Pharmacodynamics is the study of the biochemical, physiologic, and molecular effects of drugs on the body
. It involves the interactions between the drug's concentration and its effect, including receptor binding, post-receptor effects, and chemical interactions
. Pharmacodynamics places particular emphasis on dose-response relationships, that is, the relationships between drug concentration and effect
. The concentration of the drug at the receptor site influences the drug’s effect
. Pharmacodynamics is one of the two main branches of pharmacology, the other being pharmacokinetics, which is the study of how the organism affects the drug
. Both together influence dosing, benefit, and adverse effects
