Naltrexone and Varenicline: Weight Gain and Tolerability in Cigarette Smokers

Inclusion Criteria

• Between the ages of 18 and 75
• Smoking 10 or more cigarettes per day
• Fewer than 3 months of smoking abstinence in the past year
• Motivated to stop smoking

Exclusion Criteria

• Current use of opiates, and/or a urine toxicology screen positive for opiates
• Chronic pain conditions necessitating opioid treatment (naltrexone, an opioid antagonist will make these medications ineffective)
• Evidence of significant hepatocellular injury as evidence by AST or ALT >3 x normal or elevated bilirubin
• History of cirrhosis
• Any serious or unstable disease within 6 months
• Seizure risk
• Diabetes mellitus requiring insulin or oral hypoglycemic medications
• Hepatic or renal impairment
• Use of a monoamine oxidase inhibitor in the prior 14 days
• Clinically significant cardiovascular disease within 6 months
• Uncontrolled hypertension
• Baseline systolic blood pressure higher than 150 mm Hg or diastolic blood pressure higher than 95 mm Hg
• Severe chronic obstructive pulmonary disease
• History of cancer (except treated basal cell or squamous cell carcinoma of the skin)
• History of clinically significant allergic reactions
• Major depressive disorder within the past year requiring treatment
• History of or current panic disorder, psychosis, bipolar disorder, or eating disorders
• Alcohol or drug abuse/dependency within the past year
• Use of another investigational drug within 30 days
• Intention to donate blood or blood products during the treatment phase of the study
• Use of tobacco products other than cigarettes or use of marijuana
• Use of nicotine replacement therapy, clonidine, varenicline, bupropion, or nortriptyline within the month prior to enrollment or intention to use medication that might interfere with study medication
• Body Mass Index (calculated as weight in kilograms divided by the square of height in meters) less than 15 or greater than 38 or weight less than 45 kg.
• Females of childbearing potential who are pregnant, nursing, or not practicing effective contraception (oral injectable, or implantable contraceptives, intrauterine device, or barrier method with spermacide)