Naltrexone’s suppressant effects on drinking are limited to the first 3 months of treatment

Abstract

Rationale

Twelve weeks of naltrexone significantly improves drinking outcomes in alcoholics; however, the clinical benefits of naltrexone decline shortly after treatment is discontinued.

Objective

The present study investigated whether extended treatment with naltrexone significantly improved drinking outcomes.

Methods

One hundred forty-six alcohol-dependent patients received broad spectrum treatment or motivational enhancement therapy and either 12 or 24 weeks of naltrexone. The primary dependent variables were percent days abstinent and percent heavy drinking days.

Results

Using an intention-to-treat analysis, there were no significant differences in percent days abstinence or percent heavy drinking days at the end of phase 2 between patients who received 24 weeks of treatment with naltrexone ($\overline{x} = 63.23$) or patients who received 12 weeks of treatment with naltrexone followed by 12 weeks of treatment with placebo ($\overline{x} = 65.82$). Similarly, the average percent heavy drinking days was not significantly different at the end of phase 2 between the group that received 24 weeks of naltrexone ($\overline{x} = 21.9$) and the group that received 12 weeks of naltrexone followed by 12 weeks of placebo ($\overline{x} = 22.14$). Medication compliance was low in the second phase of the study. Drinking outcomes declined with declining compliance whether patients were taking naltrexone or placebo.

Conclusions

The results of this study suggest that administering naltrexone beyond an initial 12 weeks of treatment may not be beneficial to all patients and should be administered along with close medical monitoring to insure compliance.