Enantiomerism of medicinal products – a new paradigm in environmental risk assessment

Chiral pharmacologically active compounds (PACs) are
environmental pollutants. They enter the environment mainly through
insufficiently treated sewage, waste effluents from manufacturing
processes, runoff and sludge. They are bioactive, ubiquitous and
persistent with synergistic properties. Surprisingly, the environmental
fate and effects of PACs are assessed without taking into consideration
their enantiomeric forms (this is despite existing knowledge on
enantiomer dependant toxicity of PACs to humans, taking thalidomide
as a flagship example). Such an approach leads to an underestimation of
toxicity of PACs, incorrect environmental risk assessment, and direct
risk to the environment and human health, as PACs are likely to be
present in the environment in their non-racemic forms(in the case of
single enantiomer PACs racemisation in-vivo can also take place). This
presentation aims to discuss: The phenomenon of chirality in the context
of fate and effect of chiral pharmacologically active compounds (PACs)
in the environment Monitoring of several wastewater treatment plants
and receiving waters in the UK to study stereoselective biodegradation
of PACs Stereoselective biodegradation of PACs in river microcosms
Implications of enantiomer-dependant fate of PACs for prodecures
applied in environmental risk assessment