Oral vs. Injectable Naltrexone for Hospitalized Veterans With Alcohol Dependence

The proposed project is a pilot feasibility study of inpatient veterans with problem alcohol use at the William S. Middleton VA Hospital. The over-arching goal is to understand the impact of medication adherence upon engagement in behavioral treatment for alcohol use disorders. Participants will be randomized to one of two parallel study conditions: (1) an initial 50 mg oral dose of naltrexone prior to hospital discharge plus a 30-day prescription for oral naltrexone, or (2) a single 380 mg intramuscular injection of naltrexone (duration of action = 30 days) administered prior to discharge followed by a second injection one month later. The central hypothesis is that hospital-administered, long-acting injectable naltrexone, when compared to daily oral naltrexone, will reduce alcohol use in the days immediately following hospitalization. This reduced consumption, we hypothesize, will be followed by improved engagement in substance abuse treatment.

Primary Aim: Demonstrate the feasibility of the proposed recruitment methods and study design. This aim comprises two measures with corresponding goals: (1) Recruitment/enrollment-with a recruitment goal of 50 eligible and consenting subjects in an 8 month time period, and (2) Follow-up data collection with a goal of post-hospitalization follow-up data on no less than 70% of enrolled subjects.

Secondary Aims: As a pilot feasibility study, we may not anticipate sufficient power to attain statistical significance on patient-oriented outcome measures. However, it will be important for us to consider and to evaluate pertinent outcomes and potential moderators in order to (1) develop and fine-tune study design, and (2) determine effect sizes for primary outcomes so that we may calculate appropriate sample sizes for future larger study. As such, the secondary aims for the current study are:

1. To compare injectable naltrexone study to oral naltrexone in terms of attendance to recommended outpatient substance abuse treatment. We hypothesize that injectable naltrexone will be associated with improved likelihood of attending initial visits for substance abuse treatment.
2. To compare study arms in terms of ongoing alcohol consumption. We hypothesize that (1) improved medication adherence in the oral naltrexone arm and (2) assignment to injectable naltrexone will be associated with reduced alcohol consumption (number of heavy drinking days in the past 14 days) following hospital discharge.