The Medicines and Healthcare products Regulatory Agency (MHRA) has approved a low-carbon version of Trixeo Aerosphere, a triple combination inhaler for adults with moderate to severe chronic obstructive pulmonary disease (COPD), which uses the propellant, HFO-1234ze(E), and is just as safe and effective as the previous version.

COPD affects around 1.2 million people in the UK and is the second most common cause of emergency hospital admissions. Trixeo Aerosphere is used to make breathing easier and improve symptoms of COPD such as shortness of breath, wheezing and cough. It can also prevent flare-ups (exacerbations) of COPD.

The newly approved version of Trixeo Aerosphere replaces the propellant HFA-134a with HFO-1234ze(E) – a fluorinated gas with near-zero global warming potential. The propellant itself is not an active medicine but is used to deliver the inhaled dose.

This new version will be available in the UK from the second half of 2025. In the meantime, the current version of Trixeo Aerosphere will continue to be available to patients.

Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access, said:

Keeping patients safe and enabling their access to high quality, safe and effective medicines are key priorities for us.

Inhalers are a cornerstone of COPD treatment, helping manage symptoms and prevent exacerbations. However, some inhalers can also contribute to greenhouse gas emissions through their propellants.

This approval supports the continued availability of a widely used COPD treatment while enabling a transition to inhalers with a lower carbon footprint – without compromising on safety, quality or clinical benefit.

Karin Smyth, Minister of State for Health, said:

With 1.2 million people using inhalers in the UK, there is no doubt about the impact they have on the environment.

This is another example of the UK being at the forefront of delivering innovative, environmentally friendly and top-quality medicines that will benefit patients across the UK.

Through our Plan for Change, we will lower our carbon footprint in our mission towards Net Zero and rebuild our NHS.

Trixeo Aerosphere is used twice daily (two puffs in the morning and evening) as a long-term maintenance treatment. No changes have been made to the active ingredients, recommended dose or clinical use.

The MHRA’s approval is supported by clinical evidence showing that the new propellant, HFO-1234ze(E), delivers the same dose and therapeutic effect as the original formulation. The assessment included evidence on product quality, device performance and stability.

A full list of side effects for the current version of the product can be found in the Patient Information Leaflet (PIL) or the Summary of Product Characteristics (SmPC), which will be updated when the new version of the medicine becomes available.

As with all medicines, the MHRA will continue to monitor the safety and effectiveness of Trixeo Aerosphere. Anyone experiencing suspected side effects is encouraged to report them through the Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

Notes to editors  

1. The variation to the existing marketing authorisation of Trixeo Aerosphere was granted on 9 May 2025 to AstraZeneca.
2. The Summary of Product Characteristics and Patient Information Leaflet for the current version of the product can be found here. An updated SmPC and PIL will be available once the new version of the medicine is available.
3. For more information about COPD, visit: https://www.nhs.uk/conditions/chronic-obstructive-pulmonary-disease-copd/
4. The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe.  All our work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks.
5. The MHRA is an executive agency of the Department of Health and Social Care.
6. For media enquiries, please contact the newscentre@mhra.gov.uk, or call on 020 3080 7651.