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N-Acetylcysteine and Smoking Reduction

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: NCT00751257
Recruitment Status : Completed
First Posted : September 11, 2008
Last Update Posted : March 23, 2017
National Institute on Drug Abuse (NIDA)
Information provided by:
Medical University of South Carolina

Brief Summary:
N-acetylcysteine is an inexpensive agent with a benign side effect profile with preliminary studies in humans suggesting efficacy for the treatment of cocaine dependence. N-acetylcysteine has been used in clinical medicine for nearly three decades to treat chronic lung conditions, acetaminophen overdose, and experimentally to treat cocaine dependence. It is generally safe and well tolerated. The present pilot study seeks to explore safety and tolerability, ad lib smoking, visual cue reactivity, and smoking reduction rates in a group of nontreatment seeking, nicotine dependence smokers who are willing to undergo a brief trial with oral N-acetylcysteine 1200 mg twice daily.

Condition or disease Intervention/treatment Phase
Nicotine Dependence Drug: N-acetylcysteine Drug: Placebo Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 33 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized Controlled Trial of Oral N-acetylcysteine for Smoking Reduction: a Pilot Study
Study Start Date : December 2006
Actual Primary Completion Date : October 2007
Actual Study Completion Date : October 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Smoking

Arm Intervention/treatment
Experimental: 1
2400mg N-acetylcysteine (1200mg b.i.d.) for 4 consecutive weeks
Drug: N-acetylcysteine
2400mg (1200mg b.i.d., 600mg capsules, p.o.)

Placebo Comparator: 2
Identically appearing placebo pills, packaged in an N-acetylcysteine "slurry" so that placebo will retain smell similar to active NAC capsules
Drug: Placebo
Identically appearing placebo capsules, packaged in an N-acetylcysteine "slurry" so that placebo has similar odor as active NAC capsules

Primary Outcome Measures :
  1. Carbon Monoxide Levels [ Time Frame: Weekly ]
  2. Smoking Level [ Time Frame: Weekly ]
  3. Craving Levels (Questionnaire for Smoking Urges -- Brief) [ Time Frame: Weekly ]
  4. Minnesota Nicotine Withdrawal Scale (MNWS) [ Time Frame: Weekly ]

Secondary Outcome Measures :
  1. Smoking Level [ Time Frame: Daily ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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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:

  1. Be smokers motivated to reduce their cigarette usage but not seeking treatment to quit smoking at the time of screening.
  2. Be Able to give written informed consent after being presented with an IRB-approved informed consent document
  3. Be male or female of any race, between eighteen and sixty five years of age.
  4. Be in stable physical and mental health as judged by interview
  5. Be smoking 10 or more cigarettes per day for one or more years
  6. Have an expired CO reading of ≥10 parts/million prior to beginning study
  7. Test non-pregnant and use adequate birth control (female only). All female subjects will have a urine pregnancy test performed prior to the first dose of study medication.
  8. Be able to comply with protocol requirements and be likely to complete all study treatments.
  9. Live within 50 miles of the study site

Exclusion Criteria:

  1. Have current dependence, defined by DSM IV criteria, on any psychoactive substance other than nicotine, alcohol, or marijuana or physiological dependence on alcohol requiring medical detoxification.
  2. Have a history of significant hepatic, renal, endocrine, cardiac (i.e., arrhythmia requiring medication, angina pectoris, myocardial infarction,), stroke, seizure, neurological, non-drug-related psychiatric, gastrointestinal, pulmonary, hematologic or metabolic disorders.
  3. Have a history of adverse reaction/hypersensitivity to N-acetylcysteine.
  4. Have any significant active medical or psychiatric illness (e.g. schizophrenia, suicidal/homicidal ideation within the past 30 days) which might inhibit their ability to complete the study or might be complicated by administration of NAC.
  5. Used carbamazepine or Nitroglycerin within the last 14 days or any other medication felt to be hazardous if taken with NAC
  6. Have a current or past history of asthma and/or the occasional or daily use of Albuterol or other beta-agonist inhalers.
  7. Females pregnant or breast-feeding
  8. Have any medical history or condition considered by the investigator(s) to place the subjects at increased risk.
  9. Not fail to actively meet the inclusion criteria at the time of screening.
  10. Have a history of childhood or adult seizures of any cause.
  11. Be currently taking any medications (i.e., beta-blockers, stimulant medications) that might affect heart rate or skin conductance

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): NCT00751257

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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: Steven LaRowe, PhD Medical University of South Carolina
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Responsible Party: Steven D. LaRowe, Ph.D.; Research Assistant Professor, Principal Investigator, Medical Univeristy of South Carolina Identifier: NCT00751257    
Other Study ID Numbers: P50DA015369 ( U.S. NIH Grant/Contract )
P50DA015369 ( U.S. NIH Grant/Contract )
First Posted: September 11, 2008    Key Record Dates
Last Update Posted: March 23, 2017
Last Verified: September 2008
Keywords provided by Medical University of South Carolina:
smoking reduction
Additional relevant MeSH terms:
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Tobacco Use Disorder
Substance-Related Disorders
Chemically-Induced 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