N-acetylcysteine for Tobacco Use Disorder

Evaluating N-acetylcysteine as a Pharmacotherapy 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.

Study Overview

• Status: Completed
• Conditions: Smoking; Nicotine Dependence
• Intervention / Treatment: Other: Placebo; Drug: N-acetylcysteine (NAC)

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.

• Study Type: Interventional
• Enrollment (Actual): 114
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 63 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

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

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: Medical University of South Carolina
• Collaborators: National Institute on Drug Abuse (NIDA)

Publications and helpful links

General Publications

• Tomko RL, Gray KM, Oppenheimer SR, Wahlquist AE, McClure EA. Using REDCap for ambulatory assessment: Implementation in a clinical trial for smoking cessation to augment in-person data collection. Am J Drug Alcohol Abuse. 2019;45(1):26-41. doi: 10.1080/00952990.2018.1437445. Epub 2018 Mar 7.

Study record dates

Study Major Dates

• Study Start (Actual): August 30, 2016
• Primary Completion (Actual): August 1, 2019
• Study Completion (Actual): October 10, 2019

Study Registration Dates

• First Submitted: March 14, 2016
• First Submitted That Met QC Criteria: April 8, 2016
• First Posted (Estimate): April 13, 2016

Study Record Updates

• Last Update Posted (Actual): August 17, 2020
• Last Update Submitted That Met QC Criteria: July 31, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Keywords: relapse; pharmacotherapy; smoking; tobacco; nicotine; N-acetylcysteine; NAC; cessation; tobacco use disorder
• Additional Relevant MeSH Terms: Mental Disorders; Chemically-Induced Disorders; Substance-Related Disorders; Tobacco Use Disorder; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents; Antiviral Agents; Protective Agents; Respiratory System Agents; Antioxidants; Antidotes; Free Radical Scavengers; Expectorants; Acetylcysteine; N-monoacetylcystine
• Other Study ID Numbers: Pro 00052793; R34DA042228 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes