Study of hepatotoxicity of naltrexone in the treatment of alcoholism

Since a black box warning was issued by the Food and Drug Administration regarding the use of the opiate antagonist naltrexone (NTX), many clinicians have been concerned about current labeling of the potential hepatotoxicity risk of NTX in the treatment of opiate dependence and alcoholism. Despite many reports that demonstrated that the use of NTX did not cause elevation of liver enzymes, controversy concerning whether NTX is hepatotoxic continues. The current study monitored 74 alcoholic patients who received 25 mg of NTX daily in the first week and then 50 mg of NTX daily for the rest of the 12-week period. After the 12-week treatment, levels of the hepatic enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) did not show any elevation, except in one subject, and the results strongly support that NTX did not induce abnormalities in liver function tests or elevate the liver enzymes. Instead, a statistical significance of decreasing levels of ALT and AST in the liver was shown throughout the study. These findings provide further support that NTX is not hepatotoxic at the recommended daily dose and may be beneficial for patients with elevated liver enzymes.