Pharmacodynamics and pharmacology are related concepts in the field of medicine, but they are not the same thing.
Pharmacology: Pharmacology is the study of drugs and how they interact with living organisms. It encompasses a broad range of topics related to drugs, including their origins, chemical properties, mechanisms of action, pharmacokinetics (how drugs are absorbed, distributed, metabolized, and excreted by the body), and pharmacodynamics (how drugs exert their effects on the body).
Pharmacodynamics: Pharmacodynamics specifically focuses on the study of the effects of drugs on the body and the mechanisms by which drugs produce their therapeutic or toxic effects. It deals with the relationship between drug concentration at the site of action and the resulting physiological response. In other words, pharmacodynamics examines how drugs interact with specific receptors, enzymes, ion channels, or other molecular targets to produce their effects.
In essence, pharmacodynamics is a subset of pharmacology, concentrating on the mechanisms of drug action and how drugs influence the body's physiology. Pharmacology, on the other hand, encompasses a broader scope, including the study of drug properties, interactions, and their overall effects on living organisms.