Phase 4
N=181
Cannabis and Tobacco Co-use Study
Tobacco Use Disorder
Bottom Line
View on ClinicalTrials.gov: NCT04228965 ↗Enrolled (actual)
181
Serious AEs
1.1%
Results posted
Jun 2025
Primary outcome: Primary: Number of Participants With Biologically Verified 7-day Point Prevalence Tobacco Abstinence at the End of Treatment (Week 12) — 30; 40; 36; 42 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 4
- Interventions
- Varenicline (Drug); Contingency Management (Behavioral); Counseling (Behavioral)
- Age
- Adult · 18+ yrs
- Sex
- All
- Sponsor
- Medical University of South Carolina
- Primary completion
- Jun 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Participants With Biologically Verified 7-day Point Prevalence Tobacco Abstinence at the End of Treatment (Week 12) |
30; 40; 36; 42; 30; 40 | — |
| SECONDARY Cannabis Use During Tobacco Cessation Treatment (Among Co-users) |
405; 402; 376; 414 | — |
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.
Eligibility Criteria
Inclusion Criteria
- 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
- 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)
Exclusion Criteria
- 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
Data sourced from ClinicalTrials.gov (NCT04228965). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.