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Efficacy of Tyrosine in Restless Legs Syndrome

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified May 2012 by Seton Healthcare Family.
Recruitment status was:  Recruiting
Information provided by (Responsible Party):
Seton Healthcare Family Identifier:
First received: December 15, 2011
Last updated: May 10, 2012
Last verified: May 2012
Tyrosine is a non essential amino acid that is the precursor of the neurotransmitter, dopamine. Tyrosine is converted into Levodihydrophenylalanine (L-Dopa) and L-Dopa is subsequently and avidly converted into dopamine. It is well known that dopamine deficiency leads to the manifestations of restless legs syndrome (RLS). Studies have shown dopamine agonists and L-dopa to be effective in controlling symptoms. No studies to date have been done to determine the role of tyrosine in RLS. This open-label pilot study aims to determine the efficacy and tolerability of tyrosine in RLS, as current agents have limitations in treating RLS in addition to adding another possible agent to the investigators arsenal of treating RLS that maybe more cost efficient. In this pilot study, the dose of tyrosine will be escalated from 750 mg once daily by mouth (PO) up to 3000 mg once daily PO, as tolerated, in increments of 750 mg every week in patients who meet the inclusion criteria for RLS. Patients' symptoms will be monitored on a weekly basis for six weeks.

Condition Intervention
Restless Legs Syndrome (RLS)
Dietary Supplement: L-Tyrosine

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Pilot Study of the Efficacy of Tyrosine in Restless Legs Syndrome

Resource links provided by NLM:

Further study details as provided by Seton Healthcare Family:

Primary Outcome Measures:
  • International RLS Survey Group (IRLSSG20) Score [ Time Frame: 6 weeks ]
    Use of this survey to be used as a marker for severity of RLS symptoms and therefore efficacy of this medication.

Secondary Outcome Measures:
  • Clinical global impression-global improvement (CGI-I) scale [ Time Frame: 6 weeks ]
    Use of the CGI-I scale as a secondary outcome measure to determine severity of RLS symptoms and efficacy of medication.

  • Medical Outcomes Study - Sleep Scale (MOS-SS) [ Time Frame: 6 weeks ]
    Use of the MOS-SS to determine severity of RLS symptoms and efficacy of medication.

  • Case Report Form [ Time Frame: 6 weeks ]
    Use of a history and physical examination (limited neurological exam) to be used as a secondary assessment measure of RLS symptom severity and medication efficacy. They will be charted in case report format.

Estimated Enrollment: 5
Study Start Date: January 2012
Estimated Study Completion Date: May 2012
Estimated Primary Completion Date: May 2012 (Final data collection date for primary outcome measure)
Intervention Details:
    Dietary Supplement: L-Tyrosine
    L-Tyrosine 750 mg PO every day for 7 days, then increase to 1500 mg PO every day for 7 days, then increase to 2250 mg PO every day for 7 days, then increase to 3000 mg PO every day for remainder of the study.
    Other Name: NOW Brand L-Tyrosine 750 mg Tablets

Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Men and women aged 18 to 80 years and
  2. Newly diagnosed (medication-naïve) as having restless legs syndrome (using the International Restless Legs Syndrome Study Group (IRLSSG20) diagnostic criteria with a score of greater than or equal to 15, see Appendix A) and
  3. That interfered with sleep onset and/or maintenance for greater than four nights/week for a minimum of six months
  4. Currently not receiving treatment for RLS

Exclusion Criteria:

  1. Patients suffering from secondary RLS (other movement and/or primary sleep disorders, chronic renal insufficiency - calculated from the creatinine clearance, and/or iron deficiency - baseline serum ferritin level less than 10 ng/ml)
  2. Patients currently on pharmacotherapy for RLS (not medication-naïve) or previous use of pharmacotherapy for RLS in the past
  3. Patients that are pregnant and/or breastfeeding
  4. Patients that are on levothyroxine or monoamine oxidase inhibitors
  Contacts and Locations
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Please refer to this study by its identifier: NCT01494766

Contact: Hanul Bhandari, MD 5123247890
Contact: Jason Shen, MD 5123247890

United States, Texas
Seton Family of Hospitals Recruiting
Austin, Texas, United States, 78701
Contact    512-324-7890   
Principal Investigator: Hanul Bhandari, MD         
Sub-Investigator: Jason Shen, MD         
Sub-Investigator: Osvaldo Perurena, MD         
Sponsors and Collaborators
Seton Healthcare Family
  More Information

Responsible Party: Seton Healthcare Family Identifier: NCT01494766     History of Changes
Other Study ID Numbers: CR-11-146
Study First Received: December 15, 2011
Last Updated: May 10, 2012

Keywords provided by Seton Healthcare Family:

Additional relevant MeSH terms:
Psychomotor Agitation
Restless Legs Syndrome
Pathologic Processes
Neurologic Manifestations
Nervous System Diseases
Psychomotor Disorders
Neurobehavioral Manifestations
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Mental Disorders processed this record on April 26, 2017