Definition:
Study of the uptake, movement, binding and interactions of drugs in the body and how they affect drug activity.
Drug activity depends on engagement between a drug and its molecular target. Any factor affecting drug concentration at its target site, strength of binding or duration of binding will affect that drug’s pharmacological activity and clinical responses.
Broadly speaking, pharmacodynamics considers the properties of a drug that affect target engagement in the body, while pharmacokinetics considers the effect of the body on a drug.