Transient effect of inhaled fluticasone on airway mucosal blood flow in subjects with and without asthma

Topically applied glucocorticosteroids (GS) have been shown to cause local vasoconstriction in normal skin and this phenomenon is commonly used to ass ess the potency of topical GS (McKenzie skin blanching test). The purpose o f the present study was to determine if an inhaled GS, fluticasone propiona te (FP), similarly leads to vasoconstriction in the airway mucosa and if su bjects with and without asthma have differential vascular responsiveness to GS. In 10 nonsmokers with stable asthma and 10 nonasthmatic nonsmokers, ai rway mucosal blood flow ((Q) over dotaw) expressed per milliliter of anatom ical dead space and the forced expiratory volume in 1 s (FEV1) were determi ned before and serially after inhalation of FP (88 to 1,760 mu g) or placeb o. Baseline mean (+/- SE) (Q) over dotaw was 55.1 +/- 1.0 and 44.2 +/- 1.1 mu l . min(-1) . ml(-1) in subjects with and without asthma, respectively ( p < 0.001). The corresponding mean FEV1 values were 2.34 +/- 0.13 and 3.22 +/- 0.12 L (p < 0.001). FP at 880 mu g but not placebo produced a transient decrease in mean (Q) over dotaw with a nadir at 30 min and return toward b aseline at 90 min postinhalation; the maximum mean decrease was 37% in subj ects with asthma and 21% in unaffected subjects (p < 0.01); 880 pg of FP wa s the lowest effective dose. FEV1 did not change after FP administration in either group. These results demonstrate a transient vasoconstrictive actio n of inhaled FP in the airway mucosa, with a greater vascular responsivenes s in subjects with asthma than in unaffected subjects. The measurement of ( Q) over dotaw may provide a more relevant means of assessing the potency of inhaled GS than the McKenzie skin blanching test. In addition, our observa tion suggests that inhaled GS have potentially beneficial effects in asthma that is not related to their antiinflammatory action.