Lung bioavailability of hydrofluoroalkane fluticasone in young children when delivered by an antistatic chamber/mask

ObjectiveTo determine whether an antistatic valved holding chamber/mask improves lung bioavailability of hydrofluoroalkane (HFA) fluticasone in young children.Study designTwelve patients, age 1 to 6 years, with well-controlled asthma were treated with an HFA fluticasone metered-dose inhaler (Flovent HFA) twice daily (440 μg/day). The drug was delivered by tidal breathing through conventional (AeroChamber Plus) and antistatic (AeroChamber MAX) valved holding chambers (VHCs) with masks in a randomized, crossover manner, each for 3 to 7 days. When adherence was 100% at home, blood was collected for measurement of steady-state fluticasone plasma concentration (FPC) 1 hour after the last dose was administered in the clinic. FPC indicates systemic exposure directly and airway delivery indirectly. It was measured by liquid chromatography-mass spectrometry. Data were analyzed by regression analysis.ResultsThe mean ± SD FPC was 107 ± 30 pg/mL after conventional VHC and 186 ± 134 pg/mL after the antistatic VHC (P = .03). In 5 patients (40%), the antistatic VHC increased FPC by ≥ 100%, to potentially excessive levels in 4 of them; it had little effect in 7 patients.ConclusionsHFA fluticasone was delivered to the airways by both devices even though the patients could not inhale deeply and breath hold. The antistatic VHC variably increased lung bioavailability. To reduce systemic exposure, the dose should be weaned to the minimum required to maintain asthma control.