ABSTRACT
The degree of systemic drug exposure determined by plasma drug concentrations provides a critical link for evaluating differences in toxicology between species and therefore in assessing the risk of human exposure. Exposure data are usually presented in a report as the toxicokinetic profile characterizing the concentration of the drug and/or its major metabolites in blood (plasma or serum) or other tissue over time. The toxicokinetic data serve as a surrogate of the dosage given to the animal and constitute a more accurate reference to a biological response than dosage. Thus the focus of the narrative of toxicokinetic data should be on its usefulness in evaluating toxicity data and not on simply describing the rate of change of drug concentration over time.
