The environmental elephant in the office: medications

Medication optimization

Prescribing fewer medications is the most impactful action for clinicians to decrease the environmental consequences of pharmaceuticals. Medication optimization and deprescribing are often championed in primary care, recognizing that medications can cause patient harm and have high system costs (financial, system efficiency),⁹ but the environmental co-benefits of these practices may not be fully appreciated by providers.

Two common clinical scenarios illustrate the environmental co-benefits of deprescribing: legacy medications,¹⁰ which patients often take for years or decades without regular reassessment of their indication, and the overuse of OTC medications. Both scenarios pose potential risks to patient health and also contribute to substantial environmental harm through pharmaceutical waste and unnecessary resource consumption.

Prescribed legacy medications: specific class examples

Metered-dose inhalers (MDIs) can become a legacy medication when initially prescribed to pediatric patients and subsequently continued into adulthood. They are unique in that they have direct emissions during use, in addition to upstream and downstream emissions. Family physicians have an opportunity to confirm an appropriate diagnosis before prescribing MDIs long term, and to consider switching to less carbon-intensive options.¹¹ In contrast, dry-powder inhalers (DPIs) have superior drug delivery for all patients, except for those with the weakest inspiratory force. They also have a lower carbon dioxide (CO₂) equivalency. It has been estimated that switching 1 patient from an MDI to a propellant-free DPI could save between 150 and 400 kg of carbon emissions per year depending on the frequency of use.¹² One study of 6 primary care practices in Scotland found that in a group prescribed 643 MDIs annually, 104 of 128 patients were suitable for a switch to a DPI, which is equivalent to saving 12,217 kg of CO₂. This is comparable to emissions from travelling around the Earth by plane 4.5 times.¹³

Similarly, proton pump inhibitors (PPIs) should only be taken for several weeks, barring an appropriate clinical indication.¹⁴ In 2012, more than 11 million prescriptions were dispensed to Canadians.¹⁴ Based on the Centre for Sustainable Healthcare carbon emission estimates,¹⁵ PPI prescriptions alone would account for over 1400 tonnes of CO₂ emissions in 2012. This amount could easily be reduced because many patients are prescribed PPIs on a long-term basis without appropriate reconsideration.

Levothyroxine was the most dispensed drug in Canada in 2022, with more than 20.5 million prescriptions.¹⁶ Practice recommendations have concluded that levothyroxine offers no benefit to patients with subclinical hypothyroidism. This approach exposes patients to potential harms, alongside the costs and risks associated with lifelong medication management.^17,18

There is also the impact of medications never used by patients. Up to 50% of patients stop taking their prescribed antihypertensive medications within 1 year of initiation.^19,20 A small 2015 observational study in California found that 2 of every 3 dispensed medications went unused, equating to a projected national cost between $2.4 billion and $5.4 billion (US). The most common prescriptions included pain medications (23.3%), antibiotics (18%), as well as medications for chronic conditions (17%) and mental health (8.3%). These unused medications still shared the upstream environmental impacts but never provided benefits to patients. Moreover, the study cited “throwing medications in the trash” as the most common method of disposal (63%), adding to the environmental burden.²¹

Finally, there are evidence-based approaches to deprescribing medications, such as antidepressants,²² in older patients who no longer have an appropriate indication to continue treatment.

Over-the-counter medications

Over-the-counter medications have similar upstream and downstream environmental impacts as prescribed medications but are rarely addressed in the sustainability sector. These medications are often neither regulated nor consistently measured, making it challenging to accurately quantify their usage. In 2021, the Canadian OTC pharmaceutical market was valued at $3.1 billion²³ and, in 2023, non-prescription drug expenditures in Canada were forecasted to amount to $6.7 billion.²⁴

Concerns regarding the overuse of OTC medications are longstanding. A 2006 survey revealed that 75% of responding Canadian family physicians were worried about the excessive and potentially abusive use of OTC medications within their patient populations.²⁵ In the same survey, 37% of Canadians admitted to taking more than the recommended OTC medication dose (ie, earlier doses, more pills, more than the maximum per day).²⁵ For example, in Canada, there are over 350 non-prescription OTC acetaminophen–containing products on the market, with an estimated 4 billion doses sold annually.²⁶ Each year, approximately 4500 admissions to Canadian hospitals occur due to overdoses of acetaminophen alone,²⁶ which further impacts the environment due to the carbon emissions associated with hospitalization, but this is outside the scope of this article.²⁷

Polypharmacy is also not limited to prescription medications. The 2016-2019 Canadian Health Measures Survey found that Canadians aged 40 to 79 use more non-prescription medications than prescription medications. The effects of polypharmacy are further exacerbated when considering concurrent prescription and OTC product use, with 30.9% of respondents saying they used 2 or more prescription medications in combination with 2 or more non-prescription medications, and 15.8% saying they used 3 or more of each.²⁸

The environmental impact of these OTC medications is similar to that of prescription medications. If society decreased OTC use by 10%, we would save 0.1026 megatonnes of CO₂ (Appendix 1, available from CFPlus*), which is equivalent to the annual energy consumption of 24,028 homes.³

Solutions in the office: practising good medicine in sustainable medicine

Family physicians are likely familiar with the numerous resources available to practitioners from local and national groups with best practice guidelines on identifying, optimizing, and potentially prescribing a medication. To add the environmental sustainability lens to this conversation, prescribers can use the infographic “Options for the Sustainable Prescriber”²⁹ (Figure 3) from the Canadian Coalition for Green Health Care, which is a guide that encourages providers to prescribe in a way to prevent adverse effects, reduce costs to patients, and decrease environmental harms associated with unnecessary medication prescriptions. The guide also highlights the importance of patient-centred discussions, the role of social prescribing, medication optimization and deprescribing, and medication switches.²⁹

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Figure 3.

Options for the sustainable prescriber guide

Family physicians are trusted sources of information. They can review OTCs and medications prescribed outside the country in the office and make informed recommendations using a rational prescribing model.^4,9,30,31 They can recommend discontinuing OTC medications that lack evidence of efficacy, thereby reducing the risk of medication interactions, potential patient harm, and unnecessary costs to the health care system. Addressing the OTC medication problem, which largely originates from sources outside clinics, will require collaboration with pharmacists and other allied health care professionals, alongside broader systemic changes and public education initiatives.