4. Search strategies

In the past, the discovery of pharmacologically active molecules for use in medicine was usually either the result of chance observations, or the consequence of laborious screening of a large number of compounds. With the discovery of the three-dimensional structure of the various endogenous ligands, receptors and enzymes involved in the development of certain diseases, not to mention the identification of the metabolic disorders that cause them, it has become possible to initiate more rational and better-targeted avenues of research. Although there is no "magic bullet", four main research strategies leading to the emergence of new therapeutic molecules can be identified in the light of our evolving knowledge.