Suppression of craving for gamma-hydroxybutyric acid by naltrexone administration: three case reports.

Gamma-hydroxybutyric acid (GHB) is currently used to induce and maintain abstinence from alcohol. Cases of craving and desire to increase doses of GHB have been reported in both clinical trials and nonclinical self-administration. The enhancement of dopamine activity induced by GHB receptor activation might play a role in the euphoric effect and potential craving and the consequent abuse of this drug. Naltrexone (NTX), a mu-opioid antagonist, is effective in inducing and maintaining abstinence from alcohol, reducing relapses in heavy drinking and craving for alcohol in alcohol-dependent outpatients. Taking into account the alcohol antireward property of NTX, we tested its activity in reducing craving for GHB in 3 consecutive cases of alcoholics who manifested craving for this drug. In all patients the combination with NTX suppressed the craving for GHB. The antireward effect of NTX likely results from its interference with the GHB-induced dopamine release, leading to a partial blockade of the GHB reinforcing effect responsible of the craving for the drug. A combined therapy with GHB and NTX seems to be able to suppress craving for the former, thus improving the manageability and safety of treatment.