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N-acetylcysteine (NAC) for Children With Tourette Syndrome

This study has been completed.
American Academy of Child Adolescent Psychiatry.
Information provided by (Responsible Party):
Yale University Identifier:
First received: July 27, 2010
Last updated: July 21, 2014
Last verified: July 2014

July 27, 2010
July 21, 2014
July 2010
January 2014   (final data collection date for primary outcome measure)
Improvement in Tic Severity [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
Yale Global Tic Severity Scale (Total Tic Score)
Same as current
Complete list of historical versions of study NCT01172288 on Archive Site
  • Improvement of Premonitory Urges [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    Premonitory Urge for Tics Scale (PUTS)
  • Improvement in OCD Severity [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    Childrens' Yale-Brown Obsessive-Compulsive Scale (CY-BOCS)
  • Overall Improvement [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    Clinical Global Improvement Scale
  • Adverse Effects [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    Pediatric Adverse Events Rating Scale
Same as current
Not Provided
Not Provided
N-acetylcysteine (NAC) for Children With Tourette Syndrome
Double-Blind, Placebo-Controlled Trial of N-acetylcysteine (NAC) for the Treatment of Children With Tourette Syndrome

Tourette syndrome is a childhood-onset neuropsychiatric disorder characterized by multiple motor and vocal tics that last for at least a year in duration. Currently, there exist several effective pharmacological treatments for childhood tics including alpha-2 agonist medications (guanfacine and clonidine) and neuroleptics (antipsychotic) medications. These medications, however, have significant side-effects and are only partially efficacy in treating tics.

N-acetylcysteine (NAC) is a natural supplement that acts as an antioxidant and glutamate modulating agent. NAC has been used safely for decades in doses 20-40 times higher than in this trial as an antidote for acetaminophen overdose. The only side-effect commonly seen with NAC is nausea and this side-effect is seldom seen in the doses used in this trial.

NAC has recently been demonstrated to be effective in a double-blind, placebo-controlled trial in adults with trichotillomania (chronic hair pulling). Hairpulling is hypothesized to be closely related to tics because these conditions (1) have similar clinical characteristics -- both groups typically experience urges before engaging in pulling or tics, (2) neuroimaging studies suggest they involve similar brain circuits -- the basal ganglia, (3) the same pharmacological treatments (neuroleptics) may be effective for both conditions and (4) they tend to be inherited together in families. In other trials NAC has evidence of some efficacy in treating diverse psychiatric conditions such as bipolar depression, schizophrenia and cocaine dependence.

The investigators are conducting this trial to determine if NAC is an effective treatment for tics.

Not Provided
Phase 2
Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
  • Tourettes Syndrome
  • Tic
  • Drug: N-Acetylcysteine (NAC)
    1 600mg capsule twice a day for 2 weeks and then 2 600mg capsules twice a day for the remaining 10 weeks of the trial.
  • Drug: Placebo
    1 600mg Capsule twice a day for two weeks then 2 600mg capsules twice a day for the remaining 10 weeks of the study. Children receiving placebo will be offered the active intervention after the double-blind portion of the trial.
  • Experimental: N-Acetylcysteine
    Intervention: Drug: N-Acetylcysteine (NAC)
  • Placebo Comparator: Placebo
    Intervention: Drug: Placebo

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
January 2014
January 2014   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Children aged 8-17 years.
  • Primary diagnosis of Tourette syndrome or chronic tic disorder.
  • Duration of tics greater than 1 year.
  • Significant Current tic symptoms: Current YGTSS score greater than or equal to 22 with a TS diagnosis or greater than or equal to 14 with a chronic tic disorder.

Exclusion Criteria:

  • Comorbid bipolar disorder, psychotic disorder, substance use disorder, developmental disorder or mental retardation (IQ<70).
  • Recent change (less than 4 weeks) in medications that have potential effects on tic severity (such as neuroleptic medications, dopamine agonists, alpha-2 agonists (guanfacine, clonidine or prazosin), SSRIs, clomipramine, naltrexone, lithium, psychostimulants, or anxiolytics). Medication change is defined to include dose changes or medication discontinuation.
  • Recent change in behavioral treatment for Tourette syndrome or comorbid conditions (i.e. OCD) within the last 4 weeks or initiation of behavioral therapy for tics within the last 12 weeks.
  • Asthma requiring medication use within the last 3 months
  • Known hypersensitivity or previous anaphylactoid reaction to acetylcysteine or any components in its preparation
  • Positive pregnancy test or drug screening test.
  • Previous use of N-acetylcysteine (dose greater than 600mg for more than 2 weeks)
8 Years to 17 Years   (Child)
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Not Provided
Yale University
Yale University
American Academy of Child Adolescent Psychiatry.
Principal Investigator: Michael H. Bloch, MD, MS Yale University
Yale University
July 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP