Up to 95% of pharmaceuticals used in human and veterinary medicine are excreted and land in the aquatic or terrestrial environment. Most of these substances are degraded with difficulty in the environment, resulting in biological effects on bacteria, plants, and animals. Antibiotics and the development of antibiotic‐resistant bacteria are a special problem. At present, environmental damage due to pharmaceuticals is not yet an acute problem for people and animals. Particularly in the European Union, special measures have been taken to reduce the risk of environmental damage due to drugs.