Jane Scullion explores the increasing complexity of the multitude of inhaler devices we have available to us and the therapeutic options they can offer, in the second of a mini-series of feature articles.
Read this article to learn more about:
- inhaler device and therapeutic options available for the treatment of respiratory conditions, including asthma and chronic obstructive pulmonary disease
- selecting the most appropriate inhaler device and therapeutic for an individual patient.
I n a previous article we looked at the development and the distinction between our most commonly used inhalers in the UK; the metered-dose inhaler (MDI) and the less commonly prescribed dry-powder inhaler (DPI).1 Despite the steps for using these inhalers being relatively similar they require different inspiratory flow rates—inhalation should be slow and steady for the MDI and quick and deep for the DPI.2 This article looks at the increasing complexity of the multitude of MDI and DPI devices that are available and the therapeutic options they can offer.
With so many different devices available that have differing functionalities and techniques required for use, it is useful to think about the questions in Box 1 when considering device suitability for patients. It is also important to consider which therapeutic and dose equivalents are compatible for delivery by each device when considering which one to use. This is especially important when considering the administration of inhaled corticosteroids (ICS)—the therapeutic equivalent dose of different ICS varies depending on which device is used.3 The British National Formulary (BNF) provides information on inhaler devices, and the therapeutic options that can be delivered by these for asthma and chronic obstructive pulmonary disease (COPD).4
Box 1: Considerations when choosing an inhaler device
- Is it easy to prepare/load?
- Does it need shaking?
- Is there a dose counter or can you tell easily when the device is empty?
- How many doses does it contain?
- Does the dose counter count down if the person fiddles with the inhaler or is it accurate in terms of doses taken?
- Is it breath actuated or does it need coordination?
- Can you load multiple doses?
- Is there feedback that the dose has been delivered, audible or visual?
- Is there a taste or cold freon effect?
- What inspiratory flow rate do you need?
A number of questions should be asked when selecting an inhaler device to administer a drug for the treatment of a respiratory disorder:
- does the device have a range of therapeutic options?
- what is the licensed dose for each of these for asthma?
- what is the licensed dose for each of these for COPD?
- what are the licensing indications for different age groups?
Many medications are available for the treatment of respiratory disorders, and it is worth bearing in mind that not all of these are administered by inhalation. Those medications that are inhaled, can broadly be divided into two classes—bronchodilators and anti-inflammatory drugs (see Figure 1 below). When considering how to treat a patient, decisions should be made on an individual basis taking into account current guidelines and our own formulary recommendations.4,5,6
Figure 2 illustrates the therapeutic approaches that can be taken in the treatment of asthma and COPD. Similar to the number of devices there are to choose from, there are also many different therapeutics, and combinations of therapeutics, that can be administered using these. For simplicity Figure 2 does not detail the short-acting agents (short-acting muscarinic antagonists, SAMA; short-acting ß2 agonists; SABA)—but these are part of the therapeutic armoury. The drugs featured are indicated for asthma and/or COPD, and in some cases for certain patient populations—the BNF will provide more detail of these, and also of the brand names available for each drug.4
Although there are currently no long-acting muscarinic antagonists (LAMA)/ICS combinations or triple combinations of LAMA/long-acting ß2 agonists (LABA)/ICS, it is likely we will see these developed.7 There are also combined molecules in development combining both LABA and LAMA molecules.8
Prescribing the right device and the right drug
For patients requiring inhaled therapies, we should use the appropriate medication for symptoms while being aware of the availability of other drugs in the same device, device effectiveness, personal technique, inspiratory flow rate, personal experience with the device, cost, and local formularies.9 Some patients, including the elderly and children, may find it difficult to use certain inhaler devices and consideration should be given to this. In terms of prescribing, we should prescribe both the drug and the device.10 Given the growth of generic formulations and new devices it is also recommended that we should prescribe by brand name,4 this prevents the dispensing of inhaler devices that the patient may not have seen before and may not be able to use.
Having considered the right device and therapeutic option to prescribe for an individual patient, as prescribers and those involved in patient teaching we need to be capable of using and demonstrating effective use. Prescribing inhaler devices and associated medications will be an expensive and ineffective option if patients are not taught how to use them correctly.9 As I mentioned in my previous article, the BTS/SIGN British guideline on the management of asthma states that inhalers should only be prescribed to patients once they have received training in the use of the device, and have demonstrated satisfactory technique.1,6 Furthermore, the NICE guideline on Chronic obstructive pulmonary disease in over 16s: diagnosis and management recommends that a patient's ability to use an inhaler should be assessed at regular intervals by a competent healthcare professional with the correct technique being re-taught as necessary.1,5 Asthma UK provides some useful patient information on Using your inhalers including instructional videos on using different types of inhaler devices.11
In the third article in this mini-series Jane Scullion will consider issues specific to adults and children when prescribing inhalers for the treatment of respiratory conditions.
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- Scullion J. Inhalers—do you know your DPIs from your MDIs? Guidelines for Nurses 2015. Available at: www.GuidelinesforNurses.co.uk/inhalers-do-you-know-your-dpis-from-your-mdis (accessed 10 May 2016)
- Simple Steps Education. Inhaler technique—7 steps to success reminder cards. www.simplestepseducation.co.uk
- Barnes N. The properties of inhaled corticosteroids: similarities and differences. Primary Care Respiratory Journal 2007; 16 (3): 149–154.
- Joint Formulary Committee. British National Formulary. 71st ed. Chapter 3, Respiratory system. London: British Medical Association and Royal Pharmaceutical Society, 2016. Available at: www.evidence.nhs.uk/formulary/bnf/current/3-respiratory-system (accessed 10 May 2016)
- National Institute for Health and Care Excellence. Chronic obstructive pulmonary disease in over 16s: diagnosis and management. Clinical Guideline 101. London: NICE, 2010. Available at: www.nice.org.uk/guidance/CG101 (accessed 17 May 2016)
- British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 141. Edinburgh: 2014. Available at: www.sign.ac.uk/pdf/SIGN141.pdf
- Lipworth B. Correspondence: Triple inhaler therapy for COPD. Thorax 2015; 70: 991.
- Cazzola M, Lopez-Campos J, Puente-Maestu L. The MABA approach: a new option to improve bronchodilator therapy. European Respiratory Journal 2013; 42: 885–887.
- Scullion J, Holmes S. Maximising the benefits of inhalation therapy. Practice Nursing 2013; 24 (12): 592–598.
- Booth A. Using an inhaler. Respiratory Care Today 2015; 1 (1): 44–47.
- Asthma UK. Using your inhalers. Available at: www.asthma.org.uk/advice/inhalers-medicines-treatments/using-inhalers/ (accessed 11 May 2016) G