51st Annual American Academy of Family Physicians Scientific Assembly [Medscape, 1999. © 1999 Medscape, Inc.]
Herbal Therapies Steven B. Tamarin, MD


Complementary and alternative medicine are of keen interest to patients, who often come to their physicians with questions about the effectiveness of a broad range of "natural" remedies. Several presentations at this year's AAFP Scientific Assembly addressed this topic, including 2 seminars on medicinal herbs.

One presentation, by Ellen Hughes, MD,[1] associate professor of medicine and interim director of the Oscher Center for Integrative Medicine at the University of California, San Francisco, was canceled
because of Hurricane Floyd. However, her handout was made available to attendees. The other presentation was by Raul Zimmerman, MD,[2] a clinical assistant professor of family medicine at the University of South Florida College of Medicine.

A Long History

Plants have been used for their medicinal value for thousands of years. Most early medications and approximately 25% of our current
prescriptions are plant-based. Botanicals have been used as medication in this country, although their use has been confined to rural and other discrete areas. In Europe, notably in the United Kingdom, Germany, and Japan, naturopathy, or the treatment of diseases using plant-based therapies, has achieved the status of an accepted discipline. In these countries, students are formally trained in the discipline and the quality of herbal medications is regulated as much as we monitor pharmaceuticals in this country.

Scope of Use

Americans spent more than $4 billion on herbal medications in 1997.[3,4] It is estimated that in 1993, 60 million Americans used alternative therapies at a cost of $13.7 billion. Many of these patients use herbal preparations in addition to prescription drugs; approximately 70% never mention it to their physicians.

Whether or not physicians believe that herbals have value, patients are using them. The AAFP presentations underlined the need, therefore, to be informed about the risks, benefits, interactions, and science related to the use of these substances.

Are Herbal Therapies Safe?

A question raised in both presentations was whether herbal preparations are safe and effective. Prior to 1994, herbs were in a "nether" category between medication, which is regulated by the Food and Drug Administration (FDA) for safety and efficacy, and food, which is regulated for manufacturing standards and safety. Herbals were not consistently in either category and so the FDA proposed to regulate food supplements including herbals.

A public relations campaign by the supplement industry followed, which included deluging Congress with 4 million letters and faxes and commercials portraying FDA supplement policy as overly harsh. Thus, the Dietary Supplement Health and Education Act of 1994 was passed. This law classifies vitamins, minerals, herbs, and amino acids as dietary supplements and frees their manufacturers from having to test for or prove safety, efficacy, or standards of manufacturing.

In fact, the FDA must prove that a product is unsafe. This has led to several examples of how consumers have been put at risk by use of certain supplements. One example was the contaminated L-tryptophan that caused fatalities related to the eosinophilic-myositis syndrome.[5] There also have been reports of intentional contamination by analgesics, steroids, and sedatives and other undeclared prescription medications
for a more dramatic effect.[6,7] 

What Now?

So where does that leave the physician who would like to recommend botanical remedies to patients that prefer them to medications with known adverse effects?
It has been widely assumed that there is no science to support the use of herbals as medications. Until recently, the literature indeed has been scarce, particularly with regard to solid clinical studies. In
fact, now there is a large body of European and Japanese literature that assesses the medical use of a number of herbals.

One of the most useful compilations is the Report of the German E Commission, recently translated, and now published in English by the American Botanical Council 1997.[8] This commission included physicians, pharmacists, toxicologists, and botanists, who wrote approximately 400 monographs between 1978 and 1994. They evaluated the available data and determined whether there was reasonable certainty of the safety and efficacy of the medicinal use of the plants studied. They also established standard preparations and doses.

In the US, Congress has created the National Center for Complementary and Alternative Medicine,[9] which is translating data and coordinating study centers throughout the United States to review a variety of areas. Another useful source of information is the US Department of Agriculture's phytochemical and ethnobotanical database.[10] Increasingly, studies of herbal preparations and their effectiveness -- or lack thereof -- are being published in peer-reviewed medical journals.

Clinical Applications

The speakers at the AAFP meeting reviewed the clinical use of the most popular herbs with data supporting their use as well as underscoring the need for caution.[11,12]

Dr. Zimmerman discussed some well-documented drug-herb interactions. Nonsteroidal anti-inflammatory drugs may negate feverfew, for example, echinacea can potentiate the toxicity of hepatotoxic drugs, and ginkgo, ginger, and ginseng should not be used with coumadin due to their anticoagulant effects.[13,14]

Citing a poll in Good Housekeeping Magazine and data from herbal manufacturers, Dr. Zimmerman cited the most popular herbs now in use:
ginseng, garlic, ginkgo biloba, echinacea, St. John's wort, goldenseal, saw palmetto, aloe, Siberian ginseng, pycnogenol/grapseed extract, and evening primrose oil.

