AN OVERVIEW OF HERBAL MEDICINES AND ADVERSE EVENTS

The use of herbal medicines has become a part of the U.S. mainstream. Surveys suggest that about one-third of Americans use herbal products as medications. Some use herbal products with conventional medications, others use them as a replacement. For western-trained health practitioners, such use poses a dilemma. Few practitioners have received herbal medicine education during their training. A great deal of herbal medicine information is written in foreign languages, but it is slowly becoming available in English. Some of the information is available as human clinical research reports, but most includes practitioner observations and historic use records.

Conventional drugs, regulated by the Food and Drug Administration (FDA), require quality assurance in manufacturing, labeling accuracy, demonstrated safety and efficacy before marketing, and post-marketing surveillance for adverse effects. They are available, only by prescription, from a trained, licensed prescriber. On the other hand, herbal medicines are regulated as "food supplements," under the Dietary Supplement and Health Education Act (DSHEA) of 1994. As such, there are no quality assurance requirements for manufacturing and labeling. Claims on the labels about efficacy or use are loosely regulated. Yet, DSHEA requires a disclaimer on package labeling: "This statement (about use of the product) has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease."

While efforts continue to establish and regulate good manufacturing practices for herbals, no standards or guidelines exist to assure quality. There are no provisions for pre-marketing approval to demonstrate safety and efficacy. Plant materials may be misrepresented or substituted by manufacturers, or may contain environmental or man-made contaminants. They may contain little or none of the plant materials listed on the label, or an entirely different plant material than is listed on the label. Some products may have been adulterated with conventional drugs. Since herbal medicines are freely available for sale, without limitation or medical consultation, a person with a significant health problem may, through self-guidance or untrained advice, postpone seeking adequate medical care. They may even abandon conventional drug therapy in favor of herbal therapy alone.

Herbal medicines appear relatively safe, but there is limited human research or prospective/retrospective data concerning adverse events and herbal-drug interactions. They are generally less potent than their pure drug relatives because they contain a mixture of many chemicals in small quantities. Thus, they have a longer onset of action than conventional drugs. Although they appear to have a lower risk of adverse effects, herbal products are not free of risk.

Practitioners should learn about herbal medicines and other alternative therapies; keep rational, reliable herbal medicine references on hand; ask patients about their use of alternative therapies, including herbal medicines; record all findings in the patient's medical record; monitor patients carefully, and report observations of adverse/unusual events; and ask patients to keep a daily diary of all therapies they use, and to bring it in for review at each visit to a healthcare professional.

NOTE: The above reprinted from the "ISMP MEDICATION SAFETY ALERT," Volume 3, Issue 17, August 26, 1998, published by the Institute for Safe Medication Practices (ISMP). Reprinted with permission.