Abstract
For a practicing toxicologist, pharmacokinetics or more appropriately toxicokinetics is akin to a foreign language—unless it is used with some degree of regularity the vocabulary, processes, and comprehension get lost in the deep recesses in the practitioner’s mind. Only a few toxicologists use pharmacokinetics on a daily basis since toxicologists are primarily concerned with what xenobiotics do to biologic systems, whereas a pharmacokineticist’s primary focus is what biologic systems do to xenobiotics. Consequently, a small, easy-to-use quick guide reference is an attractive additional option to the toxicologist’s armamentarium. Drug Metabolism and Pharmacokinetics Quick Guide fills that option.
Measuring 12.8 cm wide, 20.3 cm long, and 1.0 cm thick, the quick guide easily fits into a laboratory coat packet, a woman’s purse or even into a trouser hip pocket. The operative word in the title is “quick.” If one is seeking a fundamental text on pharmacokinetics, look elsewhere. If you seek a quick refresher for a pharmacokinetic concept or principle or terse definition of a term, then this book will fill your need.
The book consists of 214 pages distributed among 12 chapters. Approximately half of the book addresses topics specific to pharmacokinetics such as time-course-action, drug-metabolizing enzymes, oral absorption, metabolism-based drug interactions, physiochemical properties that affect pharmacokinetics, and biologic factors that affect rate-related metrics. The remainder of the book addresses peripheral, but important nonetheless, factors that are related to the broad topic of pharmacokinetics: prediction of human pharmacokinetics, in silico tools, approved drugs, and chemical nomenclature.
Written by authors from the pharmaceutical industry gives the book what might appear to be a limited perspective. The toxicologist who practices outside the drug development world only needs to substitute toxicokinetics for pharmacokinetics for the material to have relevance. The authors do commit the sin, which toxicologist have committed freely and often, of using the word “metabolism” to describe both ADME (absorption, distribution, metabolism, and excretion), and biotransformation. However, in a specific context, the reader will not have difficulty determining what the author intended.
Individual chapters in the book are well organized and are consistent among other chapters in the book. The beginning of each chapter has organizational material consisting of an abstract of the chapter contents followed by a chapter outline. Immediately after the outline, there is a section entitled “Abbreviations” which are used in the chapter. The subject matter of each chapter begins with a section entitled “Basic Concepts” which sets the stage of the remaining body of the chapter. At the end of the chapter, there is a reference section which is broken down into “References” and “Additional Reading.” The organizational structure among the chapters validates the operative phrase “quick guide” in the book’s title.
For all of its value, the book does have some, if not flaws, certainly shortcomings. A key component of any educational text is the index, especially one that purports to be a quick reference or guide. Unfortunately, the authors, or maybe the publisher, missed an opportunity to underscore the book’s quick attribute by creating a stellar index. Instead, the index is inadequate for the purpose of being a quick guide. Were it not for the excellent organization and a no-nonsense presentation of the textual material in the chapters, the impoverished index would have been a fatal flaw of the book.
The harshness of the criticism of the index necessitates a specific example. The term “area under the curve” (AUC) is a fundamental concept in pharmacokinetics and is rightly addressed on page 2 as the first item under “1.2.1 basic concepts” in the initial chapter. Yet, the index does not have a specific entry for “AUC” and only one page reference for “area under the curve” which is not page 2, the most important page reference for AUC.
It is surprising that the Additional Reading section of “Chapter 7—Prediction of Human Pharmacokinetics” did not list Drug Metabolism in Man 1 since it is a comprehensive treatise of 773 pages covering many of the topics in Drug Metabolism and Pharmacokinetics Quick Guide. The authors could argue that since the reference is 40 years old, it is not relevant; however, in the Additional Reading section of chapter 1, they cite a 1975 reference, making an age argument moot.
While not a technical flaw or error, there is an example of a disappointing presentation of the book’s content. On page 13 (“Most drugs are orally administered.”) and again on page 47 (“The most common route is the oral route.”), the authors make a strong case for systemic exposure that occurs through oral exposure. To be sure, the oral route of exposure is also an important route for systemic exposure for xenobiotics in products that are not drugs, for example, food additives, drinking water contaminants, consumer products, and so on. Yet, the authors, when describing a 1-compartment model and a 2-compartment model, use examples of intravenous dosing and in the case of the 1-compartment model, they use an additional example of “extravascular dosing.” Surely, the authors could have used examples of oral dosing for explaining compartment models.
The glaring shortcomings of the book rapidly fade into the background due to the book’s organization and presentation. Consequently, the practicing toxicologist will find the book valuable. Furthermore, due to the reasonable cost and its compact size, Drug Metabolism and Pharmacokinetics Quick Guide is a worthy addition to a toxicologist’s personal library. The student toxicologist can also find value in the book similar to the way a student uses Cliffs Notes. 2