ABSTRACT
Given the proper circumstances, any chemical has the potential for toxicity — i.e., the same dose of a chemical or drug may be harmless if limited to oral exposure but toxic if inhaled or administered parenterally. Thus, the route and site of exposure have a signiÞcant inßuence in determining the toxicity of a substance. More frequently, a therapeutic dose for an adult may be toxic for an infant or child. Similarly, a substance may not exert adverse effects until a critical threshold is achieved. Thus, in order to induce toxicity, it is necessary for the chemical to accumulate in a physiological compartment at a concentration sufÞciently high to reach the threshold value. Finally, repeated administration, over a speciÞc period of time, also determines the potential for toxicity. The following chapter details the circumstances for exposure and dosage of a drug that favor or deter the potential for clinical toxicity.
