What are the two drug-body interactions?

• A. Pharmacology and toxicology
• B. Anatomy and physiology
• C. Chemistry and biochemistry
• D. Pharmacokinetics and pharmacodynamics

Answer: (D)

Two drug-body interactions are pharmacokinetics and pharmacodynamics. Pharmacokinetics describes what the body does to the drug—absorption, distribution, metabolism, and excretion—which helps explain how much drug reaches target tissues, how quickly effects begin, and how long they last. Pharmacodynamics describes what the drug does to the body—its mechanism of action, receptor binding, and the dose–response relationship that governs potency and efficacy. The other options point to fields of study or general sciences, not the two processes that link drug administration to effect. Understanding both PK and PD lets you predict how a drug moves through the body and how it produces its effects.