Which field studies how a drug moves through the body?

• A. Pharmacokinetics
• B. Pharmacodynamics
• C. IV Therapy
• D. Medication Profile

Answer: (A)

Pharmacokinetics describes how a drug moves through the body, covering absorption, distribution, metabolism, and excretion. This field explains how quickly a drug enters the bloodstream, how it travels to tissues, how the body chemically alters it (often in the liver), and how it is eliminated (typically by the kidneys). These processes determine when the drug starts to work, how long its effects last, and how dosing might need to be adjusted. For example, an orally taken drug may be slowed by stomach pH or food, leading to a later or lower peak effect compared to an IV dose that enters the bloodstream immediately. Pharmacodynamics, on the other hand, is about what the drug does to the body—the mechanism of action and dose–response. IV therapy is simply a route of administration, and a medication profile is a record of what a patient is taking. So the field that studies how a drug moves through the body is pharmacokinetics.