This volume describes the manner in which medicinal chemists utilize the various fields upon which they draw and the specific strategies they employ to advance promising molecules into clinical use for the treatment of disease. The text integrates a number of related scientific disciplines to provide current and comprehensive information on all aspects of drug design and discovery. Extensively revised, new topics in the fourth edition include biostructure-based and ligand-based drug design, chemical biology, natural products, imaging, neurotransmitter transporters, opioid and cannabinoid receptors, hypnotics, neglected diseases, immunomodulating agents, and antibiotics.