NIH Conference on Dietary Supplements, Coagulation, and Antithrombotic Therapies
Ann K Wittkowsky, PharmD, CACP, FASHP
Anticoagulation specialists are well aware of the potential dangers associated with concurrent use of warfarin and a number of dietary supplements. The growing rate of supplement use in the US, and the increasing number of case reports describing significant interactions between warfarin and non-drug products has elevated the level of concern about the safety of dietary supplements when used in conjunction with antithrombotic agents.
As defined by Congress in the 1994 Dietary Supplement Health and Education Act, these products include vitamins, minerals, herbals or other botanical products, and amino acids intended to supplement the diet. Unlike drugs, dietary supplements do not have to be proven safe or effective prior to marketing, and do not have to be produced according to the Good Manufacturing Practices that assure the quality of drug products in the US. Many consumers consider these products safe because they are "natural", but case reports and clinical trials have shown otherwise, particularly in patients who take these products concurrently with antithrombotic agents. Nonetheless, information regarding dietary supplement interactions with antithrombotic agents is limited.
The National Institutes of Health (NIH) recently held a 2-day conference on dietary supplements, coagulation, and antithrombotic therapies. It was sponsored by the National Heart, Lung and Blood Institute (NHLBI), in collaboration with the Office of Dietary Supplements (ODS), and the National Center for Complementary and Alternative Medicine (NCCAM), as well as a number of other centers and institutes within NIH.
The purpose of the conference was to increase understanding of the potential for dietary supplements to interfere with hemostasis and antithrombotic therapy and to "discuss current knowledge, review regulatory and safety issues, share recent clinical trial findings, and identify opportunities for further research". (http://www.nhlbi.nih.gov/meetings/coagulation/index.htm)
The conference was presented and attended by representatives of the NIH, the FDA, and experts from academia, industry, and numerous professional, regulatory and patient-advocacy organizations. Proceedings of the conference will be published in December 2005 in Thrombosis Research. Until then, background material related to the conference is available at: http://www.nhlbi.nih.gov/meetings/coagulation/index.htm. The full agenda can be viewed at: http://www.nhlbi.nih.gov/meetings/coagulation/agenda.htm
AC Forum members may also want to access additional information about dietary supplements at the ODS website, including:
IBIDS Database: International Bibliographic Information on Dietary Supplements
CARDS Database: Computer Access to Research on Dietary Supplements
***This article has been posted with the permission of the Anticoagulation Forum.***