The anti-relapse compound acamprosate inhibits the development of a conditioned place preference to ethanol and cocaine but not morphine

The effects of the anti-relapse compound acamprosate (calcium acetylhomotaurinate) on the conditioned rewarding effects of ethanol, cocaine and morphine were studied using the conditioned place preference (CPP) paradigm. During 3 days of drug conditioning, mice were pretreated with saline or acamprosate (30, 100 or 300 mg kg ^-1 i.p.) 10 min prior to the administration of ethanol (2 g kg ^-1 i.p.), cocaine (15 mg kg ^-1 i.p.) or morphine (10 mg kg ^-1 i.p.), and subsequently confined to one of two distinct conditioning chambers. On the following day, mice were tested for the expression of CPP. Acamprosate dose-dependently reduced the development of CPP to ethanol and cocaine but not morphine. When tested as the conditioning drug, acamprosate alone produced neither a conditioned place preference nor aversion. These data suggest that acamprosate can suppress the conditioned rewarding effects of ethanol and certain classes of abused substances.