Chapter 1: Drug Discovery: From Medicinal Plants to Computer-Aided Drug Design

INTRODUCTION

The first edition of Goodman & Gilman, published in 1941, helped to organize the field of pharmacology, giving it intellectual validity and an academic identity. That edition began: “The subject of pharmacology is a broad one and embraces the knowledge of the source, physical and chemical properties, compounding, physiological actions, absorption, fate, and excretion, and therapeutic uses of drugs. A drug may be broadly defined as any chemical agent that affects living protoplasm, and few substances would escape inclusion by this definition.” In practice, of course, a chemical or biological agent is considered a legal drug only if it has been approved as such by a national regulatory agency, such as the U.S. Food and Drug Administration (FDA) or the European Medicines Agency; these approved compounds are the focus of this book.

This first nine chapters of this book, General Principles, provide the underpinnings for these definitions of pharmacology and drugs by exploring the physiological, biochemical, and molecular mechanisms of drug action. This section covers drug invention, development, and regulation, as well as how drugs act in biological systems, i.e., pharmacodynamics, pharmacokinetics (including drug transport and metabolism), the influence of the gastrointestinal microbiome, and pharmacogenetics, with brief forays into pharmacovigilance and drug toxicity and poisoning. Subsequent sections deal with the use of specific classes of drugs as therapeutic agents in human subjects. The present chapter is an introduction to pharmaceuticals, their development, and the activities of the pharmaceutical industry and government surrounding the discovery, production, and use of therapeutic agents. The processes of discovery and invention of drugs have changed substantially with the general progress of biomedical sciences, the advent and improvement of computer-aided drug design, and technical advances in biochemistry and molecular biology. Some of these new capabilities are reviewed below.

ABBREVIATIONS

FROM MEDICINAL PLANTS TO COMPUTER-AIDED DRUG DESIGN

Early Experiences With Plants

The human fascination—and sometimes infatuation—with chemicals that alter biological function is ancient and begins with our long experience with and dependence on plants. Because most plants are root-bound, many produce defensive compounds that animals learn to avoid and humans to exploit or abuse. Thus, the prior of an Arabian convent came to appreciate coffee (caffeine) after noting the ...