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Completed

NCT Number: NCT05729243

Cytisine for Smoking Cessation

The goal of this clinical trial is to evaluate the safety and effectiveness of cytisine as a smoking cessation treatment in individuals with concurrent alcohol use disorder.

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Key information

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Center for Addiction and Mental Health

Toronto, Ontario, M5S 2S1, Canada

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged 18-65 years;
  • Have TUD assessed by structured clinical interview for DSM-5;
  • Have past year AUD (active) assessed by structured clinical interview for DSM-5;
  • Report daily cigarette consumption in past month and expired carbon monoxide (CO) measurement ≥10ppm at screening;
  • Have Fagerstrom Test of Nicotine Dependence (FTND55) score ≥4;
  • Have motivation to quit within 30 days i.e. Contemplation Ladder56 score ≥7;
  • Be willing and able to comply with all study procedural and assessment demands;
  • Be able to provide voluntary written informed consent.

Exclusion criteria

  • Report prolonged smoking abstinence in the past month preceding screening;
  • Be using other smoking cessation aids
  • Enrolled in another smoking cessation program
  • Be pregnant, breastfeeding, or intending to become pregnant or breastfeed;
  • Exhibit suicidal thoughts or behavior in the past month;
  • Enrolled in another study which would interfere with study procedures or represent a potential risk to the participant
  • Have a serious unstable psychiatric or medical condition preventing participation in the trial. This includes some forms of schizophrenia, ischemic heart disease, heart failure, arterial hypertension (systolic BP above 150; diastolic BP above 100), cerebrovascular diseases, occlusion of blood vessels, kidney and/or liver disease, hyperthyroidism, ulcer, diabetes, Chromaffin tumours of the adrenal medulla, and gastroesophageal reflux disease (GERD)

Treatment and study plan

cytisine

Drug

Cytisine is a nicotinic acetylcholine receptor partial agonist and is a natural health product approved by Health Canada. Cytisine has been used for a long time in Europe for smoking cessation.

Placebo

Other

A placebo identical in appearance to cytisine will be used

Primary outcomes

  1. Frequency and type of adverse events

    Time frame: Total duration of trial (24 weeks)

    To assess the tolerability of cytisine

  2. Rate of retention in the trial: number of sessions completed for each participant and number ofparticipants who withdraw

    Time frame: Total duration of trial (24 weeks)

    To assess the tolerability of cytisine

Secondary outcomes

  1. Point-prevalence abstinence

    Time frame: Week 2 and week 4

    Complete abstinence ("not even a puff") during a designated time period (7 days) prior to assessment. This will be measured at each assessment point (e.g., 2 and 4wk).

  2. Repeated point-prevalence abstinence

    Time frame: Throughout study completion, up to 24 weeks.

    Point-prevalence abstinence at each consecutive assessment point.

  3. Prolonged abstinence

    Time frame: This period will end at the end of treatment (day 25) or at final follow-up.

    Complete abstinence ("not even a puff") after an initial grace period; also known as sustained abstinence.

  4. Prolonged abstinence with lapses

    Time frame: This period will end at the end of treatment (day 25) or at final follow-up.

    Prolonged abstinence after a grace period, but some smoking is allowed (e.g., no more than 5 cigarettes; fewer than seven consecutive days of smoking).

  5. Continuous Abstinence

    Time frame: Throughout study completion, up to 24 weeks.

    Complete abstinence ("not even a puff") beginning on the TQD (i.e., with no grace period) and lasting until the assessment from target quit date (week 2) to end of treatment (day 25) and at final follow up.

  6. Physical dependence to Nicotine in Participants

    Time frame: Throughout study duration (24 weeks)

    The Fagerstrom Test for Nicotine Dependence (FTND) will be used to assess physical dependence in participants.

  7. Nicotine Withdrawal Symptoms in Participants

    Time frame: Throughout study duration (24 weeks)

    The Minnesota Nicotine Withdrawal Scale (MNWS) will be used to assess nicotine withdrawal symptoms.

  8. Nicotine Craving in Participants

    Time frame: Throughout study duration (24 weeks)

    Tiffany Questionnaire of Smoking Urges (QSU) will be used to assess nicotine craving.

Other outcomes

  1. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on anxiety.

    Time frame: Throughout study duration (24 weeks)

    Anxiety will be measured through the General Anxiety Disorder-7 (GAD-7) questionnaire.

  2. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on mood.

    Time frame: Throughout study duration (24 weeks)

    Mood will be measured by the Patient Health Questionnaire-9 (PHQ-9).

  3. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on Quality of Life.

    Time frame: Throughout study duration (24 weeks)

    Quality of Life will be measured through the WHO Disability Assessment Schedule (WHODAS).

  4. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on drinking by collecting the number of drinking days in participants.

    Time frame: Throughout study duration (24 weeks)

    Number of drinking days and drinks per day/drinking day will be collected.

  5. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on drinking by measuring the proportion of heavy drinking days in participants.

    Time frame: Throughout study duration (24 weeks)

    Percent of heavy drinking days (5+/4+ males/females)/very heavy drinking days (10+/8+ males/females) per week and per month will be collected.

  6. Tertiary Endpoints to evaluate the impact of cytisine vs. placebo on drinking by measuring the proportion of participants without heavy drinking days.

    Time frame: Throughout study duration (24 weeks)

    Percent of subjects who are abstinent, percent of subjects with no heavy drinking days and percent of days abstinent will be collected.

Sponsors and collaborators

Lead sponsor

Centre for Addiction and Mental Health

Other

Registry information

Official study title

Cytisine: Testing Its Potential as a Therapeutic Strategy for Smoking Cessation Among People With Concurrent Alcohol Use Disorder

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Feb 15, 2023
Registry last updated
Feb 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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