Quality prescribing for respiratory illness 2024 to 2027 - draft guidance: consultation

Appendix 2 - When is a dry powder inhaler (DPI) suitable or not?

For patients with asthma who are interested and happy to try a DPI, it is suggested that a DPI device is a suitable option for those who can breathe in through their mouth quickly and deeply over two to three seconds. ¹

Many patients may find DPIs easier to use, especially when given inhaler technique instruction², although teaching inhaler technique has positive impacts on disease and patient outcome for all inhalers. ³ Factors such as older age affect inhaler technique but a review was not able to determine whether this was related to dexterity, cognition, physical ability or the device. ⁴

DPIs are not an appropriate choice of inhaler for patients who are not able to generate sufficient inspiratory flow. ^4,5 An In-check® device can be used to determine inspiratory flow and this can be cross referenced to the manufacturer’s recommended minimum inspiratory flow rate for individual device types. Patients aged over 75 years with COPD have a higher prevalence of insufficient inspiratory flow required for a DPI. ⁶

Inhaler choices should be made with the patient, ensuring the right device for the right patient. ⁷

DPIs may not be suitable ⁵ for:

• frail, elderly patients
• very young patients
• patients with COPD, with peak inspiratory flow rates less than 45 L/min
• those with muscle weakness

If there is any concern that an individual is at a higher risk of asthma attack or risk of severe attack then remaining on a pMDI reliever plus spacer would seem reasonable. Table 14, SIGN 158 Consider switch to pMDI with lower global-warming potential if this is clinically appropriate (Salamol® or Airomir®).

Reassure those for whom a DPI is unsuitable that the greenest inhaler is the one that they can use effectively to have good disease control, minimise the use of their reliever inhaler and avoid hospitalisation. Good control is better for the individual, and for the environment.

References for Appendix 2 - When is a dry powder inhaler (DPI) suitable or not?

1. Usmani O, Capstick T, Saleem A. Choosing an appropriate inhaler device for the treatment of adults with asthma or COPD. MGP guidelines. 2020. https://www.guidelines.co.uk/respiratory/inhaler-choice-guideline/455503.article

2. Ramadan WH, Sarkis AT. Patterns of use of dry powder inhalers versus pressurized metered-dose inhalers devices in adult patients with chronic obstructive pulmonary disease or asthma: an observational comparative study. Chron Respir Dis. 2017; 14:309-320. https://doi.org/10.1177/1479972316687209

3. Usmani, O.S., Lavorini, F., Marshall, J. et al. Critical inhaler errors in asthma and COPD: a systematic review of impact on health outcomes. Respir Res 19, 10 (2018). https://doi.org/10.1186/s12931-017-0710-y

4. Inhaler technique: does age matter? A systematic review. Sarah Barbara, Vicky Kritikos, Sinthia Bosnic-Anticevich. European Respiratory Review Dec 2017, 26 (146) 170055; DOI: 10.1183/16000617.0055-2017. Inhaler technique: does age matter? A systematic review | European Respiratory Society (ersjournals.com)

5. Starup-Hansen, J, Dunne, H, Sadler, J, Jones, A, Okorie, M. Climate change in healthcare: Exploring the potential role of inhaler prescribing. Pharmacol Res Perspect. 2020; 8: e00675. https://doi.org/10.1002/prp2.675

6. Chen, SY., Huang, CK., Peng, HC. et al. Inappropriate Peak Inspiratory Flow Rate with Dry Powder Inhaler in Chronic Obstructive Pulmonary Disease. Sci Rep 10, 7271 (2020). https://doi.org/10.1038/s41598-020-64235-6

7. Keeley, D and Attar-Zadeh, D. Shared decision making for greener healthcare: guidance on making safe and clinically appropriate changes to inhalers. PCRS, 22 :14. 2021. https://www.pcrs-uk.org/sites/default/files/pcru/articles/2021-July-Issue-22-GHC_ChangingInhalersSharedDecisions.pdf