Discoordination between inhalation and pressurized metered-dose inhaler (pMDI) actuation when delivering inhaled corticosteroids (ICS) is a common technique error that can lead to worsened treatment outcomes. Valved holding chambers (VHCs) are thought to improve the delivered dose if inhalation is delayed, but this effect has not been sufficiently quantified. The aerodynamic particle size distribution of fluticasone propionate (FP) and ciclesonide (CIC) was studied under three conditions: inhalation initiated before actuation without a VHC, inhalation started at actuation without a VHC, and inhalation started at actuation with a VHC. We used a Next Generation Impactor connected to an anatomical adult throat model and a breathing simulator that produced a single, adult-type inhalation. We found that when inhalation was initiated simultaneously with actuation, the effective dose delivered decreased markedly for both FP and CIC compared to when inhalation was begun correctly, ie, before actuation. However, when a VHC was used and inhalation was started at actuation, delivered dose improved substantially for both medications. This protective effect of the VHC was especially pronounced for CIC, with both the fraction of particles in the 1-5 µm range and those under 1 µm returning to the same levels as when inhalation was initiated correctly. Although our study was conducted in vitro and did not involve patients, the findings likely have relevance for clinical practice. Therefore, promoting the use of VHCs in both children and adults may be beneficial, but this should be confirmed in clinical studies.
Csonka et al. (Fri,) studied this question.
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