Opioid Receptor Antagonists in the Treatment of Alcoholism.

OBJECTIVES: On the basis of the recent advances in drug therapy of alcoholism, we conducted a review on opioid receptor antagonist drugs with approved indication for the treatment of alcoholism, such as naltrexone and nalmefene. METHODS: We reviewed over 100 publications on peptides and opioid receptors, as well as studies conducted in experimental animals and in humans on the effect of opioid receptor antagonists on alcohol consumption in the treatment of alcoholism. We also reviewed the pharmacological characteristics of naltrexone and nalmefene, and the usefulness of these drugs in clinical practice. RESULTS: Much evidence has demonstrated the efficacy of naltrexone and nalmefene for the reduction of alcohol consumption, in experimental animals as well as in humans examined under experimental bar conditions; however, due to its different receptor profile, nalmefene has been associated with higher efficacy levels in reducing alcohol consumption in alcohol-dependent rats. In addition, a great number of controlled clinical trials have demonstrated the efficacy of naltrexone for relapse prevention in patients with an alcohol dependence disorder. Recent controlled clinical trials have demonstrated the efficacy of nalmefene "as-needed" in the reduction of alcohol consumption in subjects with mild alcohol dependence. CONCLUSIONS: Both naltrexone and nalmefene have proved to be safe, well tolerated, easy to manage, and efficient drugs for the treatment of alcohol dependence disorder (currently known as alcohol use disorder). On the basis of recent controlled clinical trials, nalmefene has been shown to result in a significant reduction of alcohol consumption, thereby representing a new objective that extends the therapeutic possibilities for those patients who do not wish for a continuous abstinence, but rather a reduction of alcohol consumption.