(227) Medication Adherence Monitoring in Patients Prescribed Buprenorphine/Naloxone

Abstract

We sought to assess the relationship between the frequency of urine drug monitoring (UDM) and adherence to prescribed buprenorphine/naloxone therapy, and use of illicit substances, non-prescribed opiates or benzodiazepines. Patients prescribed buprenorphine/naloxone were included if they had ≥2 urine samples (separated by ≥6 months) assessed between 2013 and 2016. Baseline and final samples were classified as positive or negative for: buprenorphine, and for any illicit substance, for non-prescribed opiates/synthetic opioids, and for benzodiazepines. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated using multiple logistic regression analysis with the following independent variables: gender, age decade, primary payor, geographic region, year tested, buprenorphine dose, and frequency of UDM. Because data were obtained from a de-identified database, this study was not submitted for IRB review. For 6,900 patients in the analysis, the rate of negative urines for buprenorphine was lower in the final urine compared to the baseline urines (10% vs 8%) and for the final sample, patients with ≥1 sample/month were significantly less likely to be negative for buprenorphine than those with 1 sample/3 months (10% vs 6%; aOR, 0.53; 95% CI, 0.41-0.70 for 1/month vs 1/3 months). A non-prescribed opiate was detected in 16% and 11% of first and last samples respectively, with the largest decline observed in those with the most frequent UDM testing (23% vs. 11%). A non-prescribed benzodiazepine was detected in 19% and 16% of first and last samples respectively, with the largest decline observed in those with the most frequent UDM testing (27% vs. 19%). Frequent urine drug monitoring may have the potential to increase adherence to prescribed buprenorphine/naloxone and decrease the use of non-prescribed opiates and benzodiazepines.