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L-5-HTP-Related EMS

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00001918
Recruitment Status : Completed
First Posted : December 10, 2002
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

In 1989 more than 1500 people who took the dietary supplement L-tryptophan for insomnia and depression developed eosinophilia myalgia syndrome (EMS)-a potentially fatal disease characterized by an excess of a type of white blood cell called eosinophils. Disease symptoms include fever, muscle aches and inflammation, and skin rashes. As many as 40 of the patients who became ill died. It is suspected that impurities in the supplements caused the disease. More recently, similar impurities have been detected in batches of a similar dietary supplement called L-5-hydroxytryptophan.

This study is designed to learn more about EMS that develops in patients taking L-5-hydroxytryptophan. The study is open to patients newly diagnosed with eosinophilia myalgia who have taken L-5-HTP. Patients in the study will have a physical examination and urine and blood tests. They may also have X rays, an electrocardiogram, magnetic resonance imaging (MRI), and a skin test for tuberculosis. They will have a psychiatric interview, take a memory test, and fill out questionnaires relating to sadness and depression.

Patients may also undergo special tests to study conduction of nerve impulses and muscle function.

Samples of patients' supplements will be taken for chemical analysis.

Condition or disease
Eosinophilia-Myalgia Syndrome

Detailed Description:

The L-tryptophan-related eosinophilia myalgia syndrome (EMS), characterized by eosinophilia, myalgias, myositis, scleroderma-like skin fibrosis and fasciitis, occurred in 1989 in over 1500 patients who had ingested L-tryptophan for sleep disturbances and depression. The identical clinical syndrome has also occurred in subjects ingesting L-5-hydroxytryptophan (L-5-HTP).

Recently, a letter to Nature Medicine reported the presence of an impurity in 6 out of 6 samples of L-5-HTP obtained randomly at health food stores. This impurity appears to be the same as the one identified in material ingested by a family (mother and 2 babies) who had developed an EMS-like syndrome after ingesting L-5-HTP.

Although there have been no definite new cases of L-5-HTP-related EMS, the FDA is currently investigating unconfirmed reports of possible new cases.

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Study Type : Observational
Enrollment : 20 participants
Official Title: L-5-Hydroxy-Tryptophan-Related Eosinophilia-Myalgia Syndrome (EMS): Clinical Patient Evaluation
Study Start Date : July 1999
Study Completion Date : August 2000

Resource links provided by the National Library of Medicine

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Patients must be at least 18 years of age.

Patients newly diagnosed with eosinophilia and myalgia, and who ingested L-5-HTP.

Subjects will be defined as having 5-L-HTP related EMS according to the diagnostic criteria originally established by the CDC for diagnosis of L-tyrptophan-related EMS.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00001918

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United States, Maryland
National Institute of Mental Health (NIMH)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
Layout table for additonal information Identifier: NCT00001918    
Other Study ID Numbers: 990136
First Posted: December 10, 2002    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: June 1999
Keywords provided by National Institutes of Health Clinical Center (CC):
Cognitive Function
Eosinophilia Myalgia Syndrome
Memory Impairment
Nerve-Muscle Biopsy
Sleep Disorders
Additional relevant MeSH terms:
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Eosinophilia-Myalgia Syndrome
Pathologic Processes
Muscular Diseases
Musculoskeletal Diseases
Neuromuscular Diseases
Nervous System Diseases
Musculoskeletal Pain
Neurologic Manifestations
Leukocyte Disorders
Hematologic Diseases