Herbal Medicines
Gregory A. Plotnikoff
Herbs, and related natural products such as spices, are the oldest and most widely used form of medicine in the world. The use of herbs for the treatment of disease and the promotion of well-being can be traced back in many cultures at least 2,500 years. For example, in the 5th century bce, Hippocrates recommended leaves and bark of the willow tree (genus Salix) for pain and inflammation. However, herbal medicines are not restricted to historical use. Today, in addition to the well-known examples of aspirin from the willow tree, digoxin from the foxglove plant Digitalis purpurea, and paclitaxel from the pacific yew tree Taxus brevifolia, both over-the-counter and prescription plantderived medications are frequently used, including anticholinergic agents, anticoagulants, antihypertensives, and antineoplastic agents. And just a small percentage of the world’s plant species provide medicines. There are likely many more waiting to be discovered. The most recently celebrated example is that of a potent antimalarial medication. Chinese scientists led by Dr. Youyou Tu discovered and isolated artemisinin from sweet wormwood (Artemesia annua L), a plant used for medicinal purposes in China for more than 2,000 years. For her work, Dr. Tu was honored with the very prestigious Lasker-DeBakey Clinical Research Award in 2011 (Miller & Su, 2011).
The most comprehensive and reliable data on the use of herbal medicine in the United States comes from the 2007 National Health Interview Survey (NHIS), a survey of 23,300 adults and 9,400 adults on behalf of a child in their household. Use of natural products, including herbs, for medicinal purposes was documented in 17.7% of the U.S. population (Barnes, Bloom, & Nahin, 2008).
The high prevalence of use in all regions of the United States and across all ages, genders, ethnicities, and medical diagnoses means that health professionals must address herbal medicine use in all patient encounters (Arcury et al., 2006; Cherniack et al., 2008). In the 2002 NHIS study, 55% of adults believed that use of complementary and alternative medicines (CAM) would support health when used in combination with conventional medical treatments (Barnes, Powell-Griner, McFann, & Nahin, 2004). This is significant. Use of herbal medicines may not be disclosed unless specifically requested by the nurse, pharmacist, or physician. Even in 2008, as many as 62.5% of regular herbal medicine users also used prescription medicines; however, only 33% routinely reported their use to their care provider (Archer & Boyle, 2008). The 2004 Council for Responsible Nutrition survey of 1,000 randomly selected U.S. adults documented that 90% looked to health care professionals, including nurses, for guidance in herbal medicine use (Ward & Blumenthal, 2005). Thus, herbal medicine warrants significant attention by all nurses.
DEFINITION
Herbal medicines, or plant-based therapies, continue to occupy a place of central importance in the world’s many healing traditions. These include the use of single herbs in many Western traditions and multiple-herb combinations in traditional Asian medical systems. Frequently, herbs are part of an overarching belief system that may involve spiritual or metaphysical components. Herbal medicines are often included in the work of shamans and other traditional healers who serve as intermediaries with the spirit world. Herbal medicines are also a tool in traditional Asian medicine and are used, like acupuncture, to open blocked channels (meridians) for the free flow of qi (life spirit or force).
Herbal medicines, also known as botanicals or phytotherapies, are one component of the range of natural products sold in the United States as dietary supplements. These include fungi-based products (mycotherapies); essential oils (aromatherapies); and vitamin, mineral, and nutritional therapies (nutraceuticals). Since the passage of the Dietary Supplement Health and Education Act of 1994 (DSHEA, U.S. Congress, 1994), these biological modifiers have been available over the counter as dietary supplements. Though neither food nor drug, these substances are still regulated by the Food and Drug Administration (FDA), but with less stringent requirements. Unlike foods and drugs, dietary supplements can be sold based on evidence of safety in the possession of the manufacturer and can only be removed from the market if the FDA can prove them unsafe under ordinary conditions of use.
Under DSHEA, herbal medicines can be sold for “stimulating, maintaining, supporting, regulating and promoting health” rather than for
treating disease. As dietary supplements rather than drugs, herbal medicines cannot claim to restore normal (or correct abnormal) function. Additionally, herbs cannot claim to “diagnose, treat, prevent, cure, or mitigate” (U.S. Congress, 1994). Herbal medicine companies can assert that their product supports cardiovascular health but not that it lowers cholesterol. To do so would suggest that the product is intended for treating a disease (hypercholesterolemia) and is therefore subject to FDA pharmaceutical regulations.
treating disease. As dietary supplements rather than drugs, herbal medicines cannot claim to restore normal (or correct abnormal) function. Additionally, herbs cannot claim to “diagnose, treat, prevent, cure, or mitigate” (U.S. Congress, 1994). Herbal medicine companies can assert that their product supports cardiovascular health but not that it lowers cholesterol. To do so would suggest that the product is intended for treating a disease (hypercholesterolemia) and is therefore subject to FDA pharmaceutical regulations.
