active pharmaceutical ingredients

Prescriptions for Cleaner Waterways

By Pradnya Bhandari

Teetering on the edge of a chair, my six-year-old self roots through the medicine cabinet, pushing aside plastic orange bottles for the gems hidden behind them: my gummy vitamins. My mother immediately asks me to come down, wondering if I had accidently gotten my hand on any of the medicines. Later, I see her pouring pills down the toilet and flushing them away into oblivion.

EPA researchers are studying pharmaceuticals in wastewater to help protect the nation’s waterways. Image courtesy of U.S. Food and Drug Administration.

EPA researchers are studying pharmaceuticals in wastewater to help protect the nation’s waterways. Image courtesy of U.S. Food and Drug Administration.

I’m sure many of us have been in the same situation, left with expired, unwanted prescriptions and pouring them down the sink or flushing them away. Medications pose a threat within the household, especially homes with children, because accidental ingestion can have severe consequences. However, have you ever thought of these discarded drugs as a problem to our environment as well?

In a recently published study, Eco-directed sustainable prescribing: feasibility for reducing water contamination by drugs, EPA scientist Christian Daughton presents ways we can prevent the active ingredients of pharmaceuticals from getting into our waterways. Traditionally, approaches to addressing such water pollution have been limited to waste disposal and wastewater cleanup.

Daughton’s research examines practices that are ultimately responsible for the entry of pharmaceuticals into our waterways, practices that could be altered to reduce or prevent pollution: disposal (like my mom flushing her old medicines when I was a kid), excretion (active drug ingredients your body flushes out instead of deactivation), bathing (which releases topically applied medications and drugs excreted via sweat) or other sources.

Daughton focused his research on the metabolism (deactivation) of active pharmaceutical ingredients and how they impact the environment. He used an existing system that categorizes drugs based on water solubility and intestinal absorption. Using this data, Daughton categorized drugs according to two distinct excretion profiles: (1) drugs that are excreted largely unchanged (and therefore retain their biological activity in the environment) and (2) drugs that are extensively metabolized (transformed usually into chemicals with less activity). He then examined published data on the occurrence of each drug in municipal wastewaters to find that drugs from the second category occur with less frequency and at lower levels.

In his paper, Daughton illustrates how such excretion profiles could be used to develop a healthcare practice called “eco-directed sustainable prescribing.” Understanding how a drug is excreted could help physicians prescribe drugs at lower doses or with less potential to be excreted and reach waterways. This would help reduce pollution and lead to cleaner waters.

For more about EPA research to reduce the amount of pharmaceuticals in the environment, see:

About the Author: Pradnya Bhandari is an intern for the science communications team in EPA’s Office of Research and Development and attends the University of Maryland.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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A Prescription for a Healthier Environment

By Dustin Renwick

Many different colored pillsNext time you’re waiting at the doctor’s office, consider how what is prescribed there could also contribute to the health of the environment.

Christian Daughton, an EPA research scientist, does just that by looking at the connection between the examination room and the expansive beauty of the outdoors in his research paper, Lower-dose prescribing: Minimizing “side effects” of pharmaceuticals on society and the environment.

The paper is a result of his Pathfinder Innovation Project that explores the idea of considering the environment and the patient as one entity.

When someone ingests a drug, not all of it is absorbed. The human body excretes parts of that medication, including active pharmaceutical ingredients (APIs) that often end up in the sewers and eventually disperse into the environment.

The most common methods for reducing APIs in nature is by treating wastewater (remediation) and organizing take-back programs, where people in a community drop off unused medications for proper disposal. For example, National Prescription Drug Take-Back Day occurred in late October.

“My interest has long been on solving the upstream problem – minimizing the generation of waste rather than its more costly remediation,” Daughton says. “That aspect has long been discounted.”

Daughton is now directing his attention to identifying and reducing inefficiencies of pharmaceuticals in health care: how they are prescribed, dispensed, and ultimately used by the patients.

His research points to two major changes that could positively affect the types and quantities of APIs that infiltrate aquatic ecosystems.

First, doctors can focus on doses. Based on patient needs, physicians can prescribe lower doses of pharmaceuticals to prevent leftover drugs as well as decrease the excreted amounts. The strategy could keep the environment cleaner, reduce costs for patients and improve therapeutic outcomes.

“The idea isn’t to benefit environment at the expense of possibly jeopardizing the patient,” Daughton says. ”It’s a win-win for environment and health care.”

A second aspect of Daughton’s research involves tracking reliable data about which APIs are extensively metabolized by the body and which are excreted unchanged.

Imagine two similar drugs. The one that the human body thoroughly processes has what’s called an “environmentally favorable excretion profile,” and that drug is likely to do less damage to the local creek.

Unfortunately, that information isn’t easy to find.

“Excretion data submitted for regulatory approval purposes isn’t sufficiently comprehensive for examining the potential for environmental impact,” Daughton says. In other words, drug companies don’t need to scrutinize an API beyond what is relevant for human safety.

“That becomes a major stumbling block” to discovering which APIs could have negative environmental impacts.

As the topic of health care moves to the forefront of national discussions, Daughton’s work points to the environment as one missing component in those conversations.

“That’s where I get this expression – treating the environment and the patient as an interconnected whole.”

About the author: Dustin Renwick works as part of the innovation team in the EPA Office of Research and Development.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.