Which field studies drug absorption, distribution, metabolism, excretion?

• A. Pharmacodynamics
• B. Toxicology
• C. Pharmacokinetics
• D. Pharmacy Practice

Answer: (C)

The main concept is how the body handles drugs over time, which is pharmacokinetics. It focuses on the four processes collectively known as ADME: absorption (how the drug enters the bloodstream), distribution (how it spreads to tissues), metabolism (how the body chemically modifies the drug, often in the liver), and excretion (how the drug and its metabolites are eliminated, mainly through the kidneys or bile). Understanding pharmacokinetics explains why drug concentrations rise and fall in the body, how long a drug stays active, and how dosing and timing affect therapeutic effect and safety.

Pharmacodynamics, in contrast, describes what the drug does to the body—its effects and mechanisms at the site of action. Toxicology deals with harmful effects, safety, and risk assessment. Pharmacy practice covers the professional aspects of dispensing medications, patient counseling, and clinical workflow.