Herbal and Nonherbal Supplements Compromise Safety and Effectiveness of Warfarin

May 13, 2010

Media Contact

Ken Demith
Heart Rhythm Society

DENVER, May 13, 2010 – Common herbal and nonherbal supplements, such as garlic, ginkgo and essential fatty acids, contribute to an increased risk of health complications in patients treated with warfarin. According to a new study released today at Heart Rhythm 2010, the Heart Rhythm Society’s 31st Annual Scientific Sessions, eight out of the top ten supplements commonly taken by American consumers have been reported to impact the effectiveness of warfarin and overall safety of the individual.

Nearly twenty percent of Americans use herbal and nonherbal supplements, yet many patients do not disclose supplement intake with physicians. A unique, new study conducted by a team of researchers from Intermountain Health Center analyzed the top 20 herbal and 20 nonherbal supplements taken by Americans based on 2008 sales data. Researchers examined supplement and drug interactions with reported changes in International Normalized Ratio (INR), bleeding and thromboembolic events.

Findings reveal that of the top ten most commonly used herbal and nonherbal supplements – glucosamine, chondroitin, co-enzyme Q10, multi-herbs, probiotic, antioxidants, melatonin, cranberry and soy – more than 90 percent have been reported to interact negatively with warfarin. Of the 40 most commonly taken supplements, 35 percent were associated with a significant change in INR, 64 percent increased the risk of bleeding and 36 percent decreased the effectiveness of warfarin.

“Most people don’t perceive herbal and nonherbal supplements as medication, so they don’t share information with their doctors about the supplements they are taking,” stated Jennifer Strohecker, PharmD, at Intermountain Medical Center in Salt Lake City, Utah. “Typically, people take supplements with the intention of improving their health; however, many supplements can have an undesirable interaction with other medications. It’s important for patients to disclose as much information as possible about how they are treating themselves to ensure they receive the highest quality of care possible.”

About the Heart Rhythm Society

The Heart Rhythm Society is the international leader in science, education, and advocacy for cardiac arrhythmia professionals and patients, and the primary information resource on heart rhythm disorders. Its mission is to improve the care of patients by promoting research, education, and optimal health care policies and standards. Incorporated in 1979 and based in Washington, DC, it has a membership of more than 6,000 heart rhythm professionals in more than 72 countries around the world. For more information, visit www.HRSonline.org.