4 Drug Action and Variability in Response Free Online FlashCards

What does pharmacodynamics describe?

Pharmacodynamics describes what a drug does to the body, including how it interacts with a target and changes a physiological response.

How can pharmacokinetics affect a drug response?

Pharmacokinetics—absorption, distribution, metabolism, and excretion—helps determine how much drug reaches its site of action.

How do affinity and efficacy differ?

Affinity is a drug’s tendency to bind a target; efficacy is its ability, once bound, to produce a response. Binding alone does not ensure activation.

What can a full agonist do at a receptor?

A full agonist binds to a receptor and can produce the system’s full response.

What does drug potency measure?

Potency describes how much drug is needed to produce a specified effect. A more potent drug generally reaches that effect at a lower concentration.

What does a graded dose–response curve measure?

A graded dose–response curve measures the size of an effect as dose or concentration changes.

How do the therapeutic window and therapeutic index differ?

The therapeutic window is the range of exposures expected to provide benefit without unacceptable toxicity. The therapeutic index compares doses associated with toxicity and therapeutic effects in a population.

What kinds of factors can make medication responses vary?

Response variation can affect drug exposure, the body’s response at a given concentration, or both. Factors include genetics, organ function, disease, interactions, administration, tolerance, and individual sensitivity.

What distinguishes a partial agonist from a full agonist?

A partial agonist activates a receptor but produces a smaller maximum response than a full agonist in the same system.

How does a competitive antagonist block an agonist?

A competitive antagonist binds without activating the receptor and prevents an agonist from binding. If binding is reversible, increasing agonist concentration can often overcome the blockade.

What makes an antagonist insurmountable?

A noncompetitive or insurmountable antagonist reduces the response in a way that increasing agonist concentration cannot fully overcome.

How does an inverse agonist differ from a neutral antagonist?

An inverse agonist reduces a receptor’s baseline activity when the receptor is active without an agonist; a neutral antagonist does not change that baseline.