% improvements in FEV1 within 15 minutes postdose with Symbicort and albuterol pMDI versus fluticasone propionate and salmeterol DPI. All treatments were well tolerated.