My Draft Book for HARRISON INTERNAL MEDICINE

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chapter9 finished finally

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10
Complementary and Alternative Medicine
Stephen E. Straus
BACKGROUND
Medicine, not long ago the domain of solitary generalists and their nurse assistants,
now engages scores of specialists and allied professionals—radiation physicists,
cytologists, nurse practitioners, psychiatric social workers, dental hygienists, and many
more—who wield tools of unprecedented ability to extend life and sustain its quality.
This evolution of the health care system has been achieved, in part, by a formidable
enterprise of critical observation and formal investigation that disproves some onceaccepted
practices and stimulates emergence of new approaches that compete for
acceptance. One need only peruse the serial editions of this textbook to comprehend
the scope of these changes.
Other factors have also affected evolutionary changes in medicine. Immigration and
related demographic changes yield increasingly diverse populations who value their
own traditions. People's expectations of health and the nature of the health care system
itself have been altered by unprecedented access to sources of information, goods, and
services; the disposable income to afford them, and a patchwork quilt of regulations
and laws that constrain medical practice on the one hand and facilitate increased
choice in health care on the other. The emergence of complementary and alternative
medicine is one manifestation of these changes in health care.

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DEFINITIONS
In every generation, medical practices exist that are not accepted by the mainstream:
they are viewed with suspicion and dismissed as implausible or irrational. For a time,
approaches that evoked some appeal, but which had not been thoroughly tested, were
deemed unconventional. Over the past decade or so, they have been called
complementary or alternative medicine (CAM), to reflect their use as adjuncts to, or as
substitutes for, more generally accepted practices, respectively. CAM does not encompass practices that have yet to be translated fully
from the laboratory into the clinic, nor practices that were well studied and disproved,
but which manage to persist in some fashion nonetheless. Rather, CAM entails
approaches with surprising pervasiveness, many of which can claim at least some
evidentiary support. Until recently, CAM could also be defined as practices that are not
widely taught in medical schools or reimbursed. However, medical students increasingly
seek and receive some instruction about CAM, while third-party payers have identified
in CAM a marketing tool to attract new, well-heeled clients. In the past few years,
another term has been coined—integrative medicine—to suggest encouragingly that
some CAM approaches, and the practitioners who deliver them, will be shown worthy of
being added to the health care repertoire.

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SCOPE
The myriad practices and products that encompass CAM (Table 10-1) can be organized
into five somewhat overlapping domains. Special diets, high doses of vitamins and
minerals, and extracts of animal or botanical products are grouped together as
biologically based CAM approaches. Massage, osteopathic and chiropractic
manipulation, and cranial-sacral therapies are grouped as manipulative and body-based
CAM approaches. Diverse forms of meditation, various uses of biofeedback, and
hypnosis are considered mind-body approaches. All three of these CAM domains have
well-accepted analogues in conventional medicine—low-fat, low-cholesterol diets;
physical therapy; psychotherapy; to name but a few.
The fourth domain is known as energy medicine, to reflect its exploitation of veritable or
putative energy fields. Today, magnets are increasingly popular health products. Over
2000 years ago, however, while Greek physicians believed that health requires a
balance of vital humors, Asian practitioners postulated the flow and balance of vital
energies and described tools to restore them. Acupuncture aims to correct energies that
flow through special meridians, or channels. Reiki, a Japanese approach, and healing
touch, a modern variant, purport to diagnose and correct one's energy by passing the
hands of an adept therapist over the patient.
The fifth domain, termed alternative systems of medicine, combines elements of the
four other domains and aims to provide primary approaches to all health needs, rather
than just adjunctive solutions to them. Western variants include practices developed by
Native Americans, homeopathy, and naturopathic medicine. Eastern variants such as
Ayurvedic medicine of India, traditional Chinese medicine, and Tibetan medicine are
rich in their use of meditative exercises and herbal products.

