[Neurobiology of alcohol and pharmacological aspects of nalmefene].

The brain imaging together with the images obtained using the supermicroscopy has recently demonstrated the chronic elevated intake of ethanol induces both functional and structural changes of neurons, a phenomenon associated to altered mental function. The most recent experimental and clinical studies have indicated the treatment with nalmefene as a specific therapy able to significantly reduce ethanol intake in ethanol-dependent patients. Thanks to its peculiar action (partial agonist for κ oppioid receptors and pure antagonist of δ and µ receptors) nalmenfene, in contrast to naltrexone (a pure antagonist at κ, δ, µ receptors) is able to rimodulate the content of dopamine in the nucleus accumbens of ethanol dependent patients. This mechanism markedly reduces the negative emotional state, disphoria, depression and anhedonia following the disregulation of the mesolimbic dopaminergic system elicited by long-term intake of high amount of ethanol.