Veterinary Pharmaceuticals

Veterinary medicinal products (VMPs) and their metabolites are complex, biologically active molecules, which are produced in large quantities and have a high potential to be released in the environment. During the marketing authorisation procedure of a VMP, a productbased environmental risk assessment (ERA) has to be provided for all new applications, including generics. When a risk to the environment cannot be excluded, the applicant may propose risk mitigation measures (RMMs). The result of the ERA of VMPs is part of the benefit/risk analysis. When the VMP presents a risk to the environment and no RMMs can mitigate this risk, the benefit/risk balance may be negative, resulting in a refusal of marketing authorisation. The potential environmental risk related to its particular use (indication, target animals, administration route, etc.) is just one of the several indicators of the environmental impact of VMPs on the environment. In a more holistic approach, emissions to the environment during the entire lifecycle of VMPs should be considered. Besides this, VMPs can be extremely toxic for non-target organisms and may have long-term effects on ecosystems. For example, antiparasitics (used in aquaculture and for pasture animals), were mainly designed as insecticides and as such are extremely toxic to invertebrates. Because of this extreme toxicity, environmental concerns for this group of compounds cannot be ignored, especially when they are released directly into the environment, as is the case in aquaculture. The effect of antiparasitics such as ivermectin on dung fauna and dung pat degradation has been shown in field experiments. Another group of compounds which have environmental concerns are antimicrobials. Antimicrobials are toxic for phytoplankton and terrestrial plants; however, themain concerns for these compounds are related to the development of antimicrobial resistance in the receiving compartments. Besides these 'expected' effects, non-expected effects may also occur, which are not dealt with within the standard ERA. After the devastating effect of diclofenac-containing VMPs on the vulture populations in South East Asia, public concern was raised on the effects of these VMPs on birds nesting in the European Union (EU). An "ad hoc'' risk assessment in relation to the use of VMPs containing diclofenac in the EU showed that serious effects on populations of vultures and other necrophagous birds cannot be excluded. Several possible risk mitigation measures were proposed (including banning the product). Veterinary medicines have been shown to occur widely in manure and soil, but they also enter ground and surface water. Compared to human medicines, the amount of monitoring data available is very limited. Effects on the environment are formally part of the pharmacovigilance system of veterinary medicines, but it is very unlikely that the effects are detected via this system. Therefore, it is important to review the environmental risk of existing VMPs which were granted marketing authorisation before the ERA guidelines were adopted.