Appropriate Use of Pressurized Metered-Dose Inhalers for Asthma

Peter S. Cogan, PhD; Brandon J. Sucher, PharmD, BCACP, CDE, AE-C


US Pharmacist. 2015;40(7):36-41. 

In This Article

Abstract and Introduction


Over the last several decades, multiple studies have identified improper asthma rescue inhaler technique as a clinically important correlate of unstable disease and increased use of healthcare services. It is believed that inconsistencies in what is described as "proper" technique by various sources may contribute to patient confusion and poor outcomes in clinical practice. It is important to review pressurized metered-dose inhaler (pMDI) protocols as defined by the literature and manufacturers, as well as to understand how the technique employed in each step affects the delivered dose. Presumably, knowledge of this information will clarify aspects of pMDI usage that are potentially confusing, as well as inform patient education and the development of effective asthma action plans.


Asthma is a chronic, debilitating, and potentially fatal pulmonary disorder characterized by persistent inflammation and reversible obstruction of the airways.[1] According to 2013 data from the CDC's National Health Interview Survey, there are currently 16.5 million adults (7%) and 6.1 million children (8.3%) living with asthma in the United States. Additionally, it is estimated that 37 million Americans (12%) will be affected by asthma in their lifetime.[2] The National Heart, Lung, and Blood Institute's 2007 Expert Panel Report 3 presents clinical practice guidelines for the diagnosis and management of asthma and identifies four components deemed essential for effective management of the disease. Inherent in these components is a recognition of the need for proper, thorough, and repeated education on the use of asthma inhalers.[1]

Despite such calls for patient education (and demonstrable efforts to impart such instruction), literature on the widespread improper use of pulmonary drug delivery devices abounds.[3–5] Perhaps just as disconcerting are the accompanying reports that healthcare providers (HCPs) are commonly unable to properly operate these devices.[5,6] A recent assessment of patient ability to properly self-administer asthma rescue medication found that only 7% of patients surveyed were able to operate a pressurized metered-dose inhaler (pMDI) per the approved protocol.[7] Equally striking was the finding that 63% of those with flawed technique missed three or more steps. A similar study from 2005 concluded that "between 28% and 68% of patients do not use MDIs or powder inhalers well enough to benefit from the prescribed medication."[5] Indeed, pMDI misuse has been associated with unstable disease, as well as with increased emergency department visitation and hospitalization.[8] Such failings present a clear challenge to asthma maintenance goals and an obvious risk to patient welfare. Even in cases in which asthma is acceptably controlled (despite poor technique), pMDI operator error contributes to an estimated $5 to $7 billion annual loss of misfired medication and to the increased frequency of adverse events resulting from the systemic exposure that accompanies undesired oropharyngeal deposition of medication.[5,9,10]