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Does N-Acetylcysteine Decrease Spontaneous Oxidation of Central Neural Dopamine in Parkinson's Disease?

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ClinicalTrials.gov Identifier: NCT03104725
Recruitment Status : Suspended (The NINDS PIRC has decided to place 17-N-0076 on administrative hold until discrepancies are resolved.)
First Posted : April 7, 2017
Last Update Posted : January 8, 2018
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) )

Brief Summary:


Parkinson s disease (PD) causes slow movement, stiffness, and poor balance. Many symptoms are due to the loss of brain cells that make the brain chemical dopamine. The cells may be damaged by the breakdown of dopamine by a process called oxidation. The drug N-acetylcysteine (NAC) can act as an antioxidant. Researchers want to test if NAC can decrease the oxidation of brain dopamine in people with PD.


To look at the effect of NAC on brain chemistry in people with PD.


People ages 18 and older with PD that was diagnosed within the past 5 years. They must be taking a monoamine oxidase inhibitor.


Participants will be screened with:

Medical history

Physical exam

Blood and urine tests

Participants will be hospitalized for 4 to 8 days.

On day 1, they will have blood and urine tests. They cannot eat or drink anything but water and their medications for several hours. Late in the morning they will have a meal.

About 2 hours later they will have a spinal tap. For this, a numbing medicine is injected into the back. A needle is inserted between the bones in the back to remove a small amount of fluid. The spinal tap may be use x-rays to see inside the body.

After the spinal tap, they will start taking NAC by mouth.

They will take NAC twice a day for 2 more days.

On the next day, they will not eat until a meal in the late morning. They will take a final NAC dose.

About 2 hours later they will have a second spinal tap.

Condition or disease Intervention/treatment
Parkinson Disease Dietary Supplement: N-Acetylcysteine Procedure: Lumbar Puncture

Detailed Description:


This study is to test whether N-acetylcysteine (NAC) inhibits the spontaneous oxidation of central neural dopamine as indicated by the cerebrospinal fluid (CSF) concentration of 5-S-cysteinyl-dopamine (Cys-DA) in patients with Parkinson s disease (PD).

Study population:

The study population comprises up to 35 patients with early (less than or equal to 5 years from diagnosis), mild, levodopa-untreated PD. The patients will be on an inhibitor of monoamine oxidase (MAO) that is prescribed for their disease.


The study has a one group, pretest-posttest design. Each patient undergoes a lumbar puncture (LP) as an inpatient at the NIH Clinical Center to obtain cerebrospinal fluid (CSF) for assays of Cys-DA, 3,4-dihydroxyphenylacetic acid (DOPAC), and related biochemicals. The second LP is done after the patient has taken at least 5 doses of NAC (2 grams orally twice per day). The LP takes place about 2 hours after the last NAC dose.

Outcome measures:

The main outcome measure is the CSF concentration of Cys-DA. Other outcome measures are levels of other catecholamine-related neurochemicals or of indices of oxidative stress. Depending on the results, an exploratory study may be done involving NAC at 1 gram orally twice per day.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 35 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Does N-Acetylcysteine Decrease Spontaneous Oxidation of Central Neural Dopamine in Parkinson's Disease?
Actual Study Start Date : September 25, 2017
Estimated Primary Completion Date : December 31, 2018
Estimated Study Completion Date : December 31, 2018

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Intervention Details:
    Dietary Supplement: N-Acetylcysteine
    Procedure: Lumbar Puncture

Primary Outcome Measures :
  1. More than or less than 10% decrease in cerebrospinal fluid level of 5-S-cysteinyldopamine [ Time Frame: 2 days ]

Secondary Outcome Measures :
  1. Cerebrospinal fluid concentration of 5-S-cysteinyldopamine [ Time Frame: 2 days ]
  2. Cerebrospinal fluid concentrations of neurchemicals [ Time Frame: 2 days ]

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.

Ages Eligible for Study:   18 Years to 99 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
  • PD diagnosed within the past 5 years
  • Taking a monoamine oxidase (MAO) inhibitor
  • Able to provide consent
  • At least18 years old


  • Taking levodopa in any form
  • Known allergy to NAC
  • Already taking an anti-oxidant dietary supplement (e.g., Olive Leaf Extract, MitoQ)
  • A condition that would increase risk from a lumbar puncture (e.g., symptomatic spinal stenosis or myoclonus)
  • History of a post-spinal headache that required treatment with a blood patch
  • On a prescribed anti-coagulant (e.g., Coumadin, Plavix)
  • Pregnant or breast-feeding
  • History of alcohol or drug abuse
  • Any medical condition thatcould put subjects at increased risk. Potential participants are excluded who have evidence of bone marrow, liver, or kidney failure based on abnormal screening lab results.
  • On a medication that could interfere with the scientific results. An example of an exclusionary drug is the catechol-O-methyltransferase inhibitor entacapone. Tricyclic anti-depressants are another type of exclusionary drug

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): NCT03104725

United States, Maryland
National Institutes of Health Clinical Center
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
Principal Investigator: David S Goldstein, M.D. National Institute of Neurological Disorders and Stroke (NINDS)

Additional Information:
Responsible Party: National Institute of Neurological Disorders and Stroke (NINDS)
ClinicalTrials.gov Identifier: NCT03104725     History of Changes
Other Study ID Numbers: 170076
First Posted: April 7, 2017    Key Record Dates
Last Update Posted: January 8, 2018
Last Verified: November 2017

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) ):
Cerebrospinal Fluid

Additional relevant MeSH terms:
Parkinson Disease
Parkinsonian Disorders
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Movement Disorders
Neurodegenerative Diseases
Antiviral Agents
Anti-Infective Agents
Respiratory System Agents
Free Radical Scavengers
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs
Cardiotonic Agents
Autonomic Agents
Peripheral Nervous System Agents
Dopamine Agents
Neurotransmitter Agents