An assessment of the systemic effects of single and repeated doses of inhaled fluticasone propionate and inhaled budesonide in healthy volunteers

Abstract

The systemic effects of single and multiple doses of inhaled fluticasone propionate (FP) and budesonide were examined in 24 healthy male volunteers (age range 18-29 years). The study was of an open, placebo-controlled, randomized, three-way crossover design. On each study day, multiple blood samples were taken over a 20 h period after drug administration (after a single dose and after the last of seven doses) and area under the curve (AUC(0-20)) for plasma cortisol and white blood cell (WBC) counts was calculated. RESULTS. The present study shows that multiple dosing with FP 1.0 mg b.i.d. for 3.5 days (seven doses) resulted in a marked cortisol suppression from placebo which, at 55%, was more than double that seen with a single dose (25% suppression). Multiple dosing with budesonide 0.8 mg b.i.d. resulted in a 34% suppression in plasma cortisol compared with a suppression of 26% with a single dose. The increase in systemic activity of FP after multiple dosing is confirmed by both the number of subjects with 0800 hours plasma cortisol values below normal limits and by the changes in WBC and differential counts. CONCLUSION. The results of the present study confirm previous findings with regard to the more marked systemic effect of FP following multiple dosing as compared with a single dose. This increase in systemic effect from single dosing to multiple dosing is significantly greater for FP than for budesonide.