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Cigarette SmokingNMRNCT01627392

Mechanisms of the Nicotine Metabolism Effect on Tobacco Dependence

A study testing Smoking abstinence in people with Cigarette Smoking, run by University of California, San Francisco at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of the study is to learn more about tobacco dependence and nicotine metabolism in African-Americans and whites, by studying to see if how fast a person metabolizes nicotine (how the body breaks down nicotine into inactive compounds) affects how dependent they are on smoking cigarettes. Read more about this study

Who is it for?
Ages 18 to 70 yearsHealthy volunteers can take part
Conditions the study is for
Cigarette Smoking
What is being tested?
Smoking abstinence
Could I receive a placebo?
No, everyone receives an active treatment
How many people
305 participants
Where
1 siteUnited States
Study dates
Jul 2012to Aug 2015
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 70 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • African-American or Caucasian
  • Age 18-70 years
  • Regular smoker of 5 or more cigarettes per day
  • Saliva cotinine of 100 ng/ml or greater

Who cannot join

  • Obese (BMI > 38) or underweight (BMI < 17)
  • Major systemic or psychiatric condition
  • Medications that are inducers of CYP2A6
  • History of alcohol abuse
  • Positive drug urine tox test
  • Pregnancy or breast feeding

Trial locations and contacts

1 site in 1 country.

United States1 site
  • San Francisco General Hospital

    San Francisco, California, 94110

Other trials in United States

About this study

The purpose of the study is to learn more about tobacco dependence and nicotine metabolism in African-Americans and whites, by studying to see if how fast a person metabolizes nicotine (how the body breaks down nicotine into inactive compounds) affects how dependent they are on smoking cigarettes. The investigators believe that people with a faster rate of metabolism may have more severe nicotine withdrawal symptoms and also may have a harder time trying to quit smoking.

Read the detailed description

Our studies will use the nicotine metabolite ratio (NMR) (the ratio between the nicotine metabolites 3'hydroxycotinine and cotinine)as a simple and clinically feasible biomarker for the rate of nicotine metabolism. The investigators hypothesize that a faster rate of metabolism leads to faster elimination of nicotine from the body and a more rapid dissipation of brain tolerance to nicotine in the interval between cigarettes, leading in turn to (1) more severe nicotine withdrawal symptoms and (2) greater subjective reward from the cigarette smoked following deprivation. These effects would help to explain why smokers with faster rates of nicotine metabolism have a poorer response to smoking cessation therapy when compared to those with slower rates of metabolism.

The investigators will explore the relationship of the NMR to the endophenotypes of withdrawal, craving and reward, with the assumption that these factors are likely intermediaries for the mechanism linking nicotine metabolism to tobacco dependence and smoking cessation rates with pharmacotherapy. Our study design uses a brief (6 hour) interval of smoking abstinence followed by a "reward" cigarette to elicit the subjective responses relating to withdrawal and reward. Because smoking behavior and severity of nicotine dependence vary by race and sex the investigators will also compare the relationship between NMR and withdrawal and reward in African American vs white smokers and in men vs women.

Secondary analyses will examine whether nicotine half-life mediates the observed effects of NMR on primary response measures.

Being tested
Smoking abstinence
Medical subject headings
Cigarette Smoking

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Smoking abstinenceBehavioural

    6 hour smoking abstinence

Study groups in NCT01627392
Study groupRoleWhat they receive
Smoking abstinenceExperimentalNot described
Receives: Behavioral: Smoking abstinence

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Nicotine withdrawal symptoms

    Total withdrawal score as measured by Minnesota Nicotine Withdrawal Scale

    Measured: 6 hours post nicotine load

Secondary outcomes (4)
  1. Cognitive performance

    Cognitive performance will be measured by n-back computerized testing

    Measured: 6 hours post nicotine load

  2. Smoking behavior: number of cigarettes

    Smoking behavior will be measured by number of cigarettes during a monitoring period following the 3rd (reward) cigarette of the protocol

    Measured: 90 minutes post-abstinence

  3. Smoking behavior: number of puffs per cigarette

    Smoking behavior will be measured by number of puffs per cigarette during a monitoring period following the 3rd (reward) cigarette of the protocol

    Measured: 90 minutes post-abstinence

  4. Smoking behavior: time to first post-reward cigarette

    Smoking behavior will be measured by time to first post-reward cigarette during a monitoring period following the 3rd (reward) cigarette of the protocol

    Measured: 90 minutes post-abstinence

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Jun 2012 (estimated)
  2. Study startJul 2012
  3. Primary completionAug 2015
  4. Study completionAug 2015

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
305 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01627392
Sponsor's protocol ID
12-08635
Acronym
NMR
Status last verified
Dec 2015
First submitted
14 Jun 2012
Last updated
3 Dec 2015
Results posted
No
Data monitoring committee
No

Publications

  • Nardone N, Shahid M, Strasser AA, Dempsey DA, Benowitz NL. The influence of nicotine metabolic rate on working memory over 6 hours of abstinence from nicotine. Pharmacol Biochem Behav. 2020 Jan;188:172836. doi: 10.1016/j.pbb.2019.172836. Epub 2019 Dec 5.

    PubMed 31812759
  • Liakoni E, Edwards KC, St Helen G, Nardone N, Dempsey DA, Tyndale RF, Benowitz NL. Effects of Nicotine Metabolic Rate on Withdrawal Symptoms and Response to Cigarette Smoking After Abstinence. Clin Pharmacol Ther. 2019 Mar;105(3):641-651. doi: 10.1002/cpt.1238. Epub 2018 Oct 25.

    PubMed 30242831

Questions about this trial

What is this clinical trial studying?

A study testing Smoking abstinence in people with Cigarette Smoking, run by University of California, San Francisco at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 3 Dec 2015. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Nicotine withdrawal symptoms (time frame: 6 hours post nicotine load). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01627392, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Dec 2015.

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