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Completed

NCT Number: NCT01494766

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.

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Key information

Conditions

Restless Legs Syndrome (RLS) Dyssomnias Mental Disorders Nervous System Diseases Parasomnias Restless Legs Syndrome Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Seton Family of Hospitals

Austin, Texas, 78701, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Men and women aged 18 to 80 years and
  • 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
  • That interfered with sleep onset and/or maintenance for greater than four nights/week for a minimum of six months
  • Currently not receiving treatment for RLS

Exclusion criteria

  • 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)
  • Patients currently on pharmacotherapy for RLS (not medication-naïve) or previous use of pharmacotherapy for RLS in the past
  • Patients that are pregnant and/or breastfeeding
  • Patients that are on levothyroxine or monoamine oxidase inhibitors

Treatment and study plan

L-tyrosine

Dietary Supplement

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

Primary outcomes

  1. 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 outcomes

  1. 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.

  2. 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.

  3. 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.

Sponsors and collaborators

Lead sponsor

Seton Healthcare Family

Other

Registry information

Official study title

Pilot Study of the Efficacy of Tyrosine in Restless Legs Syndrome

Important dates

Study start
2012
Primary completion
2012
Study completion
2012
First posted
Dec 19, 2011
Registry last updated
Apr 27, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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