Nicotine Receptor Levels and Smoking Cessation

Nicotinic Receptor Availability and Smoking Cessation Success.

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.

Study Overview

• Status: Completed
• Conditions: Smoking Cessation; Nicotine Addiction

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.

• Study Type: Observational
• Enrollment (Actual): 24

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Center for Interdisciplinary Research on Nicotine Addiction, University of Pennsylvania

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• 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).

Description

Exclusion Criteria:

In addition to the exclusion criteria used for PNAT trial [NCT01314001], participants in this trial will be excluded if they meet the following criteria:

Imaging-Related Exclusion Criteria:

1. Weigh over 299 lbs.
2. Self-reported history of head trauma or brain (or CNS) tumor.
3. Self-reported history of claustrophobia (contraindicated for PET and MRI).
4. Cochlear implant or bilateral hearing aids.
5. Pacemakers, certain metallic implants, or presence of metal in the eye as contraindicated for MRI.
6. History of gunshot wound (including BB guns).
7. Circumstances or conditions that may interfere with magnetic resonance imaging (MRI).
8. CO reading greater than 15ppm at the PET Scan Session (or at least a 50% reduction from the PNAT Intake Session).
9. BrAC reading greater than or equal to 0.01 at the PET Scan Session.
10. Positive urine drug screen for cocaine, phencyclidine, amphetamines, methamphetamines, tricyclic antidepressants, opiates, methadone, benzodiazepines, or barbiturates at the PNAT Intake Session or PET Scan Session.
11. Positive urine pregnancy (females only) screen at the PET Scan Session and/or MRI Scan Session.
12. Inability to give blood at the PET Scan Session (blood samples are required to analyze PET data).
13. Prior exposure to radioactive tracers in imaging studies or for medical reasons may be exclusionary.

General Exclusion Criteria:

1. Any medical condition, illness, disorder or concomitant medication that could compromise participant safety or treatment, as determined by the Principal Investigator or Co-investigators.
2. Inability to provide informed consent or complete the study procedures within 10 hours and/or correctly, as determined by the Principal Investigator or Co-investigators.
3. Any physical or visual impairment that would prevent completion of the cognitive tasks.
4. Participation (within the last 6 months) in other studies at our center involving similar cognitive testing procedures.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Slow metabolizers; Individuals with an NMR <0.26 will be classified as slow metabolizers.
Normal metabolizers; Participants with an NMR >= 0.26 will be classified as normal metabolizers.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acetylcholinergic Nicotine Receptor Availability as Determined by 2FA -PET Brain Imaging.	Acetylcholinergic Nicotine Receptor availability in the thalamus is decreased in smokers with slower rates of nicotine metabolism.	following overnight nicotine abstinence

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Cigarette Craving as Measured by the Questionnaire on Smoking Urges.	Measure is post-scan subtracted from pre-scan ratings. Rating is measured using the standardized, Questionnaire on Smoking Urges - Brief Version (QSU-Brief) is a standardized measure consisting of 10 statements, each rated on a Likert-like scale from 1 (Strongly Disagree) to 7 (Strongly Agree). Responses for each item are summed to produce an overall score with a range of 10-70.	Before and immediately following the PET scan.

Collaborators and Investigators

• Sponsor: University of Pennsylvania

Publications and helpful links

General Publications

• Brody AL, Mandelkern MA, London ED, Olmstead RE, Farahi J, Scheibal D, Jou J, Allen V, Tiongson E, Chefer SI, Koren AO, Mukhin AG. Cigarette smoking saturates brain alpha 4 beta 2 nicotinic acetylcholine receptors. Arch Gen Psychiatry. 2006 Aug;63(8):907-15. doi: 10.1001/archpsyc.63.8.907.

Helpful Links

• Principal Investigator
• Center for Interdisplinary Research on Nicotine Addiction
• Position Emission Tomography (PET) Center at the University of Pennsylvania

Study record dates

Study Major Dates

• Study Start: February 1, 2013
• Primary Completion (Actual): July 1, 2015
• Study Completion (Actual): July 1, 2015

Study Registration Dates

• First Submitted: February 7, 2013
• First Submitted That Met QC Criteria: February 8, 2013
• First Posted (Estimate): February 11, 2013

Study Record Updates

• Last Update Posted (Actual): March 12, 2018
• Last Update Submitted That Met QC Criteria: August 21, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Keywords: positron emission tomography; nicotine receptor
• Additional Relevant MeSH Terms: Mental Disorders; Chemically-Induced Disorders; Substance-Related Disorders; Tobacco Use Disorder
• Other Study ID Numbers: nAChR-PET-quit

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO