Article date: February 2009
By: Arun Nair, Daniel Menzies, Pippa Hopkinson, Lesley McFarlane, Brian J. Lipworth, in Volume 67, Issue 2, pages 191-198
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT
AIMS
The systemic bioavailability of inhaled fluticasone propionate (FP) depends primarily on lung absorption and can be quantified by measuring suppression of overnight and early morning urinary cortisol/creatinine (OUCC and EMUCC, respectively). The aim of the study was to determine the relative bioavailability of hydrofluoroalkane (HFA) FP to the lungs via anti‐static plastic (Zerostat‐V and Aerochamber Max), metal (Nebuchamber) anti‐static spacers and metered dose inhaler [Flixotide Evohaler (EH) (pMDI)].
METHODS
A randomized, double‐blind, double‐dummy, four‐way crossover design was used. Eighteen mild to moderate asthmatics received single doses of placebo/HFA‐FP 2 mg via the 280‐ml Zerostat‐V (ZS); 250‐ml Nebuchamber (NC); 197‐ml Aerochamber Max (AC); and pMDI (EH). Measurements of OUCC and EMUCC were made at baseline and 10 h after each dose.
RESULTS
Significant suppression of OUCC and EMUCC occurred from baseline with all three spacers, but not Evohaler (geometric mean fold suppression, 95% confidence interval): ZS, 2.74 (1.75, 4.30), P < 0.001; NC, 3.31 (1.81, 6.06), P < 0.001; AC, 4.98 (3.39, 7.31), P < 0.001; and for EH this was 1.42 (0.92, 2.21), P= 0.169 (equating to a 64, 70, 80 and 30% fall in OUCC via the ZS, NC, AC and EH devices, respectively). There were significant differences between all three spacers vs. EH. When compared with the Evohaler, the Zerostat V resulted in 48% greater suppression (P= 0.009); the Nebuchamber 57% greater suppression (P= 0.001); and the Aerochamber Max 71% greater suppression of OUCC (P < 0.001).
CONCLUSION
All three antistatic spacers significantly increased the relative systemic bioavailability of HFA‐FP compared with the standard pMDI.
DOI: 10.1111/j.1365-2125.2008.03350.x
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