Venlafaxine and desvenlafaxine to be included in the surface water Watch List

To the Editor

Last August, immersed in the second wave of COVID-19 pandemic, most of us probably missed a milestone in the history of psychopharmacology. For the first time, a psychoactive drug and its metabolite were considered as suitable for inclusion in the next ‘surface water Watch List’ (WL) under the European Union Water Framework Directive: venlafaxine and desvenlafaxine (Gomez Cortes et al., 2020) This WL is a mechanism for obtaining monitoring data on emerging pollutants (including pharmaceuticals) that may pose a significant risk in the European Union (EU) to or via the aquatic environment, but for which available monitoring data are insufficient to draw conclusions. Then, if an environmental risk is confirmed, an Environmental Quality Standard (e.g. a concentration threshold for venlafaxine in wastewater or tap water) might be set at EU level.

Concern about the detrimental effects of pharmaceuticals in the environment is growing worldwide, and especially in Europe, being probably the ‘frontrunner’ in the field of eco-pharmacovigilance. Along with other therapeutic classes, psychoactive drugs are considered a potential hazard for many organisms.

Both venlafaxine and desvenlafaxine are commonly prescribed drugs to treat depression and anxiety disorders. They were designed to act as serotonin and noradrenaline reuptake inhibitors in humans. But as monogenic bioamines are phylogenetically highly conserved, antidepressants can promote adverse effects at the behavioral and physiological levels in non-target animals. More specifically, venlafaxine has shown to affect the behavior, reproduction, development and survival of aquatic invertebrates and vertebrates (Sehonova et al., 2018). Even more worryingly, apart from being frequently detected in different aquatic environments, recent studies have provided compelling evidence that antidepressants (including venlafaxine) can accumulate in biota. One of the most striking examples estimated that platypuses in Australia received as much as half of the human antidepressant dose daily through their insectivorous diet (Richmond et al., 2018).

Thus far, healthcare professionals, including psychiatrists, have largely ignored drug pollution and its consequences. However, we are probably entering into a completely new era in pharmacotherapy, in which the environmental aspects of drugs need to be taken into account. Are we ready now to include One-Health’s philosophy, which considers the interconnection of human, animal and environmental health, in our daily practice? Probably not, but we would better start getting prepared for such a change.