[The use of pharmacological criteria in the toxicological evaluation of veterinary drugs]

Abstract

The toxicological evaluation of residues of veterinary drugs in foods of animal origin, which is done within the framework of the Netherlands Veterinary Drugs Act, is based on an EEC guide line in which, in addition to the clinical and analytical criteria, the requirements regarding the pharmacological and toxicological evaluation are laid down. In principle, this evaluation is based on classical toxicological criteria. As veterinary drugs have a specific pharmacological action, it is essential that these pharmacological effects should be in included in the toxicological evaluation in view of an adequate protection of public health. The selected starting point is that a pharmacological effect desired in a target animal is regarded as an undesirable effect in consumers. In this presentation, two examples are referred to, viz. the bèta agonist clenbuterol and the bèta-blocking agent carazolol; the approach is compared with a 'classical' toxicological evaluation. This shows that the acceptable daily intake in human individuals (ADI), based on pharmacological criteria is lower by a factor of approximately 50 than is the ADI on the basis of 'classical' toxicological criteria. This clearly illustrates the value of this approach in protecting the health of consumers.