Effects of Naltrexone on Nicotine Reinforcement
Despite preclinical evidence supporting the role of the endogenous opioid system in the reinforcing effects of nicotine, the efficacy of the opioid antagonist naltrexone (NTX) as a tobacco dependence treatment remains unresolved. Research is needed to identify those smokers for whom NTX will have the strongest beneficial effects on smoking behavior. The proposed research bridges existing knowledge of genetic, pharmacologic, and behavioral responses to nicotine, and translates this knowledge to treatment for tobacco dependence. Our immediate goal is to test whether genetic variation in the mu-opioid receptor gene predicts the effects of naltrexone (NTX) on nicotine reinforcement.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
|Official Title:||Pharmacogenetic Investigation of Naltrexone|
- choice of nicotine vs. denicotinized cigarettes in the cigarette choice paradigm
|Study Start Date:||March 2004|
|Study Completion Date:||October 2005|
The current study is a within-subject double-blind study of the effects of NTX versus PLA on the reinforcing value of nicotine, using a validated cigarette choice paradigm. Following informed consent, 40 smokers from each genotype group (n=80) will be asked to complete two 4-day study phases interspersed with a 5-7 day washout phase. Each 4-day study phase will include a 3-day drug run-up and monitoring phase, then on the 4th day participants will come to the Biobehavioral Lab (BBL) where they will take their final 50mg of study medication and complete a cigarette choice paradigm (See table 2). Following a washout phase, the 4-day sequence will be repeated with the alternative study medication. The order of study medication will be counterbalanced between subjects.
|United States, Pennsylvania|
|Tobacco Use Research Center|
|Philadelphia, Pennsylvania, United States, 19104|
|Principal Investigator:||Caryn Lerman, Ph.D.||University of Pennsylvania|