Efficacy of Tyrosine in Restless Legs Syndrome

April 25, 2017 updated by: Seton Healthcare Family

Pilot Study of the Efficacy of Tyrosine in Restless Legs Syndrome

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
5

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Austin, Texas, United States, 78701
        • Seton Family of Hospitals

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Tyrosine

Dietary Supplement: L-Tyrosine

Other Names:

NOW Brand L-Tyrosine 750 mg Tablets

-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.
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 Names:
  • NOW Brand L-Tyrosine 750 mg Tablets

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
6 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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.
6 weeks
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.
6 weeks
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.
6 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Seton Healthcare Family

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2012

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2012

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2012

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 15, 2011

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 16, 2011

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 19, 2011

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 27, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 25, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CR-11-146

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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