Pilot, eight week, open-label, within-subject cross over trial of four weeks of standard clinical care (SCC) in an outpatient substance use disorder treatment program and four weeks of SCC and varenicline among current and former tobacco smokers with frequent cannabis use.
Treating co-occurring cannabis and tobacco use disorders might reduce the health burdens associated with both substances. However, few studies have evaluated pharmacological interventions, in combination with behavioral treatment, to address co-occurring cannabis and tobacco use; these are limited by high participant attrition, poor adherence to interventions, and lack of control. Pilot, eight week, open-label, within-subject cross over trial of four weeks of standard clinical care (SCC) in an outpatient substance use disorder treatment program and four weeks of SCC and varenicline among current and former tobacco smokers with frequent cannabis use. Participants were recruited from an urban, outpatient substance use disorder treatment program that offers both intensive behavioral counseling and medications for opioid use disorder (MOUD). Participants were randomized to receive either SCC or SCC and varenicline first and then were crossed over to receive the opposite intervention. The study consisted of two 4-week treatment periods with no washout period. Outcomes are reported in pooled analyses of all participants in each treatment phase.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
7
Standard clinical care includes substance use disorder treatment program-based individual behavioral counseling at least once a month using motivational and cognitive behavioral strategies. Varenicline therapy includes a one month's supply of the medication in standard doses: 0.5 mg for 3 days, 0.5 mg twice a day for 4 days, then 1 mg twice a day for 21 days.
Standard clinical care includes substance use disorder treatment program-based individual behavioral counseling at least once a month using motivational and cognitive behavioral strategies. Varenicline therapy includes a one month's supply of the medication in standard doses: 0.5 mg for 3 days, 0.5 mg twice a day for 4 days, then 1 mg twice a day for 21 days.
Enrollment Rate
Percentage of the eleven eligible subjects willing to participate
Time frame: Baseline
Retention Rate
Retention rate was determined by the percentage of participants who completed all study visits.
Time frame: Week 8
Overall Medication Adherence
Overall medication adherence was calculated as a percentage based on the number of pills prescribed during the study, corrected for the number of pills returned, divided by the period (in days), and multiplied by 100. An aggregate percentage of pills was calculated and reported for all seven study participants.
Time frame: Upon conclusion of SCC+Varenicline treatment (4 weeks or 8 weeks based on randomization to arm/group)
Number of Participants With Treatment-Emergent Adverse Events: Upset Stomach
The number of participants with a self-reported adverse event of upset stomach was determined using a structured questionnaire of common varenicline symptoms
Time frame: Upon conclusion of SCC+VT treatment (4 weeks or 8 weeks based on randomization to arm/group)
Number of Participants With Treatment-Emergent Symptoms of Major Depressive Disorder
The number of participants with self-reported Treatment-Emergent symptoms of major depressive disorder was determined using the MINI International Neuropsychiatric Interview (M.I.N.I), a short structured diagnostic interview tool used to assess DSM-IV and ICD-10 psychiatric disorders
Time frame: Upon conclusion of SCC+VT treatment (4 weeks or 8 weeks based on randomization to arm/group)
Cannabis Craving
Cannabis craving was assessed using the Marijuana Craving Questionnaire-Short Form (MCQ-SF). The MCQ-SF is a valid and reliable, self-report instrument with 12 items rated on a 7-point Likert scale from 1 (strongly disagree) to 7 (strongly agree). The 12 items are grouped by certain characteristics and the score of each of resulting groups correlates to the intensity of the four craving dimensions (compulsivity, emotionality, expectancy, and purposefulness). Scores from the four subscales are summed with total possible scores ranging from 12 - 84. Higher scores are indicative of increased craving.
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Time frame: Week 4 and Week 8
Cannabis Withdrawal
Cannabis withdrawal was measured by the 15-item version of the Marijuana Withdrawal Checklist (MWC). Participants rated each symptom experienced during their most recent period of marijuana abstinence, based on a 4-point scale where 0 = none, 1 = mild, 2 = moderate, and 3 = severe. A total MWC score was obtained by summing the responses. Possible total scoring ranges from 0 - 45, with 0 signifying no withdrawal symptoms and 45 signifying the most severe withdrawal symptoms.
Time frame: Week 4 and Week 8
Quantity of Cannabis Use
The quantity of cannabis use over the prior 14-day period was measured using the Timeline Follow-Back (TLFB) method. TLFS is a method in which participants used a physical calendar to quantify the number of days over a specified period of time (in this study 14 days) during which cannabis was used. An aggregate value for percentage of days of cannabis use was calculated by tabulating the total number of days cannabis was used by all study participants over the prior 14-day period and dividing by the total number of calendar days over this period across the 7 participants (i.e., 14x7=98).
Time frame: Week 4 and Week 8
Frequency of Cannabis Use
The frequency of cannabis use per day was evaluated over the prior 14-day period using the Timeline Follow-Back method (TLFB), a method in which participants used a physical calendar to self-report the number times per days cannabis was used.
Time frame: Week 4 and Week 8
Number of Cigarettes Smoked Per Day
The number of cigarettes smoked per day was measured using Timeline Follow-Back (TLFB). TLFB is a method in which participants used a physical calendar to self-report the number of cigarettes smoked per day over the prior 14-day period in order to evaluate ongoing tobacco usage.
Time frame: Week 4 and Week 8
Number of Participants With Toxicology-verified Cannabis Abstinence
The number of participants with Toxicology-verified cannabis abstinence was determined by applying the TLFB method and then biochemically confirming the number of participants with a urine tetrahydrocannabinol (THC) levels less than 50 ng/ml.
Time frame: Week 4 and Week 8
Number of Participants With Biochemically-verified Tobacco Abstinence
The number of participants with biochemically-verified tobacco abstinence was determined by applying the TLFB method and then biochemically verified by measuring participant levels of expired carbon monoxide \< 8 parts per million (CO \< 8ppm). The Bedfont Smokerlyzer carbon monoxide monitor was used in the analysis.
Time frame: Week 4 and Week 8
Mean Expired Carbon Monoxide
Mean expired carbon monoxide (CO) per participant was measured using the Bedfont Smokerlyzer carbon monoxide monitor. Results reported in mean parts per million (ppm)
Time frame: Week 4 and Week 8
Number of Participants With Treatment-Emergent Suicidal Ideation Events
The number of participants with treatment-emergent suicidal ideation events was determined using the Columbia Suicide Severity Rating Scale (C-SSRS). The C-SSRS contains 6 "yes" or "no" questions in which respondents are asked to indicate whether they have experienced several thoughts or feelings relating to suicide over the past month and behaviors over their lifetime as well as during the past 3 months. An answer of "yes" to any of the six questions may indicate a need for referral to a trained mental health professional and an answer of "yes" to questions to the final three questions indicates high-risk.
Time frame: Week 4 and Week 8