Nicotine Receptor Levels and Smoking Cessation
Condition: Smoking Cessation; Nicotine Addiction
MeSH terms: Tobacco Use Disorder
Study type: Observational

Summary: 
      The investigators propose to use positron emission tomography (PET) imaging to determine
      whether nicotinic receptor availability at pretreatment predicts smoking cessation success.
      The investigators will recruit 30 smokers from those enrolled in the Pharmacogenetics of
      Nicotine Addiction Treatment clinical trial. The investigators will measure nicotinic
      receptor availability using the PET radioligand 2-[18F]FA, after overnight abstinence and
      prior to initiation of treatment.
    

Detailed description: 
      Subjects will be asked to complete a short screening session, an orientation phone call, and
      two imaging sessions: one PET imaging session and one MRI session.

      Intake Session. This session will familiarize subjects with the study procedures and risks,
      as well as determine initial eligibility for the study. Subjects will first complete an
      Imaging Screening Form with study personnel. Subjects will also complete a Magnet Safety Form
      to check for any metal in the body. Finally, subjects will complete a Scanning Registration
      Form.

      Orientation Call. Dr. Dubroff (the Principal Investigator and study physician) will call
      subjects before the PET Scan Session to review the study procedures and risks and answer any
      questions subjects might have.

      PET Scan Session. Subjects will receive a telephone call the day before the session to remind
      them to stop smoking at 9:00pm that night. At the session, they will provide a series of
      samples. These include:

        -  A urine sample to assess for the presence of study-prohibited drugs and medications
           (including cocaine, opiates, benzodiazepines, amphetamines, methamphetamines, tri-cyclic
           antidepressants, methadone, PCP, and barbiturates).

        -  Women of childbearing age will be required to take a urine pregnancy test.

        -  A breath alcohol concentration (BrAC) measurement.

        -  A breath carbon monoxide (CO) reading.

        -  Have your weight measured.

      After subjects arrive at the PET center, they will have two intravenous (I.V.) lines placed.
      A sterile solution will be dripped through the tubing to keep them open. Subjects will have
      blood pressure and heart rate taken prior to injection and three 10ml tubes of blood will be
      drawn to determine the baseline levels of radioactive tracer. After this, subjects will be
      injected with a radioactive tracer (a chemical that has a radioactive molecule attached to
      it) called 2-[18F]FA that will be pumped through one of the I.V. lines over an 8-hour period.
      During the waiting period subjects will complete two questionnaires, a brief IQ test, and
      five computer games. They will have repeated blood pressure and heart rate readings taken
      soon after the initial injection and every 45 minutes afterwards. The investigators will draw
      3 ml (half a teaspoon) of blood from the second I.V. line every 15-30 minutes to measure
      radiotracer levels.

      Just prior to beginning the scan, subjects will be asked two questions about cravings. These
      questions will be asked every 30 minutes during the scan and then once more after subjects
      have exited the scan. The investigators will draw one 3ml tube of blood at the beginning of
      the PET scan and every 30 min during the PET scan (total 5 teaspoons) from the second I.V.
      line to measure radiotracer levels.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Inclusion Criteria:

        Participants will be male and female smokers between the ages of 18 and 65 and must be
        enrolled(consented and meet all eligibility requirements) in the ongoing PNAT trial
        [NCT01314001] in order to participate in this sub-study. They must be able to provide
        informed consent and weigh less than 300 lbs (due to limitations of the PET and MRI
        scanners).
      
Keywords: positron emission tomography; nicotine receptor