Patient description: Patient A is a 30-year-old male who was admitted to the hospital after 10 days of cough, profuse nocturnal sweating and loss of appetite. He had traveled to India 1 months ago and has not any positive history of TB vaccination. He is a previously healthy man, working as an engineer in a high tech company. He doesn't smoke o use any illicit drugs. He was febrile (38 c) with heart rate of 115 b/min, respiratory rate of 22, BP of 125/75 mmHg and O2 sat of 97%. Chest X-ray showed infiltrate in the middle of left lung with diameter of 1.8 cm with signs of cavitation. The sputum smear revealed positive sputum culture for Mycobacterium tuberculosis which are sensitive of the first-line TB drugs (isoniazid, streptomycin, rifampicin and ethambutol). Lab study is reported bellow: Hgb: 13 g/dl WBC: 14000 /mm3 Plt: 300000 /ml AST: 13 U/L ALT: 15 U/L Alk P: 53 U/L Bill total: 0.6 mg/dl Na: 137 mEq/l K: 4 mEq/l Creatinine: 0.5 mg/dl BUN: 10 mg/dl ESR: 120 mm/hr

Clinical trial eligibility criteria: eligible ages (years): 18.0-65.0,  Tobacco Use Disorder Smoking Cessation Age: 18-65 years old 2. Smoking: >/= 5 cigarettes per day within the 2 months preceding the screening visit and expired CO greater than or equal to 6 ppm. 3. Able to follow verbal and written instructions in English and complete all aspects of the study 4. Have an address and home telephone number where they may be reached 5. Provide informed consent and agree to all assessments and study procedures 6. Be the only participant in their household  Within the month immediately preceding the screening visit; use of any form of tobacco product other than cigarettes on 3 or more days within a week only if the individual refuses to refrain from non-cigarette tobacco use during the course of this study 2. Within the month immediately preceding the screening visit; use of marijuana in any form on 3 or more days within a week 3. Within the two weeks immediately preceding the screening visit, involvement on more than 3 days in any formal smoking cessation activities 4. Current visual or auditory problems that in the opinion of the investigator would interfere with the completion of study assessments 5. Treatment on a continuous basis within 2 weeks before the screening visit: any contraindicated medication for Varenicline or Bupropion. 6. Uncontrolled hypertension or other major contraindications for Bupropion or Varenicline. 7. Severe renal impairment (CR Clearance <30 ml/min/1.73 m2). 8. Laboratory evaluations outside normal limits and of potential clinical significance in the opinion of the investigator 9. Meet current for psychiatric disorders or substance abuse as assessed by the MINI for items A, B, D, I, J, K, L, M and N, including a past manic or hypomanic episode as well as a lifetime psychotic disorder. 10. Subject rated as moderate to high on suicidality as assessed by the MINI. 11. Psychiatric hospitalization within 1 year of screening date. 12. A positive urine pregnancy test during the screening period. Women who are two years post menopausal, one year post-tubal ligation, or who have had a partial or full hysterectomy will not be subject to a urine pregnancy test. 13. Pregnant, breast-feeding, or of childbearing potential who is not protected by a medically acceptable, effective method of birth control while enrolled in the study 14. Use of Varenicline or Bupropion within two weeks before the screening visit. 15. History of hypersensitivity or allergic reaction to Varenicline, tricyclic antidepressant, Bupropion (Wellbutrin, Zyban) or similar chemical classes or any component of these formulations. 16. Subject considered by the investigator as unsuitable candidate for receipt of an investigational drug, or unstable to be followed up throughout the entire duration of the study