N-acetylcysteine (NAC) for 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.
Drug: N-Acetylcysteine (NAC)
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Double-Blind, Placebo-Controlled Trial of N-acetylcysteine (NAC) for the Treatment of Children With Tourette Syndrome|
- Improvement in Tic Severity [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]Yale Global Tic Severity Scale (Total Tic Score)
- 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
|Study Start Date:||July 2010|
|Study Completion Date:||January 2014|
|Primary Completion Date:||January 2014 (Final data collection date for primary outcome measure)|
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.
|Placebo Comparator: 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.
|United States, Connecticut|
|Yale Child Study Center|
|New Haven, Connecticut, United States, 06520|
|Principal Investigator:||Michael H. Bloch, MD, MS||Yale University|