Pocket Guide to Herbal Medicine E-Book

Karin Kraft

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 597

Veröffentlichungsjahr: 2004

Beschreibung

There is an herbal remedy for most ailments - and you will find the most important ones in this concise pocket guide. Co-authored by Karin Kraft, one of the members of the German Commission E, and Christopher Hobbs, a renowned North-American herbalist, this handy pocket guide gives you the decisive facts about important medicinal herbs, taking into consideration both major European monographs (Commission E and ESCOP) and up-to-date clinical trials. The book goes on to inform the reader on the usage of herbal remedies for a number of common indications.

The book gives first-hand, easy to access information on the administration of herbal remedies for the medical practitioner and herbal therapist alike. Profit from the wealth of German tradition, extended by North American experience in the usage of herbal medicines.

Leseprobe

Library of Congress Cataloging-in-Publication Data is available from the publisher

This book is an authorized and revised translation of the German edition published and cpyrighted 2000 by Georg Thieme Verlag, Stuttgart, Germany. Title of the German edition: Phytotherapie

Translator: Suzyon O'Neal Wandrey, Berlin, Germany

© 2004 Georg Thieme Verlag,Rüdigerstrasse 14, 70469 Stuttgart,Germanyhttp://www.thieme.deThieme New York, 333 Seventh Avenue,New York, NY 10001 USAhttp://www.thieme.com

Cover design: Martina Berge, ErbachTypesetting by Satzpunkt Ewert GmbH,BayreuthPrinted in Germany by Druckhaus Götz,Ludwigsburg

ISBN 3-13-126991-X (GTV)ISBN 1-58890-063-0 (TNY)                                                                                                                                    1 2 3 4 5

Important note: Medicine is an ever-changing science undergoing continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications stated in the book. Every user is requested to examine carefully the manufacturers’ leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage schedule or every form of application used is entirely at the user's own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed.

Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.

This book, including all parts thereof, is legally protected by copyright. Any use, exploitation, or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, mimeographing, preparation of microfilms, and electronic data processing and storage.

Foreword

Traditionally, Western medical knowledge from Graeco-Roman times onward has been transmitted by means of authoritative printed texts. Today, both patient and physician may be more likely to use the Internet as a first reference source. The sheer amount of medical information available on the World Wide Web and the speed of its renewal and retrieval may outpace the Caxtonian mechanics of printed textbook production, but has done little to erode the authority of the printed word. Conversely, in fact, major medical reference texts are these days being “ported” into the memory of hand-held electronic devices or on-line databases. This development, welcomed by gadgetry enthusiasts, eliminates the hefty size and weight of the printed tome, but decreases the legibility and convenience of the printed page as well as undermining the narrative qualities of the traditional medical textbook.

However, another, and only slightly less illustrious tradition has long co-existed with that of the major medical opus. This is the “vade mecum,” literally “go with me,” intended as a portable tome to be kept on hand for immediate reference. To be successful, this format requires authors to possess a high degree of intimacy and fluency with their subject matter, to be able to communicate its essentials with precision and confidence, compacting prose and condensing content without sacrificing narrative. The size of the resultant printed volume must be compact enough to make it easily portable, which nowadays translates as “pocket guide.”

The present pocket guide is a medical vade mecum devoted specifically to the field of phytotherapy (herbal medicine), authored by the German physician and phytotherapist Karin Kraft. Prof. Kraft is a member of the Commission E (the official expert committee which originally considered the safety and efficacy of phyto-medicines in Germany), and is currently a member of the supervising editorial board of ESCOP (European Scientific Cooperative on Phytotherapy). ESCOP produces the scientific monographs that provide the official core data for herbal medicines in the EU.

In Germany, phytotherapy enjoys a higher degree of integration into general medical practice than in any other European country, with physicians regularly writing millions of prescriptions for approved phytomedicines on a daily basis. In the original German edition of this pocket guide, Prof. Kraft provides the busy-general practitioner with a compact and practical reference guide that includes a materia medica of herbs, a prescriber for many conditions, and extensive data on dosage, forms of administration, safety data and technical standards for German commercial herbal products. (Special mention should made of Prof. Kraft's inclusion of an often neglected area, that of topical applications of herbal medications such as poultices and compresses, more popular in Europe than in the USA).

In North America, herbal medicine is a more marginal discipline, ultimately the legacy of a period of political opposition between medical factions at the turn of the 19th century which resulted in the effective outlawing of botanical medical practice following the Flexner Report of 1910. Although the majority of “official” medicines in the United States Pharmacopoeia were originally botanicals or botanically derived, there remains a sharp discontinuity between standard practice medicine today and its botanical past. The once widespread schools of physio-medical and eclectic botanical medicine were preserved partly through their migration to the United Kingdom, where an unbroken tradition today enables qualified British medical herbalists to diagnose and treat conditions with phyto-medicines, alongside their conventional medical colleagues. The British model is distinct again from the German experience and emphasizes the importance of understanding different cultural and national expressions of traditional herbal medicine, education, and practice.

Sensitive to such cultural variations, Thieme wisely enlisted the aid of Christopher Hobbs, a fourth-generation American herbalist, to help render the translation of Prof. Kraft's German text into the US cultural context. Hobbs, one of the most highly regarded herbal practitioners in the US, addressed this challenging task by reviewing every line of the text. Hobbs has replaced some herbs in the materia medica, suggested more appropriate local equivalents for herbal products, and annotated bi-cultural comments where relevant. He has also rewritten doses into the typically higher US forms. Meanwhile, Hobbs has deftly preserved the nuances of the German text; Prof. Kraft actively participated in, and agreed to, all the changes. The result of this bi-cultural collaboration is an almost seamless representation of the German original harmonized to the North American audience.

As more physicians in this country recognize the need to investigate the CAM (complementary and alternative medicine) modalities that are being espoused by many of their patients, a premium is inevitably placed upon reliable sources of data and clinical information about CAM. Botanical medicines in particular have sadly been the subject of excessive amounts of published secondary and tertiary “information” devoid of clinical context, and largely irrelevant to the primary care provider. By contrast, Karin Kraft and Christopher Hobbs present us with a succinct and authoritative survey of herbal medicine that is accessible to the physician and can readily be applied to everyday clinical practice. The “pocket guide” represents a unique cross-cultural and trans-disciplinary blend of reliable, accurate, and accessible information about phytotherapy; it is a mini-masterpiece of integrative medicine.

March 2004

Jonathan TreasureMedical HerbalistAshland, Oregon, USA

Preface

The use of medicinal plants to treat everyday complaints and illnesses is becoming ever more popular. This pocket guide is aimed not only at doctors and members of the various healing professions interested in phytotherapy, but also in particular at interested lay people, for whom this book is intended as a practical guide in the often confusing self-treatment market. This pocket guide is based on experiences and prescriptions that have been used in Germany for many years or even decades. If necessary, they have been supplemented by US-American remedies and suggestions for use. Where possible, available scientific literature has also been taken into account. The book includes the medicinal plants most widely used in Germany, almost all of which are also used in the US, as well as their use in the treatment of major syndromes. A general section in which production processes, quality characteristics, and legal backgrounds are explained is followed by portraits of the most important medicinal plants with references to more recent scientific literature. Illnesses and possibilities of treating them with medicinal plant preparations as well as a critical evaluation of the significance of this therapy make up the next section. A specialty of this checklist is the section “Care Involving Medicinal Plants.” Here special value was attached to practicability. A tabular section divided up into medicinal plants with brief summaries of remedies and references follows. Contact addresses and lists of manufacturers as well as a comprehensive table of contents round off the guide.

