1. Where do drug residues come from?

1.1 Medicines: composition, uses and after-uses

To understand the presence of drug residues (RoM) in the environment, and more specifically in water and aquatic environments, it is essential to identify the nature and sources of these discharges. The source of these residues is, of course, medicines and their uses. The French Public Health Code (article 5111-1) defines a medicine as "any substance or composition presented as having curative or preventive properties with regard to human or animal diseases, as well as any substance or composition which may be used in or administered to humans or animals, with a view to establishing a medical diagnosis or to restoring, correcting or modifying their physiological functions by exerting a pharmacological, immunological or metabolic action"...