What does ADME stand for in toxicokinetics?

• A. Absorption, Distribution, Metabolism, Excretion.
• B. Activation, Deactivation, Measurement, Elimination.
• C. Absorption, Degradation, Modification, Elimination.
• D. Activation, Distribution, Metabolism, Evaporation.

Answer: (A)

ADME represents the four stages that describe what happens to a chemical after exposure: Absorption, Distribution, Metabolism, Excretion. Absorption is how the compound enters the bloodstream from the exposure site. Distribution refers to its spread through the body's fluids and tissues once in circulation. Metabolism, or biotransformation, is how the body chemically alters the compound, often to make it easier to eliminate. Excretion (elimination) is how the substance is removed from the body, such as in urine, feces, breath, or sweat. These steps together determine the internal dose and timing of any toxic effects. The other options use terms that aren’t the standard components of ADME, such as Activation, Deactivation, Measurement, Degradation, Modification, or Evaporation, so they don’t fit the established framework.