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Think All Herbal Supplements Are Safe?

Are you one of many Americans taking herbal supplements in addition to prescription medicine? It is important to know that your prescription medication and herbal supplements may contraindicate each other.

According to the National Institutes of Health (NIH), herbal supplements are a type of dietary supplement that contains herbs, either singly or in mixtures. An herb (also called a botanical) is a plant or plant part used for its scent, flavor, and/or therapeutic properties.

Many herbs have a long history of use and claimed health benefits. However, some herbs have caused health problems for users, and it is important to know that just because an herbal supplement is labeled "natural", that does not mean it is safe or without any harmful effects.

Are you one of the 14% of the aging population who is consuming over 40% of over-the-counter remedies, including herbal supplements? If so, the NIH strongly encourages you to disclose all over- the- counter medications, including herbal remedies, vitamins, and supplements, to your doctor. Here is a partial list of common prescription medications used for vascular conditions, along with some of the herbal supplements that can cause a potentially harmful response.

This list includes the brand name along with the generic name, and the supplements listed can either strengthen or weaken the medication’s effectiveness. As this is a partial list, please consult your doctor with additional questions you may have about other supplements you are taking .

Plavix® (Clopidogrel): astragalus, bilberry, borage, borage seed oil, cayenne, clove, dong quai, evening primrose oil, feverfew, garlic, ginger, ginkgo biloba, ginseng (American, Panax, and Siberian), green tea, kava kava, licorice, pau d’arco, saw palmetto, stinging nettle, turmeric, valerian, vitamin E, white willow, and yarrow.

Coumadin, Jantoven® (warfarin): acerola, alfalfa, allspice, angelica, astragalus, bilberry, bladderwrack, borage, borage seed oil, bromelain, cayenne, chlorella, clove, dong quai, evening primrose oil, feverfew, garlic, German chamomile, ginger, ginkgo biloba, ginseng (American, Panax, and Siberian), grapefruit, grape seed, green tea, kava kava, kelp, licorice, niacin, papaya, pau d’arco, pineapple, psylium, quinine, red clover, rose hips, saw palmetto, soybean, spinach, stinging nettle, St. John’s wort, sweet clover, valerian, vitamin A, vitamin C, vitamin E, vitamin K, white willow, wintergreen, and yarrow.

Pletal (Cilostazol): digitalis, Indian squill, squill.

Lovenox® (Enoxaparin): alfalfa, allspice, angelica, anise, arnica, astragalus, bilberry, bladderwrack, borage, borage seed oil, bromelain, cayenne, clove, dong quai, evening primrose oil, fenugreek, feverfew, garlic, German chamomile, ginger, ginkgo biloba, ginseng (American, Panax, and Siberian), goldenseal, grape seed, green tea, kava kava, licorice, papaya, parsley, pau d’arco, pineapple, red clover, saw palmetto, stinging nettle, St. John’s wort, sweet clover, turmeric, valerian, vitamin E, white willow, wintergreen and yarrow.

Aspirin (Bufferin, Ecotrin): allspice, angelica, anise, arnica, astragalus, bilberry, bladderwrack, borage, borage seed oil, bromelain, calcium, cat’s claw, cayenne, clover, dong quai, English Hawthorn, evening primrose oil, fenugreek, feverfew, folic acid, garlic, German chamomile, ginger, ginkgo biloba, ginseng (American, Panax, and Siberian), grape seed, green tea, kava kava, licorice, onion, parsley, passion flower, pau d’arco, pineapple, potassium, quinine, red clove, saw palmetto, stinging nettle, St. John’s wort, sweet clover, turmeric, uva ursi, valerian, vitamin C, vitamin E, white willow, winter green, yarrow, and zinc.

If you are taking Plavix®, warfarin or Lovenox, garlic may increase the risk of bleeding or bruising. If you are using ginko biloba and taking aspirin, Heparin, Plavix®, ibuprofen, Lovenox®, Aleve, or warfarin, you may also have increased risk of bleeding or bruising.

Here are some other common herbs that people take without realizing the side effects or how they might interact with medications.

St. John's wort sometimes is taken for anxiety and depression. Those who also are taking antidepressants or anti-anxiety medications, such as Prozac, Zoloft, or Paxil, should beware. Mixing St. John's wort with these medicines can cause serotonin syndrome - with symptoms that may include agitation, rapid heart beat, flushing, and heavy sweating - that may be fatal.

Dong quai, which some women take for menstrual disorders and to ease symptoms of menopause, has been linked to cardiovascular problems, such as irregular heart rhythm and low blood pressure. Taking the herb along with an antihypertensive drug could cause the blood pressure to plummet, putting one at risk of stroke.

Some people take echinacea, which enhances the immune system, for the common cold. However, those who also take Lipitor, Celebrex, and Aleve face an increased risk of liver damage. Echinacea also can be harmful for those who have multiple sclerosis, diabetes, HIV infections, or allergies.

This is a partial list of interactions and should not be considered as the only list or as a comprehensive list of herbals that may interfere with prescription medications. Just remember, “herbal” or “all natural” does not necessarily mean safe. Make sure that you give your health- care provider a complete list of every medication, herbal, and dietary supplement you are taking. It may make the difference between having a bad reaction and being safe.

About the Author:

George Grossberg, M.D., is director of geriatric psychiatry at Saint Louis University School of Medicine and Samuel W. Fordyce Professor of Psychiatry. An internationally renowned geriatric psychiatrist, Dr. Grossberg is coauthor of "The Essential Herb-Drug-Vitamin Interaction Guide" and immediate past-president of the International Psychogeriatric Association. He has done extensive research on Alzheimer's disease.