Inhaler devices and global warming: Flawed arguments

Excerpts from Mark L Levy et al, BMJ Open

“In an attempt to address issues related to global warming and the contribution of pMDIs, Wilkinson et al have succeeded in generating a great deal of negative, potentially harmful media interest for patients who currently rely on these devices. They analysed the potential impact of switching therapy from pMDIs to dry powder inhalers (DPIs) in terms of changes in greenhouse gas emissions and costs to the NHS based on prescribing information in England alone. This strategy was apparently devised in a vacuum, without regard to implications for threats to patient wellbeing and safety as a consequence of their being deprived of access to pMDI therapy for COPD and asthma.

Physicians consider many factors when selecting the most appropriate inhaler device for patients other than cost if treatment is to be effective and these issues were not mentioned and was heavily biased in favour of DPIs, which are seldom appropriate for use in young children, children, elderly and infirm and those with considerable, irreversible airways obstruction. In addition, many patients rely on pMDIs for rapid relief of symptoms.

Their study addressed two possible switching scenarios in the UK (i) from pMDIs to currently prescribed DPIs, and (ii) to the cheapest available ‘equivalent’ DPIs based on drug content. While we agree with one of their conclusions that smaller volume Salamol should be prioritised over larger volume Ventolin. We have major reservations about their conclusion that switching patients’ medication from pMDIs to the cheapest available equivalent DPIs would result in large carbon savings, while ignoring possible consequences for loss of disease control and consequent morbidity and mortality from obstructive airways diseases, such as asthma, which might result in considerable patient harm.

These messages clearly have the potential to stigmatise patients with asthma and COPD for taking their essential medication, and there are anecdotal reports of children, many of whom benefit particularly from pMDI therapy, not wanting to be seen using their inhalers in public.

Conversely, there was no mention in this commentary, or indeed in the media, that correct delivery of inhaled drugs by an inhaler device, which can be used efficiently and reliably by individual patients, improves symptoms and quality of life and reduces morbidity, mortality and hospital acute care costs.

Further there was correspondingly no mention or consideration of the potential consequences where switching “goes wrong”, resulting in disease destabilisation and associated “carbon cost” of unnecessary emergency and hospital inpatient management.

Wilkinson’s comparison between the UK (70%) and Sweden (10%) pMDI use fails to account for potential differences in disease therapy indications in both countries.

There are considerable shortcomings in carbon footprint modelling in the Wilkinson et al paper.

While we are concerned about the environment and the effect humans are having on global warming, we are concerned that this article lacks balance in its discussion and conclusions and puts patients with asthma at risk of an attack through inappropriately stopping or switching inhalers.”


12 November 2019