Developing an Ecotoxicological Classification for Frequently Used Drugs in Primary Care

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Pharmaceutical Science

Background:

• Pharmaceuticals excreted by humans enter aquatic systems as they are not fully removed by wastewater treatment.
• Detected concentrations of these drugs in water bodies have shown toxic effects on aquatic species.
• Primary care prescriptions account for a significant portion of overall drug consumption.

Purpose of the Study:

• To develop an ecotoxicity classification for the most frequently sold drugs in Swiss primary care.
• To assess the environmental risk posed by these pharmaceuticals in aquatic ecosystems.
• To guide healthcare professionals towards more environmentally conscious prescribing practices.

Main Methods:

• Combined data from Swiss and European surface water quality monitoring, Swiss primary care drug sales, and API concentrations in Lake Geneva and Vaud rivers (2017-2022).
• Classified 35 Active Pharmaceutical Ingredients (APIs) into five ecotoxicity categories based on their environmental quality standards (EQS) and regulatory watch lists.
• Evaluated ecotoxicological data availability for top-selling primary care drugs.

Main Results:

• Fifteen APIs were classified as safe, eleven as intermediately safe, and nine were identified as of concern due to exceeding EQS or being on watch lists (e.g., carbamazepine, diclofenac, ibuprofen).
• Comprehensive ecotoxicological data were available for only one-third of the most sold primary care drugs.
• Significant environmental impact variations were observed even within the same drug classes.

Conclusions:

• The developed ecotoxicity classification provides a valuable tool for identifying and prioritizing environmentally concerning pharmaceuticals.
• Limited data availability highlights a critical knowledge gap for many widely prescribed medications.
• This classification can support physicians in making informed, eco-friendly prescription choices to mitigate pharmaceutical pollution in aquatic environments.