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Chapter 2: Decarbonising medicines  

Chapter 2: Decarbonising medicines  
By Emma Wilkinson
28 March 2024


Countdown to Net Zero
Climate change and the NHS
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about Climate change and the NHS

Chapter 1
Climate change and the NHS
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about Climate change and the NHS

Chapter 2
Decarbonising medicines  
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about Decarbonising medicines  

Chapter 3
Increasing the efficiency of NHS estates
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about Increasing the efficiency of NHS estates

Chapter 4
Greening NHS transport
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about Greening NHS transport

Chapter 5
Managing NHS waste sustainably
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about Managing NHS waste sustainably

Chapter 6
Expert views on NHS Net Zero
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about Expert views on NHS Net Zero

Overall medicines account for a quarter of the emissions within the NHS. Reducing overprescribing, making sure the right medicine is being used and switching to lower carbon alternatives will be a substantial part of helping the NHS meet its net zero goals.

The biggest initial focus has been around anaesthetic gases and inhalers. The latest estimate is that emissions from these alone contributes to 1,286ktCO2e or 5% of the total NHS carbon footprint. Tackling this was first set out in the NHS Long Term Plan.

Anaesthetic gases

The NHS is on track to completely decommission the use of desflurane, a volatile anaesthetic estimated to have a global warming potential 2,500 times greater than carbon dioxide.

Helgi Johannsson, consultant anaesthetist at Imperial College Healthcare Trust and vice president of the Royal College of Anaesthetists said this historic achievement had been a collaboration with NHS England and the Association of Anaesthetists.

‘I’m very proud of this work because this is probably the first time a drug has been discontinued for environmental reasons,’ he says. Given the climate emergency and the fact that there are better choices from a clinical perspective, it was a simple decision to make, he adds. ‘We were knocking on an open door with most people.’

It had already been banned Scotland last year, he notes, which was the first country to do so. ‘It is an important step because it gives us permission to start to think about the environment with everything we prescribe and every procedure we perform,’ he adds. ‘It paves the way for more difficult decisions.’

The next step will be looking at nitrous oxide which is also a ‘terrible environmental pollutant’ but will be more difficult to address because of its current role on the labour ward. The hope is for better technology to allow capture and destruction of the gas which could cut a third of all NHS anaesthetic emissions. In Sweden they have been doing this for years.

‘There is some exciting technology on the horizon,’ says Johannsson. There are also strides that could be made from better technology to reuse and recycle nitrous oxide waste from canisters.

He sees a lot of enthusiasm and awareness from colleagues, particularly around waste and single use items. But to change some of the practices around healthcare, it will need to be built into everyone’s expectation – including training and inspection – to ensure standards are being met and guidelines are being adhered to, he believes.


The other obvious place for the NHS to start is low carbon inhalers for treating patients with asthma and COPD. Most of the emissions here come from the propellant used to deliver the drug in metered dose inhalers. Lower carbon versions are available as are dry powder inhalers.

A 30% uptake of such alternatives would result in a reduction of 374 ktCO2e per year, the NHS has calculated. Resources have been developed, including by NICE and inhaler switching was included within the primary care network impact and investment fund (PCN IIF) between 2021 and 2023. Yet there has been concern that blanket switching could have a negative impact on patient care.

The evidence is clear that patients in the UK rely far too heavily on reliever inhalers. Poorly controlled asthma is contributing to more than 300,000 tons of greenhouse gas emissions in the UK every year, a recent analysis by Astra Zeneca suggested.

Dr Aarti Bansal, a GP in Sheffield and founder of Greener Practice, says sustainability and good clinical care go hand in hand. ‘This is about preventing ill health, conditions being better controlled, patients understanding their condition better and reducing duplication in the system.

‘Greener care also tends to go together with more equitable care and reducing health inequalities and asthma is a good example of that,’ she adds.

 ‘Asthma mortality rates in the UK are some of worst in Europe and most people’s asthma is not well controlled. Commissioners need to understand this because we have a responsibility to patients as well as making sure our care is more sustainable.’

Quality improvement can be done across diagnosis, disease control, choice of device and disposal, she explains. ‘There is a lot of work to be done on raising expectations of good asthma control and understanding of the disease.’ Improving asthma control would lead to a steep decline in the numbers of reliever inhalers prescribed and reduce carbon emissions from inhalers by two thirds, she adds. 

‘In the UK we tend to prescribe metered dose inhalers, which have a very high carbon footprint, but this is not the case across Europe where dry powder inhalers are more common.’ She adds that this option is often preferred by patients and comes with a dose counter for people to track how much medicine is left. 

‘It’s about integrating this into one single message about good care.’ Dr Bansal has developed a visual guide with NHS England to help guide conversations during an asthma review. Greener Practice has also developed a toolkit for practices.

Use of combination inhalers as recommended by the Global Initiative for Asthma Guidelines (GINA) is another way to make a difference to patient care and reduce the number of inhalers patients may be using by addressing the underlying inflammation. ‘We’ve got this real opportunity and a lot of these combination inhalers are coming in the lower carbon versions.’