Ms Angelika-M. Findgott from Thieme International has done a first-class job of coordinating the work of both authors and editing the manuscripts. We, the authors, know that we echo her sentiments in wishing that this pocket guide will be a practical aid to all those who are interested in using medicinal plants and will contribute to the alleviation and curing of illnesses and complaints.

Rostock in Spring 2004

Karin Kraft

Contents

Gray Section: Fundamentals of Phytotherapy

1    Fundamentals of Phytotherapy

1.1 Characteristics and Status of Herbal Medicines

1.2 From the Plant to the Remedy

1.3 Constituents and Active Principles

1.4 Herbal Formulations

1.5 Prescribing Herbal Medicines

1.6 Determination of Doses

2    General Guidelines for Use of Herbal Medicines

2.1 Potentials and Limitations

2.2 Special Patient Groups

2.3 Basics of Administering Herbal Preparations

2.4 Working Techniques

Green Section: Plant Summaries

3    Medical Plants from A to Z

Plant Summaries—A

Plant Summaries—B

Plant Summaries—C

Plant Summaries—D

Plant Summaries—E

Plant Summaries—F

Plant Summaries—G

Plant Summaries—H

Plant Summaries—I, J

Plant Summaries—K

Plant Summaries—L

Plant Summaries—M

Plant Summaries—N

Plant Summaries—O

Plant Summaries—P

Plant Summaries—R

Plant Summaries—S

Plant Summaries—T

Plant Summaries—U

Plant Summaries—V

Plant Summaries—W

Plant Summaries—Y

Blue Section: Herbal Treatment of Diseases

4    Cardiovascular Diseases

4.1 Heart Failure

4.2 Coronary Artery Disease

4.3 Functional Heart Disorders

4.4 Hypertension

4.5 Hypotension

4.6 Circulatory Disorders

4.7 Vertigo and Tinnitus

4.8 Dementia

4.9 Atherosclerosis

4.10 Chronic Venous Insufficiency (Varicose Veins)

5    Respiratory Diseases

5.1 Diseases of the Nose and Nasal Sinuses

5.2 Colds and Flu

5.3 Bronchitis

5.4 Symptomatic Cough

6    Diseases and Dysfunctions of the Digestive Organs

6.1 Diseases of the Mouth and Throat

6.2 Anorexia

6.3 Reflux, Gastritis, Gastroduodenal Ulcers, Dyspepsia

6.4 Dyspeptic Syndrome

6.5 Chronic Hepatitis and Cirrhosis of the Liver

6.6 Diseases of the Gallbladder and Biliary Tract

6.7 Diseases of the Rectum and Colon

6.8 Acute and Chronic Diarrhea

6.9 Irritable Bowel Syndrome

6.10 Constipation and Colonic Diverticulosis (Acquired)

7    Diseases of the Urogenital Tract

7.1 Urinary Tract Infections

7.2 Dysuria

7.3 Irritable Bladder

7.4 Urolithiasis

7.5 Benign Prostatic Hyperplasia

8    Diseases and Disorders of the Nervous System

8.1 Sleep Disorders

8.2 Nervous Anxiety, Tension, and Unease

8.3 Psychovegetative Syndrome

8.4 Depression and Mood Swings

8.5 Primary Headache Disorders

9    Debility, Fatigue, Adaprive and Functional Disorders

9.1 Non-age-related Debility

9.2 Adaptive and Functional Disorders of Aging

10    Immunodeficiency Diseases

10.1 Conditions Related to Acquired Immunodeficiency

10.2 Cancer

11    Rheumatic Diseases

11.1 Rheumatism and Pain

11.2 Gout

12    Gynecological Diseases

12.1 Disturbances of the Menstrual Cycle

12.2 Premenstrual Syndrome (PMS)

12.3 Dysmenorrhea

12.4 Menopausal Complaints

13    Pediatric Diseases

13.1 Introduction

13.2 Acute Febrile Infections

13.3 Mouth and Throat Inflammations

13.4 Respiratory Tract Diseases

13.5 Gastrointestinal Diseases

13.6 Urinary Tract Diseases

13.7 Psychogenic Disorders

13.8 Dermatological Diseases

14    Dermatological Diseases

14.1 Psoriasis

14.2 Eczema

14.3 Atopic Dermatitis (Neurodermatitis)

14.4 Acne and Seborrhea

14.5 Furuncles (Boils)

14.6 Hair Loss (Effluvium)

14.7 Itching (Pruritus)

14.8 Excessive Perspiration (Hyperhidrosis)

15    Open Wounds and Blunt Traumas

15.1 Wounds

15.2 Blunt Traumas and latrogenic Wounds

15.3 Leg Ulceration

Red Section: Practical Applications

16    Herbal Hydrotherapy (Balneotherapy)

16.1 Fundamentals of Hydrotherapy

16.2 Colds and Flu

16.3 Circulatory Disorders

16.4 Nervousness and Sleep Disorders

16.5 Rheumatic Pain

16.6 Inflammatory Skin Diseases

17    Standard Treatments for Cardiovascular Diseases

17.1 Arnica Wrap for Heart Ailments

17.2 Invigorating Rosemary Whole-Body Wash

18    Standard Treatments for Respiratory Diseases

18.1 Flaxseed Poultice for Sinusitis

18.2 Horseradish Poultice

18.3 Thyme Oil Compress

18.4 Thyme Chest Wrap

18.5 Mustard Wrap

19    Standard Treatments for Gastrointestinal Disorders

19.1 Hot Stomach Wrap

19.2 Hot Chamomile Wrap

19.3 Fennel Oil Wrap

19.4 Hot Yarrow Wrap

20    Standard Treatments for Urinary Diseases

20.1 Eucalyptus Oil Compress

20.2 Horseradish Poultice

21    Standard Treatments for Nervous Disorders

21.1 Mood-Enhancing Stomach Wrap

21.2 Lavender Oil Chest Compress

21.3 Lavender Oil Whole-Body Wash

22    Standard Treatments for Rheumatic and Systemic Diseases

22.1 Grass Flower Pillow

22.2 Ginger Wrap

22.3 Arnica Joint Wrap

23    Standard Treatments for Pediatric Diseases

23.1 Arnica Pulse Wrap

23.2 Mustard Powder Footbath

23.3 Lemon Neck Wrap

23.4 Fever-Reducing Whole-Body Peppermint Wash

24    Standard Treatments for Skin Diseases and Wounds

24.1 Ringer–Calendula Mixture for Wet Dressings

24.2 Ringer–Calendula Dressing for Deep Wounds

24.3 Rhatany Tincture for Wound Treatment

24.4 Arnica Wrap for Soft-Tissue Swelling

24.5 Whole-Body Wash with Heartsease Infusion

24.6 White Cabbage Compress

24.7 Egg Yolk Hair Mask

24.8 Revitalizing Hair Mask

Appendix: Glossaries, Dosages, Addresses, References, and Index

25 Herbal Oils for Musculoskeletal Diseases

26    Plant Glossaries

26.1 Latin–English Plant Glossary

26.2 English–Latin Plant Glossary

27 Dosages

28    Addresses

28.1 Professional Organizations

28.2 Suppliers

29    References and Resources

29.1 Literature

29.2 Interesting Web Sites

Index

1 Fundamentals of Phytotherapy

1.1 Characteristics and Status of Herbal Medicines

Preliminary Remarks

Herbal medicine is a scientifically recognized complementary and alternative treatment method with proven efficacy.

