Inhalers: Lifesavers for asthma, but hidden environmental threat

In the heart of Nairobi, 12-year-old Amani takes a deep breath, her small hand clutching an inhaler.

As her chest softly wheezes, she presses down on the gadget since her breathing depends on it. She trusts it, just like millions of Kenyans who rely on such devices to keep their airways open while controlling their asthma.

However, unbeknownst to her and many Kenyans, this very tool is contributing to a global problem that threatens the air we all breathe.

According to the Kenya Demographic Health Survey (KDHS) of 2022, approximately 2.5 per cent of Kenyan adults aged 15-49 reported having been diagnosed with asthma. This translates to roughly 500,000 individuals, with the actual number likely higher due to underdiagnosis.

Among children, the prevalence is even more concerning, with estimates suggesting that up to 10 per cent of Kenyan children may be suffering from asthma.

For millions of asthma sufferers worldwide, the distinctive puff of an inhaler represents a lifeline, providing instant relief from constricted airways.

Dr Juma Bwika, a pulmonologist at Aga Khan Hospital, explains the gravity of the situation.

“Asthma is a significant public health concern in Kenya. We’re seeing an increasing number of cases, particularly in urban areas where air pollution is a major trigger.”

While inhalers are lifesavers for asthma patients, they carry a hidden environmental cost.

Dr Bwika explains, “Inhalers are just devices useful in the delivery of drugs into the body. But the gases used to propel the medication, particularly in pressurised metered-dose inhalers (pMDIs), can be harmful to the environment.”

The World Health Organisation (WHO) has raised alarm about the environmental impact of inhalers. According to a 2019 WHO report, a typical inhaler containing the propellant HFA-134a has a carbon footprint equivalent to a 180-mile car journey. With millions of inhalers used globally each year, the cumulative impact is colossal.

The Journal of Allergy and Clinical Immunology: In Practice, published a study in 2020 stating that pMDIs contribute approximately 3.9 per cent of the carbon footprint from the National Health Service in the United Kingdom.

The study stresses that switching to Dry Powder Inhalers (DPIs) could reduce this impact significantly.

Historically, the pulmonologist explains, pMDIs used chlorofluorocarbons (CFCs) as propellants. These were phased out due to their harmful effect on the ozone. “The replacement? Hydrofluoroalkanes (HFAs), which, while better for the ozone, still pack a significant punch in terms of global warming potential.”

The European Respiratory Journal published findings in 2019 indicating that HFA propellants have a global warming potential up to 3,350 times higher than carbon dioxide over a 100-year period. This statistic underscores the urgent need for more environmentally friendly alternatives.

Recognising the environmental impact of their products, pharmaceutical companies are now in a race to develop more eco-friendly alternatives.

AstraZeneca recently announced the completion of clinical studies for a next-generation propellant (NGP) version of its chronic obstructive pulmonary disease (COPD) inhaler, Breztri. This new propellant, HFO-1234ze, boasts a near-zero global warming potential.

“It’s a significant step forward,” Dr Bwika notes. “But it’s important to remember that environmental considerations, while crucial, can’t be our only focus when it comes to patient care.”

The Lancet Respiratory Medicine published a review in 2020 exploring the potential of these new propellants. The review suggests that transitioning to these low global warming potential propellants could reduce the carbon footprint of pMDIs by up to 90 per cent.

For Kenyan asthma patients, the environmental impact of inhalers often takes a backseat to more pressing concerns.

“Our biggest challenge in Kenya is the cost of inhalers,” Dr Bwika says. “The cheapest inhaler probably costs about a thousand shillings, which can last between two weeks and three months, depending on the prescription,” he adds.

This financial barrier often pushes patients towards less effective, and potentially more environmentally harmful alternatives.

“A lot of patients are better off in terms of costs or affordability of going to buy tablets,” Dr Bwika explains. “We, the specialists, really frown on this because they get massive doses which have a lot more side effects.”

When prescribing inhalers, doctors like Dr Bwika must consider multiple factors.

“The first thing I think about is the patient,” he says. “Is this the right molecule, the right combination of drugs for the patient? Can they use it effectively? Do they have access to it?,” he stresses.

Environmental considerations, while important, often come as a secondary or tertiary concern in this decision-making process. “The green agenda is really, really important to us all,” Dr Bwika says. “However, for the prescriber and for the patient, it’s not necessarily the first point that we’ll consider when we are doing the prescription.”

Globally, the healthcare industry accounts for about 4 per cent of greenhouse gas emissions – slightly more than the aviation sector. Inhalers, while a small part of this, represent a tangible and achievable target for reduction.

International regulations, such as the Kigali Amendment to the Montreal Protocol and the EU’s agreement to phase out all consumption of HFCs by 2050, are driving change in the industry. These regulations are pushing pharmaceutical companies to innovate and develop more environmentally friendly alternatives.

The American Journal of Respiratory and Critical Care Medicine published a perspective piece in 2021 calling for a global strategy to reduce the carbon footprint of inhalers. The authors suggest a multi-pronged approach, including the development of low global warming potential propellants, promotion of DPIs that are clinically appropriate, and improved inhaler recycling programs.

While the development of green inhalers is a positive step, Dr Bwika sees an even better solution on the horizon.

“What will be best is the best inhalers manufactured right here in Kenya,” he suggests. “Not only would they be more affordable, but they would be safer for the environment due to reduced transportation emissions, and it would create jobs for Kenyans.”

According to Dr Bwika, no inhalers are currently manufactured locally. However, he notes that some pharmaceutical companies have production lines in East Africa, such as in Uganda, although it’s unclear if these facilities manufacture inhalers.

“In an ideal world, we’ll have all the required molecules available in the various inhaler combinations, which are good and safe for the patient, good and safe for the environment,” he says.