Risk of Relapse Among Opioid-Dependent Patients Treated With Extended-Release Naltrexone or Buprenorphine-Naloxone: A Randomized Clinical Trial

Abstract

Background and Objectives: Compare the risk of relapse to heroin and other illicit opioids among opioid‐dependent patients receiving treatment with extended‐release naltrexone (XR‐NTX) or buprenorphine‐naloxone (BP‐NLX). Methods: Re‐analyzed data from a 12‐week multicenter, open‐label, randomized treatment study with a subsequent 36‐week open‐label follow‐up study. All patients, N = 143, had completed detoxification and received at least one dose of study medication. Results: Of 143 patients (72% men), mean age 36 years, 71 received XR‐NTX and 72 BP‐NLX. The risk of first relapse and the risk of any relapse to heroin and other illicit opioids were both significantly lower in the XR‐NTX group compared with the BP‐NLX group (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.28‐0.76; P = .002, and HR, 0.11; 95% CI, 0.04‐0.29; P < .001, respectively) and (HR, 0.15; 95% CI, 0.09‐0.27; P < .001 and HR, 0.05; 95% CI, 0.03‐0.09; P < .001, respectively). There was a stable low risk of relapse among participants receiving XR‐NTX in the follow‐up. Discussion and Conclusions: Compared to BP‐NLX, patients on XR‐NTX had a substantially reduced risk of relapse to illicit opioids and showed a stable low risk of relapse over time in longer‐term treatment. Scientific Significance: Our data support XR‐NTX as a first‐line treatment option for patients with opioid addiction both in short and longer‐term treatment. This is the first European study showing that XR‐NTX significantly reduces the risk of first and any relapse to heroin use in opioid‐dependent patients compared to BP‐NLX. Our data contradict previous data from the X:BOT study, showing no significant difference in relapse risk between the groups in a 6‐month randomised controlled trial.