In North America, herbal remedies are considered dietary supplements by law and are considered safe unless proven otherwise. Manufacturing standards are not as stringent as required for pharmaceutical drugs. While only a few “structure and function” claims (such as “benefits digestion”) can be made by manufacturers, many work around that limitation by making extensive use of “third-party” advertising in magazines and through company representatives.

In Germany, herbal remedies are defined as medicinal products by German Drug Law.

German legislators regard herbs and herbal remedies as medicinal products with specific pharmaceutical characteristics. Together with homeopathic and anthroposophic medicines, herbal medicines are classified as drugs of a special system of therapeutics.

According to German law, every physician must be knowledgeable about herbal medicine. North American physicians are not required to have this training, and few classes are offered in herbs or natural medicine in medical school.

The public interest in alternative therapies for general health maintenance and supportive treatment of chronic diseases has increased tremendously.

Distinctions Between the Different Types of Therapeutic Preparations

Herbal products: One of the main distinguishing features of herbal preparations is their complex chemical composition.

Chemical or synthetic drugs: Chemically defined drugs in general contain precisely definable quantities of usually one particular active ingredient and also accompanying substances.

Homeopathic remedies: Homeopathic products are prepared according to special formulation techniques and are prescribed according to the principles introduced by Samuel Hahnemann in the early nineteenth century. His “Law of Similars” states that the remedy prescribed, in a more or less highly diluted form, to cure a given condition or disease should be a substance that induces similar symptoms in healthy individuals when given in much higher amounts.

Anthroposophic remedies: Anthroposophic remedies are prepared according to the ideas and teachings of Rudolf Steiner.

Definitions

Herbal medicine: A time-honored system of healing practiced in every culture in the world. Science has modernized the system using analytical and pharmaceutical testing. The science-based practice of herbal medicine is now called phytomedicine or phytotherapy, which is a system of therapeutics in which diseases and disorders are treated with medicinal plants and preparations made from them using scientific principles.

Medicinal herbs: Medicinal products whose active ingredients consist exclusively of medicinal plants and preparations made from them. Using modern chemical and pharmaceutical methods, a number of popular herbal remedies are nowadays “standardized” to provide consistent levels of proven identified active compounds.

Phytochemistry: The study of plant chemistry, including the identification, isolation, analysis, and characterization of plant constituents, and determination of the chemical structures of plant constituents.

Pharmaceutical biology: The field of research concerned with the extraction and development of biogenic drugs from plants and other living organisms as well as the processing and application of these drugs.

Phytopharmacology: The study of the uptake, distribution, and effect of herbal preparations and of their elimination from the body.

Active principles: Substances or substance groups definable by chemical analysis that essentially contribute to the therapeutic action of a medicinal herbal preparation.

Active ingredients of medicinal herbal preparations: Plant ingredients in their natural states and preparations made from them.

Minor constituents: Substances that have an indirect or slight effect on the therapeutic action of an herbal drug.

Single-herb herbal preparation: Herbal medicinal preparation from one medicinal plant.

Target constituents: Herbal drug preparation constituents definable by chemical analysis that are used as parameters of in-process quality control and may contribute to a characteristic pharmaceutical property.

Species, genus, family: Taxonomic terms classifying a plant. A genus may include one or more species, and a family may include one or more genera.

Research on Herbal Remedies: State of the Art

Remarkable advances in phytotherapeutic research have been made within the past 15 years.

The worldwide interest in herbal drug research is steadily increasing.

– Collaboration between universities, the dietary supplement and herbal industry, and the pharmaceutical industry is essential to promote the success of this research. In North America, government funding of human studies on the efficacy and safety of herbal preparations is just beginning.

– Comparable to research on chemically defined drugs, research on herbal preparations is also carried out using molecular biological, pharmacological, and clinical techniques of investigation.

– The findings of herbal research are published in recognized medical journals such as JAMA, the British Medical Journal, and Arzneimittelforschung.

– Researchers are developing high-quality standardized extracts with proven efficacy.

– Both basic research and clinical studies have repeatedly shown that whole-drug complexes are superior with respect to range of action and tolerability to isolated chemical constituents.

German Drug Law Provisions

Phytopharmaceutical standards: In Germany, manufacturers of herbal preparations are held to much higher standards than their counterparts in North America. According to the German Drug Law (Arzneimittelgesetz), herbal “drugs” (preparations) must meet the same standards as chemically defined drugs with respect to pharmaceutical quality, efficacy, and safety, whereas in the United States they are considered dietary supplements.

Marketing authorizations for herbal medical drugs: In Germany, applications for marketing authorization must be submitted to the Federal Institute for Drugs and Medicinal Products, accompanied by the following documents:

1. Results of physicochemical, biological and microbiological tests and a description of the testing methods (analytical testing, assessment of pharmaceutical quality)

2. Results of pharmacological and toxicological tests (assessment of drug efficacy and safety)

3. Results of clinical studies (efficacy and safety)

– If the beneficial and adverse effects, and the side effects of a preparation are already known, empirical evidence acquired by scientific methods can be submitted instead of items 2 and 3.

– Until 1994, the Commission E, a diverse group of scientists, physicians, pharmacists, physiatrists, biostatisticians, and representatives of the pharmaceutical industry was charged with the task of preparing monographs on the various medicinal plants. In this capacity, the Commission issued summaries and assessments of the published data on the pharmacology, toxicology, and clinical efficacy of 360 herbal medical preparations. These monographs are available in English, published by the American Botanical Council (see list of references, p. 479).

– This valuable and influential effort should not be overrated however. The monographs are not referenced with the primary literature, and so cannot be peer-reviewed or critically evaluated, especially since, recognizing the explosion of recent scientific work, they have not been revised in nearly 10 years.

– The German Cooperative on Phytopharmaceuticals (Kooperation Phytopharmaka) took over responsibility for revising the existing monographs in Germany in 1994. The revised monographs included a comprehensive review of the recent literature. Some of them are available in English.

– In 1994 also the ESCOP (European Scientific Cooperative on Phytotherapy) was constituted in order to actualize the monographs on an European base (see list of references, p. 479)

– This valuable and influential effort should not be overrated however. The monographs are not referenced with the primary literature, and so cannot be peer-reviewed or critically evaluated, especially since, recognizing the explosion of recent scientific work, they have not been revised in nearly 10 years.

– According to the simplified reauthorization procedure for traditional medicines, traditional medicines must be labeled as follows: Traditionally used (a) as a roborant (strengthening agent) in…; (b) for improvement of general feeling in…; (c) to enhance organ function…; (d) to prevent XYZ…; or (e) as a mildly effective medical drug in case of.… Specific diseases must not be mentioned as indications for the traditional preparation.

