Safety assurances for dietary supplements policy issues and new research paradigms

Abstract

Herbal therapies are used by more than 12% of the U.S. population each year, resulting in annual out-of-pocket expenses above $5 billion. Utilization rates are particularly high among patients with chronic diseases, and in patients frequently seen in clinic by physicians and nurse practitioners. Most physicians do not receive formal education regarding the safety of these therapies, and there is growing concern in the medical community about the potential risks to patients and the paucity of reliable information. Numerous adverse effects and interactions have been attributed to dietary supplements, based on variable levels of evidence ranging from historical use or anecdotes to pre-clinical research or high-quality clinical trials. Significant potential morbidity and costs have been indirectly associated with herb/supplement-drug interactions, including increased emergency room visits, outpatient clinic visits, and perioperative complications. However, most research has focused on efficacy rather than safety. Post-market surveillance is complicated by the uneven standardization of products between manufacturers, and in some cases between batches produced by the same manufacturer. To assure public safety around the use of dietary supplements within the framework of existing legislation and market realities, schema must evolve to more systematically monitor the safety of agents in the post-market environment; identify potentially dangerous supplements (and/or constituents); study the mechanism and potential hazards of these identified products; and clarify the process by which products may be considered for removal from the market. We discuss research and educational paradigms within this context which make use of existing surveillance mechanisms to more efficiently identify agents of particular concern. Specific examples are given.