Official Title: “Enhancing Tobacco Use Treatment for African American Light Smokers”

RATIONALE: A stop-smoking plan that includes health education counseling and bupropion may help African-American smokers stop smoking. It is not yet known whether health education counseling is more effective with or without bupropion in helping African Americans stop smoking.

PURPOSE: This clinical trial is studying health education counseling and bupropion to see how well they work compared with a placebo and health education counseling in helping African Americans smokers stop smoking.

Study Type: Observational

Study Design: N/A

Study Primary Completion Date: April 2009

OBJECTIVES:

Primary - To evaluate the efficacy of bupropion hydrochloride and health education counseling vs placebo and health education counseling for smoking cessation among African Americans who are light smokers.

Secondary - To characterize CYP2A6 activity in African Americans who are light smokers by evaluating phenotype (3'hydroxycotinine/cotinine ratio [3HC/COT]) and CYP2A6 genotype. - To evaluate the relationship between CYP2A6 activity and smoking cessation outcomes. - To evaluate CYP2A6 genetic polymorphisms associated with nicotine and cotinine metabolism in African Americans who are light smokers. - To measure baseline cotinine and metabolite levels to evaluate the nicotine metabolism phenotype of 3HC/COT. - To evaluate the relationship between nicotine metabolism phenotype of 3HC/COT and smoking cessation outcomes. - To evaluate CYP2A6 genotype as a predictor of smoking cessation outcomes.

Tertiary - To characterize CYP2B6 activity in African Americans who are light smokers by evaluating phenotype and CYP2B6 genotype. - To evaluate the relationship between CYP2B6 activity and smoking cessation outcomes. - To measure steady state bupropion hydrochloride and metabolite levels to identify a bupropion metabolism phenotype. - To evaluate the relationship between bupropion hydrochloride metabolism phenotype and smoking cessation outcomes. - To evaluate the relationship between CYP2B6 genetic polymorphisms (genotype) and blood levels of bupropion hydrochloride and active metabolites (phenotype). - To determine the effects of CYP2B6 genotype as predictors of smoking cessation outcomes.

OUTLINE: Participants are randomized to one of two arms. - Arm I: Participants receive oral bupropion hydrochloride once or twice daily in weeks 0-6. Participants also undergo 6 sessions of health education counseling conducted in person during clinic visits in weeks 0, 3, and 7 and via telephone in weeks 1, 5, and 16. The health education counseling sessions include providing information about the risks of continued smoking and the benefits of quitting, developing a quit plan, outlining a concrete quit day preparation plan, discussing strategies for successful quitting, building social support, reducing stress, recognizing and managing withdrawal and craving, overcoming barriers to abstinence, and using medication for smoking cessation. Participants receive Kick It at Swope: Stop Smoking Guide, a culturally-sensitive smoking cessation guide, to review with their study counselor during the first counseling session. - Arm II: Participants receive an oral placebo once or twice daily in weeks 0-6.

Participants also undergo health education counseling as in arm I.

Participants complete baseline questionnaires about demographics, smoking history, and psychometrics, including the following: racial identity, depressive symptoms, alcohol use, stress, smoking consequences, social support, environmental influences of smoking, adherence to study medication, nicotine withdrawal, craving, and mood.

Participants undergo serum sample collection in weeks 0 and 3. To standardize the time since the last cigarette, participants are asked to smoke one cigarette prior to serum sample collection in week 0. Samples are analyzed for nicotine metabolism phenotype and bupropion hydrochloride metabolism phenotype by liquid chromatography and mass spectrometry and CYP2A6 and CYP2B6 genotype by polymerase chain reaction and polymorphism analysis. Participants who self-report abstinence also undergo saliva sample collection in weeks 7 and 26 to measure cotinine levels to verify smoking status.

After completion of study intervention, participants are followed at 6 months.

Intervention(s) in this Clinical Trial

• Drug: bupropion hydrochloride
• Procedure: counseling
• Procedure: educational intervention
• Procedure: gene expression analysis
• Procedure: laboratory biomarker analysis
• Procedure: liquid chromatography
• Procedure: mass spectrometry
• Procedure: polymerase chain reaction
• Procedure: polymorphism analysis
• Procedure: psychosocial assessment and care
• Procedure: questionnaire administration
• Procedure: study of socioeconomic and demographic variables

Primary Measures

• Efficacy
  • Safety Issue?: No

Secondary Measures

• Characterization of CYP2A6 activity, in terms of genotype and phenotype
  • Safety Issue?: No
• Relationship between CYP2A6 activity and smoking cessation outcomes
  • Safety Issue?: No
• CYP2A6 genetic polymorphisms associated with nicotine and cotinine metabolism
  • Safety Issue?: No
• Nicotine metabolism phenotype of 3'hydroxycotinine/cotinine ratio (3HC/COT) as measured by cotinine and metabolite levels at baseline
  • Safety Issue?: No
• Relationship between nicotine metabolism phenotype of 3HC/COT and smoking cessation outcomes
  • Safety Issue?: No
• CYP2A6 as a predictor of smoking cessation outcomes
  • Safety Issue?: No
• Characterization of CYP2B6 activity, in terms of genotype and phenotype
  • Safety Issue?: No
• Relationship between CYP2B6 activity and smoking cessation outcomes
  • Safety Issue?: No
• Identification of a bupropion hydrochloride metabolism phenotype as measured by steady state bupropion hydrochloride and metabolite levels
  • Safety Issue?: No
• Relationship between bupropion hydrochloride metabolism phenotype and smoking cessation outcomes
  • Safety Issue?: No
• Relationship between CYP2B6 genetic polymorphisms and blood levels of bupropion hydrochloride and active metabolites
  • Safety Issue?: No
• CYP2B6 genotype as a predictor of smoking cessation outcomes
  • Safety Issue?: No

DISEASE CHARACTERISTICS:

• African American who has smoked ≤ 10 cigarettes per day for ≥ 2 years AND has smoked for ≥ 25 days within the past month
• Not a heavy smoker
• No other forms of tobacco within the past 30 days
• Must be interested in stopping smoking
• No other smoker in the household enrolled in this study

PATIENT CHARACTERISTICS:

• Has a home address and a functioning telephone number
• Not planning to move from the Kansas City metro area within the next 12 months
• Not pregnant or nursing
• Negative pregnancy test
• No alcohol or substance abuse within the past year
• Not currently drinking ≥ 14 alcoholic drinks per week
• No binge drinking (5 or more drinks on one occasion) on at least two occasions within the past month
• No history of seizures or head trauma
• No history of bulimia or anorexia nervosa
• No myocardial infarction within the past 30 days
• No reported use of opiates, cocaine, or stimulants
• No diabetes requiring oral hypoglycemics or insulin

PRIOR CONCURRENT THERAPY:

• More than 30 days since prior nicotine replacement therapy, fluoxetine, clonidine, buspirone, or doxepin
• No other concurrent medication that contains bupropion hydrochloride
• No concurrent psychoactive medications

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: University of Kansas

Overall Clinical Trial Officials and Contacts

Lisa S. Cox, PhD Principal Investigator University of Kansas  

Information obtained from ClinicalTrials.gov on September 04, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00666978

Study ID Number: CDR0000581423

ClinicalTrials.gov Identifier: NCT00666978

Health Authority: Unspecified

Clinical trial summary from the National Cancer Institute's PDQ® database