1.2 From the Plant to the Remedy

Origins of Medicinal Plants for the Manufacture of Herbal Products

Wild harvested herbs

– Half of all medicinal plants on the market and two-thirds of all plant species are harvested from the wild.

– For economic reasons, wild harvested herbs are preferably used in the cases of certain slow-growing plants and of plants of which there is a naturally abundant supply.

Cultivated herbs

– Cultivated herbs are used when the natural supply is not sufficient to meet demand or if a herb required for medicinal purposes is a protected plant species, such as purple coneflower, Echinacea purpurea, and goldenseal, Hydrastis canadensis.

– Advantages of controlled farming

• Uniform seed material, optimal growing conditions and harvesting times

• Reduced risk of mistaken identity or adulteration

• Reduction of impurities, microbial contamination, and residues from pesticides and heavy metals (especially in plants imported from developing countries)

– Organic farming: Ensures the maintenance of natural growing conditions and is environmentally friendly.

Cultivation of special crops

– Mainly used to enrich and optimize the primary constituents of medicinal plants. A way of standardizing active constituent levels.

– Reduces the number and quantity of undesirable substances in the plants.

– Enhances the resistance of the plants to atmospheric influences, diseases, and pests.

Quality Assurance

Homogeneous starting materials

– Homogeneity is achieved by optimization and wide-scale standardization of growing conditions (e. g., in cultures), and asexual propagation

The concentrations of constituents in a given plant (e. g., ginseng or arnica) tend to vary according to location of origin, season of harvesting, and age.

Standardized preparation process

– Manufacturers use exact specifications for analyzing parent substances—meaning the herbs and their parts used—and herbal extracts made from them, using solvents such as ethanol. Specifications for assaying the content of target or primary constituents are just as exact and are designed to ensure that the chemical composition of the herbal extracts remains consistent from batch to batch.

– Standardization ensures that the quality of medicinal plants and extracts made from them are reproducible and consistent.

– Minimum concentrations of active principles in raw (unprocessed) herbs are specified in sources such as the German and European Pharmacopeias and, lately, the US Pharmacopeia.

Insofar as the manufacturers of phytomedicines use different methods of processing, the final products may vary greatly with respect to the type and/or concentration of their ingredients. This is especially true of liquid tinctures of all kinds, including glycerites, and herb products that contain powdered herbs.

Chemical standardization: Many manufacturers today sell products that contain standardized extract powders in capsule and tablet form, and the levels of identified active constituents vary much less in these products.

Quality is ensured through good harvesting, drying, processing, and storage practices of both herbs and preparations (see also section on storage):

– Good harvesting practice takes into account the growth phase (time of year) and best time of day to harvest a given plant.

– The drying process should be performed at a suitable temperature, without overheating, and under appropriate lighting conditions.

– The plant material should be cut, cleaned, and stored without direct light exposure at an appropriate temperature in accordance with the rules of good professional practice. Herbal preparations such as liquids, capsules, or tablets should be stored away from heat and direct sunlight, preferably in glass containers that exclude oxygen.

In-process controls: The manufacturer should monitor each step of the process of converting raw materials into finished medicinal products by applying the appropriate analytical tests.

Drug safety for herbal medicinal preparations

– In Germany, herbal medicinal preparations are subject to essentially the same standards for toxicity, teratogenicity, and mutagenicity/carcinogenicity as chemically defined drugs. End user suppliers and storage specifications are described below.

– The processed plant material must be tested for a wide variety of different pesticides. In North America, manufacturers of herbal products must follow good manufacturing practices based on regulations for food products regarding cleanliness and safety. The Food and Drug Administration (FDA) does not currently require manufacturers to test herbal medicines that are generally recognized as safe (GRAS) and have been used in food products before 1 January 1958 for toxicity in the same way as pharmaceutical drugs, since manufacturers are allowed to make only minimal “structure– function” claims for herbal preparations.

Plants collected in the wild, as well as plants raised in conventional (nonorganic) farms, may have high concentrations of pesticides and/or heavy metals.

End user suppliers: Pharmacies, supermarkets, health food stores, web-based suppliers, or by direct order from certain suppliers.

Storage

– Store in a cool (not cold), dark place, out of the reach of children.

– Discard after the expiration date.

– Factors that can reduce the shelf life of herbal medicines:

• Exposure to air (keep in airtight bottles)

• Humidity

• Heat

• Light (leading to oxidation-related decomposition)

• Fungal or bacterial contamination (leading to formation of poisonous metabolites)

• Evaporation

Plants infested with pests or mold must be destroyed.

– In order to identify plants that are spoiled or infested, the plant material should be inspected for mold, altered or unpleasant odor, insects, and traces of insects (cobwebs, etc.).

– The pharmacist should be able to furnish information on the shelf life of herbal medicines (e. g., teas and other herbal remedies prepared in the pharmacy).

– Herbal preparations should be stored in containers that are airtight, waterproof, lightproof, and fragrance-free.

– Storage temperature: 10–20° C (50–68 °F).

Comparison of Efficacy

It is virtually impossible to compare the efficacy of herbal remedies prepared by different manufacturers, even when they are derived from the same plant species, because different companies use different drying, processing, and manufacturing processes, and because plants from different populations vary in constituent levels.

The therapeutic efficacy of herbal remedies with comparable concentrations of primary constituents but produced by different manufacturers may vary because of the differences in the content of minor constituents.

In the future, individual pharmaceutical companies will be required to test the efficacy and tolerability of plant extracts prepared by different manufacturing processes.

1.3 Constituents and Active Principles

Primary and Secondary Metabolism

A distinction is generally made between primary and secondary plant metabolism. The products of primary metabolism maintain the plant's vital functions, whereas the products of secondary metabolism, as far as is currently known, are not essential for the plant's immediate survival.

Products of primary metabolism: Carbohydrates, fats and proteins are basic nutrients for humans and animals, but are rarely relevant as pharmacologically active substances. Nonetheless, they may have a positive or negative effect on the efficacy of the active principles in drugs.

Products of secondary metabolism: Many secondary plant substances protect plants from feeding damage, act as storage or waste products, or ward off pests and diseases. Some are pharmacologically active.

Examples of Products of Primary Metabolism

Pectins

– Substance group: Carbohydrates.

– Example: Apple pectin.

– Structural properties: High-molecular weight compounds comprising sugarlike molecules.

– Plant sources: Found in many kinds of fruit, especially when unripe.

– Pharmacological properties: Pectins cannot be digested by endogenous intestinal juices and have a high water-binding capacity.

– Indications: Diarrhea.

• Pectins lower the pH of the bowel because they encourage growth of beneficial bacteria. This produces less favorable living conditions for the pathological bacteria that cause diarrhea (see p. 190, “Diarrhea”).

Essential omega-3 and omega-6 fatty acids

– Substance group: Fats.

– Examples: Alpha-linolenic acid and gamma-linolenic acid.

– Plant sources: Flaxseed, rape seed, evening primrose seed, etc.

– Structural properties: Fatty acids.

