title: Anti-craving drugs acamprosate and naloxone do not reduce expression of morphine conditioned place preference in isolated and group-housed rats.
abstract: Relapse prevention in clean addicts is a great challenge for addiction-therapy. As strong cravings often precede relapse, anti-craving drugs seem to be a promising way for addicts to stay clean. Naloxone and acamprosate are two candidates for anti-craving drugs that are already used for relapse prevention in alcoholic patients. However, it has to be figured out if both drugs are also effective in opiate-addicts. In order to evaluate their effectiveness, a conditioned place preference (CPP) paradigm was used in rats conditioned to 10 mg/kg, i.p., morphine. As acamprosate and naloxone have been suggested to selectively affect different types of craving (withdrawal-craving versus reward-craving), we have tried to modulate craving-behaviour by maintaining two groups of rats under different conditions (isolated versus group-housed). Thereafter, the effectiveness of acamprosate (200 mg/kg, i.p.) and naloxone (2 mg/kg, i.p.) in reducing morphine-CPP expression was evaluated. As a result, isolation produced a weak reduction in morphine-CPP development. Furthermore, acamprosate and naloxone had no effect on morphine-CPP expression. Based on the present results, we assume that the anti-craving drugs acamprosate and naloxone may not be effective for relapse prevention in opiate-addicts.
authors.affiliation: Department of Neuropharmacology, Zoological Institute, Faculty of Biology, University of Tübingen, Auf der Morgenstelle 28 E, 72076 Tübingen, Germany. schnakenstich@yahoo.com
authors.forename: Volker
authors.initials: V
authors.lastname: Herzig
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Schmidt
mesh_terms: D000077443:Acamprosate; D000427:Alcohol Deterrents / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D003216:Conditioning, Operant / Q000187:drug effects*; D004347:Drug Interactions; D008124:Locomotion / Q000187:drug effects; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012934:Social Isolation; D013037:Spatial Behavior / Q000187:drug effects; D013654:Taurine / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D000427:Alcohol Deterrents; D009292:Narcotic Antagonists; D009294:Narcotics; D013654:Taurine; D009270:Naloxone; D009020:Morphine; D000077443:Acamprosate