This dictionary provides a personal reference source, intended to complement more encyclopaedic works. First, there is an alphabetic, fully cross-indexed listing of pharmacologically active agents and their properties, containing details of some 4000 individual chemical agents including medical drugs in current use, experimental agents and toxins used as investigation tools. Over 10,000 alternative names are indexed, including chemical names, abbreviated chemical names, official pharmacological names, proprietary names and research code numbers. A key feature is that the properties of the agents are categorised, according to mechanism and use, into 300 classes, for each of which there are descriptive articles for which key literature and review references are provided. Second, there is an alphabetical glossary explaining the meaning of some 3000 biomedical terms from pharmacology, biochemistry, molecular biology, immunology, pathology, physiology, anatomy and microbiology. Emphasis in explanation isgiven to terms that can cause confusion, for example those relating to drug receptors and to endogenous mediators.