Herbal Products May Interfere with Migraine Drugs Thu Jun 19, 1:36 PM ET Add Health - Reuters to My Yahoo! By Alan Mozes NEW YORK (Reuters Health) - Commonly prescribed migraine medications can potentially be rendered ineffective or even toxic when taken along with certain popular herbal supplements, according to researchers. In addition, their study found that some supplements -- including ginkgo biloba, ginseng, St. John's wort and valerian root -- might actually trigger or worsen migraines in some people prone to them. The findings are being presented this week at the American Headache Society's annual meeting in Chicago. According to the researchers, migraine medications in the triptan class of drugs and tricyclic antidepressants -- which are used to prevent migraines in some people -- can interact with supplements such as gingko biloba, ginseng, echinacea (news - web sites) and St. John's wort. The herbs can interfere with the liver enzymes that metabolize these drugs and potentially make them toxic, they say. "In the U.S. herbal products are not standardized or regulated by the FDA (news - web sites) (Food and Drug Administration)," said study author Dr. Carla Rubingh of the University of Utah in Salt Lake City. "People see them as all-natural ... and are not informing their physicians that they are taking them." "But just because (manufacturers) say the herbs are all-natural or from plants doesn't mean that they are without side effects or drug interactions," Rubingh told Reuters Health. "These supplements need to be recognized as medications," she said. "Patients need to tell their physicians they are taking them, and physicians need to ask if they are taking them and know how they might interact with medications." Rubingh and her colleagues also caution that some herbal supplements -- often taken in the hopes of boosting memory and energy or to alleviate colds and depression -- could help trigger or worsen both migraines and so-called cluster headaches among people predisposed to them. Migraines typically involve severe pain on one or both sides of the head, sometimes accompanied by nausea, loss of appetite and blurred vision. Cluster headaches are marked by sudden, severe pain, often centered in one eye; these headaches come in waves, typically with several pain-free weeks in between. For their study, Rubingh and her colleagues used data from the FDA and other sources to rank the top-selling herbal products in the U.S. They then reviewed past research on the herbs, looking particularly at the products' mechanisms of action and possible side effects to see how they might interact with migraine drugs or contribute to headaches. For example, they explain, one mechanism of ginkgo is to boost blood flow to the brain, which might worsen migraine or cluster headaches in some people. Speaking during a telephone press conference this week, Rubingh focused on the potentially large number of patients who should be concerned about such potential drug-supplement interactions. She noted that an estimated 30 million American men and women suffer from migraine headaches, while about 2.5 million experience cluster headaches. And although the exact percentage of migraine and cluster-headache patients who take herbal supplements is not clear, Rubingh said the overlap is probably substantial since an estimated 40 percent of Americans have taken herbal supplements at some point. "So if I could tell people one thing," she said, "it would be that these patients do need to let their physician and their pharmacists know that they are taking these supplements."