This is a second edition to the original published by Springer in 2006. The comprehensive volume takes a textbook approach systematically developing the field by starting from linear models and then moving up to generalized linear and non-linear mixed effects models. Since the first edition was published the field has grown considerably in terms of maturity and technicality. The second edition of the book therefore considerably expands with the addition of three new chapters relating to Bayesian models, Generalized linear and nonlinear mixed effects models, and Principles of simulation. In addition, many of the other chapters have been expanded and updated.
This is really the only resource that gives you an in-depth understanding of linear and non-linear mixed effects modeling in the pharmaceutical industry. Most other books just touch on the concept and move on to application. The math can get quite complicated (and often hard to follow), but it's better than most anything else you can find, including the NONMEM user manuals. This book is a great place to start on any aspect of PK/PD modeling; after that, reading the citations in this book will get you the rest of the way.