– Pharmacological properties: Used in the synthesis of tissue hormones of the eicosanoid, prostaglandin, and thromboxane groups.

– Indications: Symptoms and ailments involving inflammation.

Products of Secondary Metabolism

Alkaloids

– Examples: Atropine, caffeine, morphine, colchicine, nicotine, berberine.

– Plant sources: Mainly in nightshades such as belladonna, bittersweet, and thornapple, but also in papaveraceous plants (opium poppy, greater celandine), the borage family (coltsfoot, comfrey), and the spea family (Crotalaria).

– Structural properties: Alkaloids contain nitrogen have complex structures, and undergo alkaline reactions.

– Pharmacological properties: Most alkaloids have a potent effect on the central nervous system, e. g., sympathomimetic or parasympatholytic effect.

– Indications

• Isolated alkaloids used in pure form (e. g., atropine) are highly potent drugs that are available by prescription only.

• Chelidonine (celandine), berberine, caffeine, and theophylline are less potent alkaloids.

• Pyrrolizidine alkaloids (present in members of the borage and aster family): Their significant toxicological features are hepatotoxicity and mutagenicity.

Essential oils

– Examples of individual essential oil components: Menthol, thymol, α-pinene, eugenol, chamazulene. Essential or volatile oils are highly complex mixtures of monoterpenes (containing 10 carbon atoms) and other types of compounds.

– Plant sources: Found in a variety of plants, such as conifers, and members of the mint and parsley families.

– Structural properties: Monoterpenes (e. g., menthol, thymol), sesquiterpenes (e. g., constituents of chamomile such as bisabolol), sesquiterpene lactones (parthenolide in feverfew), iridoid substances (gentopicrin in gentian root), and phenylpropane (e. g., chemicals in ginger root, eugenol).

– Pharmacological properties: Essential oils are aromatic, highly volatile, fat-soluble substances that stimulate chemoreceptors. They are readily absorbed in the gastrointestinal tract and by the skin (e. g., when used in bath salts and liniments).

Bitter substances

– Examples: Gentianin, gentiopicrin, cynaropicrin.

– Plant sources: Members of the Aster (artichoke, dandelion) and Gentian (gentian, centaury) families.

– Structural properties: Mainly derivatives of terpenes and seco-iridoides.

– Pharmacological properties: Bitter substances stimulate the reflex production of gastrointestinal secretions (especially saliva and gastric juices) via lingual taste buds.

– Indications: For treatment of dyspeptic complaints; to stimulate appetite and improve digestion and assimilation of nutrients.

Carotinoids

– Examples: β-carotene, lycopene, lutein.

– Plant sources: Colored fruit, leafy vegetables.

– Structural properties: Tetraterpene derivatives.

– Pharmacological properties: Antioxidants and immunomodulators; vitamin A precursors (β-carotene).

– Indications: Inflammation, immunodeficiency, photodermatosis.

Flavonoids

– Examples: Rutin, silymarin, kaempferol, quercetin.

– Plant sources: Found in a wide variety of plants.

– Structural properties: Flavonoids have a molecular skeleton consisting of acetic acid units and a phenylpropane group. Their pharmacological properties are determined by those of their substituents.

– Pharmacological properties: Flavonoids have a nonspecific protective effect on the capillaries, act as radical scavengers, and stabilize the cell membrane. They additionally have anticonvulsant and diuretic effects and increase the tolerance of cells to oxygen deficiency.

– Indications: For treatment of varicose veins, inflammations, edema, dyspeptic complaints and liver disorders; to stimulate bile secretion.

Tannins

– Examples: Proanthocyanides; phenolcarboxylic acids such as chlorogenic acid, cynarin, and ursolic acid.

– Plant sources

• Relatively high concentrations can be found in many parts of woody plants (e. g., oak bark) and in rose plants, blackberries, silverweed (goosewort), stag-horn, blackthorn, and tormentil.

• Lower concentrations are present in many plant-based foods and beverages (black and green tea, bilberries [blueberries]).

– Structural properties

• Phenolcarboxylic acids are derived from caffeic acid, salicylic acid, and bile acid.

• Condensed proanthocyanides consist of catechinic acids.

– Pharmacological properties: Tannins irreversibly link protein chains and have astringent action on the skin and mucous membranes. Hence, they have anti-inflammatory, styptic, counterirritant, and weakly antibacterial effects and prevent the excess secretion of mucus.

– Indications: External uses: for irritations of the skin and mucous membranes. Internal uses: for acute unspecific diarrhea.

Glycosides

– Examples: Cardiac glycosides, anthranoids, flavonol glycosides.

– Plant sources: Found in many members of the plant kingdom.

– Structural properties: Contain one or multiple sugar molecules as well as a nonsugar component that determines their pharmacological activity.

– Pharmacological properties

• Positively inotropic (cardiac glycosides); laxative (anthranoids); improve circulation (flavonol glycosides in ginkgo leaves).

• Higher doses can induce severe side effects and, in some cases, poisoning (cardiac glycosides, anthranoids).

– Indications: Cardiac failure, constipation; to improve the circulation.

Phytosterins (phytosterols)

– Examples: β-Sitosterol.

– Plant sources: Pumpkin seed, nettle root, saw palmetto fruit.

– Structural properties: Very similar to those of cholesterol.

– Pharmacological properties: Phytosterols occupy cholesterol receptors and thus lower cholesterol levels. They also stabilize cell walls and inhibit the synthesis of mediators of inflammation.

– Indications: To counteract elevated concentrations of lipids (antilipemic); for treatment of benign prostatic hyperplasia.

Saponins

– Examples: α-Hederine (ivy), diosgenin (wild yam), glycyrrhizic acid (lico-rice).

– Plant sources: Widely distributed in plants such as ivy (leaf), licorice (root-stock), and horse chestnut.

– Structural properties

• Consist of a water-soluble sugar chain and a fat-soluble component (aglycone or genin).

• Triterpene, steroid, and steroidal alkaline saponins are distinguished by their aglycone component.

– Pharmacological properties: Saponins induce local tissue irritation and reflex expectoration, inhibit the growth of microorganisms, especially fungi, and have partial anti-inflammatory and antiedematous effects.

– Indications: To emulsify watery and oily solutions and to promote the dissolution of substances that are not easily absorbed.

Most saponins retain their hemolytic properties, even when highly diluted. Hence, they should not be used to treat injuries or inflammations of the digestive organs.

Mucilage

– Examples: Arabinolactans, glucans, lichenin.

– Plant sources: Marshmallow root, Iceland moss, ribwort, linden flower.

– Structural properties: Polysaccharides.

– Pharmacological properties: Mucilaginous substances swell when added to water, forming viscous solutions or gels. Water-soluble mucilages are demulcent and reduce inflammation. Insoluble mucilages swell in the gastrointestinal tract and regulate the bowels.

– Indications: To soothe irritated mucous membranes of the mouth, throat, and gastrointestinal tract; to alleviate dry cough and to regulate the bowels.

Mustard oils

– Examples: Sinalbin, glucobrassicin.

– Plant sources: Black radish, mustard, great nasturium.

– Structural properties: Steam-volatile, pungent compounds formed by organosulfuric acids.

– Pharmacological properties: Mustard oils have antibacterial effects and induce hyperemia of the skin.

