Clinical trial NCT00257894
Conditions: Nicotine Use Disorder Nicotine Dependence Smoking Tobacco Use Disorder
Keywords: Baclofen Conditioning, Classical Nicotine Smoking
Sponsor: VA Office of Research and Development
Start date: 2005-12-01; Completion date: 2008-12-01
Enrollment: 41 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to determine whether baclofen is effective in reducing smoking urge, withdrawal, and reinforcement in moderate to heavy cigarette smokers.

Detailed description:
OBJECTIVES: The long-term objective of this research program is to improve treatments for tobacco smokers by investigating the effects of medications on self-reported and psychophysiological responses to smoking cues and on behavioral-economic measures of smoking reinforcement during a period of tobacco deprivation. The specific objectives of the present application are to investigate the dose-response effects of baclofen (a gamma-aminobutyric acid B agonist), 1) on urge, and withdrawal, and 2) on the reinforcement value of smoking as measured by choices for puffs on cigarettes versus an alternative reinforcer among current smokers after 4 hours of smoking deprivation. RESEARCH PLAN: The study will use a randomized placebo-controlled between-subjects design with 64 smokers to investigate the effects of placebo and two doses (20 or 40 mg/day) of baclofen on urge to smoke and withdrawal and on choices for smoking versus money after 4 hours of deprivation. METHODS: Participants will be healthy people who smoke at least 10 cigarettes per day and who are motivated for future smoking cessation. On Day 0, a baseline session will occur after 4 hours of smoking deprivation and on Day 10 of medication the same assessments will be repeated after the final medication dose has been stabilized for at least 3 days and after 4 hours of supervised smoking deprivation has occurred. Medication differences in urge and withdrawal and in the reinforcement value of smoking cigarettes will be investigated. Dependent measures of urge and withdrawal will be by self-report. The dependent measure of reinforcement value is the ratio of choices for cigarette puffs versus money during a subsequent 2-1/2 hr period. The choice procedure will clarify the relative reinforcement value of smoking while controlling for non-specific decreases in general activity level resulting from sedation. Nicotine self-administration during the medication period will be quantified using saliva cotinine, as a secondary effect. CLINICAL RELEVANCE: More effective interventions for tobacco use could result in less suffering and mortality and in considerable savings in health care costs associated with cardiovascular disease, pulmonary disorders, and cancer.

Arms: arm 1: Baclofen taken orally for 12 days total up to 40 mg/day maximum, divided into 3 equal portions each day. Participants receive 12 mg/day the first 3 days, 30 mg/day the next 3 days, and 40 mg/day on Days 7, 8, 9. Testing is on day 10 after the first dose is taken, with downward titration days 10-12 of 30 mg on Day 10, 20 mg on Day 11 and 10 mg on Day 12. arm 2: Placebo capsules identical to active medication, 3/day for 12 days.
Interventions: intervention 1: Baclofen intervention 2: Placebo
Intervention descriptions: intervention 1: Dosing taken orally for a total of 12 days: 40mg/day vs. 0mg/day (placebo tabs). The 40mg condition will receive 15mg/day the first 3 days(Days 1,2,3), 30mg/day for 3 days(Days 4,5,6), and 40mg/day for 3 days(Days 7,8,9). Downward titration: 40mg/day condition will receive 40mg/day(Day 10), 20mg/day(Day 11), and 10mg/day(Day 12). intervention 2: Matched placebo capsules containing inert filler taken orally for a total of 12 days

Protocol documents: