Are Herbal Therapies Worth the Risks?

Nurse Practitioner, Oct 2004 by O'Malley, Patricia, Trimble, Nancy, Browning, Melissa

Nearly 16% to 18% of all adults in the United States regularly use herbal products as part of a dietary or health regimen. In 1999, $3.3 million were spent on the purchase of herbal medicines.1 An estimated 15 million adults in 1997 combined herbal and/or vitamin therapy with prescription medications, which accounted for 18.4% of all prescription users.2

Currently, there are approximately 15 million adults at risk in the U.S. for potential adverse interactions from prescription medication, herbs, and/or vitamin supplements, including nearly 3 million adults age 65 or older.2'3 People consuming herbal therapies generally do not disclose these activities to healthcare providers for cultural or personal reasons, so potentially positive and negative outcomes are not readily identifiable. Healthcare providers unfamiliar with the uses and actions of herbs often fail to assess and monitor patients when providing services. This results in potentially negative outcomes on health and dissatisfaction with healthcare services.

This article explores the current trends in herbal therapy as well as the benefits and risks. Potential tools that nurse practitioners (NPs) can use in caring for patients who use herbal therapy will be presented. The NP has a powerful opportunity to correct the current problems of poor provider-consumer communication, false information, and inadequate monitoring of outcomes and interactions related to herbal therapy.

* Herbal Therapy in the United States

Herbs are seed-producing annuals, biennials, or perennials that do not develop woody tissue, die at the end of the growing season, and have medicinal, savory, or aromatic qualities.4 To avoid confusion regarding many available products, the terms, "botanicals" or "phytotherapeutics" may be used instead to describe any plant-derived product used for medicinal or health purposes.4

Herbal therapy was the mainstay of pharmacopeia during the early 190Os in the U.S. Today, nearly one-quarter of current pharmaceutical agents originated in whole or in part from naturally occurring chemicals in plants.5 Three plant therapies are still part of standard therapy in cardiovascular disease: Digitalis, reserpine, and aspirin.1,5

In one study of 1,539 adults in 199 land 2,055 in 1997, investigators examined the use of alternative therapies.2 Results suggested that the estimated out-of-pocket expense for herbal remedies in the U.S. was $5.1 billion dollars, representing a 380% increase in the use of herbal agents.

Why the increase in use? Certainly, public knowledge of herbals has increased over the last decade. Information is readily available through the media, journals, magazines, family, and friends. The Internet also contributed to the explosion of information and enables consumers to order products from anywhere in the world. Herbal agents are readily available in drug stores and supermarkets. Unfortunately, Web sites may not always contain reliable or accurate information.6

Whereas pharmaceutical agents are often perceived as expensive, costly, high-risk, and for the treatment of disease, herbs are perceived as natural, safe, and for promoting health. However, "natural" does not necessarily equate to safe. Lack of standardization in preparation and packaging of herbs, as well as potency problems, has resulted in variable and nonreproducible outcomes.4

Most herbal products sold in the U.S. are marketed as dietary supplements and subsequently are not required to have Food and Drug Administration (FDA) approval or regulation. Moreover, most herbs do not qualify for United States Pharmacopeia (USP) designation for meeting standards of strength, quality, purity, and labeling. Products without FDA approval or USP designation may carry a National Formulary (NF) symbol, which indicates the product has been used extensively without documented adverse risks.4 The 1994 Dietary Supplement, Health, and Educational Act (DSHEA) requires manufacturers to ensure that products placed on the market are safe. Therapeutic claims can be disseminated into the marketplace as long as the information is not misleading or product-specific. Manufacturers do not have to submit data to the FDA if product ingredients were marketed before 1994. However, new food ingredients require safety information for PDA review 75 days before the product goes to market. If the FDA suspects that an herbal agent is unsafe, the product can be removed from the market.6,7 With the increasing popularity of alternative therapies and increasing demand for information, the National Institutes of Health (NIH) established the Office of Alternative Medicines (OAM) in 1992.4,5

Since herbal products are not required to be tested in clinical trials before marketing, evidence for efficacy and interaction effects are limited.8 Clinical trials often have small sample sizes, short study timelines, and variable outcomes that fail to demonstrate efficacy of the agent.1'4 The historical use of herbs over the centuries is a strong argument against supporting evidence-based studies. Furthermore, herbs cannot be patented; therefore, the incentive for manufacturers to pursue clinical trials is low. The average cost to bring a new medication to market is an estimated $350 million to fund research and regulatory requirements.4 Therefore, adverse effects, drug interactions, dependence issues, and even favorable effects of herbs are usually identified only after many people experienced the effect of a particular herbal agent.5 Differences in quality, batch-to-batch variability, and the current regulatory environment suggest that consumers should exercise caution in purchasing and using herbal therapies.4