Herbal Supplements

Efficacy, Toxicity, Interactions with Western Drugs, and Effects on Clinical Laboratory Tests

Amitava Dasgupta, Catherine A. Hammett-Stabler, Amitava Dasgupta, Catherine A. Hammett-Stabler

• Publisher: Wiley
• Year: 2011
• ISBN:
  9780470922750
• Edition: 1
• Topic: Medicine
• Subtopic: Toxicology

HERBAL SUPPLEMENTS

An evenhanded study of pharmacological interactions between Western drugs and herbal supplements

Today, a significant percentage of Americans turn to complementary and alternative medicine practices. Despite their popularity and wide use, these products do not undergo the same pre-market testing for safety and efficacy that is required of pharmaceuticals. In Herbal Supplements: Efficacy, Toxicity, Interactions with Western Drugs, and Effects on Clinical Laboratory Tests, editors Amitava Dasgupta and Catherine Hammett-Stabler present a comprehensive introduction to both safe and unsafe herbal supplements. The book emphasizes the pharmacological interactions identified between Western drugs and herbal supplements, and the effects of herbal supplements on clinical laboratory tests.

Herbal Supplements provides a guide to the interpretation of abnormal test results in otherwise healthy subjects due to use of herbal remedies. Focusing on interactions between herbals and pharmaceuticals, sources of contamination in herbal supplements, and analytical techniques used in the investigation of herbal remedies, the book details:

• Pharmacological interactions between Western drugs and herbal supplements
• Effects of herbal supplements on clinical laboratory tests
• Key interactions between herbal supplements and various pharmaceutical drugs
• Medicinal plants and toxic effects
• Contamination of herbal supplements from metals, pharmaceuticals, and plant poisoning
• Analytical techniques, including immunoassays, used in the investigation of herbal remedies

Unbiased and literature-based, this text offers toxicologists, clinical chemists, analysts, and pharmacologists a no-nonsense take on the efficacy, toxicity, and drug interactions of herbal supplements and medicines.

Part I: INTRODUCTION AND OVERVIEW

1

INTRODUCTION TO COMPLEMENTARY AND ALTERNATIVE MEDICINE

Catherine A. Hammett-Stabler

The University of North Carolina at Chapel Hill, Chapel Hill, NC

1.1 INTRODUCTION TO COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM)

The past 109 years have witnessed amazing advances in medicine, and, without a doubt, the world’s population has benefited from the scientific discoveries elucidating the mechanisms of diseases, as well as the therapeutic interventions that followed. We live longer, healthier lives compared with our ancestors, with much of that due to medical advances. A child born at the beginning of the twentieth century had a life expectancy of ∼50 years, while a child born today can expect to reach 75–80 years, or beyond [1, 2]. True, we have yet to conquer heart disease, cancer, and many other diseases, but we are making advances in every corner. In the United States, where cancer is the second leading cause of death, the mortality rate attributed to cancer has declined steadily since 1950 for both men and women across all age groups [3, 4]. But shouldn’t we expect such benefits in a country with one of the best healthcare systems in the world? A recent World Health Organization (WHO) report suggests the benefits extend well beyond the United States as adult and childhood mortality rates around the world have declined steadily since the 1990s [5]. The reasons for this decline are many, but the WHO attributes a significant portion specifically to medical advancements. For children, oral rehydration treatment during severe diarrhea, the use of artemisinin-based combination therapies for the prevention and treatment of malaria, and the use of immunizations (for the prevention of measles, diphtheria, pertussis, tetanus, hepatitis B, and hemophilus influenzae B) made the difference. For adults, the decline in mortality rates was related to improved therapies for infectious diseases such as tuberculosis, HIV, and malaria [5].

From these and other studies, it is clear that scientific and medical advancements now permit many diseases and conditions to be diagnosed earlier and to be treated more effectively, with the end result of a longer, higher-quality life for many individuals. For this reason, it is intriguing that so many individuals have turned to and embraced the CAM treatments and systems that will be discussed in the following chapters.

1.2 WHAT IS COMPLEMENTARY AND ALTERNATIVE MEDICINE?

CAM encompasses a variety of practices and products ranging from recently introduced New Age modalities to complete medical systems that have evolved over thousands of years. Many of the practices are readily recognized as outside of allopathic (conventional or mainstream) medicine, but others are less obvious. Furthermore, some practices that were once considered CAM have moved into the mainstream. The definition applied by Eisenberg et al. 17 years ago—”medical interventions not taught widely at US medical schools or generally available in US hospitals”—has certainly changed as medical schools have initiated courses in CAM and hospitals have developed departments of integrative medicine [6–8].

