Efficacy of Naltrexone in Women's Smoking Cessation
Condition: Smoking; Smoking Cessation
Intervention: Naltrexone (drug); Placebo (for Naltrexone)
Intervention description: 50 mg q.d. for 13 weeks; Sugar pill manufactured to mimic Naltrexone tablet
Intervention MeSH terms: Naltrexone
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Enrollment: 333.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Smoking; Smoking Cessation

Summary:

      The purpose of the proposed study is to conduct a randomized, double-blind clinical trial to
      compare adjunct treatment with 50 mg oral naltrexone vs. placebo in conjunction with standard
      smoking cessation treatment with nicotine patch and counseling.

      Hypotheses:

        1. Naltrexone will improve smoking cessation quit rates, as measured at the end of active
           treatment (3 months) and during long term follow up (1 year).

        2. Weight and smoking-related variables (i.e., less weight gain, as well as reduced craving
           and withdrawal) will be important factors by which naltrexone improves smoking cessation
           outcome.

        3. These effects are predicted to be stronger in women compared to men.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Age 18-65, male or female

          2. Cigarette smoker of at least 15 but no more than 40 cigarettes daily for at least two
             years

          3. Current diagnosis of DSM-IV Nicotine Dependence, based on SCID interview

          4. Relatively healthy, with no medical or psychiatric conditions that would adversely
             interact with study parameters (see exclusion criteria for specific details)

          5. Desire to quit smoking (self-report rating of interest in quitting at least a 7 on a
             10-point scale)

          6. Nicometer® cotinine level at baseline at least a 5 on a 6-point scale

          7. Reports not quitting smoking in the past three months for more than one week duration

          8. Agrees to attend behavioral counseling sessions and complete study measures

          9. Has stable residence and telephone and can provide the name of an outside household
             collateral family member or close friend

        Exclusion Criteria:

          1. Substance Dependence in the last one year (other than DSM-IV Nicotine Dependence) or
             any history of Opioid Dependence (lifetime)

          2. Major psychiatric disorder in the last one year, including Axis I disorders or any
             history of moderate/severe Axis II Disorder, Bipolar Disorder or Psychotic Disorder,
             based on SCID interview and standard cut-off thresholds on screening questionnaires

          3. Past or current medical disorders (cardiovascular, hepatic, neurological, endocrine,
             etc.) which may adversely interact with study measures

          4. Clinically significant lab test abnormalities, positive urine toxicology, or positive
             pregnancy test

          5. Currently pregnant, plans to become pregnant, or lack of effective birth control over
             next three months, and/or currently lactating, or plans for breastfeeding over next
             three months

          6. History of adverse reaction to opioid antagonist or nicotine replacement treatment

          7. Use of any medication that may adversely interact with study measures
             (antidepressants, phenothiazines, benzodiazepines, etc.); recent or regular use of an
             opioid medication

          8. Unwillingness to attend smoking cessation treatment sessions, take the nicotine patch,
             or be randomized into medication or placebo conditions, or be available for follow-up
             assessments

          9. Unwillingness to agree to DNA analysis.