What is the focus of pharmacodynamics?

The focus of pharmacodynamics is to understand how a drug affects an organism. This field examines the biochemical and physiological mechanisms by which drugs exert their effects on the body, including the interactions between drugs and their target sites such as receptors, enzymes, and ion channels. It encompasses the dose-response relationship, therapeutic effects, side effects, and the overall impact of the drug on biological systems.

This understanding is crucial for optimizing drug therapy, as it helps in determining the right dosage, identifying potential side effects, and understanding variations in patient responses due to individual differences in physiology or genetics. While pharmacokinetics, which includes aspects such as the absorption, distribution, metabolism, and excretion of drugs, plays a complementary role, pharmacodynamics specifically focuses on the effects the drugs have once they are administered.