Excess drugs are threat to animals and the environment

Pharmaceutical compounds and their breakdown molecules are being found throughout the world’s ecosystems, prompting scientists to call for the industry to implement its own green reforms.

In a comment published in the journal Nature Sustainability, 17 chemists and biologists from across the globe outline the hazards posed by active pharmaceutical ingredients (APIs), and the need for a reformed drug life cycle and sustainable molecule design.

APIs, they say, pose a “major and escalating risk to biodiversity, ecosystem services and public health”. They argue the risk of pharmaceutical contamination is a hazard at the level of other environmental pressures like invasive species, climate change and habitat loss.

“Evidence has been mounting for decades that trace concentrations of pharmaceutical pollutants and their mixtures can cause severe developmental, physiological, morphological, and behavioural changes in wildlife,” says Bob Wong, a behavioural and reproductive ecologist at Monash University and one of the study’s co-authors.

“For example, male fish exposed to estrogens found in the birth control pill exhibit feminisation and reproductive failure, leading to population collapse, while vultures exposed to anti-inflammatory drugs have undergone severe population crashes due to toxic effects.”

According to the researchers, such toxicities can occur at very small levels – parts per million or even billion.

The persistence of ingredients essential for drug delivery is partly due to the body’s effectiveness at disposing of material it doesn’t need. Any compounds surplus to medical need are promptly filtered and excreted by the body.

These chemicals are already out of sight, but after the flush button is pushed, they’re also pumped out of mind.

In the environment though, they have been found throughout plant and animal habitats.

The authors say improving pharmaceutical design – ‘greener’ drugs, in effect – would see products retain their medical benefit while degrading rapidly after excretion by humans or animals. Biodegradation into carbon dioxide and water would result in a lower ecological footprint from the pharmaceutical sector.

This concept of ‘benign by design’ has already been trialled in antibiotic manufacture, but cost, time and patent pressures are barriers to greener pharmacy being embraced.

Still, the authors say incentives beyond environmental concerns could be introduced at the beginning of the drug design process.

Education for prescribers and patients about the sustainability profile of drugs could also help alleviate some of the pressures, say some of the other Monash University scientists who contributed to the report.

“We urgently need to implement strategies to minimise environmental impacts across the entire pharmaceutical life cycle,” says drug discovery biologist Lauren May.

“This includes promoting sustainable prescribing practices, increasing public awareness about the environmental impact of medicines, enhancing wastewater treatment processes, and actively pursuing eco-friendly drug design.”

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