Pharmacology

Pharmacology is the science of drugs and medications, including a substance's origin, composition and interaction with biological systems; specifically through pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. The discipline examines these interactions through pharmacokinetics (what the body does to the drug) and pharmacodynamics (what the drug does to the body), both of which determine how a substance alters normal or abnormal biochemical function. Substances with medicinal properties are classified as pharmaceuticals, while the term drug encompasses any chemical agent that alters biological processes.

The field encompasses drug composition and properties, functions, sources, medicinal chemistry, drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, chemical biology, therapy, medical applications, toxicology, and antipathogenic capabilities. The two main areas of pharmacology are pharmacodynamics and pharmacokinetics. Pharmacodynamics studies the effects of a drug on biological systems, and pharmacokinetics studies the effects of biological systems on a drug. In broad terms, pharmacodynamics discusses the chemicals with biological receptors, and pharmacokinetics discusses the liberation, absorption, distribution, metabolism, and excretion (LADME) of chemicals from the biological systems.

Pharmacology is not synonymous with pharmacy, though the two terms are frequently confused. Pharmacology is a branch of medical and biological sciences which encompasses the research, discovery, and characterization of chemicals exhibiting biological effects, alongside the elucidation of cellular and organismal function in relation to these chemicals. In contrast, pharmacy, a health services profession, is concerned with the application of the principles learned from pharmacology, pharmaceutics, medicinal chemistry, pharmacognosy, clinical pharmacy and others in its clinical settings; whether it be in a dispensing or clinical care role. In either field, the primary contrast between the two is their distinction between direct-patient care, pharmacy practice, and the science-oriented research field, driven by pharmacology.