Food Toxicology 2(2+0)

Lesson 4 : General Principles of Toxicology

Potency and toxicity

Potency of a compound is related to its toxicity. A more potent toxicant elicits a toxic response at lower concentrations, and vice versa. The dosages range between the dose producing a lethal effect and the dose not producing a lethal or desired effect. Death is the ultimate extreme in toxicity; however, other effects are possible, from desirable through just undesirable to harmful. Examples can be found with drugs, because drugs have side effects. As a rule, a chemical is a drug if undesirable actions are not significant in comparison with desirable actions. Morphine produces analgesia but also respiratory depression, and antihistamines or penicillin may initiate undesirable immunological actions. Undesirable effects are dose-related too. Thus, in the board view, any adverse effect or potentially undesirable side effect can be used to determine a dose–response curve.