Do not routinely prescribe metered-dose inhalers but dry powder inhalers.

Type of practice


Asthma and Chronic Obstructive Pulmonary Disease (COPD) have therapeutic benefits from inhalation medications, available in two pharmaceutical formulations: metered-dose inhalers and dry powder inhalers. Consequently, the prescription preference should be directed towards the latter for three distinct reasons:
• Ease of Administration: dry powder inhalers obviate the necessity for spacers or specific maneuvers, thus affording simplified utilization.
• Efficacy: powder formulations exhibit enhanced penetration into the distal airways compared to aerosol sprays, thereby optimizing therapeutic impact.
• Environmental Sustainability: aerosol inhalers employ hydrofluorocarbon propellants, potent greenhouse gases, thereby bearing a carbon footprint over 40 times higher than that of dry powder inhalers. This environmental burden is so substantial that it is estimated to account for 4% of the entire healthcare sector’s carbon emissions in the United Kingdom.
However, the choice must be shared with the patients and based on individual benefits and risks, also according to age and general conditions.


1. Kerwin EM et al. ELLIPTA dry powder versus metered-dose inhalers in an optimized clinical trial setting. J Allergy Clin Immunol Pract. 2019;7:1843-49.
2. Wilkinson A, et al. The environmental impact of inhalers for asthma: a green challenge and a golden opportunity. Br J Clin Pharmacol. 2022;88:3016-22.
3. Fidler L et al Pressurized metered-dose inhalers and their impact on climate change. CMAJ 2022;194:E460.
4. How to Reduce the Carbon Footprint of Inhaler Prescribing. A Guide for Healthcare Professionals in the UK stewardship of pressurised metered-dose inhalers -
5. Born KB, Levinson W, Vaux E Choosing Wisely and the climate crisis: a role for clinicians BMJ Quality & Safety Published Online First: 02 June 2023



Attention. Please note that these items are provided only for information and are not intended as a substitute for consultation with a clinician. Patients with any specific questions about the items on this list or their individual situation should consult their clinician.