Varenicline for the Treatment of Cannabis and Tobacco Use Disorders in Veterans

Who can take part

• Meet DSM-5 criteria for cannabis use disorder and use cannabis at least 3 days per week in the last 30 days
• Meet DSM-5 criteria for tobacco use disorder and smoke at least five cigarettes or report vaping 5 mg of nicotine daily
• Males and female Veterans aged 18 and over
• Be interested in quitting or reducing cannabis and tobacco use
• If female and of childbearing potential, must agree to use acceptable methods of birth control for the duration of the trial
• Must consent to random assignment, and be willing to commit to medication ingestion
• Must be able to read and provide informed consent
• Must have body weight >110lbs (50kg) and have BMI between 18 and 35 kg/m2
• Must function at an intellectual level and have knowledge of the English language to sufficiently allow for accurate completion of assessments

Who cannot take part

• Lifetime history of DSM-5 Bipolar I or II Disorder, Schizophrenia or other psychotic disorder. Stably treated MDD, Dysthymia, GAD, Social Phobia, PTSD, and Specific Phobia diagnoses are acceptable (i.e. same dose of medication/psychotherapy has been prescribed for at least 2 months prior to screening and no changes in current medication/psychotherapy expected during course of the trial)
• Concomitant use of psychotropic medications, with the exception of stable doses (defined as no dosing adjustments in the past two months) of non-MAO-I antidepressants, non-benzodiazepine anxiolytics, and ADHD medications
• Current use of medications prescribed for mania or psychosis (these medications may be allowed if used for other indications)
• Current use of bupropion, amitriptyline or nortryptiline or other medication known to have drug interactions with varenicline
• Individuals taking an investigational agent within the last 30 days before baseline visit
• Individuals with severe renal impairment
• Moderate or severe non-cannabis substance use disorders within the past 60 days with the exception of tobacco use disorder
• Individuals with clinically significant medical disorders or lab abnormalities
• Individuals with clinically significant cardiovascular disease in the past 6 months (e.g., myocardial infarction, CABG, PTCA, or severe or unstable angina)
• Individuals with clinically significant cerebrovascular disease in the past 6 months such as TIA, CVA, or stroke
• Hypersensitivity to varenicline
• Women who are pregnant, nursing, or plan to become pregnant during the course of the study
• Suicidal ideation or behavior within the past 6 months. Subjects who are believed to be at suicidal (answers 'yes' on questions 4 or 5 of C-SSRS) or homicidal risk will be referred to assessment by a mental health professional