Today, the National Center for Complementary and Alternative Medicine (NCCAM) has broadened the definition to “a group of diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine” [9]. NCCAM further distinguishes between CAM and complementary medicine consisting of those practices used in conjunction with allopathic (conventional) medicine, whereas alternative medicine encompasses those practices used instead or in place of allopathic medicine [9]. The Center also uses the term “integrative medicine” to describe the combination of allopathic medicine with those CAM treatments that appear “to be safe and have merit based upon scientific study” [9] (though it is not clear how safety and efficacy were demonstrated for this definition).

Using the NCCAM classification scheme, practices can be divided into five categories (Table 1.1):

• Biological-based therapies employ naturally occurring substances derived from plants, animals, and minerals, such as herbal preparations (the most widely used of all CAMs), botanicals, and dietary supplements.
• Energy therapies include both those involving energy fields believed (by practitioners) to surround and penetrate the body, as well as the application of an energy field (magnetic, electric, or electromagnetic) to the body. Examples include Reiki, bioelectromagnetic therapy, and therapeutic touch.
• Manipulative and body-based practices apply physical stimulation, movement, manipulations, and massage or rubbing of muscles and other soft tissues to stimulate blood flow and oxygenation for preventative or healing purposes. Chiropractic, osteopathic manipulation, and therapeutic massage are among the most popular.
• Mind–body therapies use a number of techniques to enhance the mind’s ability to control bodily functions. Examples of practices within this classification include meditation, yoga, prayer, tai chi, biofeedback, and relaxation.
• Whole medical systems are quite complex and often include combinations of practices from the aforementioned groups. A number of these have evolved over thousands of years, notably, traditional Chinese medicine, Indian Ayurvedic medicine, and Arabic Unani medicine.

TABLE 1.1 NCCAM Classifications of Complementary and Alternative Practices

Whole medical systems Mind–body medicine Biological-based practices Manipulative and body-based practices Energy medicine

Agreeably, the practices listed in Table 1.2 are quite varied, and often overlap between the broad categories given. Many individuals would also argue that some, however, are not CAMs but are recreation or even conventional forms of therapy. For example, is the massage enjoyed at a spa a practice of CAM? Is the practice of taking a daily vitamin? If tai chi and yoga are CAM, is running? How should prayer for health and spirituality be classified (some surveys have considered prayer for health a form of CAM practice) [10]. Are these truly complementary and alternative medical practices or perhaps an overclassification? Added to the controversy is the question as to when does a practice make the transition from CAM to conventional—and how? Does the transition occur simply out of acceptance, or must there be sound evidence supporting its use?

TABLE 1.2 Listing of Practices Defined as CAM

Acupuncture/acupressure Alexander technique Aromatherapy Ayurvedic medicine Autogenic training Autologous blood therapy Bach flower remedies Balneotherapy Bioelectromagnetic therapy Biofeedback and bioresonance Bone setting Chelation therapy Chinese herbal medicine, traditional Chinese medicine Chiropractice therapy Colonic irrigation Counterirritation Craniosacral therapy Crystal therapy

Cupping diets Dietary supplements Electromagnetic therapy Enzyme therapy Herbal medicine Homeopathy Hydrotherapy Hypnotherapy Iridology Kampo Kinesiology Kirlian photography Laser therapy Massage Meditation Mental healing Naturopathy Osteopathic manipulation Pulse diagnosis

Phytomedicine Prayer Qi gong Reiki Reflexology Relaxation therapy Spa therapy Spiritual healing Tai chi Thalassotherapy Therapeutic touch Tongue diagnosis Traditional medicine Trager psychophysical integration Transcranial magnetic stimulation Vega testing Water injection Yoga

