Our planet or our patients-is the sky the limit for inhaler choice?

Inhalational Drug Devices: Revisiting the Linchpin of Asthma Management

Asthma remains a prevalent condition among all age groups globally. First-line treatment requires the delivery of medications into the distal respiratory tract via inhalers. Using appropriate inhaler techniques is a significant challenge in achieving disease control. A variety of inhalers are available for treating asthma, and selecting the appropriate inhaler type for any given patient is crucial to achieving and maintaining symptomatic control. This review will discuss the anatomy and physiology behind drug delivery via inhalers, the types of inhalers currently available for use, nebulizers, and future directions in the delivery of inhaled medications for asthma.

Successful Use of Easyhaler® Dry Powder Inhaler in Patients with Chronic Obstructive Pulmonary Disease; Analysis of Peak Inspiratory Flow from Three Clinical Trials

INTRODUCTION

There is increasing pressure to use environmentally friendly dry powder inhalers (DPI) instead of pressurized metered-dose inhalers (pMDI). However, correct inhalation technique is needed for effective inhaler therapy, and there is persistent concern whether patients with chronic obstructive pulmonary disease (COPD) can generate sufficient inspiratory effort to use DPIs successfully. The aims of this study were to find clinical predictors for peak inspiratory flow rate (PIF) and to assess whether patients with COPD had difficulties in generating sufficient PIF with a high resistance DPI.

METHODS

Pooled data of 246 patients with COPD from previous clinical trials was analyzed to find possible predictors of PIF via the DPI Easyhaler (PIFEH) and to assess the proportion of patients able to achieve an inhalation flow rate of 30 l/min, which is needed to use the Easyhaler successfully.

RESULTS

The mean PIF was 56.9 l/min and 99% (243/246) of the study patients achieved a PIF ≥ 30 l/min. A low PIF was associated with female gender and lower forced expiratory volume in 1 s (FEV1), but the association was weak and a statistical model including both only accounted for 18% of the variation seen in PIFEH.

CONCLUSIONS

Based on our results, impaired expiratory lung function or patient characteristics do not predict patients' ability to use DPIs in COPD; 99% of the patients generated sufficient PIFEH for successful dose delivery. Considering the targets for sustainability in health care, this should be addressed as DPIs are a potential option for most patients when choosing the right inhaler for the patient.

TRIAL REGISTRATION

Two of three included trials were registered under numbers NCT04147572 and NCT01424137. Third trial preceded registration platforms and therefore, was not registered.

Metered dose inhalers in the transition to low GWP propellants: what we know and what is missing to make it happen

INTRODUCTION

The urgency to replace the propellants currently in use with the new sustainable ones has given rise to the need for investigation and reformulation of pMDIs.

AREAS COVERED

The reformulation requires in-depth knowledge of the physico-chemical characteristics of the new propellants, which impact the atomization capacity and the plume geometry. Among the investigated propellants, HFA 152a, due to its lower vapor pressure and higher surface tension compared to HFA 134a, deliver larger particles and has a higher solvent capacity toward lipophilic drugs. On the other hand, HFO 1234ze has properties more similar to HFA 134a, but showed lower reproducibility of the generated spray, indicating a possible high susceptibility to variation in the consistency of the dose delivered. In addition, the device components currently in use are compatible with the new propellants. This allowed promising preliminary results in the re-formulation of pMDIs by academia and pharma companies. However, there is little information about the clinical studies required to allow the marketing of these new products.

EXPERT OPINION

Overall, studies conducted so far show that the transition is technically possible, and the main obstacle will be represented by the investment required to put the product on the market.

Environmental impact of inhaler devices on respiratory care: a narrative review

Climate change is a huge and present threat to human health. This article aims to deepen the knowledge about the environmental impact of inhaler devices on their carbon footprint for patients and health professionals, providing information that allows a better choice of the type of device to be prescribed for the treatment of asthma and COPD. This narrative and nonsystematic review was carried out by searching databases (PubMed, Google Scholar, SciELO, and EMBASE) for articles published between 2017 and 2022, written in Portuguese or in English, using the search words "inhalation device" OR "environmental." The review showed that global warming cannot be addressed by focusing only on inhaler devices. However, the devices that we use to treat respiratory diseases such as asthma and COPD, which are diseases that are aggravated by climate change, are also causing that change. Therefore, health professionals, patient organizations, and industries should take a lead in health policies to offer affordable alternatives to inhalers containing hydrofluoroalkane.

Reducing carbon footprint of inhalers: analysis of climate and clinical implications of different scenarios in five European countries

BACKGROUND

Inhaled therapies are key components of asthma and chronic obstructive pulmonary disease (COPD) treatments. Although the use of pressurised metered-dose inhalers (pMDIs) accounts for <0.1% of global greenhouse gas emissions, their contribution to global warming has been debated and efforts are underway to reduce the carbon footprint of pMDIs. Our aim was to establish the extent to which different scenarios led to reductions in greenhouse gas emissions associated with inhaler use, and their clinical implications.

METHODS

We conducted a series of scenario analyses using asthma and COPD inhaler usage data from 2019 to model carbon dioxide equivalent (CO2e) emissions reductions over a 10-year period (2020-2030) in the UK, Italy, France, Germany and Spain: switching propellant-driven pMDIs for propellant-free dry-powder inhalers (DPIs)/soft mist inhalers (SMIs); transitioning to low global warming potential (GWP) propellant (hydrofluoroalkane (HFA)-152a) pMDIs; reducing short-acting β2-agonist (SABA) use; and inhaler recycling.

