Human and Veterinary Antibiotics Used in Portugal-A Ranking for Ecosurveillance

Antibiotics represent a pharmacotherapeutic group widely used in both human and veterinary medicine for which ecosurveillance has been continually recommended. It is urgent to rank the antibiotics and highlight those that may pose potential risk to the environment, a key step for the risk management. The absence of this type of contributions applied to the Portuguese reality supported the idea of compiling the data presented herein. With such purpose the most recent and representative data is used to draw a comparative contribution of each antimicrobial classes according to their intended use, i.e., in human versus veterinary medicine. The aim was to assess: (1) the amount and patterns of antimicrobials usage between human and animals; (2) the qualitative comparison between the antimicrobial classes used in each practice (human and veterinary) or specific use; (3) the potential to enter the environment, metabolism, mode of action and environmental occurrences. This manuscript will, thus, identify priorities for the environmental risk assessment, considering the ranking of the antimicrobials by their usage and potential environmental exposure. Ultimately, this study will serve as a basis for future monitoring programs, guiding the policy of regulatory agencies.