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Final version (DIGITAL) - G4N Respimat supplement

This supplement has been commissioned and funded by Boehringer Ingelheim Ltd and developed in partnership with Guidelines for Nurses. Please see bottom of page for full disclaimer.

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Foreword

Jane Scullion, Respiratory nurse consultant, University Hospitals of Leicester NHS Trust

In the following article, Dr Kevin Gruffydd-Jones provides an update on the re-usable Respimat® Soft Mist™ inhaler (SMI), highlighting its distinctive features and encouraging us to consider the impact on the environment of the inhaler devices we prescribe. This is important to us nurses as we are often the key healthcare professionals assessing our patients’ requirement for medication and providing essential training on the use of devices.

For our daily clinical practice, the advantages of the device for patients are of great importance. The new re-usable inhaler offers an established range of bronchodilator medications in a device that is designed to be patient friendly and deliver drugs effectively to the airways. The majority of patients in a study showed a preference for the Respimat device over a metered dose inhaler,1 and the soft mist produced allows those with low inspiratory flow rates to still gain benefits from their medication.2 The inhaler has simple features, such as a clear dose counter to make patients aware of when they should order their replacement cartridges before they run out. There is also a locking mechanism that prevents usage when all of the doses have been delivered, so people aren’t using an empty device; and finally, an improved base facilitates gripping and turning, which may be important for people with poor grip and hand strength.3 The design of the device enables us to effectively teach our patients how to use it with a range of bronchodilator options.

Finally, it is important to consider the advantages of the re-usable Respimat SMI on the environment. All health and social care actions affect the environment, and the NHS has a large carbon footprint,4 which inhaler devices play a role in. In the UK, it is estimated that more than 65 million inhalers are prescribed every year,5 with the most prevalent device being the pressurised metered dose inhaler (pMDI), followed by the dry powder inhaler (DPI), and a far smaller proportion of other types of inhalers such as nebulisers.6 Of concern are the propellant fluorinated gases (F-gases) used in pMDIs, regarded as potent greenhouse gases with global warming potential (GWP). The Government’s Environmental Audit Committee, in their 2017 scrutiny of F-gases, recommended a 2022 NHS target of 50% of all inhalers to have lower GWP impact, proposing that one way to do this is to increase the proportion of DPIs prescribed and decrease prescribing of pMDIs.7 Another option I would suggest would be to reduce the overall number of devices used by a patient by using the re-usable, propellant-free Respimat SMI for the delivery of long-acting bronchodilators.

Conflicts of interest

Jane Scullion has received honoraria or support from Chiesi, AstraZeneca, Napp, Mundipharma, Mylan, Teva, Boehringer Ingelheim, MIMS, ARNS and NIP. She is a member of the NHS England Sustainable Inhaler Committee, Director of Education for UKIG, and a member of ADMIT.

References

  1. Schürmann W et al. Treat Respir Med 2005; 4: 53–61.
  2. Dalby R, Eicher E, Zierenberg B. Med Devices (Auckl) 2011; 4: 145–155.
  3. Dhand R, Eicher J, Hansel M et al. Int J COPD 2019; 14: 509–523.
  4. The King’s Fund. Sustainable services: Future trends. www.kingsfund.org.uk/projects/time-think-differently/trends-sustainable-services (Accessed 1 November 2019). 
  5. British Lung Foundation. Which inhalers are kindest for the environment? www.blf.org.uk/your-stories/which-inhalers-are-kindest-to-the-environment (Accessed 1 November 2019).
  6. Usmani O. Ther Clin Risk Manag 2019; 15: 461–472.
  7. House of Commons Environmental Audit Committee. UK progress on reducing F-gas emissions. Available at: https://publications.parliament.uk/pa/cm201719/cmselect/cmenvaud/469/469.pdf

The re-usable Respimat® Soft Mist™ inhaler

Dr Kevin Gruffydd-Jones, FRCGP, GP, Box, Wiltshire

Introduction

The Respimat® Soft Mist™ inhaler (SMI) is a handheld propellant-free device that produces a slow-moving, long-lasting mist of drug for inhalation. The original Respimat inhaler has been available since 2007, but in September 2019 it became available in the UK as a re-usable device. 

This article highlights the main features of the Respimat SMI, compares it with other inhaler types, describes the key features of the re-usable device, and discusses the environmental impact of its use. 

 

 

Mechanism of action of the Respimat SMI

The active drug used with the Respimat inhaler is formulated in aqueous solution with benzalkonium chloride as a preservative.1 When a cartridge containing the drug is inserted into the base of the inhaler, the device needs to be primed to expel air from the drug solution flow path. To load a dose, the patient has to turn the base of the device by half a turn. This tightens the helical spring that lowers and opens up the non-return valve, drawing a metered volume of the drug solution via the capillary tube into the loading chamber. The drug is delivered when the patient presses the dose-release button, which uncoils the spring.1 Figure 1 shows the internal design of the Respimat inhaler. 

