Overview of Herbal Medicines

Overview of Herbal Medicines

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.