Extended-release naltrexone (XR-NTX) attenuates brain responses to alcohol cues in alcohol-dependent volunteers: A bold FMRI study

Oral naltrexone reduces heavy drinking, but is less consistent as an abstinence promoter, whereas once-monthly extended-release naltrexone (XR-NTX) also maintains abstinence. The present study sought to determine if alcohol cue reactivity is attenuated by XR-NTX. Twenty-eight detoxified alcohol-dependent adult male and female volunteers received a single i.m. injection of either XR-NTX or placebo under double-blind conditions. An fMRI/cue reactivity procedure was conducted immediately before and two weeks after injection. At baseline, alcohol-related visual and olfactory cues elicited significant increases in orbital and cingulate gyri, inferior frontal and middle frontal gyri. Subsequently, brain activation was significantly altered in XR-NTX-treated individuals. These affected brain regions are associated with the integration of emotion, cognition, reward, punishment, and learning/memory, suggesting that XR-NTX attenuates the salience of alcohol-related cues. Such an effect on brain function may interrupt the processes associated with “slips” and relapse, which may account for XR-NTX's ability to maintain abstinence. •We exposed alcohol-dependent participants to alcohol and neutral cues during imaging•fMRI was measured before and 4 weeks after injection of extended release naltrexone•Naltrexone reduced the salience of olfactory and visual alcohol cues•Naltrexone altered the BOLD signal activation patterns•Naltrexone may interrupt the processes associated with “slips” and “relapse”