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多些了

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PATTERNS OF USE
Despite its enormous success, contemporary western biomedicine has features that can
discourage patients: many diseases, especially chronic ones, are not cured or even
adequately ameliorated; existing treatments can impose serious adverse reactions; and
the care is fragmented and impersonal. CAM, despite its lack of proof, appeals to many
because its practitioners are optimistic. They spend a lot of time talking with and
touching their patients. CAM empowers patients to make their own health choices, its
natural products are believed to be inherently healthier and safer than synthetic ones,
a nd care is provided
in a “holistic” fashion, meaning that the broader medical, social, and emotional
contexts of illness are considered in designing the treatment plan.
The very first large survey by Eisenberg in 1993 surprised the medical community by
showing that >30% of Americans use CAM approaches. Countless studies since then
have extended these conclusions by surveying specific demographic groups and patient
populations. The Centers for Disease Control and Prevention (CDC) study of nearly
31,000 American adults revealed that in 1999 29% had used one or more modalities,
with spiritual approaches, herbal medicine, chiropractic, and massage being the most
prevalent. Over 1% underwent acupuncture treatment that year. Surveys among
patients with cancer showed that 30 to 86% used CAM, with highest rates in those with
more advanced disease and undergoing aggressive treatments. Similarly, among AIDS
patients, 36 to 91% are reported to use CAM. In devastating chronic illnesses like
these, CAM is called upon to provide hope of cures when conventional medicine cannot,
to extend life, to ameliorate treatment side effects, and to provide emotional and
physical comfort. While somewhat subject to vagaries of definition as to what counts as
a CAM treatment, surveys have shown that Americans are willing to pay for these
services out of pocket, with an estimated $7 billion each year on vitamins and mineral
supplements, $4 billion on herbals and other natural products, and nearly $4 billion
more on sports supplements. Eisenberg reported that total CAM expenditures in 1997
approached $30 billion, with more visits to practitioners for CAM services than to
physicians in general.

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FIELDS OF PRACTICE
Osteopathic Medicine
Founded in 1892 in the American heartland by the physician Andrew Taylor Still,
osteopathic medicine was based originally on the belief that manipulation of soft tissue
and bone can correct a wide range of diseases of the musculoskeletal and other organ
systems. Over the ensuing century, osteopathy evolved progressively towards
conventional (allopathic) medicine. Today, the training, practice, credentialing,
licensure, and reimbursement of osteopathic physicians is virtually indistinguishable
from those of allopathic physicians, with 4 years of osteopathic medical school followed
by specialty and subspecialty training and certification by organizations such as the
American Board of Internal Medicine. Some osteopathic physicians continue to practice
spinal manipulation, primarily as a tool to address specific musculoskeletal complaints.

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Chiropractic Medicine
In 1895, Daniel David Palmer founded in Missouri the first school of chiropractic
medicine to teach manipulation of the spine. Palmer believed that subluxations, or
partial dislocations of vertebrae, cause disease by impinging on key nerve roots. Today,
chiropractors undertake 5 years of training in basic and relevant clinical sciences.
Increasingly, they complete additional postgraduate training in radiology and outpatient
therapeutics, primarily of musculoskeletal conditions, although within the discipline
there are factions that continue to perform manipulation for many other pathologic
entities. Chiropractors also advise on nutrition, exercise, and other health maintenance
approaches. Over 70,000 doctors of chiropractic medicine are licensed to practice in all
states and the District of Columbia.

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Acupuncture
A venerable component of traditional Chinese medicine, acupuncture has emerged in
recent decades as a free-standing clinical discipline. Over 3000 American physicians
have acquired targeted postgraduate training that permits them to practice acupuncture
in over 40 states and the District of Columbia. Over 4000 non-MDs have taken far more
extended training, leading to licensure to practice independently or under the
supervision of a physician.
Massage Therapy
Drawing upon millennia of empirical knowledge, some 80 American schools instruct
students in an array of the soft tissue manipulative approaches that constitute
massage. Thirty-one states and the District of Columbia license trainees to perform
therapeutic massage.
Naturopathic Medicine
Eleven states license practitioners of naturopathy, a discipline that emerged in central
Europe in the late eighteenth century. That conventional treatments of the day were
usually ineffective, if not overtly harmful, stimulated the search for safer and more
“natural” approaches—naturopathy is one of them. The concept underlying this
discipline is that the body possesses powerful mechanisms for self-healing that a
properly instructed practitioner could harness. About 1400 naturopathic physicians have
completed 4 years of education in basic and clinical sciences and are licensed to
manage a predominantly outpatient population. Conventional and unconventional
diagnostic tests and medications are prescribed with an emphasis on relatively low
doses of drugs, herbal medicines, special diets, and exercises.

