Mechanisms of the Nicotine Metabolism Effect on Tobacco Dependence (NMR)

This study is not yet open for participant recruitment.

Verified June 2012 by University of California, San Francisco

Sponsor:

Information provided by (Responsible Party):

University of California, San Francisco

ClinicalTrials.gov Identifier:

NCT01627392

First received: June 14, 2012

Last updated: June 22, 2012

Last verified: June 2012

History of Changes

Tracking Information
First Received Date ^ICMJE	June 14, 2012
Last Updated Date	June 22, 2012
Start Date ^ICMJE	July 2012
Estimated Primary Completion Date	November 2014 (final data collection date for primary outcome measure)
Current Primary Outcome Measures ^ICMJE (submitted: June 22, 2012)	Nicotine withdrawal symptoms [ Time Frame: 6 hours post nicotine load ] [ Designated as safety issue: No ] Total withdrawal score as measured by Minnesota Nicotine Withdrawal Scale
Original Primary Outcome Measures ^ICMJE	Same as current
Change History	Complete list of historical versions of study NCT01627392 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures ^ICMJE (submitted: June 22, 2012)	Cognitive performance [ Time Frame: 6 hours post nicotine load ] [ Designated as safety issue: No ] Cognitive performance will be measured by n-back computerized testing Smoking behavior [ Time Frame: 6 hours post nicotine load ] [ Designated as safety issue: No ] Smoking behavior (number of cigarettes, number of puffs per cigarette, time to first post-reward cigarette) will be assessed during a 90-minute monitoring period following the 3rd (reward) cigarette of the protocol
Original Secondary Outcome Measures ^ICMJE	Same as current
Current Other Outcome Measures ^ICMJE	Not Provided
Original Other Outcome Measures ^ICMJE	Not Provided

Descriptive Information
Brief Title ^ICMJE	Mechanisms of the Nicotine Metabolism Effect on Tobacco Dependence
Official Title ^ICMJE	Mechanisms of the Nicotine Metabolism Effect on Tobacco Dependence
Brief 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. 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.
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.
Study Type ^ICMJE	Interventional
Study Phase	Not Provided
Study Design ^ICMJE	Intervention Model: Single Group Assignment Masking: Open Label Primary Purpose: Basic Science
Condition ^ICMJE	Cigarette Smoking
Intervention ^ICMJE	Behavioral: Smoking abstinence 6 hour smoking abstinence
Study Arm (s)	Experimental: Smoking abstinence Intervention: Behavioral: Smoking abstinence
Publications *	Not Provided
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.

Recruitment Information
Recruitment Status ^ICMJE	Not yet recruiting
Estimated Enrollment ^ICMJE	320
Estimated Completion Date	June 2015
Estimated Primary Completion Date	November 2014 (final data collection date for primary outcome measure)
Eligibility Criteria ^ICMJE	Inclusion Criteria: 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 Exclusion Criteria: 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
Gender	Both
Ages	18 Years to 70 Years
Accepts Healthy Volunteers	Yes
Contacts ^ICMJE	Not Provided
Location Countries ^ICMJE	United States

Administrative Information
NCT Number ^ICMJE	NCT01627392
Other Study ID Numbers ^ICMJE	12-08635
Has Data Monitoring Committee	No
Responsible Party	University of California, San Francisco
Study Sponsor ^ICMJE	University of California, San Francisco
Collaborators ^ICMJE	Not Provided
Investigators ^ICMJE	Not Provided
Information Provided By	University of California, San Francisco
Verification Date	June 2012
^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP

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