Quality prescribing for respiratory illness 2024 to 2027 - draft guidance: consultation

Environmental Considerations

To play our part in tackling the climate crisis, NHS Scotland is aiming to become a net-zero health service by 2040 at the latest. We are part of an international coalition of over 60 countries to date who have committed to developing a low-carbon health system.

The propellant used in metered dose inhalers (MDIs) prescribed for asthma and chronic obstructive pulmonary disease (COPD) are powerful greenhouse gases with global warming potentials of 1,430 or 3,220 times greater than CO2 depending on the type. Around 4.5 million MDIs were dispensed in Scotland in 2020/21, we estimate that this accounts for 79,000 tonnes of CO2 a year. This compares with 430,000 tonnes of CO2 from building energy use each year and is more than the emissions from the NHS fleet and waste combined. Reducing emissions from MDIs is essential to achieving our net-zero goals.

Research has so far shown that switching to a greener, environmentally-friendly dry powder inhaler (DPI) works well for most people. It is therefore in the interests of both patients and the environment that we make improvements to the way that asthma and COPD are managed. The NHS can improve outcomes for patients and reduce the number of short-acting reliever inhalers that are used. DPIs, which do not use propellant, are also suitable for many patients and have a far lower carbon impact than MDIs. We can reduce emissions through changes in prescribing practices e.g. implementing regular medication reviews of patients to optimise care, and that for those people on MDIs and considering the switch to DPI as part of their review, supporting them to switch to DPIs where those are suitable for them.

As long as an individual’s healthcare professional shows them how to use their new inhaler, and it can be used well, changing from a MDI to DPI is not linked to symptoms getting worse or asthma attacks.

Most adults find DPIs easier to use than MDIs because it is easier to get the technique right. DPIs are breath-actuated though, which means a user would need to be able to inhale the powder. Some people may find it hard to do this, therefore, if a DPI is not right a change will not be recommended. If an individual does switch and they do decide to try a DPI and find that it doesn’t suit well, they can ask to change back.

The existing SIGN Guidance on the Management of Asthma supports this approach. It states:

“Prescribers, pharmacists and patients should be aware that there are significant differences to the global-warming potential of different MDIs and that inhalers with low global warming potential should be used where they are likely to be equally effective. Where there is no alternative to MDIs, lower volume HFA134a inhalers should be used in preference to large volume or HFA227ea inhalers.”^[1]