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Homeopathic Medicine
The late eighteenth century also witnessed the emergence of homeopathy, another
discipline that reacted to toxicity of the allopathic approaches of the day. It was
developed by Samuel Hahnemann, a German physician, who postulated that substances
that cause particular side effects in a well person may be used to treat or prevent such
symptoms in an ill person if administered in miniscule amounts—what is known as “the
doctrine of similars.” For example, contact with poison ivy (Rhus toxicodendron)
causes an itchy, blistering rash. Highly diluted extracts of poison ivy are recommended
to treat chickenpox. The nascent field of homeopathy used blinded tests on volunteers,
presaging to some extent the use of placebo-controlled trials, to prove which materials
were the most able to induce or relieve symptoms. By the mid-nineteenth century
homeopathy had gained considerable presence in the American medical establishment
and may, in fact, have facilitated the development of immunization and allergen
desensitization, both of which utilize very small quantities of materials to elicit
measurable biologic outcomes. Today, however, homeopathy is accepted less fully in
the United States than in some other countries: it is the largest of all CAM practices in
the United Kingdom, Germany, and France and is widely used in India. Only three
states license the practice of homeopathy. The relative decline of homeopathy relates,
at least in part, to the field's inability to articulate a rational mechanism as to why
products that are diluted more than 1060-fold, vastly greater than Avogadro's number,
could incite biologic effects. Nonetheless, homeopathic remedies are readily available
and commonly recommended by naturopathic physicians and other licensed and
unlicensed practitioners.

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Other Disciplines
There are numerous other CAM practices, among which some involve formal training,
such as that leading to a Doctorate of Oriental Medicine, or extended apprenticeships,
as in learning herbal medicine. Unfortunately, most of the other fields have no agreed
upon practice standards, credentialing processes, requirements for continuing
education, or accountability.

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REGULATION
As indicated above, some CAM disciplines are carefully regulated. CAM products,
however, are not strongly regulated. Herbal medicines, and dietary supplements more
generally, occupy a unique regulatory status that affords the public remarkable freedom
of choice but also many undesired challenges, summarized below. Elements of virtually
all traditional healing approaches, herbal medicines were presumed safe long before
the implementation of stringent drug regulations by the U.S. Food and Drug
Administration (FDA). In 1994, the United States Congress passed the Dietary
Supplements Health and Education Act (DSHEA) that permits sale of dietary
supplements “over-the-counter,” as it were, but without the requirement imposed on
manufacturers of prescription or classic over-the-counter drugs to prove their products
to be safe and effective before marketing. Supplements can be removed by the FDA
from the market only if they are proven to be hazardous. Dietary supplements, however,
cannot legally claim to prevent or treat any disease. They can, however, claim to
maintain “normal structure and function” of body systems. For example, a product
cannot claim to treat arthritis, but it can claim to maintain “normal joint health.”
Homeopathic products predate FDA drug regulations and are sold with no requirement
th at they be proven effective. It would be reasonable
to assume, however, given the extent to which homeopathic products are diluted, that
most of them are safe.

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SAFETY
Despite their lack of apparent toxicities, homeopathic products, like all other CAM
products and practices, do convey one type of risk, namely, that people will pursue
them in lieu of more conventional modalities that are proven to be beneficial. Members
of the public have considerable freedom to determine what is in their own best interest,
even if those decisions deny them effective treatment, although the courts have found
the rights of parents to withhold treatment of their children to be limited in instances of
life-threatening illnesses. Investigators, however, have a broad ethical obligation to not
withhold proven treatments for serious illnesses for the sake of testing unproven ones.
Additional risks are imposed by the use of other CAM approaches: injuries inflicted by a
practice, inherent toxicities of the modality, and interference by the modality with more
conventional treatments.

