Phytopharmacy: An Evidence-Based Guide to Herbal Medicinal Products by Sarah E. Edwards, Inês da Costa Rocha, Elizabeth M. Williamson, and Michael Heinrich. Chichester, UK: Wiley-Blackwell; 2015. Softcover, 403 pages. ISBN: 978-1-118-54356-6. $70.00.
This is a welcome new addition to the modern literature on herbal medicine, written by a prestigious team of authors. It is pitched as a guide for health professionals who are not already converted to the benefits of herbs. All authors are based in pharmacy schools, and the target audience is indicated in the title. The book’s aim is to help people who know little about herbs make better judgments when they encounter patients who are inclined to take them. Included in the audience are “expert patients” (the term is formally used by the National Health Service in the United Kingdom for patients, usually with chronic disease, who are offered more discretion in determining their treatment plan, perhaps as the hub of a network of health professionals).
This last point indicates that the book is clearly directed to a UK audience (which is made clear in the “How to Use” section). There is much in the introduction about the complexities of European regulation of herbs, either as medicines or as food supplements (“botanicals”). Thus, the book’s relevance to readers in other regions is limited. However, it is still an important addition to bookshelves around the world.
The average pharmacist, physician, or nurse in the United States might be surprised that some of these things are considered medicines at all and that many products include official Patient Information Leaflets (PILs). They may also be moderately impressed by the quality of the information available about clinical judgments on the use of these medicines. The authors discuss the use of “phytomedicine” in conventional medical and pharmaceutical practices in mainland Europe as well. Reflecting this for a wider audience is a useful service.
The vast majority of the text is devoted to 115 monographs running from açaí (Euterpe oleracea, Arecaceae) to yohimbe (Pausinystalia johimbe, Rubiaceae), using the common English names as titles. Each monograph opens with a status position at the top right, denoting the medicinal status and the authors’ own rating system of the evidence base. A quick count indicates that just over half of the herbs in the list have medicinal status. Most are “traditional herbal remedies,” meaning the product has been registered in the UK as a traditional herbal medicinal product. (This requires a full pharmaceutical dossier of quality, a full safety assessment and monitoring procedure, and a “traditional use” indication, based on an agreed plausible claim for a self-limiting condition suitable for self-medication that has been applied for at least 30 years). Seven monographs relate to herbs that have been used in fully licensed medicines, an earlier regulatory route for products that could demonstrate evidence of efficacy as well as meet other pharmaceutical requirements.
The rating system goes up to five stars (actually leaves). This top level denotes that the herb is on the UK market with full marketing authorization and has a widely acknowledged evidence base of clinical trials and meta-analyses. There are only five monographs that earn this rating: cannabis (Cannabis sativa, Cannabaceae), which is available in the UK only by prescription; chili/capsicum (Capsicum annuum, Solanaceae); colloidal oatmeal (Avena sativa, Poaceae) as a topical; peppermint (Mentha x piperita, Lamiaceae) leaf oil; and senna (Senna alexandrina, Fabaceae) fruit and leaf.
Monographs with four leaves have “robust” clinical evidence. These are: centella (Centella asiatica, Apiaceae; also called gotu kola) herb; German chamomile (Matricaria chamomilla, Asteraceae) flower; echinacea (Echinacea spp., Asteraceae) herb and root; ginkgo (Ginkgo biloba, Ginkgoaceae) leaf extract; hawthorn (Crataegus monogyna, Rosaceae) leaf, flower, and fruit; horse chestnut (Aesculus hippocastanum, Sapindaceae) seed extract; ispaghula/psyllium (Plantago ovata, Plantaginaceae) seed husk; ivy (Hedera helix, Araliaceae) leaf; kalmegh (Andrographis paniculata, Acanthaceae) herb; lavender (Lavandula spp., Lamiaceae) oil; linseed/flaxseed (Linum usitatissimum, Linaceae); pelargonium (Pelargonium sidoides, Geraniaceae) root; St. John’s wort (Hypericum perforatum, Hypericaceae) herb; and saw palmetto (Serenoa repens, Arecaceae) berry, which downplays the resounding negativity of the latest Cochrane review.1
A remarkable reflection of the idiosyncrasies of the regulatory process is that neither centella nor hawthorn have medicinal status (the latter because there are no agreed upon indications for minor self-limiting conditions suitable for self-medication, since hawthorn is used for cardiac conditions).
Two monographs have a skull-and-crossbones icon denoting an overriding caution: butterbur (Petasites hybridus, Asteraceae), in spite of the fact that there are medicinal products with low-pyrrolizidine alkaloids available across Europe, and graviola (Annona muricata, Annonaceae). Generally, as expected, the default position in the monographs is that if there is little evidence of safety, herbs are not recommended during pregnancy and lactation, and often not for children either.
The monograph structure provides the key headings expected and found in other therapeutic dossiers. With many monographs to cover in a portable reference book, and an audience that is not likely to compound prescriptions for an individual patient, the detail in each monograph is less than in a text designed for herbal practitioners. Similarly, conclusions are based on evidence rather than traditional practice and reputation. In the ginger monograph, for example, the “Indications/Uses” summary hints at the overwhelming worldwide, historical reputation of this remedy for cold-induced respiratory and digestive conditions, but the rest of the monograph focuses on indications (e.g., nausea) based on clinical research and other scientific evidence.
There are also a smaller number of citations than one would see in a European Scientific Cooperative on Phytotherapy (ESCOP) or American Herbal Pharmacopoeia (AHP) monograph. In this text, the many hundreds of possible citations for St. John’s wort have been reduced to 20, for example. However, it seems that the focus is on relevance to this audience and systematic reviews rather than comprehensiveness. Papers are generally up-to-date with the 2013 cut-off for this edition. This is entirely appropriate for the target audience.
It would be helpful in future editions to have an index or two. A list of botanical and drug names would be useful, and, for some in the target audience, it could be helpful to list the evidence ratings and medicinal status. Future editions might also refer to regulatory status outside the UK and Europe, to help broaden the appeal of the text.
- Tacklind J, MacDonald R, Rutks I, Stanke JU, Wilt TJ. Serenoa repens for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews. 2012;12:CD001423. doi: 10.1002/14651858.CD001423.pub3.