N-acetylcysteine for Tobacco Use Disorder

Phase 2

Completed

• Conditions: Nicotine Dependence; Smoking
• Interventions: Other: Placebo; Drug: N-acetylcysteine (NAC)

• Registration Number: NCT02737358
• Lead Sponsor: Medical University of South Carolina

Brief Summary

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.

Detailed Description

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.

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2016-03-14
• Study First Submitted QC: 2016-04-08
• Study First Posted: 2016-04-13
• Study Start: 2016-08-30
• Primary Completion: 2019-08-01
• Study Completion: 2019-10-10
• Status Verified: 2020-07
• Results First Submitted: 2020-07-31
• Results First Submitted QC: 2020-07-31
• Last Update Submitted: 2020-07-31
• Results First Posted: 2020-08-17
• Last Update Posted: 2020-08-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 114

Inclusion Criteria

1. Age 18-65
2. 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
3. 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)
4. Willing to engage in a 3-day quit attempt as part of study procedures
5. Willing to abstain from cannabis use during study procedures (since inhaled cannabis will affect breath carbon monoxide readings).
6. If female, agreement to use birth control (any form) to avoid pregnancy during study procedures

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Exclusion Criteria

1. 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
2. Current pregnancy or breastfeeding
3. Current use of medications with smoking cessation efficacy
4. Known hypersensitivity to NAC
5. Use of carbamazepine or nitroglycerin (or any other medication deemed to be hazardous if taken with NAC) within 14 days of study participation

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Matched placebo will be given to half of the study participants.
N-Acetylcysteine (NAC)	N-acetylcysteine (NAC)	NAC will be given to half of the study participants. The dose of NAC will be 2400 mg per day (1200 mg taken twice per day as two 600 mg capsules)

Primary Outcome Measures

Name	Time	Method
Number of Participants With Biochemically-verified Abstinence From Smoking on Days 1-3 of the Protocol.	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 Outcome Measures

Name	Time	Method
Days to Relapse to Smoking Among Abstinent Participants	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).
Number of Participants With 7-day Point Prevalence Abstinence at the 8-week End-of-treatment Visit	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).

Trial Locations

Locations (1)

Medical University of South Carolina; 🇺🇸 Charleston, South Carolina, United States