Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized, Multicenter, Double Blind, Placebo Controlled Study Evaluating The Efficacy Of Varenicline In Cessation Of Oral Smokeless Tobacco Use
Brief Summary: The primary goal of this study is to compare efficacy of varenicline to placebo for cessation of use of smokeless tobacco.


Options:
A: Inclusion Criteria:

* currently smoking at least 10 cigarettes per day (confirmed by high exhaled carbon-monoxide (CO))
* 18 years or older
* interested in quitting within the next 30 days
* one or more pre-defined medical illnesses (including cardiovascular disease, other vascular disease, chronic pulmonary disease, cancer, hypertension, diabetes, hyperlipidemia, and recurrent pulmonary infections)

Exclusion Criteria:

* contraindications to pharmacotherapy (including unstable angina, myocardial infarction within 2 months, severe arrhythmia, seizure disorder, serious mental illness requiring antipsychotic medications)
* current use of other tobacco products (smokeless tobacco, cigars, pipes, etc.), bupropion, clonidine, nortriptyline, or nicotine replacement medications
* unable to give consent
B: Inclusion Criteria:

* Male or female daily smokeless tobacco users aged 18 years and older, who are motivated to stop use of all tobacco products.
* Subjects must be daily users of nicotine containing smokeless tobacco and using smokeless tobacco on at least 8 occasions per day averaged over a week.
* Have used smokeless tobacco for at least 1 year prior to screening with no period of abstinence \>3 months in the past year.

Exclusion Criteria:

* Subjects using nicotine containing products (including smoking tobacco) other than smokeless tobacco for 3 months prior to screening.
* Subjects with exhaled Carbon Monoxide (CO) \>10 ppm at baseline.
* Subjects who have used varenicline, bupropion, or NRT within 3 months of screening.
* Subjects currently or within the past 12 months requiring treatment for depression or have a current or prior history of panic disorder, psychosis, bipolar disorder or any other serious mental illness.
C: Inclusion Criteria:

* Subjects must have smoked an average of at least 10 cigarettes per day during the past year and over the month prior to the screening visit, with no period of abstinence greater than 3 months in the past year.

Exclusion Criteria:

* Subjects who have used bupropion (Zyban, or Wellbutrin) previously.
D: Inclusion Criteria:

* Have no known serious medical conditions;
* Male;
* Are 18-65 years old;
* Smoke an average of at least 10 cigarettes per day;
* Have smoked at least one cumulative year;
* Have an expired air carbon monoxide (CO) reading of at least 10ppm;
* Able to read and understand English;
* Express a desire to quit smoking in the next thirty days.

Potential subjects must agree to use acceptable contraception.

Potential subjects must agree to avoid the following:

* participation in any other nicotine-related modification strategy outside of this protocol;
* use of tobacco products other than cigarettes, including pipe tobacco, cigars, e-cigarettes, snuff, and chewing tobacco;
* use of experimental (investigational) drugs or devices;
* use of illegal drugs;
* use of opiate medications.

Exclusion Criteria:

* Hypertension;
* Hypotension with symptoms;
* Coronary heart disease;
* Lifetime history of heart attack;
* Cardiac rhythm disorder (irregular heart rhythm);
* Chest pains (unless history, exam, and electrocardiogram (ECG) clearly indicate a non-cardiac source);
* Cardiac (heart) disorder (including but not limited to valvular heart disease, heart murmur, heart failure);
* History of skin allergy;
* Active skin disorder (e.g., psoriasis) within the last five years;
* Liver or kidney disorder (except kidney stones, gallstones);
* Gastrointestinal problems or disease other than gastroesophageal reflux or heartburn;
* Active ulcers in the past 30 days;
* Currently symptomatic lung disorder/disease (including but not limited to Chronic obstructive pulmonary disease (COPD), emphysema, and asthma);
* Brain abnormality (including but not limited to stroke, brain tumor, and seizure disorder);
* Migraine headaches that occur more frequently than once per week;
* Recent, unexplained fainting spells;
* Problems giving blood samples;
* Diabetes treated with insulin; non-insulin treated diabetes (unless glucose is less than 180mg/dcl and HbA1c is less than 7%);
* Current cancer or treatment for cancer in the past six months (except basal or squamous cell skin cancer);
* Other major medical condition;
* Current psychiatric disease (with the exception of anxiety disorders, Obsessive Compulsive Disorder (OCD) and ADHD);
* Suicidal ideation (within the past 10 years) or lifetime occurrence of attempted suicide;
* Current depression;
* Bulimia or anorexia;
* Use of opiate medications for pain or sleep (non-opiate medication for pain or sleep will be allowed) within the past 14 days;
* Smoking more than one cigar a month.
* Alcohol abuse;
* Significant adverse reaction to nicotine patches, bupropion / Wellbutrin / Zyban or Chantix / varenicline in the past.
* Current participation or recent participation (in the past 30 days) in another smoking study at our Center or another research facility.
* Current participation in another research study.

Use (within the past 30 days) of:

* Illegal drugs (or if the urine drug screen is positive for tetrahydrocannabinol (THC), Cocaine, Amphetamine, Opiates, Methamphetamines, phencyclidine (PCP), Benzodiazepines, or Barbiturates),
* Experimental (investigational) drugs;
* Psychiatric medications including antidepressants, anti-psychotics or any other medications that are known to affect smoking cessation (e.g. clonidine);
* Smokeless tobacco (chewing tobacco, snuff), pipes or e-cigarettes;
* Wellbutrin, bupropion, Zyban, Chantix, varenicline, nicotine replacement therapy or any other smoking cessation aid.

Answer: B