Pharmacokinetic and Pharmacodynamic Principles for Toxicology.

Pharmacokinetic and pharmacodynamic interactions between drugs and the body play a vital role in the therapeutic effects of drugs as well as their toxicity. Toxic effects may evolve from high doses of drugs or from alterations in the absorption, distribution, metabolism, and excretion of those drugs. The effective dose of a drug is influenced by the initial dose, route of administration, drug formulation, and bioavailability. This effective dose, in conjunction with the frequency of dosing, duration of exposure, and pharmacodynamic variability, directly affects the toxicity experienced in the body.