pharmacology

Pharmacology (from Greek φάρμακον, pharmakon, "drug"; and -λογία, -logia) is the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals. The field encompasses drug composition and properties, interactions, toxicology, therapy, and medical applications and antipathogenic capabilities. The two main areas of pharmacology are Pharmacodynamics and Pharmacokinetics. The former studies the effects of the drugs on biological systems, and the latter the effects of biological systems on the drugs. In broad terms, Pharmacodynamics discusses the interactions of chemicals with biological Receptors, and Pharmacokinetics discusses the absorption, distribution, metabolism, and excretion of chemicals from the biological systems. Pharmacology is not synonymous with pharmacy, which is the name used for a profession, though in common usage the two terms are confused at times. Pharmacology deals with how drugs interact within biological systems to affect function. It is the study of drugs, of the reactions of the body and drug on each other, the sources of drugs, their nature, and their properties. In contrast, pharmacy is a biomedical science concerned with preparation, dispensing, dosage, and the safe and effective use of medicines.
Dioscorides' De Materia Medica is often said to be the oldest and most valuable work in the history of pharmacology.[2] The origins of clinical pharmacology date back to the Middle Ages in Avicenna's The Canon of Medicine, Peter of Spain's Commentary on Isaac, and John of St Amand's Commentary on the Antedotary of Nicholas. Clinical pharmacology owes much of its foundation to the work of William Withering. Pharmacology as a scientific discipline did not further advance until the mid-19th century amid the great biomedical resurgence of that period. Before the second half of the nineteenth century, the remarkable potency and specificity of the actions of drugs such as morphine, quinine and digitalis were explained vaguely and with reference to extraordinary chemical powers and affinities to certain organs or tissues. The first pharmacology department was set up by Buchheim in 1847, in recognition of the need to understand how therapeutic drugs and poisons produced their effects
Early pharmacologists focused on natural substances, mainly plant extracts. Pharmacology developed in the 19th century as a biomedical science that applied the principles of scientific experimentation to therapeutic contexts.
Divisions
Clinical pharmacology
The medical field of medication effects on humans
Neuropharmacology
Effects of medication on nervous system functioning.
Psychopharmacology
Effects of medication on the brain; observing changed behaviors of the body and read the effect of drugs on the brain.
Pharmacogenetics
Clinical testing of genetic variation that gives rise to differing response to drugs.
Pharmacogenomics
Application of genomic technologies to new drug discovery and further characterization of older drugs.
Pharmacoepidemiology
Study of effects of drugs in large numbers of people
Toxicology
Theoretical Pharmacology
Study of metrics in Pharmacology
Posology
How medicines are dosed It also depends upon various factors like age, climate, weight, sex etc
Pharmacognosy
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 also known as deriving medicines from plants
Behavioral Pharmacology
Is the study of the effects of drugs on behavior. It includes preclinical and in vivo research, such as small animal and rodent testing used to evaluate behavioral responses to novel drug treatment.
Environmental Pharmacology
Study of Pharmaceuticals and personal care products in the environment
http://en.wikipedia.org/wiki/Pharmacology