N-acetylcysteine for Tobacco Use Disorder

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.

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

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