Advances in knowledge and technology have revolutionized the process of drug development, making it possible to design drugs for a given target or disease. Building on the foundation laid by the previous three editions, Smith and Williams' "Introduction to the Principles of Drug Design and Action", Fourth Edition includes the latest information on topics such as gene therapy, computer-aided design, and molecular techniques including proteomics. Using real-world examples that illustrate the principles of drug design, the author explores the discovery of lead compounds and their manipulation in the production of non-toxic, metabolically stable drug candidates that will interact with target receptors in a predicted fashion. See what's new in the Fourth Edition: Fully updates and expands the contents; coverage of agonists and antagonists of neuro-transmitters; information on the design of stable peptide-like drugs; the human genome and its impact on drug discovery and development; and advances in therapy and pharmacokinetics. Adopting a from-the-bench-to-the-marketplace approach, the book provides a thorough grounding in rational drug design. It emphasizes principles and elucidates a framework for basic drug design into which current and, more importantly, future drugs will fit.