___________ is the pharmacokinetics of a drug under conditions that produce toxicity or excessive exposure.

• A. Pharmacokinetics
• B. Toxicodynamics
• C. Toxicokinetics
• D. Pharmacovigilance

Answer: (C)

When exposure is toxic or excessive, the body’s handling of a drug can change in ways that raise risk. This area is toxicokinetics, which describes how absorption, distribution, metabolism, and excretion behave under conditions that produce toxicity. It explains why high or overdose levels can lead to disproportionately high blood and tissue concentrations—for example, enzyme saturation can slow metabolism, or organ impairment can reduce clearance.

In contrast, pharmacokinetics covers how a drug is processed under normal conditions, toxicodynamics focuses on the harmful effects that result from the drug’s action on the body, and pharmacovigilance is about monitoring safety and adverse reactions after a drug is in use.