Addressing the Problem of Noncompliance With Inhalers By Design: the ‘patient-friendly‘ Approach

Keywords::

• aerosol delivery
• compliance
• ergonomics
• feedback
• inhaler design

The issue of the noncompliant use of oral inhalers by patients has been known about for some time [1]. However, the problem has recently become more prominent [2] following several publications by clinicians, in particular those containing guidance about inhaler selection from the Aerosol Drug Management Improvement Team group in Europe [101]. This expert clinical group has acknowledged that the ability of the patient to use the device properly is critical [3–5]. Inhaler mishandling, which is part of the noncompliance issue, is associated with reduced control of obstructive lung disease [6]. It therefore needs to be treated as a matter of concern by all stakeholders involved in the chain of medication supply to the patient or caregiver. Training the patient and/or caregiver, as well as the prescribing clinician, in the correct inhaler preparation and use is an essential component in the process towards achieving reliable and repeatable medication delivery [5]. However, it appears that by itself, even repeated instruction is insufficient to achieve improved compliance in the long term [7], as there is a tendency for patients or caregivers to forget what they have learned as time elapses since the training event. For example, in the case of pressurized metered dose inhaler (pMDI) use, this situation possibly arises because coordinating inhaler actuation with the desired inhalation maneuver is inherently difficult to master in a long-term reliable fashion. As another example, when a dry powder inhaler (DPI) is prescribed as an alternative to a pMDI, apart from the basic requirements that the patient not blow into the inhaler and be capable of generating adequate inspiratory flow to aerosolize the medication [8], the large variety of designs currently available may make it difficult to develop patient-use practices that are both intuitive and universal [2]. If nebulizer treatment is prescribed, the patient has a largely passive role in the medication-delivery process, merely needing to breathe tidally during the treatment. However, there is the possibility that the device may be misused by removing the mouthpiece from their mouth to hold a conversation or to wander off to some other activity without completing delivery of the intended dose [9]. Despite continuing efforts aimed at the clinician level to address the problem of noncompliance through the publication of best-practice reviews that focus on the advantages and disadvantages of the various inhaler types [10,11], the evidence currently available points to little or no progress having been made with patient compliance [2,12,13]. It is therefore time to re-think how to involve the patient or caregiver more closely in the process of improving the situation.

During the past 10 years, there has been a gradual realization that choosing the inhaler that the patient prefers, rather than the one favored by the clinician, or that is most readily available, should result in better outcomes in terms of long-term correct use in accordance with the manufacturer‘s intentions that are expressed as instructions for use on the patient insert [14]. The underlying logic is simple; get the patient to cooperate from the beginning by involving them in the decision-making process and, therefore, partnering with the prescribing clinician. However, inhaler/add-on device manufacturers can also assist as collaborators in this process. Addressing the principle of patient preference is at the heart of an initiative that is becoming increasingly recognized by inhaler manufacturers as pertinent to the noncompliance problem, resulting in the so-called ‘patient-friendly‘ approach to inhaler/add-on design. Improved ergonomics (patient-handling) are a key component, as ergonomics respond directly to patient-posed questions, such as “can I use it intuitively?” and “am I able to actuate it with my arthritis?” Another highly important component is the incorporation of feedback aids to inform the user/caregiver of the status of their inhaler/add-on. These aids address questions of the type: “how do I know I am getting my medication?” and “is my add-on device working properly?” Such patient-friendly initiatives that aid the patient in the medication delivery process are supported by the more obvious aspects such as size, shape and function, which have been traditionally addressed during the design process. Examples of patient-friendly solutions can readily be given for specific inhaler types. Thus, for pMDI-based therapy, a mechanical device applying additional leverage to depress the medication canister actuating the inhaler could be part of the solution for those with insufficient manual dexterity. However, it is well understood that prescribing a well-designed valved holding chamber, together with the pMDI, will greatly improve medication delivery efficacy for patients with poor inhaler technique who inadvertently delay inhaling their medication when actuating their inhaler. Delayed inhalation may arise from several causes including poor manual dexterity, an underlying chronic disease such as Parkinsonism affecting overall motor skills or simply low cognitive ability [10]. It is perhaps less well known, however, that such add-on devices are now available with an indicator that confirms to the patient/caregiver correct operation of the inhalation valve, a feature that is critical if a facemask is being used [15]. Furthermore, the use of conductive or charge-dissipative antistatic materials in inhaler construction avoids the need for the patent/caregiver to take precautions to mitigate adverse effects on medication delivery efficacy that are caused by the presence of electrostatic charge. Returning to the valved holding chamber example, charge-dissipative, yet transparent polymers are now available to be used in chamber-body construction. This particular improvement in design helps the user or caregiver avoid the need to prewash the device before initial use to eliminate electrostatic charge, yet aerosol-plume development is still visible [16]. Multidose DPIs come with an integral dose counter, yet the same is not always true for pMDIs, especially those marketed outside of the USA where the US FDA has since 2003 provided guidance to manufacturers to include this patient-friendly aid [102]. It is self-evident that the incorporation of a dosage-remaining indicator or counter provides knowledge to the user concerning timely replacement [17]. This improvement obviates the need to resort to inappropriate methods for assessing the medication remaining, such as immersing the pMDI canister in water. It also minimizes the risk of running out of medication altogether, which can be critical in the case of so-called ‘rescue‘ therapeutics used to treat reversible airways diseases.

Moving on to nebulizer-based therapy, the problem of the patient who interrupts treatment part-way through can readily be addressed with a breath-actuated nebulizer that only operates whilst the patient is inhaling [11].

Although it is more difficult to design a low-resistance DPI to disperse the aerosol for effective delivery of medication to the lungs, low-resistance devices may be more easily tolerated by patients with severe chronic obstructive pulmonary disease [18], if not already using a nebulizer.

Further initiatives that are patient friendly can involve improving the visual appearance of the inhaler/add-on device. Although not directly connected with the medication delivery process, this aspect is especially important with young children and adolescents, who may otherwise resist treatment (in the case of toddlers) or simply not use the inhaler at all. Patient instruction leaflets can be designed with font sizes that are readable without optical aids, and the careful use of graphics illustrating the correct use and maintenance of the inhaler/add-on can avoid language-related problems that may exist for users for whom the language of the insert is not their mother tongue.

Finally, it should be noted that this patient-friendly approach to inhaler design can be provided without the need for sophisticated electronics [19] and the associated relatively high cost, making them more likely to be reimbursed by paying authorities, an important consideration for both prescribers and patients.

In conclusion, stakeholders involved with the provision of new drug products and associated devices should give serious consideration to the incorporation of low-cost aids that assist the patient or caregiver through the entire process of taking their inhaled medication, from receipt at the dispensing pharmacy to the time when replacement is required [20].

Financial & competing interests disclosure

The Editorial is written from an inhaled medication device manufacturer‘s perspective. The author is a full-time employee of Trudell Medical International, manufacturer of some of the devices used as examples in the article. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.