Pharmacology
Introduction
Pharmacology is the branch of biology concerned with the study of drug action. A drug can be broadly defined as any man-made, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function.
History
The discipline of pharmacology can be divided into many sub disciplines each with a specific focus. The history of pharmacology dates back to the earliest civilizations where the use of plants with medicinal properties was observed. The first pharmacological experiments were conducted by Avicenna in the 11th century, marking the beginnings of pharmacology as a separate science.
Drug Composition and Properties
Pharmacology studies the effects of drugs and how they can interact with the biological systems of the human body. Drugs can be composed of small molecules, biologics, or complex macromolecules, and are often designed to interact with specific protein targets.
Pharmacodynamics
Pharmacodynamics is the study of how a drug affects an organism, whereas Pharmacokinetics is the study of how the organism affects the drug. Both together influence dosing, benefit, and adverse effects.
Pharmacokinetics
Pharmacokinetics describes how the body affects a specific drug after administration through the mechanisms of absorption and distribution, as well as the chemical changes of the substance in the body (e.g. by metabolic enzymes such as cytochrome P450 or glucuronosyltransferase enzymes), and the effects and routes of excretion of the metabolites of the drug.
Pharmacogenomics
Pharmacogenomics is a form of individualized medicine. Pharmacogenomics looks at how the genetic makeup of an individual affects his/her response to drugs. The term pharmacogenomics is often used interchangeably with pharmacogenetics.
Clinical Pharmacology
Clinical pharmacology is the science of drugs and their clinical use. It is underpinned by the basic science of pharmacology, with an added focus on the application of pharmacological principles and methods in the real world.
Toxicology
Toxicology is the study of the adverse effects, molecular targets, and characterization of drugs or any chemical substance in excess (including those beneficial in lower doses).
Posology
Posology is the study of how medicines are dosed. This depends upon various factors including age, climate, weight, sex, elimination rate of drug, genetic polymorphism and time of administration.
Pharmacognosy
Pharmacognosy is a branch of pharmacology dealing especially with the composition, use, and development of medicinal substances of biological origin and especially medicinal substances obtained from plants.