[Comparison of the bronchodilator effect of salbutamol between pressure metered dosed inhaler and dry powder inhaler in patients with stable bronchial asthma].

Recently, dry powder inhaler (DPI) was more available than pressure metered dosed inhaler (pMDI) for the inhalation therapy of the respiratory disease. But there are differences in the lung deposition of the drug in these devices. We investigated the bronchodilator effect of salbutamol inhalation with two device, pMDI and Tubuhaler on the stable 8 asthmatic patients. The time course of FEV1 had a no significant difference between two devices. DeltaAUC (=difference between area under the curve for time course of increase in FEV1 via pMDI and via DPI) and Deltamax FEV1 (=difference between maximum increases in FEV1 following inhalation of salbutamol via pMDI and DPI) were defined as the index of difference of bronchodilator effect between the two devices. PMDI was more effective on improving the pulmonary function in subjects with severely decreased FEV1 and FEV1% than DPI. These results may reflect the correlation of inspiratory flow rate and drug deposition. PMDI is still useful on the part of asthmatic patients with decreased pulmonary function.