Overall primary care is responsible for a significant proportion of the NHS carbon footprint because that is where most of the prescribing happens. Overdiagnosis and deprescribing are other areas where primary care can have a big impact on sustainability. It has been estimated that 10% of medicines are overprescribed and up to 50% of those for long-term conditions are not taken as intended.


Dr Bansal is also clinical net zero lead for the Humber and North Yorkshire ICB and she recognises there is a need to resource practices to do this work. ‘There is a huge amount of money to be saved if we invest in improved asthma care, just from direct prescription savings never mind the wider impact on better quality of life or employment. This is the right thing to do for patient health inequalities, and the environment but it is also sensible for an NHS that is under a huge amount of financial stress.’

In Brighton, Dr Abigail Fry a GP at Mile Oak Medical Centre has had protected time to work with all five practices in her PCN to identify quick wins on sustainability using the RCGP Green Impact for Health Toolkit. Projects they have worked on include inhaler prescribing and a blister pack recycling scheme in the surgery.

‘We’re also taking part in a national study to deprescribe blood pressure medication in older people and through structured medication reviews with our practice pharmacists we have been trying to reduce opioid prescribing,’ she says.

Data on Open Prescribing shows that metered dose inhalers now make up around 42% of all inhaler prescribing in her practice compared with more than 60% three years ago and a current national average of roughly 55%. The steepest decline has been in the last year when it was a real focus for them.

‘We did our carbon footprint as a practice and 75% was in prescribing and 25% was inhaler prescribing,’ she explains. But to address this, practices who are under a huge amount of strain will need incentivising, she says. ‘People are too busy to do this without resource and it’s hard to change people’s behaviour and the way they have always done things.’

She adds: ‘The ideal way to do this is through medicines optimisation incentive schemes at the ICB level. When it was in the IIF people did start to concentrate on it but they made it too difficult to achieve.’ Dr Fry also believes that every PCN needs to have a sustainability lead to set the expectation. 


Hospitals have also done work around prescribing including switching from intravenous to oral antibiotics where appropriate because not only is the carbon footprint much lower, it reduces cost and chance of infection it improves patient experience.

In Dorset, their sustainable strategy has been based around optimising health from the start, explains ICB medicines sustainability lead Tracy Lyons. With a background in hospital pharmacy, it was the four principles of sustainable healthcare that transformed her thinking, with the starting point being prevention. ‘The most sustainable medicine is the one you don’t need,’ she says. ‘We have to make sure we have optimised the patient’s health with clear evidence-based pathways. A big part of that is making sure patients are offered a healthy lifestyle and that we’re promoting the benefits of non-drug therapies.’

This year they are piloting a service finder project that helps identify schemes, based on postcode, that help people improve their quality of life during a consultation – it could be around safe cycling or gardening clubs, etc. It is based on a similar scheme developed by North East and North Cumbria called Making Every Contact Count.

They run a ‘Pill School’ for children which teaches them to swallow medicines which has a lower environmental impact because of packaging waste but also less sugar. Their ‘Open the Bag’ campaign to give patients the power to say at the point of collecting their medicines from the pharmacy whether they actually need it all. ‘We also look at using medicines with a lower carbon footprint but we try to do more towards the beginning around whether you need it in the first place.’

‘The thing we’re really proud of is this year we have started an ‘Only Order What you Need’ campaign to address the fact that a lot of patients felt they had to reorder all their medicines every time or they would miss out. We have sent information into GPs, pharmacists and we’ve done a media blitz.’

In the first month of the campaign, they have seen a 3% drop in prescription requests across the ICB, she says, and up to 16% in the practices that have engaged the most. ‘That is huge in terms of staff time, environmental impact and it empowers patients who don’t end up with cupboards full of medicines they don’t need.’

It is the type of project that appeals across the board because it frees up time, reduces the drug bill, cuts waste and has real tangible benefits, she adds. After spending £5,000 on advertising and resources, they have seen a fall in their drugs budget of £230,000 in just one month.

‘What we have really tried to do is build sustainability into every day decision making that leads to better outcomes for patients,’ she says.

At the national level the NHS has enormous power in drug procurement and supply chains and that has to be an England-wide part of the initiative, she adds. ‘As we work our way along there, pharmaceutical companies are aware that in order to interact with the NHS, they need to up their game.’

The NHS has set out a detailed net zero supplier roadmap to align with its targets for 2030. It means that for all contracts over £5 million, suppliers will be obliged to publish a carbon reduction plan.

Later this year, the Royal Pharmaceutical Society (RPS) will also be publishing a toolkit to help pharmacies – in both community and hospital – work towards green standards. There are six domains, one of which is clinical practice and will include activities around reducing unnecessary repeat prescribing and optimising respiratory care, including recycling of inhalers, as well as reviewing the need for dosset boxes, explains Wing Tang head of professional standards at the RPS.

He adds, ‘We are making it as simple as possible because for the bulk of people we will have to bring them along the journey. Once this is in place, we will be able to show that becoming greener isn’t as onerous as people might think it is.’

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