NCT06688539 · Medical University of South Carolina
E-cigarette Cessation in Adults Who Co-use Cannabis
(VapeCAT)
What this study is about
The purpose of this study is to better understand tobacco outcomes using a commonly prescribed stop smoking medication (varenicline) and financial incentives for adults who also use cannabis. Varenicline is not FDA approved for e-cigarette cessation, but is FDA approved for cigarette cessation.
View original scientific description
The purpose of this study is to better understand tobacco outcomes using a commonly prescribed stop smoking medication (varenicline) and financial incentives for adults who also use cannabis. Varenicline is not FDA approved for e-cigarette cessation, but is FDA approved for cigarette cessation. Investigators are also interested in how cannabis/marijuana and tobacco interact during a tobacco quit attempt. All participants will receive e-cigarette cessation treatment for 12 weeks.
Interventions
DRUG
Varenicline Pill
In this study, all participants will be administered active medication for a 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 e-cigarette 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.
Primary outcome measures
7-day point prevalence tobacco abstinence at the end of treatment (Week 12)
Time frame: Final 7 days of treatment (Week 12)
7-day point prevalence abstinence from e-cigarettes at the end of treatment (Week 12) will be assessed via biochemical verification (urinary cotinine; ng/ml) and will be compared to cigarette abstinence rates from the parent study (as historical controls)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Between the ages of 18 and 40 years old
- Use e-cigarettes daily or near daily in the past month
- Must submit a positive instant-read urine cotinine test at screening (≥ 200 ng/ml)
- Be interested in quitting use of e-cigarettes
- Must be willing to take varenicline for the standard 12-week course of treatment
- Self-reported use of cannabis on at least 10 out of the past 30 days or must submit a positive qualitative urinary cannabinoid test at screening (\> 50 ng/ml)
Exclusion criteria
- Any serious or unstable medical/psychiatric disorder (including severe substance use disorders, other than cannabis or tobacco use disorders) in the past three months that may interfere with study performance
- Use of cigarettes on 10+ days in the past 30
- Currently pregnant or breastfeeding
- Current use of medications with smoking cessation efficacy
- Use of any medications that would interfere with varenicline
Where
- Charleston, South Carolina
- Lancaster, South Carolina
- Pickens, South Carolina
Collaborators
National Cancer Institute (NCI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 12, 2026 · Source of record for eligibility and locations