Influence of the 5-HT1A receptor agonist ipsapirone on voluntary alcohol intake in rats.

The effect of the azapirone derivative ipsapirone on anxiety and the free-choice consumption of alcohol was studied in male rats. Animals were housed three in a cage with a different composition each day to increase anxiety. The animals were offered a two-bottle free choice consumption of tap water or a 5% ethanol solution. Ipsapirone was given in the drinking fluid daily at about 10 mg/kg per day. As expected, social unstable groups exhibited a higher level of anxiety as compared to social stable groups. Ipsapirone reduced significantly the anxiety in the unstable group. Pretreatment with ipsapirone before alcohol exposure resulted in a marked decrease of subsequent ethanol intake by about 45% as compared to drug free control animals. Administration of the drug to rats already drinking alcohol showed a similar decrease of ethanol intake by about 50%. These results indicate that the relatively specific 5-HT1A receptor agonist ipsapirone, given orally, reduces anxiety as well as alcohol initiation or maintenance in rats.