<unk>  is a branch of medicine, biology and<unk> aceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism (sometimes the word<unk> acon 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<unk> aceuticals. 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, chemical biology, therapy, and medical applications and antipathogenic capabilities. The two main areas of<unk>  are<unk> acodynamics and<unk> acokinetics.<unk> acodynamics studies the effects of a drug on biological systems, and<unk> acokinetics studies the effects of biological systems on a drug. In broad terms,<unk> acodynamics discusses the chemicals with biological receptors, and<unk> acokinetics discusses the absorption, distribution, metabolism, and excretion (ADME) of chemicals from the biological systems.<unk>  is not synonymous with<unk> acy and the two terms are frequently confused.<unk> , 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,<unk> acy, a health services profession, is concerned with the application of the principles learned from<unk>  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 distinctions between direct-patient care,<unk> acy practice, and the science-oriented research field, driven by<unk> .
Pharmacology
Biochemistry
Toxicology
Cardiophysics
Immunology
Nutritional science
Radionics
Biomarker