The environmental impact of inhalers

It may be surprising, but asthma inhalers have a significant carbon footprint – in particular metered-dose inhalers (MDIs) which make up over 70% of the inhalers prescribed for asthma management each year in New Zealand.

MDIs contain hydrofluorocarbons (HFCs) – a propellant that pushes the medication out of the inhaler device so it can be breathed in. However, HFCs are also known to contribute to global warming as they contain climate-change gases. For example, the carbon footprint of a standard (200-puff or 100-dose) salbutamol inhaler amounts to approximately 28kg of carbon dioxide per inhaler.

A recent Pharmacy Today article described each inhaler as being “approximately equal to driving a new Toyota Corolla (with carbon dioxide emissions under 100g/km) for over 300km under typical road conditions.”

In comparison, dry-powder inhalers (DPIs) have a much smaller carbon footprint of approximately 1kg per device. DPIs rely on the patient inhaling, or sucking in, the medication from the inhaler, and therefore do not require a propellant, hence much less of a carbon footprint.

Because of how prevalent asthma is, and how common these medications are in the treatment of the condition, the overall carbon footprint is significant. For example, in the UK, MDI carbon emissions are estimated to account for four percent of the entire National Health Service (NHS) emissions budget. Here in New Zealand, healthcare is responsible for approximately 5 percent of New Zealand’s overall carbon emissions, with primary and community care prescription medication making up over two-thirds of our climate footprint - MDIs being the number one culprit.

Our rates of asthma are much higher in New Zealand in comparison to global figures, with 1 in 7 children and 1 in 8 adults suffering with asthma, compared to 1 in 11 children, and 1 in 12 adults in the UK.

The new NZ Adolescent and Adult Asthma Guidelines, developed by the Foundation’s working group of respiratory health experts led by Professor Richard Beasley, state “The lower carbon footprint of dry powder devices (less than 10 per cent of [pressurised metered-dose inhalers]) should be considered...” The guidelines’ updated recommendation is to use a single 2-in-1 budesonide/formoterol DPI inhaler, containing both a preventer and a reliever medicine to treat asthma symptoms. This means that DPIs (or dry-powder inhalers) are now the preferred first-line treatment for adult and adolescent asthma, instead of the traditional MDI - therefore potentially reducing the carbon footprint of asthma medication in New Zealand. Furthermore, there are currently only two budesonide/ formoterol inhalers funded by Pharmac in New Zealand - which happen to both be DPIs.

Professor Beasley recommends that health professionals recall patients who solely use a ‘blue’ reliever inhaler, and replace it with a combination inhaler, and that this should be the immediate priority for health professionals in New Zealand.

However, despite how increasingly important it is becoming to consider environmental factors in all industries, it’s important to remember that there will always be a place for MDI inhalers, especially for patients who may not have enough breath to inhale from a DPI.

To summarise, those who need to use an MDI should continue to do so, as DPIs are not suitable for everyone. It is also important to note that patients should never alter what is prescribed to them without the advice of a healthcare professional.

So what’s the difference?

Sometimes, it can seem overwhelming at just how many different inhalers there are. ‘Puffer’ inhalers (also called metered-dose inhalers or MDIs) are the most common inhaler device and these are generally used with a spacer.

However, there are also other types of inhaler devices, depending on which inhaler medication you have been prescribed, some of which contain a dry powder that is sucked in, rather than delivered via an aerosol.