Inhalation treatment of respiratory conditions such as asthma and COPD is the predominant mode of therapy for the simple and logical reason that applying pharmacological agents to the target organ reduces the drug dose, maintains good efficacy, as well as reduces potential systemic adverse effects. To this end, there are now multiple systems for delivering therapeutic agents either as single or fixed dose combinations of two or three agents. The focus of this article is on the delivery devices and potential challenges with multiple device options rather than the therapeutic agents. It is important to recognize that even the best therapeutic agents cannot be effective unless they are delivered to the correct target organ or site.
Given the wealth of treatment and delivery options, it is surprising that treatment of COPD remains less than optimal and reported rates of device use errors remain high (Sanchis J et al. 2016, Molimard et al. 2017). This topic has been broadly discussed in the latest Global Initiative for Obstructive Lung Disease (GOLD 2021) report, with an emphasis on effective training and appropriate device selection for COPD patients. In a recent study, only 23% of patients discharged from the hospital demonstrated appropriate use of dry powder inhalers (Sulaiman et al. 2017). It is important to note that despite significant improvements in device design and a greater understanding of drug delivery issues, such as aerodynamics of particle flow as well as optimal particle size for pulmonary delivery, device error rates have remained high for decades (Sanchis et al. 2016). It is now well-recognized that education and training are key components of proper inhaler use, which requires regular assessment and the implementation of the “teach back” method (Dantic 2014). The importance of continued assessment is highlighted by the observation that the training effect does not persist (Press et al. 2016).