Which term is the study of the mechanism of action of drugs?

Which term is the study of the mechanism of action of drugs?

• A. Pharmacodynamics
• B. Site of Action
• C. Pharmacokinetics
• D. Onset of Action

Answer: (A)

The mechanism by which a drug produces its effects is studied by pharmacodynamics. This field looks at how drugs interact with their targets—such as receptors, enzymes, or ion channels—and how these interactions translate into physiological changes. It encompasses the mechanism of action, receptor binding, dose–response relationships, and the relationship between drug concentration and effect. Why this fits best: pharmacodynamics is specifically about what the drug does to the body and how it achieves its effects at the molecular and cellular levels. In contrast, site of action refers to the location in the body where the drug acts, not how it works; pharmacokinetics deals with what the body does to the drug (absorption, distribution, metabolism, excretion); and onset of action is about the time it takes for effects to begin, not the mechanism itself.

The mechanism by which a drug produces its effects is studied by pharmacodynamics. This field looks at how drugs interact with their targets—such as receptors, enzymes, or ion channels—and how these interactions translate into physiological changes. It encompasses the mechanism of action, receptor binding, dose–response relationships, and the relationship between drug concentration and effect.

Why this fits best: pharmacodynamics is specifically about what the drug does to the body and how it achieves its effects at the molecular and cellular levels. In contrast, site of action refers to the location in the body where the drug acts, not how it works; pharmacokinetics deals with what the body does to the drug (absorption, distribution, metabolism, excretion); and onset of action is about the time it takes for effects to begin, not the mechanism itself.