Injury
Physical and manipulative interventions can harm patients. In past decades, reused
acupuncture needles transmitted hepatitis B virus infection; today, the standard of care
requires disposable needles. Aggressive massage can cause soft tissue injuries. Spinal
manipulation of patients with unrecognized vertebral lesions has been associated with
cord injuries, and cervical manipulation has been associated with stroke. These appear
to be rare events.

Inherent Toxicity
While the public may believe that “natural” equates with “safe,” it is abundantly
clear that natural products can be toxic. Misidentification of medicinal mushrooms has
led to liver failure. Contamination of tryptophan supplements caused the eosinophiliamyalgia
syndrome. Herbal products containing particular species of Aristolochia were
associated with genitourinary malignancies. In 2001, extracts of kava, long used by
Pacific Islanders for its mild anxiolytic and sedative properties, were associated with
fulminant liver failure. A number of products, including the popular Ginkgo biloba, are
known to prolong bleeding times and have been associated with postoperative
hemorrhage. Among the most controversial is Ephedra sinica, or ma huang, a product
used in traditional Chinese medicine for short-term treatment of asthma and bronchial
congestion. The scientific basis for these indications was revealed when ephedra was
shown to contain the ephedrine alkaloids, especially ephedrine and pseudoephedrine.
With the promulgation of the DSHEA regulations, supplements containing ephedra and
herbs rich in caffeine flooded the U.S. marketplace, claiming to promote weight loss
and to enhance athletic performance. Reports of severe and fatal adverse events in
young and, in some cases, well-known Americans led to calls for removal of ephedracontaining supplements.

Herbal-Drug Interactions
The constituents of natural products may not only be toxic but may also interfere with
the metabolism of life-saving drugs. This effect was illustrated most profoundly with the
demonstration in 2000 that consumption of St.-John's-wort interferes with the
bioavilability of the HIV protease inhibitor indinavir. Later studies showed its similar
interference with metabolism of topoisomerase inhibitors such as irinotecan, with cyclosporine, and with many other drugs. The breadth of interference stems from the
ability of hyperforin in St.-John's-wort to upregulate expression of the pregnane X
receptor, a promiscuous nuclear regulatory factor that promotes the expression of many
hepatic oxidative, conjugative, and efflux enzymes engaged in drug and food
metabolism.

