N-acetylcysteine for Tobacco Use Disorder

Study Overview
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Brief Summary
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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
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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.

Official Title
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Evaluating N-acetylcysteine as a Pharmacotherapy for Tobacco Use Disorder

Conditions
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Nicotine Dependence, Smoking

Intervention / Treatment
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* Drug: N-acetylcysteine (NAC)
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Matched placebo will be given to half of the study participants. | Other: Placebo<br>* 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.<br>|
| Active Comparator: N-Acetylcysteine (NAC)<br>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) | Drug: N-acetylcysteine (NAC)<br>* NAC or matched placebo will be given to study participants for 8 weeks.<br>* Other names: NAC;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Biochemically-verified Abstinence From Smoking on Days 1-3 of the 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. | Days 1-3 of the study protocol | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Days to Relapse to Smoking Among Abstinent Participants | 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). | Days 4-56 of the study protocol | 
| Number of Participants With 7-day Point Prevalence Abstinence at the 8-week End-of-treatment Visit | 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). | Days 49-56 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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nicotine, tobacco, smoking, cessation, N-acetylcysteine, NAC, pharmacotherapy, relapse, tobacco use disorder