Are Dietary Supplements Interacting with Medications and Causing Harm?

Combining dietary supplements and medications can have serious and even fatal consequences. Dietary supplements are products designed to provide the body with the nutrients it needs, according to Walls. These supplements can interfere with the prescription medications you're taking, he says. Chemical interactions can be minor or dangerous, weakening your medications and making them less effective, or making your prescriptions more powerful.

An observational study showed that herbal supplements are associated with adverse events of all levels of severity and affect all age groups. The problems that result from taking supplements and medications together can be especially hazardous if you are going to have surgery or if your prescription has a “narrow therapeutic range.” Unless patients make sure that all providers have an up-to-date list of medications and supplements, providers may not know precisely what patients are taking or report the risks related to those drugs and supplements. Botanical supplements (such as garlic, ginger, ginkgo biloba, echinacea, and others) are made from plant material, so many of them are sold as “natural products.” Echinacea, ginkgo biloba, glucosamine, omega-3 fatty acids and garlic were the most commonly used supplements. However, dietary supplements aren't totally safe and taking them can pose risks, especially for people being treated for cancer.

In 1994, Congress defined a dietary supplement as a product that is taken orally and that contains a “dietary ingredient” intended to supplement the diet. Supplements can affect how your body responds to anesthesia and medications you may need before, during, and after surgery. And remember: regardless of what the supplement manufacturer says, dietary supplements are not intended to treat, diagnose, cure, or alleviate the effects of diseases. It is important to talk to your health care team before taking large doses of any vitamin, mineral, or other supplement.

Unfortunately, there isn't enough clinical evidence to know exactly how these supplements interact with all medications or with each other. Improvements in obtaining information on the use of HDS (Herbal Dietary Supplements) and other medications and in providing electronic decision-making support on interactions between supplements and medications may be important in preventing ED (Emergency Department) visits in ambulatory care. Phillips received the NIH K24-AT000589 mid-career researcher award from the NIH's National Center for Complementary and Alternative Medicine (NCCAM). Patients were asked after 10 days and again after 3 months if they “regularly took any non-prescription medications, such as herbal supplements and other dietary supplements” in order to better understand how these substances interact with each other.