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ACQUIRING EVIDENCE
CAM evolved through an entirely different epistemologic framework than contemporary
biomedicine. Empirical observations of individual patients constitute the primary
evidentiary base on which CAM practices are guided and taught. Nonetheless, over the
past few decades, thousands of studies have been performed of various CAM
approaches, including hundreds of trials involving herbals, acupuncture, or
homeopathy. To date, however, no single approach has been proven effective in a
convincing way. (If they had, the practice would no longer be considered CAM!) Several
factors contribute to this lack of convincing evidence. The vast majority of CAM studies
have been seriously flawed by lack of appropriate controls, bias on the part of the
investigators, small sample sizes, reliance on highly subjective and nonvalidated
measures of benefit, and by inappropriate statistical tests.
There are in addition, a series of methodologic issues that challenge even the betterdesigned
CAM studies. No uniform practice guidelines exist, and the herbal products
marketed in the United States are highly variable in quality and composition. Some
CAM practices are not amenable to blinding. For example, both the patient and the
practitioner would know if spinal manipulation had been performed. These problems are
not unique to CAM, however, as they also complicate attempts to study conventional
practices such as psychotherapy or surgery. Efforts are now being made to randomize
patients to other equally demanding control interventions, and acupuncture at
traditional needling points is being compared to needling at what are arguably irrelevant
points.
Even with ongoing improvements in study design and conduct, issues of belief stand in
the way of comprehending and accepting the results of some CAM studies. Many
physicians are reluctant to believe positive outcomes of exotic approaches that have
not emerged through the classic experimental paradigm by which drugs and biological
agents are now developed, namely, the orderly progression from preclinical testing
through three phases of clinical trials. More importantly, it is difficult to accept results
that are counterintuitive or whose mechanism cannot be rationally explained. A
powerful example of this dilemma involves studies of homeopathy. Some clinical trials
of homeopathy for asthma, infantile diarrhea, and other common conditions reported
positive results. Two systematic reviews of homeopathy trials gleaned an overall
favorable impression of the clinical trials data, concluding that the treatments were
more beneficial than placebo. Even the best trials and these reviews have been
criticized on methodologic grounds. It remains unclear what evidence could compel a
tidal change in belief about the benefits of homeopathy when there remain no cogent
explanations for how substances diluted to the point at which only solute remains could
exert physiologic effects.
By contrast, while methodologic problems continue to plague acupuncture trials, belief
has been growing even in academic centers that acupuncture may be effective. The
emerging acceptance of acupuncture may result, in part, from its widespread availability and use in the United States today: the CDC estimated that >1% of adult Americans
received acupuncture treatments in 1999. Acupuncturists are now practicing within
major medical centers, providing an ancillary approach to pain management. Yet, its
acceptance may stem from more than just its communal appeal. Since the mid-1970s,
studies have revealed palatable explanations for how needling may moderate pain and,
not just by rephrasing the traditional explanation that acupuncture restores the flow of
vital energies along meridians, for which there remain no known anatomic correlates.
Rather, biochemical and imaging studies have shown that needling triggers the release
of endogenous opioids that bind to specific receptors in the very brain regions that
mediate the beneficial effects of narcotic analgesics.

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EXISTING EVIDENCE
Numerous CAM approaches lack coherent explanations and any credible body of data regarding their safety and effectiveness. And, while it is difficult to conclude decisively that an approach lacks any merit, it is quite feasible to discern that its effect size, or degree of benefit, is too small to be worth pursuing further. Over the past century, many approaches failed—one need only think back to the exotic electrical devices, procedures, and tonics that fell out of fashion. Two questions are often asked: (1) Whether any of the more contemporary CAM modalities deserve to be rejected? (2) Whether data showing it to be ineffective would change anyone's mind about using it? The case of laetrile is instructive in this regard. This extract of apricot seeds was touted in the 1970s as a cure for solid tumors. Thousands crossed the Mexican border to be treated. The lack of any positive preclinical data discouraged oncologists from agreeing
P.70 to study laetrile, until public pressure required that an answer be obtained. Two studies in the 1980s showed no benefit of laetrile treatment. Today, some continue to seek the product, but the numbers are vastly smaller than before meaningful data were obtained. A similar fate befell a cocktail of drugs used for cancer patients through the 1970s and 1980s by Dr. Luigi DiBella in Italy, once large studies revealed it to have no detectable impact on the course of a variety of advanced cancers.
In contrast, modalities that have been well tested and found ineffective are still in fairly common practice. For example, the renowned biochemist and peace activist Linus Pauling proclaimed vitamin C to be the answer to the common cold. Numerous, high-quality studies failed to demonstrate clinically important effects of vitamin C in preventing or treating viral colds. The early studies were criticized for using too little of the vitamin, yet doses that well exceeded its bioavailability also proved negative. Nonetheless, ingestion of extra vitamin C remains a common habit in individuals who perceive the onset of cold symptoms. For most people, this practice is wasteful but not harmful; however, people with iron overload (either hemochromatosis or chronic transfusion requirement) can be damaged by vitamin C, which generates free radicals in the setting of iron excess.
Despite the failure of some CAM approaches, early studies have yielded positive or at least encouraging data for a number of them. Good sources of information include the Natural Medicines Comprehensive Database (www.NaturalDatabase.com) and National Institutes of Health (NIH) websites such as http://ods.od.nih.gov; http://nccam.nih.gov/health/ and http://www3.cancer.gov/occam/information.html.