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A Study of Oral N-Acetylcysteine in Children With Autism Spectrum Disorders

This study has been completed.
National Alliance for Autism Research
Information provided by (Responsible Party):
Indiana University ( Indiana University School of Medicine ) Identifier:
First received: March 27, 2007
Last updated: June 3, 2014
Last verified: June 2014
The purpose of this study is to determine whether treatment with oral N-acetylcysteine (NAC) will improve behavior problems often associated with autism spectrum disorders.

Condition Intervention Phase
Autistic Disorder
Asperger Syndrome
Child Development Disorders, Pervasive
Drug: N-acetylcysteine
Drug: Placebo
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: A Pilot Study of Oral N-Acetylcysteine in Children With Autism Spectrum Disorders

Resource links provided by NLM:

Further study details as provided by Indiana University:

Primary Outcome Measures:
  • Clinical Global Impression - Severity done at Screen, Baseline, and at the end of week 12 of treatment [ Time Frame: performed at screen, baseline, and end of treatment at week 12 ]
  • Clinical Global Impression - Improvement done at the end of weeks 4, 8, and 12 of treatment [ Time Frame: performed at end of weeks 4, 8, and 12 of treatment ]

Secondary Outcome Measures:
  • Aberrant Behavior Checklist done at Baseline and end of weeks 4, 8, and 12 [ Time Frame: Performed at end of weeks 4, 8, 12 ]
  • Social Responsiveness Scale done at Baseline and end of weeks 4, 8, and 12 [ Time Frame: Performed at baseline and end of weeks 4, 8, and 12 of treatment ]
  • Pervasive Developmental Disorder Behavior Index done at Baseline and end of week 12 [ Time Frame: Performed at Baseline and end of week 12 ]
  • Vineland Adaptive Behavior Scales done at Baseline and end of week 12 [ Time Frame: Performed at Baseline and end of week 12 ]

Enrollment: 32
Study Start Date: March 2007
Study Completion Date: November 2009
Primary Completion Date: August 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Target dose for n-acetylcysteine is 60 mg/kg/day. Capsules available in 300 mg and 600 mg strengths.
Drug: N-acetylcysteine
Capsules available in 300 mg or 600mg strength. Target dose of n-acetylcysteine will be 60mg/kg/day TID. Dosage will be increased to this target dose from week 1 to week 3 barring side effects. Dose reduction will be allowed at any time for adverse side effects. Maximum dose of n-acetylcysteine will be 4200mg/day.
Placebo Comparator: 2
Subjects randomized to placebo arm will receive capsules identical in size and appearance to those subjects receiving study drug. Placebo capsules contain in active ingredients.
Drug: Placebo
Subjects randomized to placebo arm will receive placebo pill for duration of study.

Detailed Description:

Autism is increasingly being recognized as a common disorder with enormous public health significance. The core symptoms of autism include severe deficits in social relatedness and communication, and interfering repetitive behavior. No medications have been shown to consistently improve any of these symptoms.

The central hypothesis of this study is that NAC will improve behavioral manifestations of autism which may include core or associated symptoms. We plan to test our hypothesis and complete the objectives of this project by pursuing the following specific aims:

  • Evaluate the efficacy of oral NAC in a 12-week, double-blind, placebo-controlled study involving 32 children and adolescents with autism spectrum disorders.
  • Evaluate the safety and tolerability of oral NAC in 32 children and adolescents with autism spectrum disorders.

Ages Eligible for Study:   4 Years to 12 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 4 to 12 years.
  • Diagnosis of autistic disorder, Asperger's disorder, or PDD NOS.
  • If taking concomitant psychotropic medications, the medication must be at a constant dose for 60 days with no dose changes planned for the duration of the trial.
  • Able to swallow capsules.

Exclusion Criteria:

  • Presence of any medical condition that significantly increases risk or hampers assessment (e.g., unstable hypertension or cardiac disease, unstable asthma, kidney disease, unstable seizure disorder, pregnancy or any other medical condition as determined by the investigator).
  • Weight < 15 kg.
  • Subjects taking concomitant medications or supplements known for their glutamatergic effects (e.g., dextromethorphan, D-cycloserine, amantadine, memantine, lamotrigine, riluzole) or antioxidant properties (high dose vitamin supplements, DMG, TMG, many alternative treatments) within 30 days of the baseline visit with the exception of short term use of dextromethorphan as needed as a cough suppressant. The use of this medicine must be stopped at least 7 days prior to the baseline visit. Regular multivitamins will be allowed.
  • Subjects taking daily acetaminophen or nonsteroidal anti-inflammatory drugs within 30 days of the baseline visit.
  • Profound mental retardation as evidenced by a mental age below 18 months.
  • Subjects taking concomitant medications with the potential for pharmacokinetic or pharmacodynamic drug-drug interactions (e.g., carbamazepine) within 30 days of the baseline visit.
  • Subjects who are likely to experience significant changes in their ongoing psychosocial or medical treatments for autism over the course of the trial (e.g., initiation of new behavioral therapy, initiation of new medication or alternative treatment [e.g., chelation]). Minor changes in ongoing treatment (e.g., missed therapy sessions due to holiday/vacation; planned break in therapy due to school holidays) will not be considered significant.
  • History of prior treatment with NAC.
  • Evidence of hypersensitivity/allergy to NAC.
  • Presence of certain neurodevelopmental disorders such as Fragile X Syndrome, Tuberous Sclerosis, or other neurological disorders known to be associated with autism or autistic features.
  • Diagnosis of Rett's disorder, childhood disintegrative disorder, schizophrenia, bipolar disorder, another psychotic disorder, or substance abuse disorder.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00453180

United States, Indiana
Riley Hospital for Children - Christian Sarkine Autism Treatment Center
Indianapolis, Indiana, United States, 46202
Sponsors and Collaborators
Indiana University School of Medicine
National Alliance for Autism Research
Principal Investigator: Kimberly A Stigler, M.D. Indiana University School of Medicine
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Indiana University School of Medicine Identifier: NCT00453180     History of Changes
Other Study ID Numbers: 0611-10
Study First Received: March 27, 2007
Last Updated: June 3, 2014

Keywords provided by Indiana University:
Autistic Disorder
Pervasive Developmental Disorder
core symptoms
Autism Spectrum Disorders
Asperger's Disorder
Pervasive Developmental Disorder Not Otherwise Specified
Pervasive Developmental Disorders

Additional relevant MeSH terms:
Child Development Disorders, Pervasive
Autism Spectrum Disorder
Autistic Disorder
Asperger Syndrome
Developmental Disabilities
Pathologic Processes
Neurodevelopmental Disorders
Mental Disorders
Antiviral Agents
Anti-Infective Agents
Respiratory System Agents
Free Radical Scavengers
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs
Antidotes processed this record on April 27, 2017