The Handbook of Clinically Tested Herbal Remedies by Marilyn Barrett, PhD, ed. Binghamton, NY: The Haworth Herbal Press; 2004. 1435 pp (two volumes). ISBN 0-7890-1068-2. $179.95. ABC Catalog #B528.
A few months back I was reviewing a study on the use of the Ginkgo biloba extract EGb 761 for diabetic retinopathy for my Clinical Update column in HerbalGram (subsequently published in issue #66). Struggling to find supporting clinical trials, I turned to a new herbal textbook sent to me in October 2004 by my good friend and pharmacognosist Marilyn Barrett, PhD. The book was an immense help as it directed me not only to trials on retinopathy but also to obscure human pharmacological trials on the effect of ginkgo on retinal blood flow as well as general circulation.
The Handbook of Clinically Tested Herbal Remedies is a guide to over 160 herbal products that have been tested in clinical trials, and it reviews over 360 clinical trials on these products. In addition to 32 single herb products, the two volumes also cover 10 herbal formulas that have been clinically studied as well. Part 1 of the textbook includes introductory chapters on basic fundamentals of herbal medicine such as history and regulation, product characterization, standardization, bioavailability, efficacy, safety, pharmacopoeial monographs, and the motives for conducting clinical studies both in the United States and Europe. In addition to Dr. Barrett, the authors of this section are veritable who’s who of experts in the field of evidence-based herbal medicine, including the late Dr. Varro Tyler; Tieraona Low Dog, MD, of the University of Arizona’s Program for Integrative Medicine; V. Srinivasan of the United States Pharmacopeia; Roy Upton of the American Herbal Pharmacopeia; and Joerg Guenwald, PhD, a leading expert on European phytomedicines and one of the editors of the PDR for Herbal Medicines.
Part II serves as an introduction to the herbal product overviews by describing the method used to gather information on products and trials. This includes an evaluation of clinical trial quality and the guidelines used by reviewers to grade the level of evidence provided by clinical trials on the selected products.
The overview of individual products begins in Part III. For each product section, the following is provided: (1) identification of the preparations used in reviewed clinical trials; (2) a summary table to provide a quick reference to the specific product used, manufacturer, dose, indication, and number of trials; (3) a summary of reviewed clinical trials; (4) adverse events or side effects; and (5) detailed overviews of the product and clinical studies. When available, post marketing surveillance studies, systematic reviews and meta-analyses, epidemiological studies, and information on pharmacopeial monographs are also covered.
The details on the clinical studies include the trial design, inclusion and exclusion criteria, endpoints (outcome variables), results, side effects, and authors’ comments. Also included in this analysis of individual studies are comments by the reviewer assigned for each respective section of the book. Talk about a time saver for those of us seeking detailed clinical information on herbal products!
In addition to the obvious praise due Dr. Barrett, it is important in reviewing The Handbook to acknowledge the companies that kindly shared the clinical studies completed on their products as well as the product specifications. Textbooks such as this one and The ABC Clinical Guide to Herbs, which also provides details as to which specific proprietary phytomedicinal products were employed in many clinical trials, would not have been possible without the cooperation of these manufacturers.
The Handbook has become one of the primary textbooks I refer to when seeking clinical research information on herbal medicines. It is not only an exhaustive overview of safety and efficacy data on key herbal medicines, but also an invaluable guide to which specific commercial products have actually been used in clinical trials—important information for the health care professional or educator trying to sort through the myriad of generic herbal products on store shelves today. Congratulations to Dr. Barrett on the creation of a magnum opus on herbal medicine that is sure to become one of the key references used by medical libraries and health care professionals worldwide.
—Donald J. Brown, ND