Randomized Controlled Trial of a Mobile Phone Intervention for Improving Adherence to Naltrexone for Alcohol Use Disorders

Background: Naltrexone is a front-line treatment for alcohol use disorders, but its efficacy is limited by poor medication adherence. This randomized controlled trial evaluated whether a mobile health intervention could improve naltrexone adherence. Methods: Treatment-seeking participants with an alcohol use disorder (N = 76) were randomized to intervention and control conditions. All participants received naltrexone (50 mg/day) with a medication event monitoring system (MEMS) and a prepaid smartphone, and received a daily text message querying medication side effects, alcohol use, and craving. Those in the intervention arm received additional medication reminders and adherence assessment via text message. Results: The primary outcome, proportion of participants with adequate adherence (defined as ≥80% of prescribed doses taken through Week 8), did not differ between groups in intent-to-treat analyses (p = .34). Mean adherence at study midpoint (Week 4) was 83% in the intervention condition and 77% in the control condition (p = .35). Survival analysis found that the intervention group sustained adequate adherence significantly longer (M = 19 days [95% CI = 0.0–44.0]) than those in the control group (M = 3 days [95% CI = 0.0–8.1]) during the first month of treatment (p = .04). Medication adherence did not predict drinking outcomes. Conclusions: These results suggest that in the context of daily monitoring and assessment via cell phone, additional text message reminders do not further improve medication adherence. Although this initial trial does not provide support for the efficacy of text messaging to improve adherence to pharmacotherapy for alcohol use disorders, additional trials with larger samples and alternate designs are warranted. Trial Registration: ClinicalTrials.gov: NCT01349985