RESULTS

Transition to low-GWP pMDIs and forced switching to DPI/SMIs (excluding SABA inhalers) would reduce annual CO2e emissions by 68%-84% and 64%-71%, respectively, but with different clinical implications. Emission reductions would be greatest (82%-89%) with transition of both maintenance and SABA inhalers to low-GWP propellant. Only minimising SABA inhaler use would reduce CO2e emissions by 17%-48%. Although significant greenhouse gas emission reductions would be achieved with high rates of end-of-life recycling (81%-87% of the inhalers), transition to a low-GWP propellant would still result in greater reductions.

CONCLUSIONS

While the absolute contribution of pMDIs to global warming is very small, substantial reductions in the carbon footprint of pMDIs can be achieved with transition to low-GWP propellant (HFA-152a) inhalers. This approach outperforms the substitution of pMDIs with DPI/SMIs while preserving patient access and choice, which are essential for optimising treatment and outcomes. These findings require confirmation in independent studies.

Health-care Resource Requirements and Potential Financial Consequences of an Environmentally Driven Switch in Respiratory Inhaler Use in England

Background: To reduce greenhouse gas emissions, national initiatives advocate the phasing down of respiratory inhalers that use a fluorinated gas as a propellant (pressurised metered-dose inhalers [pMDI]). Nevertheless, pMDIs continue to be an effective and common choice. Objective: To assess the potential financial impact of patients with asthma or chronic obstructive pulmonary disease (COPD) switching from pMDIs to dry powder inhalers (DPIs) in a representative primary care network (PCN) population of 50 000 and the English National Health Service (NHS). Methods: Epidemiological data were combined with current inhaler use patterns to estimate the resources and costs associated with this transition, varying patient acceptance scenarios. Results: Depending on the approach, resource requirements ranged from £18 000 - £53 000 for a PCN, and from £21 - £60 million for the English NHS. Discussion: Significant funds are needed to successfully manage targeted inhaler transitions, together with counselling and follow-up appointment with an appropriately skilled clinician to assess the patient's inhaler technique and ensure disease control. Conclusions: Targeted transition of inhalers must achieve a balance between environmental impacts, organisational factors, and patient requirements. The resources for managing a switch can be substantial but are necessary to appropriately counsel and support patients, whilst protecting the environment.

The Impact of Inhaler Device Regimen in Patients with Asthma or COPD

Many inhaler devices with varying handling requirements for optimal use are available for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Patients may be prescribed different device types for reliever and maintenance medications, which may lead to confusion and suboptimal device use. We aimed to understand whether simplifying inhaler regimens by employing a single device type in patients who use multiple devices or prescribing a device with which a patient was already experienced could improve clinical and economic outcomes in asthma and COPD management. A targeted literature search was performed and additional articles were identified through hand searching citations within screened publications. A total of 114 articles were included in the final review. Findings suggest that simplifying inhaler regimens by applying the same type of inhaler for concomitant inhaled medications over time minimizes device misuse, leading to improved clinical outcomes and reduced health care use in patients with asthma or COPD. Physicians should consider a patient's suitability for a device and training needs when prescribing an inhaled medication and before changing the medication type or dose, especially when suboptimal treatment outcomes are observed. Further research is required to determine whether consistent use of the same device type is associated with better treatment adherence and persistence in patients with asthma or COPD. Nevertheless, this literature review identified clinical benefits and reduced health care use with simplified inhaler regimens.

The Climate is Changing for Metered-Dose Inhalers and Action is Needed

Increases in global temperature are already having a significant impact on our climate. The hydrofluorocarbon (HFC) propellants used today in pressurized metered-dose inhalers (pMDIs) have global warming potential (GWP) many times that of carbon dioxide. Their use, together with all other emissive uses of HFCs, is being phased down under the Montreal protocol. This has prompted calls to switch patients to dry powder inhalers (DPIs). This paper presents a new analysis of the top 15 respiratory drug markets by drug class. It shows that a switch to DPIs would be economically feasible for most countries and most drugs. However, a wholesale switch of reliever medications, notably short-acting  β-agonists, would lead to significant increases in the cost of these life-saving medications. Reviewing the evidence, whilst most patients are capable of using DPIs, the very young, very old and those undergoing an acute exacerbation still require a pMDI. Thus, there is a clinical and economic need to have both pMDIs and DPIs available. At the same time, it is projected that the reduction in non-medical uses of propellants is likely to give rise to a 5-fold increase in their cost for pMDI uses and is likely to hit the Western world in 2025. This may lead to a price increase in reliever medication that will make it unaffordable for the poorer communities in some markets. At the same time, opportunities to save money by developing new formulations using propellants with lower GWP, such as HFC 152a or HFO 1234ze(E), are described. Two companies have made this commitment, but neither currently have a strong presence in reliever medication. For them, or other companies, now is the time to act; 2025 is not far away in terms of product development timescales and the climate cannot wait.

Environmental impact of inhalers for respiratory diseases: decreasing the carbon footprint while preserving patient-tailored treatment

Patients with asthma and Chronic Obstructive Respiratory Disease (COPD) rely on three main device classes for inhalation therapy: metered-dose inhalers (MDIs), dry powder inhalers (DPIs) and soft-mist inhalers (SMIs). The carbon footprint (CF) of these inhalers differs with MDIs having a higher impact than DPIs and SMIs due to the propellant in MDIs. However, the certified CF of specific MDI products may differ significantly. MDIs still represent an essential option for many patients. Consequently, novel approaches shall be considered to balance environmental goals with patient health and well-being while maintaining a diverse range of choices for patients and physicians.