This has raised questions about what constitutes a disease. The FDA originally defined a disease as any deviation, impairment, or interruption of the normal structure or function of any part, organ, or system of the body that is manifested by a characteristic set of one or more signs and symptoms. This definition generated many concerns. “Normal structure” appeared to be normed to a 30-year-old man and therefore did not account for gender or aging. For example, are menopause and menstrual cramps diseases? With no signs or symptoms, is hypercholes terolemia a disease or a risk factor? After significant public outcry, the FDA adopted the definition of disease found in the Nutrition Labeling and Health Act of 1989. Disease is currently considered damage to an organ, part, structure, or system of the body such that it does not function properly (e.g., cardiovascular disease) or a state of health leading to such (e.g., hypertension).
SCIENTIFIC BASIS
Significant research has been done using Western biomedical/scientific models on numerous single herbal agents. Beginning in 1978, the German government’s Bundesgesunheitsamt (Federal Health Agency) began evaluating the safety and efficacy of phytomedicines. The health professionals charged with doing so, known as the Commission E, met until 1994 and evaluated 300 herbal medicines, of which they recognized 190 as suitable for medicinal use. The complete reports have been translated and are available from the American Botanical Council (2000).
Beginning in 1996, significant meta-analyses and review articles of single herb products began appearing on a regular basis in leading Western medical journals. These are readily accessible via the National Library of Medicine’s PubMed website (www.ncbi.nlm.nih .gov/PubMed). Compiling data from similar studies for analysis (metaanalysis) is complicated by the fact that many studies published to date have left out important information, including naming the specific plant species studied (e.g., echinacea versus Echinacea purpurea, E. pallida, or E. angustifolia); the parts used (stems, leaves, or roots); the form (pressed juice, powdered whole extract, aqueous extract, ethanol extract, or aqueous-ethanol extract); and the formulation (stated proportions of water to alcohol or specifically extracted fractions and concentrations).
Standardization of herbal medicines is crucial both for scientific study and consumer protection. Standardization is equated with reproducibility, guaranteed potency, quality of active ingredients, and documentable effectiveness. However, with herbal medicines, standardization presents several problems. First, the active ingredient may not be known. Second, there may be more than one active ingredient. Third, both content and activity of an herbal medicine may be related to the means of extraction and processing. This significantly complicates both research and counseling for health professionals and consumers.
A growing number of health care professionals are studying the effects of these substances. With an increase in the FDA’s involvement, we can look forward to a more reliable herb market. Expanded knowledge of herbal indications may augment the safety and efficacy of herbal therapies for patients.
INTERVENTION
Technique
Herbal medicines and dietary supplements need to be addressed in clinical settings in the same manner one addresses pharmaceutical agents. Every health professional needs to be aware of the wide use of herbal medicines and other dietary supplements. Efficient and effective patient advocacy means including questions on alternative therapies as a standard part of each patient interview. Reasonable questions include: “Are you using any herbs? Vitamins? Dietary supplements?” Follow-up questions could cover: “What dose? What source? What directions are you following? Why are you taking it?” Asking about the source of information can be quite helpful, as in, “Are you working with any other health professionals?” As with all good interviewing, listening for understanding rather than agreement or disagreement enhances the therapeutic alliance. In addition to knowing the type of herb used, the dose of each herb, and the intended purpose of each herb, gathering information regarding the duration of herb use will also be helpful in assessing patients and providing the best possible care.
Unfortunately, professionals often do not ask such questions and up to 69% of CAM-using patients do not volunteer such information (Graham et al., 2005). This “don’t ask, don’t tell” policy makes no sense in patient care. All health professionals need to create a safe environment that is conducive to patients’ open sharing of important information, such as herbal use or use of other complementary/alternative therapies without fear of ridicule or other negative responses. “Ask, then, ask again” is a practice policy foundational to safe and effective patient care.
Precautions
A common misconception regarding herbal medicines is that herbs have no side effects because they are natural. However, herbs do indeed have side effects and may be toxic or poisonous if not used appropriately. Consider the toxicity of such widely used natural products as coffee, cocaine, and tobacco. Another dilemma is patient use of herbs in lieu of their prescribed medications. Although herbs may be a good option in particular cases and conditions, the decision to decline medications should be based on fully informed judgments in partnership with a health professional.
