The new edition of a bestseller, this book covers the principles of chemistry and biology necessary to understand drug action at the cellular level. The book places special emphasis on the chemical and physical properties of drugs, drug absorption and distribution, drug interactions with cellular receptors, drug metabolism and elimination, and the genetic basis for variations in drug response. The book includes revision and updates of chapters. It also includes new material on pharmacogenomics, cancer chemotherapies, and drug-receptor and drug-enzyme interactions.