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A Study of N-Acetyl Cysteine in Children With Autism

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00627705
Recruitment Status : Completed
First Posted : March 3, 2008
Results First Posted : May 18, 2017
Last Update Posted : May 18, 2017
Information provided by (Responsible Party):
Antonio Hardan, Stanford University

Brief Summary:

The purpose of the study is to test the tolerability and efficacy of N-Acetyl Cysteine (NAC) in children with Autism. NAC is a compound that increases the levels of Glutathione, the body's main antioxidant. Glutathione is a compound in the blood that is part of a natural defense system (the antioxidant system). Anti-oxidants protect the body from damage caused by internal toxins called "free radicals." It is possible that children with Autism tend to have lower levels of glutathione, an important compound in our bodies that helps combat the effects of toxic free radicals.

We hope that by studying the antioxidant system in more detail, we will increase our understanding of the reasons why people develop Autism so that we can design better ways to treat individuals with this condition. This study is meant to test the safety tolerability of NAC and its effectiveness in the treatment of behavioral difficulties in children with autism. It will also examine the possible benefit of this agent in improving the core deficits in autism such as social deficits.

Condition or disease Intervention/treatment Phase
Autistic Disorder Drug: N-Acetyl Cysteine Other: Placebo - sugar pill Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 43 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Double-blind , Randomized, Placebo Controlled Study of N-Acetyl Cysteine in Autism.
Study Start Date : February 2008
Actual Primary Completion Date : September 2010
Actual Study Completion Date : September 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: N-Acetyl Cysteine
active compound N-Acetyl Cysteine
Drug: N-Acetyl Cysteine

Phase 1: Oral, 900 mg daily for 4 weeks Phase 2: Oral, 900 mg twice daily 4 weeks Phase 3: Oral, 900 mg three times daily for 4 weeks

Entire intervention lasts for 12 weeks (drug administration is continuous).

Other Name: NAC

Placebo Comparator: Sugar pill
Placebo or sugar pill
Other: Placebo - sugar pill

Phase 1: Oral, 900 mg daily for 4 weeks Phase 2: Oral, 900 mg twice daily 4 weeks Phase 3: Oral, 900 mg three times daily for 4 weeks

Entire intervention lasts for 12 weeks (drug administration is continuous).

Other Name: Placebo

Primary Outcome Measures :
  1. Total Number of Subjects With Reported Side Effects as Assessed by Dosage Record and Treatment Emergent Symptom Scale (DOTES) [ Time Frame: 4, 8, and 12 weeks ]
    The Dosage Record and Treatment Emergent Symptom Scale (DOTES) provides information on the presence, frequency, and severity of side effects reported during the course of the trial.

  2. The Clinical Global Rating Scale (CGRS) Improvement Subscale Score [ Time Frame: 12 weeks ]
    Score range 1-7 (lower score mean more improvement compared to baseline)

  3. Glutathione (GSH) Levels in Peripheral Blood, Measured by State-of-the-art High-performance Liquid Chromatography (HPLC) [ Time Frame: 12 weeks ]
    Data not collected. The laboratory was not able to measure Glutathione levels.

  4. Irritability Subscale of the Aberrant Behavior Checklist (ABC) [ Time Frame: baseline and 12 weeks ]
    Aberrant Behavior Checklist (ABC) Irritability Subscale Score (range 0-45); higher scores mean higher irritability

Secondary Outcome Measures :
  1. The Aberrant Behavior Checklist Total Score (ABC) [ Time Frame: 4, 8, and 12 weeks ]
    Total score was not analyzed since we analyzed the sub scales. Additionally, the authors of the instrument do not recommend analyzing the total score.

  2. Social Responsiveness Scale (SRS) [ Time Frame: 12 weeks ]
    SRS total score (range 0-195); higher scores mean more social impairment

  3. Sensory Profile Questionnaire (SPQ) [ Time Frame: 12 weeks ]
  4. Glutathione (GSH) Metabolism Intermediates in Peripheral Blood [ Time Frame: 12 weeks ]

Information from the National Library of Medicine

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Ages Eligible for Study:   3 Years to 12 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Outpatients between 3.0 and 12.11 years of age inclusive
  2. Males and females who are physically healthy
  3. diagnosis of autism based Diagnostic and Statistical Manual (DSM-IV-TR) criteria, the Autism Diagnostic Interview-Revised, and expert clinical evaluation
  4. Clinical Global Impression Severity rating of 4
  5. Care provider who can reliably bring subject to clinic visits, can provide trustworthy ratings, and interacts with subject on a regular basis
  6. Ability of subject to swallow the compound
  7. Stable concomitant medications for at least 2 weeks
  8. No planned changes in psychosocial interventions during the open-label N-Acetyl Cysteine trial

Exclusion Criteria:

  1. DSM-IV-TR diagnosis of schizophrenia, schizoaffective disorder, or psychotic disorder not otherwise specified
  2. Prior adequate trial of N-Acetyl Cysteine
  3. Active medical problems: unstable seizures, significant physical illness (e.g., serious liver or renal pathology)
  4. Pregnancy or sexually active females
  5. Subjects taking antioxidant agents and glutathione prodrugs will be excluded from the study except if they have been off these compounds for at least 4 weeks

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): NCT00627705

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United States, California
Stanford University School of Medicine
Stanford, California, United States, 94305
Sponsors and Collaborators
Stanford University
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Principal Investigator: Antonio Hardan, MD Stanford University
Publications of Results:
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Responsible Party: Antonio Hardan, Professor, Stanford University
ClinicalTrials.gov Identifier: NCT00627705    
Other Study ID Numbers: SU-02012008-995
First Posted: March 3, 2008    Key Record Dates
Results First Posted: May 18, 2017
Last Update Posted: May 18, 2017
Last Verified: April 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Additional relevant MeSH terms:
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Autistic Disorder
Autism Spectrum Disorder
Child Development Disorders, Pervasive
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