Are Your Patients Taking Herbal Meds?
Alternative medicine has achieved widespread popularity in the United States in recent years. One survey of trends in alternative medicine use found that people in the U.S. visit alternative medicine practitioners more frequently than primary care physicians.1 Another recent survey of alternative medicine use in 3,106 pre-surgical patients found that 22 percent of patients were taking herbal remedies and 51 percent were taking vitamins.2 The greatest use of these therapies occurred among women between the ages of 40 and 60. The most common herbs used were echinacea, gingko biloba, St. John’s wort, garlic and ginseng.2 Through the wealth of information available on the Internet and via the media, consumers often choose to take herbs, vitamins and other supplements prior to consulting with their primary care provider. Since these products are marketed as “natural,” consumers are led to believe that dietary supplements are safe and free of side effects and/or potential complications. However, unlike prescription medications, dietary supplements and herbs are not regulated by the Food and Drug Administration (FDA). As a result, these products are not required to go through the FDA approval process or comply with quality assurance measures. Therefore, product consistency is often unreliable. For example, an analysis of ginseng products found that the amount of active ingredient varied 10-fold between brands, with some brands containing no active ingredient at all.3 Undocumented use of dietary supplements can cause a number of problems, especially in the perioperative period. Potential problems of herbs include toxicity due to overdose, contamination, quality control, physiological changes on bodily systems and adverse drug reactions.4 In addition, the use of herbs can potentially cause coagulation disorders, cardiovascular side effects, water and electrolyte disturbances, endocrine effects, hepatotoxicity and/or prolongation of the effects of anesthesia. Given these potential side effects, it is imperative to question patients specifically about herbs and supplements prior to performing any surgical procedure. To complicate the situation, rigorous studies have yet to be conducted on the effects and potential drug interactions of most of the herbs and dietary supplements used by patients today.4 Much of the information currently known about problems associated with herb and/or dietary supplement use comes from case reports. In such cases, dosages and other concomitant drug use are not often mentioned. The paucity of experimental data on the side effects and potential drug interactions of dietary supplements warrant caution whenever they are used in the perioperative period. As a result, the American Society of Anesthesiology recommends that physicians specifically ask about preoperative herb and supplement use, and that patients stop taking herbal preparations two weeks prior to any procedure.5 With this in mind, we will take a closer look at the potential physiologic effects and drug interactions of some of the most commonly used herbs and dietary supplements, specifically gingko biloba, garlic, St. John’s wort, ginseng and echinacea. A Closer Look At Gingko Biloba Gingko biloba is an extract from the leaves of the gingko tree, the world’s oldest living tree. It is recommended primarily for dementia and intermittent claudication, but is often used to treat depression, erectile dysfunction of vascular origin, macular degeneration and vertigo as well.6 Glycosides and terpene lactones are two active ingredients in gingko. The glycosides are responsible for the antioxidant activity of gingko as well as inhibition of platelet aggregation. The terpene lactones increase circulation to the brain and other parts of the body, and may exert a protective effect on nerve cells.6 The usual dose of gingko is 120 to 240 mg QD. Side effects include mild headache, stomach upset and prolonged bleeding time.6 In addition, some serious bleeding problems have occurred secondary to the use of gingko. One 61-year-old man taking 120 mg of gingko QD for six months developed prolonged bleeding with a subsequent subarachnoid hemorrhage.7 After the patient discontinued the gingko, his bleeding time returned to normal.