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L-5-HTP-Related EMS

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: December 10, 2002
Last Update Posted: March 4, 2008
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.
Information provided by:
National Institutes of Health Clinical Center (CC)

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.

Eosinophilia-Myalgia Syndrome

Study Type: Observational
Official Title: L-5-Hydroxy-Tryptophan-Related Eosinophilia-Myalgia Syndrome (EMS): Clinical Patient Evaluation

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 20
Study Start Date: July 1999
Estimated Study Completion Date: August 2000
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.


Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
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.

  Contacts and Locations
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 ClinicalTrials.gov identifier (NCT number): NCT00001918

United States, Maryland
National Institute of Mental Health (NIMH)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
  More Information

ClinicalTrials.gov Identifier: NCT00001918     History of Changes
Other Study ID Numbers: 990136
First Submitted: November 3, 1999
First Posted: December 10, 2002
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:
Eosinophilia-Myalgia Syndrome
Pathologic Processes
Muscular Diseases
Musculoskeletal Diseases
Musculoskeletal Pain
Neurologic Manifestations
Nervous System Diseases
Neuromuscular Diseases
Signs and Symptoms
Leukocyte Disorders
Hematologic Diseases