time. Adverse drug effects - unwanted effects of a medicine that are typically not noticed by the individual (e.g. a reduction in the white cell count or a change in the serum uric acid concentration) Adverse drug reactions - unwanted effects of the drug that the individual experiences (e.g. a sore throat because of a reduced white cell count or an attack of gout because of an increased serum uric acid concentration) Toxicology - the discipline that deals with the adverse effects of chemicals Drug interactions - the study of how drugs interact with each other. A drug may negatively or positively affect the effects of another drug; drugs can also interact with other agents, such as foods, alcohol, and devices. Drug development - the processes of bringing a new medicine from its discovery to clinical use, usually culminating in some form of clinical trials and marketing authorization applications to country-specific drug regulators, such as the US FDA and the UK's MHRA. Molecular Pharmacology - the discipline of studying drug actions at the molecular level; it is a branch of pharmacology in general. Pharmacogenomics - the study of the human genome in order to understand the ways in which genetic factors determine the actions of medicines. History Medicinal uses of plant and animal resources have been common since prehistoric times. Many countries, such as China, Egypt, and India, have written documentation of many traditional remedies. A few of these remedies are still regarded as helpful today, but most have them have been discarded, because they were ineffective and potentially harmful. For many years, therapeutic practices were based on Hippocratic humoral theory, popularized by the Greek physician Galen (129 – c. AD 216) and not on experimentation. In around the 17th century physicians started to apply use methods to study traditional remedies, although they still lacked methods to test the hypotheses they had about how drugs worked. By the late 18th century and early 19th century, methods of experimental physiology and pharmacology began to be developed by scientists such as François Magendie and his student Claude Bernard. From the late 18th century to the early 20th century, advances were made in chemistry and physiology that laid the foundations needed to understand how drugs act at the tissue and organ levels. The advances that were made at this time gave manufacturers the ability to make and sell medicines that they claimed to