NCT04228965

Cannabis and Tobacco Co-use Study

A Prospective Trial of Varenicline and Incentives for Tobacco Cessation in Adults

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 181 (actual)
• Sponsor: Medical University of South Carolina · Academic / Other
• Sex: All
• Age: 18 Years – 40 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to better understand tobacco outcomes using a well-known stop smoking medication, varenicline, and financial incentives with tobacco users. The investigators are also interested in how cannabis/marijuana and tobacco interact during a tobacco quit attempt. All participants will receive tobacco cessation treatment (varenicline) for 12 weeks. This study will recruit adult tobacco users (ages 18-40) who are motivated to quit smoking cigarettes.

Detailed description

Cannabis co-use among tobacco users is exceedingly common and rates of co-use appear to be increasing among adults in the US, which is consistent with overall increases in cannabis use rates among US adults. Given the current cannabis landscape, further increases in cannabis use are likely and may result in continued increases in the co-use of cannabis and tobacco. Despite high rates of co-use, there is little consensus regarding treatment recommendations for this population and an understanding of the impact of co-use on successful cessation. The literature on the impact of co-use on tobacco cessation outcomes specifically has been mixed and fraught with limitations, including methodological variation, lack of biochemical verification to confirm cannabis use status and severity, and variations in study samples. Currently, no prospective studies have been conducted to evaluate the impact of cannabis use on tobacco cessation outcomes. Further, no studies have collected cannabis use changes during tobacco cessation treatment to assess for concurrent reductions, abstinence, or of greater concern, compensatory (i.e., increased) use as a result of tobacco reduction/abstinence. This study is a prospective 12-week tobacco cessation trial using established methods and outcomes typical of tobacco cessation trials, but specifically recruiting co-users of cannabis. The aims of this proposed study are to; 1) examine the impact of cannabis co-use on tobacco cessation outcomes among co-users compared to tobacco only participants (Aim #1), 2) among cannabis co-users, assess changes in cannabis use during tobacco treatment (Aim #2), and 3) assess for a dose-dependent impact of cannabis co-use severity on tobacco cessation (Exploratory Aim #1).

Conditions

• Tobacco Use Disorder

Interventions

Type	Name	Description
DRUG	Varenicline	Varenicline is a medication approved by the Food and Drug Administration for the treatment of tobacco use disorder among adults (ages 18 and over). In this study, all participants will be administered active medication for the recommended 12 week treatment period. The standard dose titration schedule will be used, which includes 0.5 mg once per day (q.d.) on Days 1-3, 0.5 mg twice per day (b.i.d.) on Days 4-7, and 1.0 mg b.i.d. starting on Day 8. Dosing of 2.0 mg per day will be maintained for the next 11 weeks, for a total of 12 weeks of active treatment for all study participants.
BEHAVIORAL	Contingency Management	Contingency management procedures will be implemented and financial incentives will be provided at weekly visits contingent on tobacco abstinence verified through urinary qualitative cotinine (starting at Week 2). A set amount of $20 per study visit will be delivered based on a negative qualitative urinary cotinine result.
BEHAVIORAL	Counseling	Psychosocial counseling will be administered by trained research staff leading up to the target quit date and throughout the study. Counseling will include motivational enhancement for medication adherence and tobacco cessation. The content of counseling will be skills-based and will focus on enlisting social support, recognizing smoking triggers, managing craving/withdrawal/stress, etc.

Timeline

• Start date: 2020-01-28
• Primary completion: 2024-06-12
• Completion: 2024-09-13
• First posted: 2020-01-14
• Last updated: 2025-06-15
• Results posted: 2025-06-15

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study