Inhaled Respiratory Therapy and Global Warming

INTRODUCTION

It is estimated that the healthcare sector is responsible for the emission of 4.5% of greenhouse gases (GHG), equivalent to approximately 17 million tons of CO₂, contributing directly to global warming and climate crisis(1). There are several elements that influence the carbon footprint within this sector. Among them is the not inconsiderable role of pressurized inhalers using hydrofluorocarbon propellants (HFCs), also known as hydrofluoroalkanes (HFA).

Spain has made a commitment to limit greenhouse gas (GHG) emissions through Law 7/2021, of May 20, 2011, of climate change and energy transition. This law, within the European Union’s Climate and Energy Framework 2021-2030(2), aims to reduce GHG emissions of the Spanish economy as a whole by at least 23% by 2030 compared to 1990 and thus achieve climate neutrality by 2050(3). 

On the other hand, as of January 1, 2025, Regulation (EU) 2024/573 will come into force, which obliges those marketing inhalers containing GHGs to specify on the labeling of their products the information relating to the carbon footprint generated by them(4).

In the field of pharmaceuticals, there are numerous initiatives on the part of the various players in the sector designed to meet these objectives. Thus, in recent years, in the case of inhaled therapy, inhalers have been marketed, such as refillable devices that reduce the amount of waste(5). But, undoubtedly, one of the strategies that will most influence the reduction of GHG emissions is the reduction in the use of pressurized cartridge inhalers (PMDI) and the promotion of the use of dry powder inhalers (DPIs) and soft mist inhalers (FMIs) in the management of respiratory diseases. It has been estimated that a forced change of inhalers can lead to a 76 - 84% reduction in GHG emissions related to PMDI(6).

PMDI are devices characterized by containing the active drug in suspension/solution with a propellant gas. The propellants currently used are from the HFC family, specifically HFA-134a and HFA-227. These gases are characterized by an excellent human safety profile; however, they contribute to global warming, with an atmospheric lifetime of 14.6 and 36.5 years, respectively(7,8). Currently, research is being conducted on new, less polluting HFC propellants that could reduce the carbon footprint by up to 90%, such as HFO-1234ze and HFO-1234yf (both in the preclinical study phase) or HFA-152a, which is already being evaluated in clinical trials (9–13).

Climate change represents a direct threat to the respiratory health of the population, both by aggravating prevalent chronic diseases and by contributing to the emergence of new diagnoses of asthma and chronic obstructive pulmonary disease (COPD), with children and the elderly being particularly vulnerable to these effects(1,14).

OBJECTIVE

To analyze the type and pattern of use of bronchial inhalers in the Galician population during one year, as well as to estimate their impact on the carbon footprint derived from their use.

METHODOLOGY

Contexto y población estudiada

Observational, descriptive and retrospective study conducted in the autonomous community of Galicia between January and December 2023.

Galician patients with pharmaceutical benefits from the Servizo de Galego de Saúde (SERGAS) have been included, which represent 98.4% of the total Galician population according to health card data as of December 2023. Patients receiving treatment with bronchial inhalers for their respiratory pathology were selected and stratified by age to identify the vulnerable population.

The therapeutic groups reviewed were R03A (Adrenergics, inhaled) and R03B (Other agents for obstructive airway conditions, inhaled). These groups include four types of presentations: nebulization ampoules, pressurized metered-dose inhalers, dry powder inhalers, and soft mist inhalers. Additionally, a distinction was made for salbutamol PMDI, as they do not have an alternative format and are widely used for rescue purposes.

Nebulization ampoules were excluded from the analysis due to their particularities, as they are solutions or suspensions that do not contain propellants and are used in clinical practice only in specific cases where the use of other types of inhalation devices is not possible.

Data collection and evaluation of results

A team of pharmacists from the Servizo de Xestión da Prestación Farmacéutica collected, through corporate information systems, the demographic data of Galician users registered with health cards and the number of packages dispensed through medical prescriptions for each type of inhaler during the study period, regardless of their format or prescription setting.

The following descriptive variables were defined:

• Number of inhaler packages (TOTAL INH): includes all inhaler presentations, except for those in nebulizer ampoule format.
• Number of PMDI packages: includes all presentations in the form of pressurized canisters. Within this group, a classification was made according to the type of propellant (HFA-134a, HFA-227).
• Number of DPI packages: includes all presentations in the form of dry powder inhalers.
• Number of SMI packages: includes all presentations in the form of fine mist inhalers.

The carbon footprint was calculated for each clinical name with presentation and format (CDPF). For this purpose, the carbon footprint (kg CO2eq) of each presentation was taken into account using the data published in the reports of PrescQIPP, a non-profit program to support National Health Service (NHS) organizations in improving prescribing(15) and the ECODES report prepared by the Ecology and Development Foundation with the support of the Ministry for Ecological Transition and the Demographic Challenge(16). 

For those specialties that were not included in any of these reports, the availability of this information was consulted with the marketing laboratory. The kg CO₂eq per container was multiplied by the number of containers dispensed during the study period for each presentation. 

The presentations were then grouped by CDPF, thus obtaining the total carbon footprint for each CDPF.

Statistical analysis

The results were analyzed using descriptive statistics. The overall data and the percentage of the analysis population were presented, differentiating the population defined as vulnerable. To calculate the carbon footprint generated, we analyzed (in total number and percentage) the number of inhaler containers and kg CO2eq generated, globally and broken down by type of inhaler (PMDI, DPI, SMI). Within the PMDI, the data were broken down by type of propellant.

RESULTS

In 2023, the Galician population was 2,634,046 (51.96% women), of which 283,562 (10.76%) were under 15 years old and 695,459 (26.4%) were over 64 years old. The number of patients receiving SERGAS pharmaceuticals for treatment with inhaled respiratory therapy was 312,761 (11.87%), including 46,347 under 15 years old and 132,705 over 64 years old.

The population especially vulnerable to the effects of climate change includes these two age groups, which represent 37.16% of the total population and 57.25% of the patients included in the study.

In 2023, a total of 1,711,344 inhaler packages were dispensed to Galician patients with pharmaceutical benefits from SERGAS, equivalent to a carbon footprint of 15,247,142 kg CO2eq. Table 1 provides a breakdown of the number of packages and the calculated carbon footprint in kg CO₂eq for each CDPF.

 

Table 1. Number of Packages and Carbon Footprint by CDPF

Table 1. Number of Packages and Carbon Footprint by CDPF (continued1)

Table 1. Number of Packages and Carbon Footprint by CDPF (continued 2)

Table 1. Number of Packages and Carbon Footprint by CDPF (continued 3)

According to the type of device, out of the total inhaler packages dispensed to Galician patients with pharmaceutical benefits from SERGAS in 2023, 50.94% were DPI, 43.17% were PMDI (including salbutamol presentations), and the remaining 5.89% were SMI, as shown in Table 2.

Regarding the propellant used in ICPs, 90.69% of the dispensed ICP inhalers contain HFA-134a, as shown in Table 3.

 

In Galicia, on 2023, a total of 312,293 packages of salbutamol were dispensed, which represents 46.14% of the carbon footprint attributed to the use of inhalers. Salbutamol packages account for 42.28% of PMDI packages.

Table 2. Number of Packages and Carbon Footprint by Device Type

Table 3. Number of Packages and Carbon Footprint by Type of Propellant in PMDIs

DISCUSSION

One of the most striking findings of this study is that, although PMDI account for only 43.17% of the packages consumed among the Galician population, they are responsible for 95.43% of the total carbon footprint associated with the use of inhalers in Galicia. This result is slightly lower compared to the national figure, as it is estimated that around 52% of inhalers in Spain are ICPs, with an annual average of 15 million units sold, which translates to approximately 400,000 tons of CO₂ emissions annually (1). Published data from some European countries show lower ICP consumption percentages than in Galicia: 13% in Sweden, 20% in Denmark, and Finland. This is because these countries limit the use of ICPs in rescue therapy and for patients who need to use an inhalation chamber (8).

Particularly relevant is the role of salbutamol, a fast-acting bronchodilator widely used as rescue therapy(10,17), which is currently only available in PMDI format. This drug accounts for almost half of the PMDI packs consumed in Galicia and practically half of the carbon footprint attributed to inhalers in this autonomous community. The overuse of salbutamol has a high environmental impact beyond its indisputable therapeutic value. Hence the importance of developing formulations of this drug in another type of less polluting device and thus reducing the carbon footprint.

