Predictors of Self-Reported Adherence to Naltrexone Medication in an Outpatient Treatment for Problem Drinking

Abstract

Objective: The opioid antagonist naltrexone has been proven as an efficacious treatment for alcoholism. However, in clinical trials the reported medication adherence has often been poor, being one of the key problems associated with naltrexone treatment. There are very few studies on predictors of nonadherence, although this information would help clinicians to identify their non-compliant patients. This study investigated predictors of medication adherence in an outpatient treatment programme consisting of naltrexone and cognitive behavioural therapy (CBT). Patients were instructed to take one tablet on each day they perceived as a risk of drinking alcohol (as-needed dosing), preferably 1 to 2 hours before anticipated time of drinking. Participants were patients (n=299) who attended a treatment programme in an outpatient clinic. Method: Predictors of medication adherence (defined as using medication in ≥ 80% of situations of drinking) during the first five months of the treatment programme were investigated with logistic regression analyses. Results: Average naltrexone adherence in this study was 78%. Poor adherence with naltrexone was associated with unemploymentand high craving for alcohol at treatment entry. Conclusions: Adherence to naltrexone was generally high compared to many naltrexone studies using daily medication. Patients with high craving for alcohol may have lower adherence to naltrexone or other opioid antagonists and need practical and therapeutic strategies for improving adherence.