1.3 DEMOGRAPHICS OF CAM

Interestingly, the demographics of CAM use in the United States have changed little over the past 17 years. The majority of studies characterizing the use of CAMs in this country are based upon the data generated through the National Center for Health Statistics of the Centers for Disease Control and Prevention (CDC) [10, 11]. There are additional, though smaller, surveys focusing on specific subpopulations. When reviewing any of these, it is important to realize that the data acquired are directly dependent upon both the survey tool and the surveyor. As mentioned previously, there is disagreement as to what is a CAM, and surveys differ with regard to what is or is not included. For example, the 2007 National Health Interview Survey (NHIS) survey included nine additional CAM therapies and 10 additional biological-based products not captured in the 2002 survey. The 2002 survey included prayer as a CAM practice, though the 2007 survey did not. Neither survey included the use of some types of home remedies. The point here is that these surveys, while extremely valuable, have limitations when trying to discern specific details regarding CAM use and may, in fact, underestimate utilization (a problem reemphasized in subsequent sections). Several investigators have tried to probe more deeply into the differences in CAM use and in practices between the various populations that make up this country’s citizenship. The results of these studies reflect the diversity of ethnicity and demonstrate the need for much more work in this area.

About 40% of adults report using at least one form of CAM within the previous year, most often in pursuit of general good health or to prevent illness [10, 11]. Biological-based therapies are, by far, the CAM of choice with ∼20% of respondents reporting use of these types of products (Table 1.3). Deep breathing exercises, meditation, and manipulation therapies round out the more popular practices. Consistently, surveyors find the person who chooses to use a CAM is most likely to be a middle-aged Caucasian female with a higher education level and of higher economic status. It is extremely important to recognize, however, that CAMs are used by all ages and all populations.

TABLE 1.3 Ten Most Popular Biological-Based Products, 2002 versus 2007

2002 (Past Year)	2007 (Past 30 Days)
Echinacea (40.3%)	Fish oil/omega-3 (37.4%)
Ginseng (24.1%)	Glucosamine (19.9%)
Ginkgo biloba (21.1%)	Echinacea (19.8%)
Garlic (10.9%)	Flaxseed oil (15.9%)
Glucosamine (14.9%)	Ginseng (14.1%)
St. John’s wort (12.0%)	Combination herb pills (13.0%)
Peppermint (11.8%)	Ginkgo biloba (11.3%)
Fish oils/omega fatty acids (11.7%)	Chondroitin (11.2%)
Ginger (10.5%)	Garlic supplements (11.0%)
Soy supplements (9.8%)	Coenzyme Q10 (8.7%)

In fact, the 2007 survey found ∼12% of U.S. children use a CAM [11]. Not surprisingly, the parents of these children are more likely to turn to these therapies and, accordingly, the children tend to use practices similar to those used by the parent(s): herbal products followed by manipulation therapies and deep breathing exercises [11]. This may have been the case for sometime, as between 26% and 80% of young, college-age adults (∼18–21 years) (Table 1.4) have reported using a CAM within the past year since the late 1990s [12–15]. Consistent with other surveys, herbals and supplements are the CAM of choice for this group and are used in pursuit of health and as preventatives.

TABLE 1.4 Use of CAMs by College Students

N	%	Products
1000	26.3	Ginseng, echinacea, protein power/amino acids
272	48.5	Echinacea, ginseng, St. John’s wort, ginkgo biloba, ephedra, chamomile
1754	51.0	Echinacea, ginseng, St. John’s wort, chamomile, ginkgo biloba
506	79.0 58.0	Green tea, ginseng, chamomile, ginger, echinacea

CAM use peaks between ages 50 and 59 (44.1%) but is relatively consistent from ages 18 to 84 (36.3% and 32.1%, respectively). Many are surprised to discover that older individuals use CAMs at rates similar to younger individuals. Biological-based products, notably, supplements, were most frequently reported in the NHIS survey. Others have found many of this population turn to a range of home remedies involving materials readily available to them such as vinegar, baking soda, and homegrown or local herbs [16]. Even those living under supervised, or semisupervised, conditions such as in assisted living facilities are found to use CAMs. A limited survey conducted by Moquin et al. found that 5–9% of residents in assisted living facilities used some kind of herbal remedy [17]. More concerning was the fact that the use of such was not known to the facility staff in many cases. Since the older population is more likely to be receiving prescriptive medications, their use of herbals is important as some of these are known to increase the risk of adverse drug reactions (ADRs) when combined with prescriptive medications. If herbal use is not documented or suspected in such an individual, the ensuing ADR could be misdiagnosed and could lead to inappropriate care.

Adequate documentation of CAM use, both on the part of the patient/individual and the healthcare provider, remains a significant problem. This problem is not unique to the United States but is reported worldwide with less than half of patients who use CAM reporting such activities to their healthcare providers [18–22]. Although most physicians, nurses, and other providers are now tra...