The use of complementary and alternative medicine (CAM) has grown dramatically over the past 10 years. Alternative medicine refers to treatment options used in place of conventional medicine, whereas complementary medicine refers to therapies used in conjunction with, but not instead of, conventional medicine. In 1990, Eisenberg and colleagues conducted a survey of the prevalence of unconventional therapy use in the United States. The investigators found that 34% of respondents used at least one type of unconventional therapy in the past year. The majority used CAM to treat chronic rather than life-threatening conditions.
Because of the growing popularity of these therapies, the National Institutes of Health (NIH) established the Office of Alternative Medicine (OAM) in 1992. The OAM became the National Center for Complementary and Alternative Medicine (NCCAM) through a congressional mandate in 1998. The primary purpose of the NCCAM is to conduct and support basic and applied clinical research and research training on CAM. Two of its main focuses are to evaluate the safety and efficacy of widely used natural products and to support pharmacologic studies evaluating drug interactions.
When still designated as the OAM, this office classified alternative medicine into seven categories: (1) diet and nutrition, (2) mind-body techniques, (3) bioelectromagnetics, (4) alternative systems of medical practice (traditional and folk remedies), (5) pharmacologic and biological treatments, (6) manual healing methods, and (7) herbal medicine. Overall, the NIH defines "alternative medicine" as therapies that are unproved.
Today, CAM is used primarily to provide symptomatic relief or as preventive therapy for common disease states including arthritis, cardiovascular conditions (hypertension, hyperlipidemia), and illnesses that might be avoided or alleviated through enhancement of the immune system (coughs, colds). A more recent study by Eisenberg and colleagues showed that the use of alternative medicine in the United States has risen to 42% as of 1997. Independent variables that have contributed to the rapid growth of CAM use include distrust of and/or dissatisfaction with conventional medical care, a desire for control over health matters, a holistic health philosophy, chronic health problems, and overall poor health status.
The use of CAM among cancer patients is also rapidly expanding. In this patient population, CAM is generally used to minimize the side effects of or serve as an alternative to conventional chemotherapy. A recent review of 26 surveys showed that the prevalence of CAM use among cancer patients ranged from 7% to 64%. This wide range may be attributed to differences in the definitions of CAM used by each group of investigators and/or differences in patient populations specific to the study site.
Currently, there is much concern about this trend because CAM is often perceived as "natural" and, therefore, harmless. However, it is important to remember that some conventional medicines are derived from plants and are among the more toxic medicines available today. Examples include digoxin(Drug information on digoxin) (foxglove) and vinca alkaloids (Madagascar periwinkle). Among the most common types of CAM being used, herbal therapies can interact with conventional medicines and various disease states or organ systems, leading to significant morbidity.
Besides the potential harm associated with the use of CAM, another major concern is the avoidance or abandonment of conventional therapy and its implications. This is most important in cancer patients who are diagnosed early and have a limited window of opportunity in which to benefit from conventional therapy.