Figure 1 REspimat supplement - internal mechanism

Figure 1: Schematic diagram of the internal mechanism of the Respimat inhaler.2

The mechanical power of this action drives the drug solution through a series of fine channels of silicon wafer enclosed in a ‘uniblock’ (see Figure 2), causing two fine jets of liquid to emerge through the twin nozzles of the uniblock. These fine jets converge on each other at such an angle that a slow-moving aerosol, ‘soft mist’, is produced.1

The soft mist is delivered with a high fine particle fraction of 75% (nearly double the value reported for aerosols emitted by a standard pressurised metered dose inhaler [pMDI] or dry powdered inhaler [DPI]) and with a slow velocity (3–10 times slower than the aerosol emitted from a pMDI).1 This allows low oropharyngeal deposition and high lung deposition, minimising oropharyngeal side-effects and reducing the dose of drug that needs to be used to be effective. In addition, the spray duration of the Respimat SMI is considerably longer than for pMDIs (1.2 seconds vs. 0.15–0.36 seconds, respectively), allowing a longer time for the patient to coordinate their inhalation with the release of the drug.1

nozzle

 

Figure 2: Schematic diagram of the Respimat uniblock nozzle.3

Respimat SMI vs other devices

Lung deposition

A study analysing lung and oropharyngeal deposition of fenoterol[A] (a short-acting beta2 - agonist) when administered via the Respimat SMI compared to when administered via a pMDI or pMDI plus spacer in healthy volunteers, showed that the mean oropharyngeal deposition of fenoterol was significantly lower via Respimat SMI than via pMDI (37.1% vs 71.1%, respectively). Lung deposition was significantly higher via Respimat SMI than via pMDI (39.2% vs 11%, respectively).4 Comparable results were obtained in a similar study performed on patients with asthma.5

The re-usable Respimat SMI 

In the UK, the re-usable version of the Respimat inhaler was launched in September 2019. The original Respimat inhaler was updated to simplify assembly, optimise daily use, and make it re-usable with up to six cartridges. 

Figure 3 highlights the differences and retained features between the disposable and re-usable inhalers.

Disposable vs reusable

Figure 3: Differences between the disposable (left) and the re-usable (right, front and back) Respimat SMI; features that have been added or changed in the re-usable version are labelled in red.

Key features of the re-usable device compared to the disposable are:

  • a locking device attached to the cartridge rather than to the device, which prevents further use of the device when the cartridge is empty and releases a safety catch allowing the clear base to be pushed away, alerting the user that the cartridge needs replacing
  • an improved dose counter on the cartridge, with the number of doses left clearly displayed; the dose counter changes colour when only 10 doses are left, clearly indicating to the patient that the cartridge will need to be replaced soon (Figure 4)
  • a longer base to improve grip and to make twisting the device easier. 

Comparative studies performed by Dhand et al. showed that the re-usable Respimat inhaler has improved usability compared to the disposable device, but no differences in drug delivery, aerosol particle size, and required inhalation method across multiple cartridge use.6 Performance of the re-usable Respimat inhaler has been shown to be comparable to that of the disposable inhaler, so lung deposition and clinical data established on the disposable inhaler can be applied to the re-usable one.6

Moreover, small-scale studies in patients with asthmas and/or COPD (n=16) showed that 4 people out of 16 felt that the process was ‘equally easy’ in both inhalers, while the remaining 12 people considered the cartridge insertion process to be ‘easier’ or ‘much easier’ with the reusable Respimat than with the disposable Respimat.Patients particularly liked the easily readable dose counter.6

Respimat cartridge

 

 

Figure 4: New cartridge dose counter

Environmental benefits of the re-usable Respimat SMI 

The NHS Long Term Plan for England 20197 has committed the NHS to reducing greenhouse gas emissions from inhalers. Traditional pMDIs use hydrofluoroalkane (HFA) propellants, which have a high global warming potential.

The re-usable Respimat SMI is propellant-free, and, due to its re-usability, is potentially more environmentally friendly. In fact, re-using the inhaler with more than one cartridge further reduces its product carbon footprint (PCF).

