Focus on Alternative and Complementary Therapies
www.pharmpress.com/fact
Focus Alternat Complement Ther©2005 Pharmaceutical Press
Focus Altern Complement Ther 2003; 8: 456
Reviewed by MH Pittler, Exeter, UK
Regardless of whether the conventionally trained physician chooses to incorporate aspects of herbal medicine into clinical practice the fact is that many patients and healthy consumers use herbal products and seem convinced that they improve or maintain health. This patient/consumer-driven popularity of herbal medicine has put pressure on physicians to learn more about the clinical effectiveness and safety of herbal medicines. Mark Blumenthal, founder of the American Botanical Council – a well-respected institution aimed at ‘… promoting the responsible use of herbal medicine’ – has edited this well-referenced guide, which most physicians and other professionals will find useful in their search for reliable information. One interesting feature of this book is the continuing education (CE) credit post-test containing 50 questions. It is designed to meet the CE needs of physicians, naturopaths, dieticians, pharmacists and nurses, and was developed in collaboration with the Texas Medical Association, Southwest Texas University, the Texas Nurses Association and the Texas Pharmacy Association. It includes relatively easy questions such as: ‘In Germany, physicians often prescribe herbal medicines, true or false?’ A more controversial matter is the question in which the student is asked to recommend a herb for an elderly woman with agitation, insomnia and general anxiety disorder and lists kava kava (Piper methysticum) as the single correct answer. Following the ban of P. methysticum because of suspected hepatotoxicity in many countries and given that this book is distributed worldwide, this question should have been removed.
Published and distributed by the American Botanical Council and Thieme this book contains ‘science-based’ information on 29 herbs ranging from bilberry, black cohosh and cat’s claw to saw palmetto, St John’s wort and valerian, as well as 13 proprietary herbal products including Pycnogenol, Mastodynon and Prostagutt. Each herb analysis includes a two-page clinical overview for quick reference, a one-page patient information sheet and a monograph with detailed information on primary and potential uses, dosage, chemistry, pharmacological actions, mechanism of action, contraindication, adverse effects, drug interactions, regulatory status and clinical evidence. The appendix lists common trade names of commercial products tested in clinical trials, company contact information and offers a list of the 37 most popular herbs according to sales figures in the USA.
The strength of this book clearly lies in the data on botanical and pharmacological aspects. This is where the authors feel most comfortable and the relevant sections provide reliable information. In other areas, however, the rigour one would have hoped for in a clinical guide is largely missing. For example, a section where the authors detail the methods used for searching the literature and the inclusion/exclusion criteria used would have been helpful. This means that the reader cannot be certain as to whether all of the relevant literature, positive as well as negative, needed to make a clinical decision was included. While for some herbs (e.g. Crataegus) clinical studies were only included until 1999 (missing RCTs published more recently),1,2 for other herbs (e.g. Ginkgo biloba) trials were included up to 2002. The absence of appraising the evidence according to design, size of the trials and statistical power is one of the reasons why the authors use the phrase ‘science-based’ rather than ‘evidence-based’ when describing the book. These, and other limitations including safety aspects (for example, safety data for use during pregnancy and lactation are largely missing for many herbs; the authors report, in these cases, ‘no known restrictions’) are important to realise when using this book as a clinical guide and it seems sensible to consult other evidence-based approaches when making clinical decisions involving herbal medicines.
