TABLE OF CONTENTS Toxicodynamics is the study of toxic actions on living systems, including the reactions with and binding to cell constituents, and the biochemical and physiological consequences of these actions. The following chapter is devoted to toxicokinetics. What is the difference between toxicodynamics and toxicokinetics? When your friend drinks a few glasses of whisky and he or she breathes over you the next day with a foul smelling odour, you are dealing with toxicokinetics. The ethanol from the whisky is transformed within the body to acetaldehyde (and later to acetic acid) and this gives a nasty odour. This transformation needs water, and this again leads to the development of a thirst. These phenomena are not in themselves toxic to your friend but are manifestations of toxicokinetics, the way in which the body handles potentially toxic substances.
If your friend continues to drink whisky or other alcoholic beverages excessively on a regular basis, there is a chance that he or she will develop cirrhosis of the liver, a toxic effect. Excessive ethanol injures the liver by blocking the normal metabolism of protein, fats, and carbohydrates. In cirrhosis of the liver, scar tissue replaces normal, healthy tissue, blocking the flow of blood through the organ and preventing it from working as it should. In this situation you are dealing with toxicodynamics, the mechanism by which a toxic effect is produced.
The father of toxicology, Philippus Aureolus Theophrastus Bombastus von Hohenheim (better known as Paracelsus), formulated in early 1538 the...
