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Effectiveness of N-Acetylcysteine (NAC) in Treating Cocaine Dependent Individuals - 1 (NAC)

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. Identifier: NCT00218491
Recruitment Status : Completed
First Posted : September 22, 2005
Results First Posted : January 15, 2019
Last Update Posted : January 15, 2019
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
Robert Malcolm, Medical University of South Carolina

Brief Summary:
Currently, no effective drug treatment exists for cocaine dependence. Glutamate levels are disrupted with long-term cocaine use. N-acetyl cysteine (NAC) is a drug that is metabolized by the body to form cysteine, an active compound that normalizes glutamate levels. The purpose of this study is to determine the safety and effectiveness of NAC in treating cocaine dependent individuals.

Condition or disease Intervention/treatment Phase
Cocaine Dependence Drug: N-Acetylcysteine Drug: Matching Placebo Phase 2

Detailed Description:

Currently, no effective pharmacological treatment exists for cocaine dependence. Long-term use of cocaine disrupts normal glutamate levels. If addicts stop using cocaine, glutamate levels drop, which encourages addicts to continue seeking the drug. NAC is a drug that increases intracellular cysteine levels, which in turn leads to normalization of glutamate levels. Currently, NAC is used for the treatment of cystic fibrosis, heart disease, and acetaminophen overdose. Since NAC has the capability of restoring normal glutamate levels, it holds potential as a treatment for cocaine dependence. The purpose of this study is to determine the safety and effectiveness of NAC in treating cocaine dependent individuals. In addition, this study will evaluate cocaine craving and withdrawal symptoms in individuals taking NAC.

Participants in this double-blind, placebo-controlled trial will be randomly assigned to receive either NAC or placebo. All participants will undergo an initial evaluation, which will include a physical examination, an electrocardiogram, blood samples, urine tests, and cue reactivity measures. Participants in the NAC group will receive either 600 mg or 1200 mg of NAC, two times each day for 8 weeks. In addition, all participants will receive cognitive behavioral therapy throughout the study on a weekly basis. Cocaine use will be confirmed by a urine drug screen test, three times each week. Participants will be assessed on a number of biomedical and psychosocial variables known to influence cocaine treatment outcomes. After Week 2, participants will repeat the cue reactivity procedures, which will include measuring a participant's craving response when exposed to conditioned reminders of prior cocaine use.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 111 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Controlled Trial of N-Acetylcysteine (NAC) for Cocaine Dependence
Study Start Date : November 2005
Actual Primary Completion Date : May 2010
Actual Study Completion Date : May 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: 1200mg N-Acetylcysteine
1200mg N-Acetylcysteine
Drug: N-Acetylcysteine
1200mg N-Acetylcysteine

Experimental: 2400mg N-Acetylcysteine
2400mg N-Acetylcysteine
Drug: N-Acetylcysteine
2400mg N-Acetylcysteine

Placebo Comparator: Matching Placebo
Matching Placebo
Drug: Matching Placebo
Matching Placebo

Primary Outcome Measures :
  1. Number of Participants That Achieved Study Compliance [ Time Frame: 8 weeks ]
    Drug and placebo compliance were measured by urine riboflavin levels. Study compliance was defined as 80% or greater weekly urine riboflavin levels equal to or greater than 1500 ng/ml

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Meets DSM-IV criteria for cocaine dependence, as determined by a mini-SCID interview
  • Currently dependent on cocaine
  • Seeking treatment for cocaine abuse at the time of study entry
  • Currently uses cocaine by smoking, nasal, or intravenous route of administration.
  • Stable physical and mental health, as judged by an interview and physical examination
  • If female, demonstrates a negative pregnancy test and agrees to use an adequate method of contraception for the duration of the study
  • Lives within a 50 mile radius of the research program center and has reliable transportation

Exclusion Criteria:

  • Meets DSM-IV criteria for dependence on any psychoactive substance other than cocaine, alcohol, nicotine, or marijuana
  • Physiological dependence on alcohol, which requires medical detoxification
  • History of significant liver, kidney, endocrine, cardiac (e.g., arrhythmia requiring medication, angina pectoris, myocardial infarction), stroke, seizure, neurological, non-drug-related psychiatric, gastrointestinal, pulmonary, hematologic, or metabolic disorders (e.g., homocystinuria)
  • History of an adverse reaction to cocaine, including loss of consciousness, chest pain, psychosis, or seizure
  • History of adverse reaction or hypersensitivity to N-acetyl cystine (NAC), or a similar drug
  • Significant active medical or psychiatric illness that might inhibit the ability to complete the study
  • Active high blood pressure, defined as a mean of three sitting blood pressure readings of 145/95 or higher within a 10-day period
  • History of or current asthma
  • Occasional or daily use of albuterol or other beta-agonist inhalers
  • Use of carbamazepine, phenytoin, nitrous oxide, methotrexate, 6 azauridine triacetate, or nitroglycerin within the 2 weeks prior to study entry
  • Use of very large doses of folate, cyanocobalamine (vitamin B12), or pyridoxine (vitamin B6) as prescribed by a health care professional; individuals taking very large doses of these vitamins on a self-initiated basis may enter the study if they are willing to stop use 14 days prior to study entry and to use a standard generic multiple vitamin instead
  • Pregnant or breastfeeding
  • Required by the court to obtain treatment for cocaine dependence
  • Not seeking treatment for cocaine dependence
  • Anticipating elective surgery or hospitalization within 20 weeks of study entry
  • Failure to have a consistent residence for the 4 weeks prior to study entry
  • History of childhood or adult seizures
  • Participated in cocaine treatment (clinical or research) within 30 days of study entry

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 identifier (NCT number): NCT00218491

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United States, South Carolina
Medical University of South Carolina
Charleston, South Carolina, United States, 29425
Sponsors and Collaborators
Medical University of South Carolina
National Institute on Drug Abuse (NIDA)
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Principal Investigator: Robert Malcolm, M.D. Medical University of South Carolina

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Responsible Party: Robert Malcolm, Professor of Psychiatry, Family Medicine & Pediatrics, Medical University of South Carolina Identifier: NCT00218491     History of Changes
Other Study ID Numbers: NIDA-19903-1
R01DA019903 ( U.S. NIH Grant/Contract )
First Posted: September 22, 2005    Key Record Dates
Results First Posted: January 15, 2019
Last Update Posted: January 15, 2019
Last Verified: December 2018
Keywords provided by Robert Malcolm, Medical University of South Carolina:
Cocaine Dependence
Additional relevant MeSH terms:
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Cocaine-Related Disorders
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Anesthetics, Local
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents
Vasoconstrictor Agents
Dopamine Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Dopamine Agents
Neurotransmitter Agents
Antiviral Agents
Anti-Infective Agents
Respiratory System Agents
Free Radical Scavengers
Protective Agents