– Indications: Used externally to increase the blood flow.

1.4 Herbal Formulations

General Formulations

Objectives of processing

– To increase the concentrations of active principles.

– To eliminate undesirable constituents.

– The pharmacologically active principles of different species of a medicinal plant genus can differ. The goal is to obtain high-quality extracts from a defined plant species with the highest possible concentrations of the active principles.

Starting materials

– In some cases the whole plant, but usually only the plant component with the highest concentration of active principles (i. e., flowers or roots).

– The composition of extracts made from the same plant may vary according to which part of the plant was used for its preparation (e. g., nettle leaf extract vs. nettle root extract).

Traditional dosage forms (result of processing of the herb)

– Tea (species)

– Decoction (decoctum)

– Infusion (infusum)

– Maceration (maceratio)

– Juice (succus)

– Syrup (sirupus)

– Tincture (tinctura)

– Extract (extractum)

Modern pharmaceutical preparations (made with pharmaceutical excipients)

– Capsules

– Tablets

– Film-coated tablets

– Sugar-coated tablets

– Ointments

– Creams

Preparations from Fresh Plant Material

Plant juice

– Definition: The liquid obtained by pressing and crushing freshly harvested plant material (plant parts).

– Preparation: Prepared from freshly harvested plant parts. Expressed juice primarily contains water-soluble plant constituents.

– Storage: Once opened, the bottle should be closed and stored in a refrigerator and the rest discarded after one week. The contents should be discarded after the expiration date specified on the label.

– Medicinal action: Usually relatively weak, except in rare cases (expressed Echinacea juice, for example).

Distillates

– Definition: Formulations obtained by extracting active principles from fresh or dried plant material by steam distillation.

– Preparation: Obtained by separating the steam-volatile constituents of fresh or dried medicinal plants by vaporization.

– Storage: See p. 5.

– Medicinal action: Determined by the water-volatile constituents (e. g., mustard oils, essential oils) contained in the distillate.

Oily extracts

– Definition: The preparation obtained by dissolving the fat-soluble constituents of a medicinal plant in, for example, olive oil, almond oil, or peanut oil.

– Preparation: Prepared by immersing the freshly cut or dried plant parts in a vegetable oil and allowing them to stand, usually at room temperature, until the fat-soluble constituents have been extracted.

– Storage: These preparations are relatively unstable and should therefore be prepared in small quantities (see p. 5 for storage instructions).

Extracts

Definition

– Extracts are prepared by dissolving medicinal plants in a solvent to separate their active principles from extraneous substances.

– The type of formulation (aqueous, alcoholic) depends on the type of solvent used (water, alcohol).

– Extracts are characterized as either dry or liquid depending on the concentration of residual solvent in the final product.

The composition of and uses for preparations from the same plant may differ between the various preparation techniques. Hence, any extract produced by a special preparation technique is a unique active substance.

Process of manufacturing plant extracts: See Fig. 1.

Aqueous extract

– Definition: An extract prepared using water as the extracting agent. These extracts mainly contain water-soluble constituents and few lipid-soluble components.

– Disadvantages: The individual constituents are relatively unstable, and microorganisms can multiply rapidly.

Alcohol extract

– Definition: An extract prepared using ethanol and water mixed at various ratios and concentrations, called the menstruum.

– Preparation

• In Germany the standard procedure calls for the plant material to be cut into pieces and then steeped in the menstruum (macerated) for several hours; in the North American standard the fresh or dried and powdered plant material is macerated in the menstruum for a week to 10 days and the liquid is then pressed out with a hydraulic press (if available).

• The drug is repeatedly steeped in the menstruum, strained and concentrated (percolation) until completely extracted.

– Advantages

• Ethanol (grain alcohol) is an excellent extracting agent. At higher volume concentrations, it can also extract lipophilic drug constituents, such as essential oils.

• Alcohol preserves the extracts for a longer times (up to 2 to 3 years).

• Alcohol assists rapid absorption of the active ingredients.

Tincture

– Definition: A solution prepared by macerating or percolating a medicinal herb in various concentrations of ethanol.

• According to the German Pharmacopeia (DAB 1996), dry extracts made by using suitable concentrations of ethanol are also defined as tinctures.

Fig. 1 The process of manufacturing plant extracts.

– Preparation: Tinctures are prepared using 1 part drug and 5 parts extractant or, with high-potency constituents like atropine from belladonna, 1 part drug and 10 parts extractant.

– Storage (see p. 5): Should not be stored for more than one year owing to the potential instability of certain compounds in the extract. Some studies by Bauer, a leading authority on echinacea, and co-workers show the stability of echinacea tincture under normal conditions to be 2 to 3 years with about 30% reduction in some important constituents per year. (Personal communication, Rudi Bauer, PhD, 1987.)

Many tinctures should not be used undiluted.

Fluid extract (fluid extract)

– Definition: An alcoholic preparation of a medicinal herb containing higher concentrations of plant constituents than are found in conventional tinctures. One part of fluid extract generally corresponds to one part of the parent herb calculated on a dry-weight basis. This concentration has to be achieved by evaporating off some of the alcohol.

– Preparation: As for tinctures.

Dry extracts (powdered extracts)

– Definition: Solid preparations obtained by condensing and drying fluid extracts. A powdered extract contains generally 95% solids and 5% water residue (moisture). A native extract or native dry extract contains only plant extract material and is free of additives.

– Preparation

• Fluid extracts are separated from solvents by carefully heating the extract and allowing the solvent to evaporate, often in a vacuum chamber by freeze-drying or spray-drying.

• The selected drying method has a decisive effect on product quality; for example, excessive heat degrades some active constituents.

• Adjuvants and carriers such as highly dispersed silica, lactose, and methylcellulose are sometimes added to prevent caking and to adjust the final extract concentration. Extracts that are adjusted to 5: 1 (meaning that 1 part of the finished extract is equivalent to all the desirable and active constituents of 5 parts of the dried herb) are typical.

• The package labeling provides information on the parent plant or plant part, the extractant, and the dried herb/extract ratio (HER). An HER of 10: 1 means that 10 parts of the plant material yielded 1 part extract. A low HER (such as 1: 2) indicates a high concentration of the active compounds in the plant material.

Special extracts

– Definition: Extracts that undergo special extraction and purification processes to separate, concentrate, and free them from toxic and undesirable substances.

– Preparation

• Special extracts are made from raw extracts.

• The raw extract undergoes special extraction and purification processes to increase the concentration of desirable active principles.

• Toxins and undesirable substances that do not contribute to the medicinal action of the preparation are removed.

• This treatment reduces the risk factors associated with the native material, and often provides a finished product that is many times more concentrated in one or more active constituents than is the parent herb, such as the highly concentrated and standardized ginkgo extract typically sold in consumer products (50: 1). Hence, the effects of the special extract can no longer be compared with those of the raw materials.

Medicinal Teas

Definition: Herb teas, such as orthosiphon or lobelia, with a strong medicinal action. Best used under the guidance of an experienced health care professional such as a naturopathic practitioner or herbalist. Many milder teas like ginger, peppermint, and chamomile have some medicinal qualities, but are usually considered safe to use at home with care. The use and sale of many of these herb teas fall under the food laws in North America; beverage teas, see p. 479).

