Per capita consumption of pharmaceuticals is increasing globally, but few of us give much thought to the environmental consequences of our ever-increasing reliance on medication.

Between 30 and 90 percent of the active ingredients in pharmaceuticals are excreted unchanged after consumption, and enter the environment via sewage treatment works.

Alongside metabolites and degradation products, they contaminate water and soil, threatening wildlife and human health.

Incorrect disposal of unwanted drugs and pollution from pharmaceutical manufacturing plants further compounds the problem.

‘Benign by design’

The amount of drugs released into the environment is set to increase in the near future due to the expanding and aging global population.

Increasing recognition of this problem is fuelling interest in developing new pharmaceuticals – or re-designing existing ones – to be more environmentally friendly, or ‘benign by design.’

This includes drugs that are better absorbed by the human body, or that biodegrade more rapidly in the environment.

For example, by structurally modifying propranolol – a commonly used and highly persistent beta blocker – researchers have been able to synthesise a derivative that breaks down much more easily in the environment than its parent compound.

Green incentives

Encouraging the pharma industry to adopt greener drug discovery routes and development practices represents a key challenge for the future.

Potential green incentives include patent extensions for environmentally friendly drugs, and medical policies that promote the use of greener drugs over similar compounds that are less environmentally friendly.