Pharmacokinetics describes what?

• A. What the drug does to the body
• B. The therapeutic uses of a drug
• C. The chemical composition of a drug
• D. What the body does to the drug

Answer: (D)

Pharmacokinetics describes what the body does to a drug, focusing on how the drug is absorbed, distributed, metabolized, and finally excreted (ADME). These processes determine the drug’s concentration in the blood and tissues over time, which in turn controls how fast it starts acting, how strong the effect is, and how long it lasts. For example, how quickly a drug is absorbed affects onset, how widely it spreads to different tissues depends on distribution, how it’s broken down can change its activity, and how it’s eliminated sets the duration of action. This concept is distinct from pharmacodynamics, which looks at what the drug does to the body in terms of effects and mechanisms.