Structure activity relationship in toxicology.

One of the basic principles of the modern pharmacological research is that there is a close correlation between the chemical structure and the pharmacological effect. In contrast to pharmacology, in toxicology high doses of the drugs are used in order to provoke toxic symptoms generally realized through other receptors than the pharmacological effect. The evaluation of the structure activity relationship (SAR) in toxicology is hindered by the fact that it is not possible to establish in every case that the toxic effect 1. is developed by the original compound or its metabolite(s) 2. is realized through one or more receptors. Furthermore it is necessary to take into consideration that the studies in toxicology are not carried out with so many compounds as the studies in pharmacology and--horrible dictu--the toxicological data are not always public. Thus the prediction of the toxicity of a compound on the base of its chemical structure is difficult, and the prediction whether a new drug is toxic to such an extent that excludes its development, is impossible. What we can do is trying to predict--in the knowledge of the metabolism of the drug--its possible carcinogenic, hepatotoxic, CNS etc. toxic effect.