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:

* Age 18 years or older
* English speaking
* Smoked at least 100 cigarettes/lifetime
* Smoke 5 or more cigarettes per day
* Interested in quitting smoking (preparation or contemplation stage of change)
* Enrolled in Einstein/Montefiore methadone program for 12 weeks or more
* Receiving methadone in clinic three, four, five or six times per week
* No more than 2 methadone clinic misses in prior 14 days
* Agree to use contraception for the duration of the trial (among women with reproductive potential)
* Willing to participate in all study components
* Able to provide informed consent

Exclusion Criteria:

* Serious or unstable HIV/AIDS, liver, cardiovascular, or pulmonary disease
* Psychiatric instability
* Women who are pregnant, breastfeeding, or contemplating pregnancy
* Creatinine clearance \<30 mL/min
B: Inclusion Criteria:

1. Adult (≥21 years of age), seeking treatment for smoking cessation.
2. Able to speak English,
3. Active smoking (Cigarettes Per Day (CPD) ≥5), and exhaled Carbon Monoxide (CO) ≥8 ppm
4. Agree to participate in this randomized smoking cessation trial with follow up assessments up to 12 months.

Exclusion Criteria:

1. Pregnancy or breast feeding,
2. Active use or recent use (\< or equal to 1 month) of medication or e-cigarettes for nicotine dependence/smoking cessation, or use of e-cigarettes for more than 9 days in the prior month,
3. Allergy to nicotine patch, lozenge, or varenicline,
4. Unwillingness to prevent pregnancy during the medication phase and 1 month afterwards (women only),
5. Significant cardiac conditions (myocardial infarction, unstable angina, coronary angioplasty, cardiac bypass) or serious arrhythmia in past 6 months,
6. Current heavy alcohol consumption (≥6 drinks/day, 6 days/week),
7. Active psychosis or poorly controlled depression within the past 6 months,
8. Any prior suicide attempt or suicidal ideation within the past 6 months,
9. End stage renal disease with hemodialysis.
C: Inclusion Criteria:

* Participant is a current smoker (≥ 10 cigarettes per day in the preceding\\ six months);
* Participant is willing to make a quit attempt in the 2-4 weeks after initial screening for eligibility;
* Participant is 18 years of age and older;
* Participant is willing to provide informed consent.

Exclusion Criteria:

* Participant is currently using or has used any intervention medications in the previous 6 months (i.e, Champix (varenicline); and/or Nicotine replacement therapy (patch, gum, inhaler, lozenge));
* Participant has contraindication(s) to any of the following smoking cessation medications:

  * Nicotine replacement therapy (allergic reaction to adhesive; serious cardiac arrhythmias (e.g., tachycardia); participant is during the immediate post-myocardial infarction period (i.e. incident has occurred within the last 10 days); severe or worsening angina pectoris; participant has had a recent cerebral vascular accident);
  * Varenicline (end-stage renal disease; use of cimetidine (by participants with severe renal impairment); previous allergic reaction to varenicline);
* Pregnant or breastfeeding women or those intending to become pregnant in the next year;
* Current or previous (in the last 3 months) substance abuse;
* Unable to provide informed consent due to unstable psychiatric symptoms (e.g., active, untreated psychosis or suicidality);
* Participant is unable to read and understand English or French;
* In order to prevent contamination across groups, only one person per household may participate.
D: 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.

Answer: D