Which term refers to how drugs impact the body?

The term that refers to how drugs impact the body is pharmacodynamics. This concept encompasses the study of the effects of a drug on biological systems, including its mechanism of action, the physiological effects it produces, and the relationship between drug concentration and effect. Essentially, pharmacodynamics addresses what the drug does to the body, including interactions with receptors, enzyme systems, and other targets within the organism that lead to therapeutic outcomes or side effects.

Understanding pharmacodynamics is crucial for predicting how a drug will behave and the potential responses in different individuals. This also includes aspects such as the drug's therapeutic window, efficacy, and potency, which are essential for determining appropriate dosages and treatment plans.

In contrast, pharmacokinetics refers to how the body affects a drug, including absorption, distribution, metabolism, and excretion, while metabolism specifically pertains to the biochemical processes that change a drug into a more excretable form. Bioavailability relates to the proportion of a drug that enters the systemic circulation intact, which is an important factor in pharmacokinetics but does not directly address the effects of the drug itself on the body. Thus, pharmacodynamics is the most appropriate term for describing how drugs impact bodily functions.