Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids.

Background: Dietary supplements that contain ephedra alkaloids (sometimes c alled ma huang) are widely promoted and used in the United States as a mean s of losing weight and increasing energy. In the light of recently reported adverse events related to use of these products, the Food and Drug Adminis tration (FDA) has proposed limits on the dose and duration of use of such s upplements. The FDA requested an independent review of reports of adverse e vents related to the use of supplements that contained ephedra alkaloids to assess causation and to estimate the level of risk the use of these supple ments poses to consumers. Methods: We reviewed 140 reports of adverse events related to the use of di etary supplements containing ephedra alkaloids that were submitted to the F DA between June 1, 1997, and March 31, 1999. A standardized rating system f or assessing causation was applied to each adverse event. Results: Thirty-one percent of cases were considered to be definitely or pr obably related to the use of supplements containing ephedra alkaloids, and 31 percent were deemed to be possibly related. Among the adverse events tha t were deemed definitely, probably, or possibly related to the use of suppl ements containing ephedra alkaloids, 47 percent involved cardiovascular sym ptoms and 18 percent involved the central nervous system. Hypertension was the single most frequent adverse effect (17 reports), followed by palpitati ons, tachycardia, or both (13); stroke (10); and seizures (7). Ten events r esulted in death, and 13 events produced permanent disability, representing 26 percent of the definite, probable, and possible cases. Conclusions: The use of dietary supplements that contain ephedra alkaloids may pose a health risk to some persons. These findings indicate the need fo r a better understanding of individual susceptibility to the adverse effect s of such dietary supplements. (N Engl J Med 2000;343:1833-8.) (C) 2000, Ma ssachusetts Medical Society.