Adherence Across FDA-Approved Medications for Alcohol Use Disorder in a Veterans Administration Population

Abstract

U.S. Food and Drug Administration (FDA)-approved medications exist for the treatment of alcohol use disorders. However, their effectiveness depends on proper adherence to the prescribed regimen. Differences in adherence across medications may have implications for clinical outcomes and may provide helpful information in considering treatment options. This study aims to identify significant differences in adherence if present. A retrospective chart review was conducted in the Veterans Integrated Service Networks (VISN)-7 region of Veterans Affairs hospital and community-based outpatient clinics within South Carolina and Georgia. Prescriptions of FDA-approved alcohol use disorder medications from 2010 through 2015 were reviewed. Adherence was determined by the proportion of days the veteran had oral or injectable medication available over a 6-month period as noted by medication fills (reported as 0%-100% medication availability). We compared adherence for specific medications using chi-square, t test, logistic regression for dichotomous outcomes, and linear regression for continuous outcomes. A total of 715 subjects and 807 medication trials were included. Mean adherence (percentage of days that medication was available) was 41.3% for disulfiram, 44.7% for acamprosate, 49.8% for oral naltrexone, and 54.6% for extended-release injectable naltrexone. The mean adherence was significantly different between disulfiram and oral naltrexone (p = .002) as well as disulfiram and extended-release injectable naltrexone (p = .004). Adherence of 80% was achieved in 11.9%, 19.4%, 22.7%, and 24.4% of treatment courses with disulfiram, acamprosate, naltrexone, and extended-release injectable naltrexone, respectively. These differences were significant for disulfiram versus oral naltrexone (p = .004) and disulfiram versus extended-release injectable naltrexone (p = .05). These results demonstrate that overall adherence to medication-assisted treatment for alcohol use disorder is low across all medications. When directly compared, disulfiram had significantly lower adherence than both oral and extended-release injectable naltrexone.