Query: Pharmacology deals with the development, discovery, and characterization of chemicals which show biological effects.

Relevant passages:
Pharmacology <=SEP=> Pharmacology is the branch of biology concerned with the study of drug action , where a drug can be broadly defined as any man-made , natural , or endogenous ( from within body ) molecule which exerts a biochemical or physiological effect on the cell , tissue , organ , or organism ( sometimes the word pharmacon is used as a term to encompass these endogenous and exogenous bioactive species ) . 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 , synthesis and drug design , molecular and cellular mechanisms , organ/systems mechanisms , signal transduction/cellular communication , molecular diagnostics , interactions , toxicology , chemical biology , therapy , and medical applications 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 absorption , distribution , metabolism , and excretion ( ADME ) of chemicals from the biological systems . Pharmacology is not synonymous with pharmacy and the two terms are frequently confused . Pharmacology , a biomedical science , deals with the research , discovery , and characterization of chemicals which show biological effects and the elucidation of cellular and organismal function in relation to these chemicals . In contrast , pharmacy , a health services profession , is concerned with application of the principles learned from pharmacology in its clinical settings ; whether it be in a dispensing or clinical care role . In either field , the primary contrast between the two are their distinctions between direct-patient care , for pharmacy practice , and the science-oriented research field , driven by pharmacology .   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 Rudolf 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 . Today pharmacologists use genetics , molecular biology , chemistry , and other advanced tools to transform information about molecular mechanisms and targets into therapies directed against disease , defects or pathogens , and create methods for preventative care , diagnostics , and ultimately personalized medicine .