– The concentrations of active principles in medicinal teas are determined by the relative proportion of the herbs to extractant (water), the degree of cutting or grinding of the herb, the recommended water temperature, and the steeping time.

– Disadvantages: It is difficult to determine the exact dosage; combined components may become separated. Cutting or powdering of herbs often drastically reduces their shelf life by allowing oxygen to reach and degrade active constituents.

– Suppliers of medicinal teas: Pharmacies, drug stores, health food stores, herb shops, and supermarkets.

– Preparation: Leaves, flowers, and other plant materials are cut coarsely to finely. Wood, bark, and root materials are cut finely or pulverized.

– Storage: Keep dry and store in metal tins or dark jars to prevent direct light exposure. The expiration date should be indicated on the label.

Types of tea preparations

– Loose tea: Available as single-herb preparations and as tea mixtures. Tea mixtures do not usually contain more than seven different plant species. Traditional Chinese tea formulas often contain 6 to 15 different herbs. Those with as many as 20 to 30 herbs cannot reliably be used to achieve selective or specific effects.

– Tea bags

• Definition: Small filter bags in which finely chopped herbal teas are enclosed.

• Suitability: All herbs with constituents readily extractable with boiling water.

• Advantages: The small particle size of the tea yields a high degree of extraction of the constituents. Tea bags are easy to use and ensure uniformity of dose and composition.

• Disadvantages: Some of the volatile substances are lost during preparation and storage and certain constituents undergo oxidation upon exposure to the air.

• The individual tea bags should be separately wrapped in airtight packets.

– Instant teas

• Definition: Tea preparation that readily dissolves in water. Powdered teas contain around 8–10% extractable plant constituents in addition to fillers, carriers, flavor enhancers, and colorants (e. g., sugar, dextrin, gelatin, acacia). To prepare tea granules, liquid drug extracts are sprayed onto a carrier and dried. Tea granules consist mainly of sugar, with plant constituents comprising only 2–3% of the final product. Many Chinese medicinal tea blends are available in this form.

Diabetics must be aware of the relatively high sugar content. Since essential oils are lost during the comminution process, they are sometimes added at a later phase of the manufacturing process.

Methods of tea preparations (see also p. 27)

– Infusion: Preparation made by pouring boiling water onto the fresh or dried herbs and allowing them to steep in order to extract their medicinal principles. Suitable for the preparation of delicate or finely chopped herbs (leaves, flowers, seeds, bark, and roots) with volatile and thermolabile constituents (e. g., essential oils).

– Decoction: Prepared by boiling fresh or dried herbs in water for 10 to 60 minutes to extract their medicinal principles. Suitable for the preparation of hard or very hard plant materials (woods, barks, roots) or herbs with sparingly soluble constituents (e. g., silicic acid).

– Maceration (cold extract): Prepared by allowing a tea herb to steep in cold water for several hours to extract its active principles. Suitable for the preparation of mucilage-containing herbs such as flaxseeds or psyllium seeds whose high concentrations of starches and pectins would cause them to gelatinize if prepared with boiling water. Also used to prevent the extraction of undesirable constituents that dissolve in hot water.

1.5 Prescribing Herbal Medicines

Prescription and reimbursement of costs

– In some European countries, as well as China, properly-prescribed herbal preparations are reimbursable by law.

– In North America, herbal preparations, even when prescribed by a licensed practitioner, are not reimbursable by insurance companies or HMOs. This is slowly changing, as more research-based evidence of the cost-effectiveness of herbal remedies emerges.

Reading and writing prescriptions

– The Latin terminology should be used in written prescriptions so that the medicinal herb in question can be readily identified at the pharmacy, where the drug containers are labeled with the Latin terms.

– The English and Latin terms for the most important plant parts are listed in

Table 1

. English and Latin names and abbreviations of plant parts

English Name Latin Name

Singular (Plural)

Abbreviation

Leaf

folium (folia)

fol.

Flower

flos (flores)

flor.

Fruit

fructus (fructus)

fruct.

Herb

herba (herbae)

herb.

Root

radix (radices)

rad.

Rhizome

rhizoma (rhizomae)

rhiz.

Bark

cortex (cortices)

cort.

Writing prescriptions for teas, tinctures and other special preparations: The prescription must tell the pharmacist how much of which drugs to use, which ratio of each drug to use, and so forth.

Prescription format: The standard Latin abbreviations should be used in written instructions for the pharmacist. The most important terms and abbreviations used in written prescriptions are summarized in Table 2.

Table 2

Latin terms and abbreviations used in prescription writing

Latin Abbreviation

Derivation

English Equivalent

Aa

ana partes aequales

(equal parts) of each

aqu.

aqua

water

add.

adde

add

aut simil.

aut similia

or similar

c.

cum

with

cc, conc.

concisus

cut

cont.

contusus

crushed

d.

da

give

d.s.

detur signetur

give and label as follows

Ft

fiat

make, prepare

Gtt

gutta, guttae

drops

Inf

infunde

make an infusion

m.

misce

mix

M ft spec.

misce fiat species

mix and make a tea

M ft ungt.

misce fiat unguentum

mix and make an ointment

M. D. S.

misce, da, signe

mix, give, label as

p.c.

post cibum

after meals

pulv.

pulvus, pulveratus

powder, pulverized

Rx

recipe

take

S.

signa

label, mark

spec.

species

tea

supp.

suppositorium

suppository

tal. dos.

tales doses

such doses

tct., tr.

tinctura

tincture

ungt.

unguentum

ointment

1.6 Determination of Doses

The proper dose in herbal medicine is always a matter to be considered in clinical practice.

Several factors should be taken into account when determining the proper dose, as follows.

– The cultural context in which the herb is used

– Federal or state regulations

– The potential toxicity or strength of each herb

– The relative concentration or strength of the product

– The dose form, i. e., tincture, standardized extract, etc.

– The age, strength, and needs of the individual taking the preparation

– The duration of administration

Cultures vary as to how much of an herb or herb preparation is taken at a dose, and over how long a period.

– For instance, native Americans were used to drinking several cups of strong teas made by boiling the herbs. Consumption leading to vomiting was common as a means of cleansing the system. This would not be acceptable in most technologically developed nations today.

– In China, a common herb prescription contains from 5 to 10 herbs, and the daily dose for each is in the range of 3–12 grams. Many herb tea prescriptions given for therapeutic use contain about 60–200 grams of dried herbs. These are to be boiled for up to an hour and 2–3 cups of the strong brew are consumed over the course of a day.

In Germany and other European countries, as well as North America, standardized extracts are commonly prescribed in tablets and capsules, as well as teas and hydroethanolic tinctures. Some standardized extracts are highly concentrated. For instance, Ginkgo biloba leaves are extracted to produce a 50: 1 concentrate. One part of the finished extract represents the active flavonoids and terpenes from 50 parts of the leaves.

