This book lays out the science of pharmacometrics and its application to drug development, evaluation, and patient pharmacotherapy; providing a comprehensive set of tools for the training and development of pharmacometricians. With key updates, the new edition includes new ideas and concepts while at the same time containing ideas that provide a window into the ever-expanding frontier of pharmacometrics and its continued impact on drug development, regulation, and evaluation. In particular, model-based meta-analysis and modeling unusual data is expanded as these approaches have become much more widely used and warrant detailed treatment. A companion website contains pattern for writing codes and appendices featuring pointers to codes.