Opioid antagonists and alcohol consumption [Antagonistas opioides y consumo de alcohol]

Introduction. Alcoholism is considered a chronic, progressive and frequently mortal disease; it is a primary phenomenon rather than a sign or symptom of other diseases. With the aim to reduce the alcohol consumption and the relapse in alcoholics, several pharmacological strategies have been applied; among them the opioid antagonists have been successfully used. The scope of the present study is to show experimental evidence of the effect of different opioid antagonists on alcohol consumption on the base of their receptor specificity in different pharmacological strategies. Development. Alcohol consumption increases the release of endogenous opioids; therefore, the opioid receptor blocked apparently decreases the rewarding alcohol effects. On this base, the unspecific antagonists as naloxone and naltrexone are the more used in clinic; these substances bind with different affinity to mu, delta and kappa receptors. Specific opioid receptor antagonists have been studied with the scope to clear up the participation of the different opioid receptors modulating the alcohol intake. Although, there is inconsistency in the findings, these studies suggest that the delta and mainly the mu receptors have an important participation modulating alcohol consumption. Conclusion. There is sufficient evidence that the opioid system play an important role in the alcohol dependence; however, it is necessary to study integrally the different neurochemistry systems with the scope to understand the neurophysiologic mechanisms underlying the alcohol addiction. © 2007, Revista de Neurología