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Tobacco Use DisorderPhase 4NCT04228965

Cannabis and Tobacco Co-use Study

A Phase 4 study testing Varenicline, Contingency Management and Counseling in people with Tobacco Use Disorder, run by Medical University of South Carolina at 3 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 to 40 years
Conditions the study is for
Tobacco Use Disorder
What is being tested?
Varenicline, Contingency Management and Counseling
Could I receive a placebo?
No, everyone receives an active treatment
How many people
181 participants
Where
3 sitesUnited States
Study dates
28 Jan 2020to 13 Sep 2024
Phase
Phase 4
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 40 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Between the ages of 18 and 40 years old
  • Must be able to understand the study and provide written informed consent
  • Daily cigarette smoker for ≥ 6 months, smoking ≥ 5 cigarettes per day
  • Must submit a breath carbon monoxide (CO) sample of ≥ 7 parts per million (ppm) at the screening visit
  • Be interested in quitting smoking tobacco cigarettes (defined as a 5 or above on a 10-point Likert scale assessing interest in quitting [1=not at all interested, 10=extremely interested])
  • Must be willing to take varenicline for the standard 12-week course of treatment
Show all 9Show fewer
  • If female, agreement to use birth control (any form) to avoid pregnancy during study procedures
  • Additional inclusion criteria will be implemented for cannabis co-users, which include:
  • Self-reported use of cannabis on at least 10 out of the past 30 days or submit a positive qualitative urinary cannabinoid test at screening (limit of detection is 50 ng/ml)

Who cannot join

  • Any serious or unstable medical/psychiatric disorder (including severe substance use disorders, other than cannabis or tobacco use disorders) or other significant concern in the past three months that may interfere with study performance, impact participant safety, compliance with study procedures, or potentially confound the interpretation of findings
  • Currently pregnant, lactating, or contemplating pregnancy in the next 6 months
  • Current use of medications with smoking cessation efficacy
  • Use of any medications that would interfere with varenicline
  • No regular use of other tobacco or nicotine products other than combustible cigarettes (e.g., smokeless tobacco, electronic cigarettes, etc.) in the past month prior to the quit attempt

Trial locations and contacts

3 sites in 1 country.

United States3 sites

  • Medical University of South Carolina - Charleston

    Charleston, South Carolina, 29403

  • Medical University of South Carolina - Florence

    Florence, South Carolina, 29505

  • Behavioral Health Services of Pickens County

    Pickens, South Carolina, 29671

Other trials in United States

About this study

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

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.

Read the 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).

Being tested
Varenicline, Contingency Management, Counseling
Keywords
Smoking Cessation
Medical subject headings
Tobacco Use Disorder, Smoking Cessation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • VareniclineDrug

    Also called Chantix

    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.

  • Contingency ManagementBehavioural

    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.

  • CounselingBehavioural

    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.

Study groups in NCT04228965
Study groupRoleWhat they receive
Co-Use GroupOtherCannabis and tobacco co-use group.
Receives: Drug: Varenicline; Behavioral: Contingency Management; Behavioral: Counseling
Tobacco Only GroupActive comparatorTobacco only group.
Receives: Drug: Varenicline; Behavioral: Contingency Management; Behavioral: Counseling

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants With Biologically Verified 7-day Point Prevalence Tobacco Abstinence at the End of Treatment (Week 12)

    7-day point prevalence abstinence from tobacco at the end of treatment (Week 12) will be assessed via biochemical verification (urinary cotinine; ng/ml) and will be compared between cannabis co-users and tobacco only controls.

    Measured: Final 7 days of treatment (Week 12)

Secondary outcomes (1)

  1. Cannabis Use During Tobacco Cessation Treatment (Among Co-users)

    Among cannabis co-users (n=110), cannabis use (based on urinary cannabinoids [ng/ml]) during the final 4 weeks of tobacco treatment (Weeks 9-12) will be assessed.

    Measured: Final 4 weeks of study treatment (Weeks 9-12)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Jan 2020
  2. Study start28 Jan 2020
  3. Primary completion12 Jun 2024
  4. Study completion13 Sep 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Single group
Masking
None (open label)
Enrolment
181 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04228965
Sponsor's protocol ID
00086954
Other IDs
R37CA237245
Status last verified
Jun 2025
First submitted
11 Dec 2019
Last updated
15 Jun 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Walters KJ, Baker NL, Tomko RL, Gray KM, Carpenter MJ, McClure EA. Determining the impact of cannabis use and severity on tobacco cessation outcomes: study protocol for a prospective tobacco treatment trial. BMC Psychol. 2023 Jan 25;11(1):25. doi: 10.1186/s40359-023-01060-2.

    PubMed 36698194

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Varenicline, Contingency Management and Counseling in people with Tobacco Use Disorder, run by Medical University of South Carolina at 3 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 15 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Biologically Verified 7-day Point Prevalence Tobacco Abstinence at the End of Treatment (Week 12) (time frame: Final 7 days of treatment (Week 12)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04228965, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jun 2025.

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