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Completed

NCT Number: NCT02737358

N-acetylcysteine for Tobacco Use Disorder

The purpose of this study is to assess the effects of administering N-Acetylcysteine (NAC) to assist in initial cessation and/or relapse prevention in adult cigarette smokers.

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Key information

Conditions

Nicotine Dependence Behavior Chemically-Induced Disorders Disease Attributes Mental Disorders Pathologic Processes Pathological Conditions, Signs and Symptoms Recurrence Smoking Substance-Related Disorders Tobacco Use Disorder

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Medical University of South Carolina

Charleston, South Carolina, 29425, United States

About this study

The aim of this study is to assess the effects of N-acetylcysteine (NAC) on initial cessation and relapse prevention in adult cigarette smokers. Specifically, this study has the following aims: Aim 1) Examine the efficacy of NAC, compared to placebo, in helping smokers achieve three days of continuous abstinence; Aim 2) Among those who maintain initial 3-day abstinence, examine the time to relapse over the 8-week intervention between NAC and placebo groups; Aim 3) Assess 7-day point prevalence abstinence at the 8-week end-of-treatment study visit in order to obtain effect sizes and estimates of variability to power a randomized clinical trial.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18-65
  • Daily smoker for ≥6 months, smoking approximately ≥5 cigarettes per day on average in the past month or must meet the criteria for nicotine dependence
  • Be interested in quitting smoking (defined as a 2 or above on a 10-point Likert scale assessing readiness and interest in quitting (1=not at all ready/interested, 10=extremely ready/interested)
  • Willing to engage in a 3-day quit attempt as part of study procedures
  • Willing to abstain from cannabis use during study procedures (since inhaled cannabis will affect breath carbon monoxide readings).
  • If female, agreement to use birth control (any form) to avoid pregnancy during study procedures

Exclusion criteria

  • Any serious or unstable medical/psychiatric disorder (including severe substance use disorders, other than tobacco use disorder) in the past month that may interfere with study performance based on PI judgment
  • Current pregnancy or breastfeeding
  • Current use of medications with smoking cessation efficacy
  • Known hypersensitivity to NAC
  • Use of carbamazepine or nitroglycerin (or any other medication deemed to be hazardous if taken with NAC) within 14 days of study participation

Treatment and study plan

N-acetylcysteine (NAC)

Drug

NAC or matched placebo will be given to study participants for 8 weeks.

Other names: NAC

Placebo

Other

Matched placebo (2 capsules taken in the morning and evening) will be taken by study participants for eight weeks. All participants will receive brief smoking cessation counseling and support.

Primary outcomes

  1. Number of Participants With Biochemically-verified Abstinence From Smoking on Days 1-3 of the Protocol.

    Time frame: Days 1-3 of the study protocol

    Abstinence will be measured through biochemical verification via breath carbon monoxide. Abstinence is defined as a 75% reduction in carbon monoxide values (parts per million) from smoking baseline levels.

Secondary outcomes

  1. Days to Relapse to Smoking Among Abstinent Participants

    Time frame: Days 4-56 of the study protocol

    Relapse to smoking will be measured through carbon monoxide-verified relapse at weekly study visits among those who abstained during the 3-day quit attempt. Relapse (return to smoking) will be defined as carbon monoxide values (in parts per million) that do not meet abstinence criteria (i.e., 75% reduction from baseline smoking levels).

  2. Number of Participants With 7-day Point Prevalence Abstinence at the 8-week End-of-treatment Visit

    Time frame: Days 49-56

    Seven day point prevalence abstinence will be measured through biochemical verification via breath carbon monoxide and urinary cotinine analysis. Abstinence is defined as a 75% reduction in carbon monoxide values (parts per million) from smoking baseline levels and a negative urine cotinine measure (<80 ng/mL).

Sponsors and collaborators

Lead sponsor

Medical University of South Carolina

Other

Collaborators

  • National Institute on Drug Abuse (NIDA)

Registry information

Official study title

Evaluating N-acetylcysteine as a Pharmacotherapy for Tobacco Use Disorder

Important dates

Study start
2016
Primary completion
2019
Study completion
2019
First posted
Apr 13, 2016
Registry last updated
Aug 17, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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