Teas and tinctures in Europe tend to be of lower concentration than in North America, and the recommended daily dose also seems to be lower. In Germany and Europe, mother tinctures made with an extract ratio of 1: 10 are often favored. This means that 10 parts of the finished tincture represent most of the desirable and active constituents from only 1 part of the herb. This is called a “mother tincture.” For instance an ounce of echinacea mother tincture made at this concentration would represent 1/10 of an ounce of dried echinacea root or leaves, or about 3 grams. If the recommended dose were 1–2 mL, 3 times/day, the patient would receive the equivalent of about 100–200 mg of dried herb, 3 times/day, or up to 600 mg/day. By comparison, a common daily dose of Chinese herbs can be up to 200 grams of herbs boiled and consumed as a tea. While it has been argued that hydroalcoholic tinctures are more absorbable by the body and so have a stronger impact than teas, the difference would be slight compared with the great difference in doses between the two cultures.

In North America, as in Europe, standardized extracts are commonly sold and prescribed by practitioners. Chinese herb tea and tablet prescriptions are also widely used.

Hydroalcoholic tinctures are usually manufactured at a concentration of anywhere from 3: 1 to 10: 1, and most are around 5: 1. The recommended dose listed on bottles of these tincture products tends to be 20 to 80 drops, several times daily. More experienced western herbal practitioners tend to prescribe up to 5 mL of a hydroalcoholic tincture, 3 to 5 times/day, as an initial therapeutic dose, and about 1–2 mL, 2 to 3 times/day as a maintenance dose.

Based on all these differences, how is one to best determine the dose for each individual for any given clinical encounter? This has to be determined on the basis of a knowledge of the strength of the herb, the strength of the preparation, the quality and freshness of the herbs that went into the product, and of course the size, weight, age, and needs of the patient.

In Table 5, usual German doses are given, along with the usual North American dose. We recommend that you adjust the dose within this range of doses, again based on the individual situation. Use common sense. Smaller people need a smaller dose than a very large person. Young children need a smaller dose than an adult. Very young children usually need only a few drops to obtain a therapeutic response. Weak or sensitive individuals need (or can tolerate) a smaller dose than a robust, healthy person. Do not think of the dose as static and fixed for all circumstances. Use your best judgement, taking account of the situation, and always adjust the dose rather than dispensing an herb in the same dose for every situation and person.

In the plant summaries this book maintains the German dosages of the original, however, please refer to the dosage table 337 f for American doses.

Usually it is best to start a person on a new herb or formula at the minimum dose to check for sensitivity and response before going on to a larger dose if no response is noted. For long-term use the dose can often be half of the therapeutic dose as a maintenance dose.

2 General Guidelines for Use of Herbal Medicines

2.1 Potentials and Limitations

Clinical Applications of Herbal Medicine

Primary indications

– Gastrointestinal diseases

– Colds and flu

– Liver and gallbladder diseases

– Psychovegetative diseases

– Circulatory problems and decreased mental performance

– Sleep disorders

– Diseases of the kidney and efferent urinary passages

– Prostatic diseases

– Diseases of the female genital tract

– Varicose veins

– Convalescent care

– Prevention of degenerative diseases

– Supportive (adjuvant) treatment

Indicated for adjuvant therapy only in

– Severe diseases

– Infectious diseases

– Emergency medicine

Advantages of herbal medcines

– Although recent reports highlight a few problems with herb–drug interactions such as St. John's wort reducing plasma levels of antirejection and antiretroviral drugs, the overall chance of most herbal preparations interfering with the safety and efficacy of synthetic drugs is small, on the basis of actual human reports. Many published comments about herb–drug interactions in the literature and popular press involve theoretical interactions only. More work needs to be performed in this new area of research.

– Herbal medicines have a wide therapeutic range (the gap between therapeutic and toxic doses is very large) and, thus, a superior risk-to-benefit ratio. A number of recent published studies involving thousands of patients show that patient reports of adverse effects are close to those reported for placebo.

– Herbal medicines provide a high level of treatment safety.

– When given a choice, patients with the conditions listed above tend to accept them more readily than synthetic drugs, thereby increasing compliance.

– Herbal medicines facilitate the transition from acute short-term to chronic long-term treatment.

– Herbal medicines can replace some of the conventional synthetic drugs used to treat patients with chronic diseases, such as chronic fatigue syndrome, and multiple morbidity syndromes. This is important because their synthetic counterparts often have considerable side effects.

Disadvantages of herbal medicines

– Herbal medicines are often not potent enough to treat severe illnesses by themselves, except sometimes with a long-term course.

– Diseases may be drawn out unnecessarily when self-prescribed herbal drugs are taken improperly.

– The improper long-term use of certain herbal preparations, such as the pyrrolizidine alkaloid-containing herb comfrey, can lead to severe side effects.

Self-Care Management

Owing to budget restrictions and the reduced number of drugs covered under many health insurance plans, the role of herbal self-treatment is increasing.

In self-care management, the responsibility for correct herb use and dosage lies with the patient.

As a result, side effects and interactions with other drugs are more likely to go unnoticed by these patients.

It is therefore imperative that all herbs and herbal remedies be accurately labeled with adequate instructions and warnings. Ideally, the patient will consult a qualified health care professional such as a physician trained in herbal medicine, trained herbalist, or naturopathic physician before initiating self-treatment with any herbal remedy. The advice of a physician should also be sought when herbal preparations are used together with pharmaceutical drugs, and obviously with severe ailments.

In North America, according to recent studies, most patients do not inform their physician about herbal use. This may be because most medical doctors are uninformed about some of the current research regarding the safety and efficacy of herbal preparations. This is not surprising, since they rarely receive training or continuing education in this area. Perceived disapproval from a physician may also play a role in this choice.

Role of the Physician

The physician should be informed of the use of herbal remedies to avoid unnecessary or excessive treatment and unwanted interactions with synthetic drugs (physician-supervised self-care management).

Since physicians should be able to advise patients about the limitations of self-care management, doctors must have a solid knowledge of herbal medicine. Patients often tend to be more responsive about informing physicians concerning herbal use when they feel the physician is knowledgeable and, as far as possible, unbiased.

Not all herbal medicinal products are safe and gentle. The improper long-term use of certain herbs can lead to serious side effects. Therefore, herbal remedies should not be used for extended periods without the supervision of a physician or other appropriately experienced health care provider.

2.2 Special Patient Groups

Preliminary Remarks

Owing to their low rate of side effects, the use of herbal remedies is increasing in certain patient groups, particularly in chronically ill children, pregnant and nursing mothers, and senior citizens.

Certain precautions may be observed when treating allergy sufferers and intensive-care patients with herbal remedies.

Infants and Children

Pharmacokinetics

– The pharmacokinetic and pharmacodynamic responses of infants and small children to herbal remedies are different from those of adults. As a result, the therapeutic range of an herbal drug will also differ in children and adults.

– These differences are attributable to the underdevelopment of organ structure and function in children and differences in receptor structures.

– Drugs are retained longer in a child's body owing to the lower rates of excretion and metabolism.

Basic rules for treatment of pediatric patients

– The treatment of pediatric patients with herbal medicinal preparations should be carried out under the supervision of a physician and/or other appropriately experienced health care provider, if the persons who take care of the child are not experienced in herbal medicine, or the disease is more serious or longer lasting. A herbal remedy suitable for use in children should be selected and administered at the lowest dose possible.

– Generally, the herbal preparation should be administered according to the supplier's recommendation.