Clinical Trials

Inclusion Criteria

• Age at least 18 years
• Has provided written informed consent
• Has smoked greater than or equal to 10 cigarettes per day for at least 6 months
• Able to complete all study visits
• In good health as determined by the investigator
• Has ability to participate fully in all aspects of the study and keep scheduled appointments
• Is motivated to stop smoking

Exclusion Criteria

• Pregnant, lactating or likely to become pregnant during the trial and not able or willing to use contraception
• Another household member participating in the study
• Bupropion or varenicline allergy
• Current use (previous 30 days) of a tobacco dependence treatment and unable or unwilling to discontinue use
• An unstable medical condition or unstable angina, myocardial infarction, or coronary angioplasty (past 3 months) or an untreated cardiac dysrhythmia
• A history of renal failure or was on renal dialysis
• History of seizures
• As defined by the C-SSRS (Columbia-Suicide Severity Rating Scale), current non-specific suicidal thoughts or lifetime history of a suicidal attempt defined as "potentially self-injurious act committed with at least some wish to die, as a result of act"
• History of closed head trauma associated with > 30 minutes of loss of consciousness, amnesia, skull fracture, subdural hematoma, or brain contusion
• History of psychosis, bipolar disorder, bulimia or anorexia nervosa
• Current moderate or severe depression as assessed by a score of ≥ 20 on the Beck Depression Inventory, Second Edition (BDI-II) 10
• Active substance abuse other than nicotine
• Current (past 14 days) use of an antipsychotic, monoamine oxidase inhibitors, or drugs known to interact with bupropion SR;
• Recent dose change of antidepressant (within last 3 months)
• Untreated hypertension or baseline systolic blood pressure > 180 or diastolic > 100
• Current treatment with another investigational drug for tobacco dependence (previous 30 days)
• Current use of bupropion or varenicline (previous 30 days)