These potential environmental benefits were examined in a study which compared the PCF of Respimat with that of pMDIs.8 The PCF looks at the carbon footprint of the product during its life cycle, including production, packaging, usage, and disposal, and is expressed in kg CO2 equivalent (eq). This study found that the PCF of the Respimat was approximately 20 times lower than a pMDI (0.78 kgCO2eq vs. 14.59 kgCO2eq, respectively), mainly due to the lack of propellant in the Respimat, and found a further reduction of 73% in the PCF after 6 months’ use of the re-usable versus disposable Respimat when six cartridges are used with one inhaler (due to the lower carbon impact of using less material in manufacturing the device).8

Use of the re-usable Respimat SMI in clinical practice

International9,10 and national11,12 asthma and COPD guidelines emphasise the importance of inhaler choice and technique linked to outcomes. It is generally acknowledged that there is no one inhaler type that ‘fits all’ and inhaler prescription should be tailored to the individual patient. The National Institute for Health and Care Excellence (NICE) produced a clinical decision aid for patients with asthma to help them and the prescriber to come to a decision on which inhaler to prescribe.13

The key features that a patient is asked to consider are:

  • being able to use the inhaler correctly and easily
  • being able to tell how many doses are left in the inhaler
  • having to clean the inhaler frequently
  • being able to carry the inhaler around
  • that the inhaler has a low carbon footprint.

In line with this, the re-usable Respimat SMI has been shown to have high patient acceptability,1 a distinct cartridge counter, a clear dose indicator,6 and lower carbon footprint compared to pMDIs.8

Instructions on how to use the re-usable Respimat SMI are shown in Figure 5.

How to use Respimat

Figure 5: How to use the re-usable Respimat SMI

Summary

The re-usable Respimat SMI was introduced in the UK in September 2019. It incorporates many of the features of the original Respimat device, which delivers a propellant-free slow-moving, long-lasting soft mist aerosol with improved lung deposition, lower environmental impact, and more time for co-ordinated inhalation with release of drug, than traditional pMDIs. The re-usable inhaler has the additional advantage of an updated design to to improve cartridge exchange and a clearer dose counter.

The ability to use the same device with up to six cartridges increases convenience for the patients and further reduces the environmental impact of inhaler use. 

Conflicts of interest

Kevin Gruffydd-Jones has acted as a consultant and spoken on behalf of GlaxoSmithKline, AstraZeneca, Teva, Napp, Boehringer Ingelheim, Novartis, and Chiesi. He is a member of the NHS England Sustainable Inhaler Committee.

References

  1. Dalby R, Eicher E, Zierenberg B. Development of Respimat® Soft MistTM Inhaler and its clinical utility in respiratory disorders. Med Devices (Auckl) 2011; 4: 145–155.
  2. Boehringer Ingelheim Ltd. Data on file. Pharmaceutical development report for Respimat® ReUsable® 2017; document number: q00240658-01.
  3. Watchel H, Kattenbeck S, Dunne S et al. The Respimat® development story: patient-centered innovation. Pulm Ther 2017; 3: 19–30.
  4. Newman S, Brown J, Steed K et al. Lung Deposition of fenoterol and flunosolide delivered using a novel device for inhaled medicines. Chest 1998; 113: 957–963.
  5. Pitcairn G, Reader S, Pavia D et al. Deposition of corticosteroid aerosol in the human lung by Respimat Soft Mist inhaler compared to deposition by metered dose inhaler or by Turbohaler dry powder inhaler. J Aerosol Med 2005; 18: 264–272.
  6. Dhand R, Eicher J, Hansel M et al. Improving usability and maintaining performance: human-factor and aerosol—performance studies evaluating the new reusable Respimat inhaler. Int J COPD 2019; 14: 509–523.
  7. NHS England. NHS Long Term Plan 2019. Available at: www.longtermplan.nhs.uk (accessed 26 November 2019).
  8. Hänsel M, Bambach T, Wachtel H. Reduced Environmental Impact of the reusable Respimat® Soft MistTM Inhaler compared with pressurised metered-dose inhalers. Adv Ther 2019; doi.org/10.1007/s12325-019-01028-y
  9. Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. 2019 report. Available at: goldcopd.org/gold-reports/ (accessed 26 November 2019).
  10. Global Strategy for Asthma Management and Prevention 2019. Global Initiative for Asthma (GINA) 2019. Available at: www.ginasthma.org (accessed 26 November 2019).
  11. NICE. Chronic obstructive pulmonary disease in over 16s: diagnosis and management. NICE guideline 115. NICE, 2019. Available at: www.nice.org.uk/NG115
  12. British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 158. Available at: www.sign.ac.uk/assets/sign158.pdf (accessed 26 November 2019).
  13. NICE. Asthma: diagnosis, monitoring and chronic asthma management. Tools and resources. NICE guideline 80. NICE, 2017 www.nice.org.uk/ng80/resources (accessed 26 November 2019).
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This supplement has been commissioned and funded by Boehringer Ingelheim Ltd and developed in partnership with Guidelines for Nurses. Boehringer Ingelheim Ltd suggested the topic and author, and carried out full medical approval on all materials to ensure factual accuracy and compliance with the ABPI Code of Practice. The sponsorship fee included an honorarium for the author. The views and opinions of the author are not necessarily those of Boehringer Ingelheim Ltd, or of Guidelines for Nurses, its publisher, advisers, or advertisers. No part of this publication may be reproduced in any form without the permission of the publisher.

PC-GB-100148 V2

Date of preparation: June 2020