The dietary supplement industry has grown dramatically since the passage of the Dietary Supplement and Health Education Act (DSHEA) in 1194.
As typified by the below noted statistics, people are now taking an interest in participating in and maintaining their own health. Recent surveys indicate that more than half of the U.S. adult population use dietary supplements. According to Nutrition Business Journal in their 1998 Annual Industry Overview, consumers spend more than $12 billion on dietary supplements annually. Herbals encompass about a third of the $12 billion.
The successful use of herbal products for a variety of medical ailments is without question. However, some of the conditions that herbs are recommended for are not always suitable for self-treatment and may not be a substitute for proper medical care. In 1997, 23 million Americans took herbs for reasons such as headaches, hypertension, depression, weight loss, and sexual stamina.
Many consumers believe that botanical products are "natural" and, therefore, safe and effective, and are not fully aware that herbs are not regulated by the Food and Drug Administration (FDA) and can be toxic and potentially fatal if used excessively or in combination with certain over-the-counter or prescription drugs.
Historically, herbs and drugs were presented as two very different treatment modalities that rarely, if ever, were used together. Today, it is quite common for a patient to seek a botanical treatment while taking prescription medications.
An estimated 15 million Americans take herbal remedies and/or high-dose vitamins concurrently with prescription medications ; however, it appears that many patients are not forthcoming about their use of these products. More than 60percent of the people who use alternative therapies do not tell their health care providers.
Dietary supplements, particularly botanical products, were previously distributed mainly in health food store. Now, herbs are sold in supermarkets, department stores, retail pharmacies and via the Internet.
With that in mind, pharmacists are now in a position to help educate the public about the us of herbal products. The pharmacist needs to be aware of the possible interactions between herbs and pharmaceutical drugs.
Highlighted are six commonly used herbs, some of their noted uses, and their potential interactions with certain medications and/or therapeutic categories. Because published information may be unreliable and, in many cases, interactions are not reported in medical literature, some of the highlighted interactions may not be tested or proven. It is suggested that products with the same action will present the greatest chance of herb-drug interactions.
1.Echinacea is promoted for its ability to help support the body's natural defense systems. It has become extremely popular for the treatment of colds, influenza, and other respiratory tract infections.
Echinacea could cause hepatotoxicity and, therefore, should not be used with other known hepatoxic drugs, such as Nizoral®, methotrexate, Cardarone®, or anabolic steroids.
Echinacea may increase the action of anticoagulant therapy. Monitoring drug response would be recommended.
The German Commission E considers the use of Echinacea contraindicated for patients undergoing treatment for severe, chronic progressive disease. As such, Echinacea should not be combined with the following type of medications:
antineoplastic agents;
antiretroviral agents;
immunosuppressives; and,
Prednisone® or other corticosteroids.
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2. Feverfew has been reported to be effective for the prevention of migraines.
Since Feverfew is a serotonin antagonist, it may interact with drugs that potentiate serotonin. Patients should avoid combining Feverfew with tricyclic antidepressants, serotonin reuptake inhibitors (SSRIs), and monoamine oxidase (MAO) inhibitors.
Feverfew could also increase the risk of bleeding in people taking heparin, warfarin, Coumadin®, aspirin, Plavix®, Ticlid.®
Nonsteroidal antiinflammatories may negate the usefulness of Feverfew in the treatment of migraine headaches.
3. Ginkgo biloba is often promoted for improving the symptoms of Alzheimer's disease, memory loss, impaired mental performance, dizziness, ringing in the ears, and circulatory disorders.
Ginkgo biloba inhibits platelet-activating factor (PAF); therefore, it may pose a hazard with anticoagulants, such as heparin, warfarin, Coumadin, aspirin, Plavix, Ticlid.
It has also been suggested that Ginkgo biloba may also interact with the following therapeutic categories and medications:
thiazide diuretics;
tricyclic antidepressants; and,
Zyban®
The American Herbal Products Association suggests that Ginkgo biloba may interact with monoamine oxidase (MAO) inhibitors.
4. Ginseng is commonly promoted to help fight fatigue, improve performance and as a stress reducer.
Ginseng may alter bleeding time and should not be used concomitantly with heparin, warfarin, Coumadin, aspirin, Plavix, or Ticlid.
There have also been reports in literature of possible interactions with Ginseng and phenelzine and Ginseng and digoxin.
Ginseng should not be used with estrogens or corticosteroids because of possible additive effects.
5. A few studies have demonstrated that Saw Palmetto has the ability to improve symptoms associated with benign prostate hypertrophy.
Because Saw Palmetto berries have both estrogenic and antiestrogenic activity, it should not be used in combination with contraceptives or hormone replacement therapy (HRT). Saw Palmetto also has the ability to inhibit 5-a-reductase; therefore, patients taking Proscar and Propecia may want to avoid Saw Palmetto.
6. St. John's Wort is commonly used by consumers to treat mild to moderate depression.
Since St. John's Wort contains a photoactive chemical, it should not be taken with photosensitizers, such as tetracylines, ot during prolonged activity in the sun.
There have also been case reports that theophylline, digoxin, cyclosporin, and oral contraceptives interact adversely with St. John's Wort.
Because St. John's Wort may have serotonin reuptake action, it is best to avoid serotonin reuptake in hibitors (SSRIs), monoamine oxidase (MAO) inhibitors, and Ultram®.
In a recent study, St. John's Wort substantially decreased indinavir plasma concentrations.
Because of the high tannin content of St. John's Wort, it should not be taken at the same time as iron supplements, ephedrine, pseudoephedrine, or codeine.
| Fifteen million Americans are at risk for herb-and/or vitamin-drug interactions. |
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