Another factor to consider is the footprint generated by the device itself, depending on whether it is reusable or whether it is recycled at the point provided for this purpose. In Spain, the authorized system for the collection of medicines for human use is SIGRE, a non-profit organization that guarantees the correct environmental treatment of packaging and leftover medicines of household origin. Although this subject was not analyzed, studies indicate that only 42.9% of people use the SIGRE point at the community pharmacy to dispose of used inhalers or empty cartridges for proper recycling and that only one third of users report having received instructions on how to properly manage used inhalers(10,18,19).

Inhalers are considered non-substitutable drugs, and their choice should be based on clinical factors, such as age and inspiratory flow, patient satisfaction and cost, among others(10,17,20). In fact, some authors consider that appropriateness and clinical criteria should be prioritized at the time of prescription and treatment should be individualized(20). However, numerous studies suggest that opting for more sustainable inhalers is an effective strategy to reduce the carbon footprint of the healthcare system(20-24). Thus, in recent years the concept of “ecoprescribing” has emerged: the incorporation of environmental criteria as another factor to be taken into account in drug selection(19). The involvement of healthcare professionals is necessary for an efficient use of resources, which also includes an environmental perspective. This is evident in the incorporation of recommendations in the main reference guidelines on the management of respiratory diseases, which now include environmental impact as another factor to be taken into account in the choice of inhaler device for the treatment of patients with asthma and COPD. The 2023 GEMA guideline, for example, mentions regarding device type selection “Until these [less polluting HFC propellants] become available, the use of dry powder or mist devices may be preferable in new patients > 6 years or with inspiratory flow > 30 l/min” (10,17,19).

On the other hand, the environmental impact is not only influenced by the type of device and its correct disposal. Treatment optimization, patient education and pharmacotherapeutic adherence are equally important factors that will allow better control of the disease and indirectly influence the footprint generated by the treatment. Good management of the respiratory patient, with optimal treatment and correct adherence, will result in a lower use of drugs by reducing the need for rescue and therefore a lower generation of waste and carbon footprint(19).

For decades, SERGAS has been promoting various strategies to align itself with international practices that prioritize sustainability. In 2023, the Galician Circular Economy Strategy was presented, a document that establishes the roadmap towards a comprehensive healthcare system and in which the circular economy is established as a management model to reduce the environmental impact and ensure the sustainability of the Galician public healthcare system (8,25). It also promotes the training of professionals and patients through the creation of comprehensive care protocols(26) or the renowned patient school (https://escolasaude.sergas.es) with the aim of optimizing treatments and patient adherence. Among the measures directly related to the environmental impact of PMDI, the inclusion of specific circular economy indicators for these treatments in the management agreements (ADX) of the Galician healthcare areas by 2024 and the development of protocols by the Central Autonomous Commission of Pharmacy and Therapeutics (CACFT) to promote a more efficient and sustainable use of inhalers stand out(27).

Among the limitations of this study, it should be noted that only data on inhalers dispensed by prescription to Galician patients with SERGAS pharmaceutical benefits were included, thus leaving out of the analysis approximately 2% of the Galician population, as well as inhaler packages dispensed in hospitals in the autonomous community. On the other hand, 50,572 (2.87%) inhalers were discarded because they did not have a kg CO2eq value, of which 2.6% (n=1,316) corresponded to PMDI. Although these values represent a low percentage compared to the information presented in this study, they should be taken into account when interpreting the results. Likewise, for the calculation of the carbon footprint it has been considered that all the containers are used at 100% of their capacity, which does not reflect the reality with total accuracy, since some inhalers may be discarded before they are completely used up.

CONCLUSION

This study shows the high environmental impact derived from the use of inhalers, mainly PMDI, in Galicia during the year 2023, being the SERGAS pioneer in carrying out a detailed analysis estimating the carbon footprint generated, as well as in implementing circular economy strategies in the health sector.

The transition to more sustainable inhalation devices and the development of new propellants together with the formulation of salbutamol in less polluting devices are essential steps that will reduce the carbon footprint of the healthcare sector.

Given the initiatives promoted in the SERGAS and especially since the inclusion of monitoring indicators related to circular economy from 2024, it would be of interest to carry out further studies to check how these measures impact on the reduction of the carbon footprint emitted by the ICPs.

 

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