April 17, 2000 (San Francisco) -- If a trip to the grocery store has left you feeling awash in a sea of herbs and dietary supplements, it's no wonder. There are more of these products on the market than ever before, and it's often difficult to know which ones are safe to take.
Earlier this year, for example, researchers at the National Institutes of Health (NIH) discovered that St. John's wort can interfere with AIDS drugs. The Food and Drug Administration (FDA) has warned that this herb may also cause trouble for people who've had organ transplants, as well as those who take common drugs for heart disease, high blood pressure, depression, and certain cancers. Mainstream research on how other herbs might interact with medications is just beginning.
But experts say that following a few basic guidelines can help you use herbs and supplements safely. Start with this basic assumption: If herbs work, then they can interact with other drugs, says Varro Tyler, dean emeritus of the Purdue University School of Pharmacy and Pharmacological Sciences.
"Use a little common sense," he says. Don't use both an herb and a prescription drug for the same purpose. For instance, if you take kava kava to relieve anxiety, don't also take Valium. If you take ephedra as a pick-me-up, don't use it with caffeine. And remember, many herbs such as garlic, ginger, ginkgo, and feverfew can act as blood thinners. So you shouldn't take them with aspirin or other drugs that thin the blood.