Pressurised metered dose inhalers (pMDIs) are used to deliver treatment to individuals with respiratory diseases. Whilst the technology within pMDIs has not significantly changed in the last 25 years, some changes in legislation and supply have taken place. These have been driven by pragmatism, cost and most recently concerns about the environmental impact of the propellants used within their manufacture. A major issue affecting patients in most countries, is the large number of pMDIs without an integrated dose counter (IDC). This makes it difficult or impossible for patients to monitor the number of remaining doses. This article will review how pMDIs work, their environmental impact and the adverse clinical effects of not having an IDC. It will also look at the scale and cost of the issue as well as ways in which individuals can safely assess if their pMDI is empty of medication. We conclude there is an urgent need for IDCs on short acting beta agonist (SABA) pMDIs to be made mandatory as this is likely to reduce asthma exacerbations and deaths. Whilst waiting for this to happen, patients should be shown how to weigh their SABA canister to identify when it needs to be replaced.
FJ et al. (Fri,) studied this question.