Predischarge Injectable Versus Oral Naltrexone to Improve Postdischarge Treatment Engagement Among Hospitalized Veterans with Alcohol Use Disorder: A Randomized Pilot Proof-of-Concept Study

Background: Injectable naltrexone for alcohol use disorders (AUDs) has been efficacious in several studies. It has not been (i) compared head-to-head with oral naltrexone or (ii) examined in the hospital setting as an intervention that might facilitate treatment attendance after hospital discharge. Methods: Fifty-four hospitalized veterans identified as having DSM-IV-TR alcohol dependence were randomized to receive (i) a 50 mg oral naltrexone plus a 30-day prescription or (ii) a 380 mg intramuscular naltrexone injection prior to discharge. Of 113 veteran inpatients deemed eligible based on screening criteria, 54 met final eligibility criteria and were enrolled and randomized. Baseline data included demographics, alcohol consumption, and comorbidity. Measures of treatment initiation and engagement and alcohol consumption were reassessed at 14- and 45-day follow-ups. Results: Thirty-five participants (64.8%) completed the entire study protocol (received a study medication and completed 14-and 45-day follow-ups). Among those who received a study medication (n = 45), 77.8% completed all follow-up interviews. This pilot study was not designed to have sufficient statistical power for hypothesis testing, and thus, as expected, there were no significant differences between groups in medication adherence (self-report of > 80% of daily doses taken in oral group; receipt of second injection in the injection group), treatment engagement (at least treatment 3 visits in the 30 days postdischarge, and 2 or more visits per month in each of the 3 months following discharge) or alcohol consumption at 14 or at 45 days (p > 0.05). The median number of drinks among the entire cohort in the 2 weeks prior to hospitalization (128 drinks) was significantly higher than at day 14 (0 drinks, p < 0.001) or day 45 (0 drinks, p < 0.001). Rates of medication adherence were 62% in the oral group and 61% in the injection group. Conclusions: Results indicate feasibility for larger, more definitive study. Both groups had significant reductions in alcohol consumption over time and high-treatment engagement rates. Both oral and injectable formulations are feasible to initiate prior to discharge for hospital inpatients identified as having an AUD.