One of the most popular and widely used herbs is St. John's wort, which is reported to be effective for mild to moderate depression and to have few adverse effects. The dose is 300 mg 3 times daily as .3%
hypericin.[15]

Ginkgo biloba has recently become popular following reported modest improvement of cognitive functioning in some people with dementia caused by Alzheimer disease or cerebrovascular disease. In addition, ginkgo is used for sexual dysfunction caused by selective serotonin reuptake inhibitors and in peripheral vascular disease. The dose range is 80 to 240 mg/day 2 or 3 times daily.[16]

Kava kava is used for anxiety, insomnia, and muscle tension, but there is concern regarding drug and alcohol interactions, and a yellow scaly rash has been reported at high doses (>9 g/day). The dose is 100 mg 3 times daily of kava extract WS 1490.[17]

Studies indicate that saw palmetto is safe and effective for the symptoms of benign prostatic hyperplasia. The usual dose is 160 mg of standardized extract containing 85% to 95% fatty acids and sterols (Permixon) 3 times daily. The main adverse effects are gastrointestinal.[18,19,20]

Echinacea is used for short-term treatment and prevention of respiratory infections. There are numerous preparations and doses.[21,22] Some data support the use of milk thistle as a liver protective in mild cases of alcoholic cirrhosis.[23]

Garlic is used to improve lipids and hypertension.[24,25]

Feverfew is used for the prophylaxis of migraine and cluster headaches.[26]

Finally, ginger is used as an antiemetic, especially in pregnancy.[27]

Summary

As more data regarding the safety and efficacy of herbal preparations become available, especially in the prestigious peer-reviewed literature, and as more standardized preparations from reputable manufacturers come to the market, perhaps physicians will be in a more comfortable position to inform patients about the appropriate use of botanical medicinals.

References

Hughes E. Botanicals: what are your patients taking? Programs and abstracts from the 1999 Scientific Assembly of the American Academy of Family Physicians; September 16-19, 1999; Orlando, Fla. Abstract 503.
Zimmerman RL. Herbal therapies: new for 1999. Programs and abstracts from the 1999 Scientific Assembly of the American Academy of Family
Physicians; September 16-19, 1999; Orlando, Fla. Abstract 033.

Astin JA. Why patients use alternative medicine: results of a national study. JAMA. 1998;279:1548-1553.
Johnston B. One-third of nation's adults use herbal remedies: market estimated at $3.24 billion. Herbalgram. 1997;40:49.
Ko RJ. Adulterants in Asian patent medicines. N Engl J Med.
1998;339:847.
Gertner E, Marshall PS, Filandrinos D, Potek AS, Smith TM. Complications resulting from the use of Chinese herbal medications containing undeclared prescription drugs. Arthritis Rheum. 1995;38:614-617.

Slifman NR, Obermeyer WR, Aloi BK, et al. Contamination of botanical dietary supplements by Digitalis lanata. N Engl J Med. 1998;339:806-811.
Blumenthal M, Busse WR, eds. Klein S, trans. German Commission E
Monographs. Austin, Tex: American Botanical Council; 1997.
Available at: http://altmed.od.nih.gov.
Available at: www.ars-grin.gov/duke.
O'Hara MA, Kiefer D, Farrell K, Kemper K. A review of 12 commonly used medicinal herbs. Arch Fam Med. 1998;7:523-536.
Varro T. Herbs of Choice: The Therapeutic Use of Phytochemicals. New York, NY: Pharmaceutical Products Press; 1994.

Miller L. Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions. Arch Intern Med.
1998;158:2200-2211.
Cupp ML. Herbal remedies: adverse effects and drug interactions. Am Fam Physician. 1999;59:1239-1244.
Linde K, Ramirez G, Mulrow CD, Pauls A, Weidenhammer W, Melchart D. St. John's wort for depression; an overview and meta-analysis of randomized clinical trials. BMJ. 1996;313:253-258.

Le Bars PL, Katz MM, Berman N, Itil TM, Freedman AM, Schatzberg AF, and the North American EGb Study Group. A placebo-controlled, double-blind randomized trial of an extract of Ginkgo biloba for dementia. JAMA.
1997;278:1327-1332.
Volz HP, Kieser M. Kava-kava extract WS1490 versus placebo in anxiety disorders: a randomized placebo-controlled 25-week outpatient trial.
Pharmacopsychiatry. 1997;30:1-5.

Carraro, JC et al. Comparison of phytotherapy (Permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients. Prostate
1996;29:231-240.
Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA. 1998;280:1604-1609.
Lowe FC, Ku JC. Phytotherapy in treatment of benign prostatic hyperplasia: a critical review. Urology. 1996;48:12-20.

Melchart D, Linde K, Worku F, et al. Results of five randomized studies on the immunomodulatory activity of preparations of echinacea. Altern Complement Med. 1995;1:145-160.
Melchart D, Linde K. The Cochrane Collaboration Database of Systematic
Reviews. Jan 1999. Available at:
http://hiru.mcmaster.ca/cochrane/default.htm.

Flora K, Hahn M, Rosen H, Benner K. Milk thistle (Silybum marianum) for the therapy of liver disease. Am J Gastroenterol. 1998;93:139-143.
Isaacsohn JL, Moser M, Stein EA, et al. Garlic powder and plasma lipids and lipoproteins: a multicenter, randomized, placebo-controlled trial.
Arch Intern Med. 1998;158:1189-1194.

Berthold HK, Sudhop T, von Bergmann K. Effect of a garlic oil preparation on serum lipoproteins and cholesterol metabolism: a randomized controlled trial. JAMA. 1998;279:1900-1902.
Murphy JJ, Heptinstall S, Mitchell JR. Randomised double-blind placebo-controlled trial of feverfew in migraine prevention. Lancet.
1988;2:189-192.
Aikins Murphy P. Alternative therapies for nausea and vomiting of pregnancy. Obstet Gynecol. 1998;91:149-155.

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