Will Carroll, Joy Conway, Miguel Román-Rodríguez, Richard W. Costello, Nicola Scichilone, Richard Dekhuijzen, Mark L Levy, Birthe Hellqvist Dahl, Federico Lavorini, Mathieu Molimard, Celeste Barreto, Stephen Holmes, Job F M van Boven, Nicholas Roche, Omar S. Usmani, Jane Scullion, Lavorini, Federico, Barreto, Celeste, van Boven, Job F M, Carroll, Will, Conway, Joy, Costello, Richard W, Dahl, Birthe Hellqvist, Dekhuijzen, Richard P N, Holmes, Stephen, Levy, Mark, Molimard, Mathieu, Roche, Nichola, Román-Rodriguez, Miguel, Scichilone, Nicola, Scullion, Jane, Usmani, Omar S, Repositório da Universidade de Lisboa, Value, Affordability and Sustainability (VALUE), Real World Studies in PharmacoEpidemiology, -Genetics, -Economics and -Therapy (PEGET), and Groningen Research Institute for Asthma and COPD (GRIAC)
© 2020 The Authors. Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/), Spacers are pressurized metered-dose inhaler (pMDI) accessory devices developed to reduce problems of poor inhaler technique with pMDIs. Spacers that feature a 1-way inspiratory valve are termed valved holding chambers (VHCs); they act as aerosol reservoirs, allowing the user to actuate the pMDI device and then inhale the medication in a 2-step process that helps users overcome challenges in coordinating pMDI actuation with inhalation. Both spacers and VHCs have been shown to increase fine particle delivery to the lungs, decrease oropharyngeal deposition, and reduce corticosteroid-related side effects such as throat irritation, dysphonia, and oral candidiasis commonly seen with the use of pMDIs alone. Spacers and VHCs are not all the same, and also are not interchangeable: the performance may vary according to their size, shape, material of manufacture and propensity to become electrostatically charged, their mode of interface with the patient, and the presence or otherwise of valves and feedback devices. Thus, pairing of a pMDI plus a spacer or a VHC should be considered as a unique delivery system. In this Rostrum we discuss the risk potential for a patient getting switched to a spacer or VHC that delivers a reduced dose medication.