Patients' Perceptions and Beliefs Regarding Herbal Therapies
We evaluated the demographics and beliefs regarding safety and efficacy of herbal therapy among individuals in Iowa and assessed the willingness to discuss the use of these products with health care providers. We distributed 1300 surveys to two random samples: patients attending eight clinics, and residents of the state (mailing). Data were categorized according to herb use and compared between users and nonusers. The response rate was 61% (794 people), with 41.6% of respondents reporting herb use. They were predominately white women and were likely to have had education beyond high school (p<0.05). Their use of prescription drugs was high (p<0.05). Although users rated safety and efficacy of herbs higher than nonusers (p<0.05), both groups believed that health care providers should be aware of use and would provide this information.

A report published in 1993 estimated that one of every three people in the United States had tried at least one form of alternative medicine. Use of these therapies was relatively widespread and did not differ by gender or health insurance coverage; however, use patterns varied among ethnic groups, being greatest among whites and less common among African-Americans, Hispanics, and Asians. Furthermore, rates of use were significantly high among individuals with incomes greater than $35,000, aged 25-49 years, and with some college education. Unfortunately, consumer demographics were not stratified according to type of alternative medicine, for example, herbal therapies, massage therapy, and healing touch.

A follow-up study reported an increase in the number of respondents using alternative therapies from 33.8% in 1990 to 42.7% in 1997. Areas with the greatest increase in use were herbal medicines, massage therapy, megavitamins, self-help groups, folk remedies, energy healing, and homeopathy. Furthermore, the authors estimated that consumers in the United States spent approximately $5.1 billion on herbal therapies alone in 1997. One alarming point revealed by this survey was the high prevalence of concurrent consumption of herbal products and prescription drugs. In fact, it was estimated that approximately 15 million adults had consumed dietary supplements, including herbs, concurrently with prescription drugs, and 60% of them had not disclosed this fact to their physicians.

The U.S. Food and Drug Administration provides little to no regulation or guidance concerning herbal therapies. The Federal Food, Drug, and Cosmetic Act of 1938 and the Kefauver-Harris Drug Amendment of 1962 require pharmaceutical manufacturers to demonstrate the safety and efficacy of their products before marketing to the general public. Before enactment of these regulations, herbal products were touted widely as remedies for ailments ranging from anxiety to heart failure. After passage of these laws, many companies complied by either demonstrating safety and efficacy or by removing products from the marketplace. However, as a result of ambiguity in the legislation, manufacturers could reclassify herbal products as nutritional supplements and continue to sell them in the absence of safety and efficacy data as long as no claims of efficacy were printed on product labels.

Because herbal products officially are classified as dietary supplements, they are exempt from legislation requiring postmarketing surveillance of safety. As a result, data regarding the safety profiles of many herbal products are scarce. Furthermore, patients are less likely to report voluntarily adverse reactions resulting from use of an herbal product compared with adverse events resulting from consumption of prescription drugs. This puts the burden of identifying and reporting herb-related adverse events on health care providers, and with relative lack of published safety data for most of these products, the need for vigilance is evident.

Ma huang, an herbal product also known as ephedra, contains approximately 1% ephedrine. As a result it would be expected to have central nervous stimulatory potential similar to that reported for ephedrine. Ephedrine-containing products generally are contraindicated in patients with various cardiovascular conditions, diabetes, and thyroid disease, and in those taking monoamine oxidase inhibitors. In addition, several drug-drug interactions have been reported with ephedrine, including theophylline and cardiac glycosides. Thus similar drug interactions might be expected in patients taking ma huang and one of these agents. Since the law does not require disclosure of contraindications and precautions for herbal compounds, this information typically does not appear on product labels. Therefore, people may consume ephedra (or other herbal products) unaware of potential adverse effects.

Although many drugs and herbals may be safe when taken alone, the risk of significant interactions increases when several agents are ingested in combination. Sequelae of such interactions may include discomfort, exacerbation of an underlying illness, and possibly death. Although health care practitioners may intervene so that patients avoid harmful drug-herb combinations, they cannot do so if patients do not inform them, voluntarily or after questioning, about use of unconventional therapies.