Effects of inhalation of steroids on lung permeability in patients with asthma.

This study evaluated the effect of inhalation of steroids on lung permeability in patients with asthma by measuring the clearance of Tc-99m DTPA aerosol from the alveolar to vascular space. Twenty patients with asthma were studied in the supine position with a gamma camera and the clearance half time (T 1/2) was calculated. The base line lung permeability study was performed before treatment with inhalation of 100 micrograms beclomethasone dipropionate four times daily for 1 week, then the study was repeated. After treatment with inhalation of steroid, there was a change in T 1/2 from 76.4 +/- 37.4 minutes to 86.6 +/- 48.2 minutes (P = 0.08). This preliminary study suggests that lung permeability is not altered by inhaled steroid therapy.