L-TRYPTOPHAN, OTHER DIETARY SUPPLEMENTS WILL BE SPOTLIGHTED BY FDA
L-TRYPTOPHAN, OTHER DIETARY SUPPLEMENTS WILL BE SPOTLIGHTED BY FDA task force at a public hearing scheduled for Aug. 29-30, FDA Center for Food Safety & Applied Nutrition Deputy Director Douglas Archer told the House Government Affairs/Human Resources Subcommittee July 18. Subcommittee Chairman Weiss (D-N.Y.) convened the House hearing to review regulatory activities related to L-tryptophan and other amino acid dietary supplements. Archer informed the subcommittee that Commissioner Kessler established a task force on dietary supplements to review regulatory policies and "recommend a course of action with respect to these products." The task force, chaired by Deputy Associate Commissioner for Regulatory Affairs Gary Dykstra, held its first meeting in April, and anticipates making final recommendations in "late 1991," Archer said. The public hearing will be held at the Masur Auditorium at the National Institutes of Health campus in Bethesda, Md., beginning at 8:30 a.m. A July 16 Federal Register notice of the meeting says questions to be addressed include: how FDA should define dietary supplements; what should be the goals of regulation in addition to safety; should FDA, perhaps in conjunction with the United States Pharmacopeia, establish product standards; and does FDA currently have adequate statutory authority to regulate dietary supplements. The specific health claims of dietary supplements are being considered separately as part of implementing the 1990 Food and Nutrition Labeling Act. Archer said the task force is considering supplements in three groups: amino acids, vitamins and minerals and other types of supplements. Archer also informed the subcommittee that the Federation of American Societies of Experimental Biology's report on amino acids is expected in December 1991 ("The Pink Sheet" Feb. 11, T&G-10). "FDA will use this report to establish its enforcement priorities with regard to these products," he said. Regarding eosinophilia-myalgia syndrome (EMS), which has been associated with L-tryptophan and led the agency to request a recall of the supplement on Nov. 17, 1989 following several reports of the syndrome earlier that month, Archer said FDA is continuing several studies in conjunction with NIH and the Centers for Disease Control. One of the "most significant breakthroughs" has been development of a rat model for EMS, he said. However, it "is not yet clear whether the illness is associated with a contaminant, L-tryptophan itself, or even due to individual abnormalities in L-tryptophan metabolism," he commented. Archer expressed concern that unscrupulous merchants may still be selling oral dosage L-tryptophan. FDA views any continued marketing of the oral dosage product as a "very serious violation" of the FD&C Act, to be "vigorously" pursued, including "criminal prosecution if appropriate." However, "enforcement alone will not solve the problems that led to the EMS epidemic in 1989," Archer said. For example, "doctors should not be telling patients to take products such as L-tryptophan and L-lysine for drug purposes." In addition, despite the recall, "some consumers may be hoarding the product." Demand for the product is increased by "confusion created by health claims for foods," a confusion that FDA "is working to correct," he noted. In his opening statement, Rep. Weiss characterized the 1989 EMS outbreak as a consequence of "FDA's deliberate decision to ignore, rather than enforce, the law." He said that "in 1985, Canada made L-tryptophan available only as a prescription drug. Consequently, there are only 11 EMS cases reported in Canada and, in 10 of those cases, the victims purchased L-tryptophan in the United States." Archer explained that while L-tryptophan has never been approved for marketing in oral dosage form and there "is no condition for which [L-tryptophan] is generally recognized as safe and effective," it was not "until the recent incidents that human toxicity was reported." He added: "Because of the apparent minimal safety concerns, FDA chose to take no further actions as [L- tryptophan] cases were resource intensive and appeared to be not winnable so long as no health problem existed." A review of the November 1989 epidemic found 30 reported cases of EMS and no deaths, Archer said. To date, 31 deaths and more than 1,500 EMS cases have been reported to CDC, but fewer than 1% of cases had onset after the recall was requested.
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