Naltrexone reduces the relative reinforcing value of nicotine in a cigarette smoking choice paradigm.
BACKGROUND
Human behavioral pharmacology studies can examine how medications that target different neurotransmitter systems influence different aspects of smoking. Naltrexone and bupropion have been shown to alter ad lib smoking behavior; however, medication effects on nicotine reward in a cigarette choice paradigm have yet to be investigated.


OBJECTIVE
This study explored the effects of an acute dose of naltrexone, bupropion, or placebo on the relative reinforcing value of nicotine from cigarette smoking using new nicotine and de-nicotinized (Quest, 0.6 and 0.05 mg = "denicotinized") cigarettes.


METHODS
In a double-blind, within-subjects design, 26 dependent smokers participated in three experimental cigarette smoking sessions following pretreatment with either naltrexone (50 mg), bupropion (300 mg), or placebo. After medication administration and 2 h of monitored deprivation from cigarettes and food, participants rated their responses to the initial exposure to the cigarettes and then participated in four choice sessions over a 2-h period during which they could take four puffs from either cigarette.


RESULTS
The relative reinforcing value of nicotine, as measured by the number of nicotine puffs chosen out of 16, was significantly lower following naltrexone compared to placebo. There were no effects of an acute dose of bupropion on nicotine choices.


CONCLUSIONS
These results suggest that naltrexone may reduce the relative reinforcing effects of nicotine via cigarette smoking and support ongoing investigation of opioid antagonists as potential smoking cessation pharmacotherapies.
Rukstalis
Margaret
M
Tobacco Use Research Center, University of Pennsylvania, 3535 Market Street, Suite 4100, Philadelphia, PA 19104, USA. rukstali@mail.med.upenn.edu
Jepson
Christopher
C
Strasser
Andrew
A
Lynch
Kevin G
KG
Perkins
Kenneth
K
Patterson
Freda
F
Lerman
Caryn
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D016642:Bupropion / Q000494:pharmacology; D002755:Choice Behavior / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009271:Naltrexone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D012054:Reinforcement, Psychology; D016540:Smoking Cessation / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000188:drug therapy*
D009292:Narcotic Antagonists; D016642:Bupropion; D009271:Naltrexone; D009538:Nicotine