Interviewing for herbal medicine use is crucial for identifying those patients at risk for interactions with prescription medications or for excessive bleeding in surgery. Patients with special risks of drug interactions include those taking the following pharmaceutical agents: anticoagulants, hypoglycemics, antidepressants, sedative-hypnotics, antihypertensives, and medications with narrow therapeutic windows such as digoxin and theophylline. The significance of having knowledge of the ingestion of herbal medicines is illustrated in the list of known interactions of St. John’s wort with commonly prescribed agents (see Exhibit 21.1).
Pregnancy, lactation, breastfeeding, and child care are special topics in herbal medicine use. For these situations, the most authoritative references are cited in Exhibit 21.2. In the absence of clinical trial data, use is guided by historical experience or breast milk analysis. Herbs that increase breast milk production, such as fenugreek, are frequently recommended by the International Board of Certified Lactation Consultants (IBCLC).
Exhibit 21.1. Effect of St. John’s Wort on Bioavailability of Selected Medications
St. John’s wort decreases the bioavailability of:
Calcium channel blockers
Coumadin
Cyclosporine
Digoxin
Irinotecan
Oral contraceptives
Protease inhibitors
Simvastatin
Tacrolimus
Theophylline
Note: The effect can remain strong for weeks after stopping ingestion.
Exhibit 21.2. Suggested Additional Reading for Pregnancy, Breastfeeding, Lactation, and Child Care
Hale, T. W. (2004). Medications and mother’s milk: A manual of lactational pharmacology (11th ed.). Amarillo, TX: Pharmasoft Medical Publishers.
Humphrey, S. (2004). The nursing mother’s herbal. Minneapolis, MN: Fairview Press.
Kemper, K. J. (2002). The holistic pediatrician (2nd ed.). New York, NY: Perennial Currents.
Romm, A. J. (2003). The natural pregnancy book. Berkeley, CA: Ten Speed Press.
Exhibit 21.3. Five Key Patient Teaching Points
1. Just because it is natural does not mean it is safe.
2. Just because it is safe does not mean it is effective.
3. Labels may not equal contents.
4. Self-diagnosis and self-treatment can result in self-malpractice.
5. Herbs are never a replacement for an emergency room.
Nursing skills include the ability to counsel. Exhibit 21.3 lists key teaching points regarding herbal medicines. Herbal therapies are only safe if herbs are prepared in the right way and used for the precise indication, in the correct amounts, for the exact duration, and with appropriate monitoring. Potential herb-herb and herb-drug interactions should be considered when patients are using herbal products. The lack of national standards in the collection and preparation of herbal products complicates this field in the United States. Because many herbs have potential or actual risks that need to be recognized, it is important for health providers to have reliable and accessible sources of information to prevent adverse herb-related reactions and also to identify and manage complications of herbal therapies; Exhibit 21.4 cites selected reputable herbal references.
All serious adverse reactions should be reported to the FDA through the MedWatch program at 1-800-332-1088 or at www.fda.gov medwatch. An example of a complication associated with herbal therapy is illustrated in the case of the use of Ma huang (Ephedra), marketed in the United States until recently as a major ingredient in formulations for weight reduction. Because use of this herb had been linked to numerous adverse cardiovascular events, including stroke, myocardial infarction, and sudden death (Haller & Benowitz, 2000), the FDA banned sales of this herb in April 2004.
Exhibit 21.4. Websites and Additional Resources
American Botanical Council
(www.herbalgram.org)
American Nutraceutical Association
(www.americanutra.com)
Blumenthal, M., Goldberg, A., & Brinckmann, J. (Eds.). (2000). Herbal medicine—The expanded Commission E Monographs. Austin, TX: American Botanical Council.
FDA Center for Food Safety and Applied Nutrition—a link to report adverse events
(www.cfsan.fda.gov/˜dms/aems.html)
HerbalGram magazine—published quarterly by the American Botanical Council and the Herb Research Foundation
(www.herbalgram.org)
Herb Research Foundation
(www.herbs.org)
Micromedex Alternative Medicine Database—an authoritative, full-text drug-information resource; includes alternative medicine and is one of the most comprehensive resources for herbal medicine.
(www.library.ucsf.edu/db/micromedex.html)
National Center for Complementary and Alternative Medicine
(www.nccam.nih.gov)
Springhouse. (2005). Nursing Herbal Medicine Handbook (3rd ed.). Philadelphia, PA: Lippincott, Williams, & Wilkins.
Tarascon Pocket Pharmacopoeia—contains a section on herbal and alternative therapies and has a PDA version that may be downloaded for a free trial.
(www.tarascon.com)
USES
Given the volume and variety of products, herbal medicine knowledge relevant for nursing practice cannot be summarized quickly. This chapter addresses three of the most important herbs from an evidence-based perspective. The reader will note that there is a significant range in scientific data available on each and the theoretical risks should be acknowledged and carefully considered both by patients and health professionals. Further, the clinical knowledge related to combining herbal products with prescription and nonprescription drugs is only in the developmental stages; much remains to be known about interactions and side effects.
Chronic illness (such as cancer or autoimmune disease or chronic pain), surgery, and use of prescription medications are three situations in which herbal medicine reviews by nurses are important. Echinacea does stimulate the immune system, but this is not necessarily a positive effect. Ginkgo biloba’s pharmacological activity places people at risk in surgery. St. John’s wort is effective for depression but can render many prescription medications ineffective or even toxic as previously noted. Readers should be aware that many herbs have a sufficient evidence base and potential as alternatives to Western medicine. However, herbal medicine in the United States is a very broad and multicultural phenomenon; it is difficult to know all products used by or all products of potential benefit to patients. Readers should be aware that there are reputable clinical resources readily accessible for assistance in informed decision making (e.g., see Exhibits 21.2 and 21.4).
The recent legalization of marijuana (Cannabis sativa) for distribution through approved dispensaries in 16 states and the District of Columbia deserves special attention. Medicinal marijuana is the first herbal medicine to require a prescription in the United States. Even before such changes in state laws, several prescription forms of cannabinoids existed in the United States and Canada. Dronabinol and Nabilone were used for treatment of nausea and vomiting associated with chemotherapy or anorexia with weight loss in patients with AIDS. However, since 1970, marijuana as an herbal medicine has been considered a Schedule 1 substance and therefore illegal and without medical value. This understanding has been challenged by the discovery of what has been termed the endocannabinoid system. The presence of cannabinoid receptors CB1 and CB2 in the central nervous system (CNS) and elsewhere suggests the possibility of many promising pharmaceutical applications (Bostwick, 2012; Bostwick, Reisfield, & DuPont, 2013).
The most frequent medical use of the leaves and flowering tops of the marijuana plant is for pain and muscle spasticity (Borgelt, Franson, Nussbaum, & Wang, 2013). Safety concerns for all patients include dizziness, impaired memory and cognition, increased risk of schizophrenia in adolescents, as well as accidental ingestions by children and pets. A cannabis withdrawal syndrome has also been described (Crippa et al., 2013). Cannabis use disorders (CUD) exist, especially among persons with a diagnosis of substance abuse and bipolar illness personality disorders. Nurses and all health professionals will increasingly need to screen patients for appropriate medical use (Lev-Ran, Le Foll, McKenzie, George, & Rehm, 2013).
Echinacea (Echinacea angustifolia, E. pallida, E. purpurea)
Echinacea is the most commonly used herbal medicine in the United States, used by people of all ages, genders, and ethnicities. This includes
19.8% of herbal medicine-using adults and 37.2% of herbal medicine-using children (Barnes et al., 2008). North American gardens commonly contain Echinacea, also known as the purple coneflower. It was traditionally used by Native Americans and early settlers as a remedy for infections and for healing wounds. Several components, particularly the alkamides and caffeic acid derivatives, have clear pharmacological activity (Barnes, Anderson, Gibbons, & Phillipson, 2005). In vitro research suggests an immunostimulatory effect principally by macrophage, polymorphonuclear leukocyte, and natural killer cell activation (Barrett, 2003). Monocyte secretion of tumor necrosis factor-alpha (TNF-á) is particularly stimulated (Senchina et al., 2005).
19.8% of herbal medicine-using adults and 37.2% of herbal medicine-using children (Barnes et al., 2008). North American gardens commonly contain Echinacea, also known as the purple coneflower. It was traditionally used by Native Americans and early settlers as a remedy for infections and for healing wounds. Several components, particularly the alkamides and caffeic acid derivatives, have clear pharmacological activity (Barnes, Anderson, Gibbons, & Phillipson, 2005). In vitro research suggests an immunostimulatory effect principally by macrophage, polymorphonuclear leukocyte, and natural killer cell activation (Barrett, 2003). Monocyte secretion of tumor necrosis factor-alpha (TNF-á) is particularly stimulated (Senchina et al., 2005).
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