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

TitleRisk of Relapse Among Opioid-Dependent Patients Treated With Extended-Release Naltrexone or Buprenorphine-Naloxone: A Randomized Clinical Trial AuthorsArild Opheim, MSc1,2; Zhanna Gaulen, MSc1,3; Kristin Klemmetsby Solli, MSc, PhD4,5,6; Zill-e-Huma Latif, MD, PhD7; Lars Thore Fadnes, MD, PhD1,2; Jūratė Šaltytė Benth, MSc, PhD8,9; Nikolaj Kunøe, MSc, PhD10; Lars Tanum, MD, PhD5,11 1Department of Addiction Medicine, Haukeland University Hospital, Norway, 2Institute of Global Public Health and Primary Care, University of Bergen, Norway 3Department of Clinical Dentistry, University of Bergen, Norway 4Norwegian Centre for Addiction Research, University of Oslo, 0315 Oslo, Norway, 5Department of Research and Development in Mental Health Services, Akershus University Hospital, 1478 Lorenskog, Norway, 6Vestfold Hospital Trust, 3116 Tonsberg, Norway 7Groruddalen Psychosis Outpatient Department, Akershus University Hospital, 0963 Oslo, Norway 8Institute of Clinical Medicine, Campus Ahus, University of Oslo, P.O.Box 1171, 0318 Blindern, Norway, 9Health Services Research Unit, Akershus University Hospital, P.O. Box 1000, 1478 Lorenskog, Norway 10Lovisenberg Diaconal Hospital P.O. Box 4970, 0440 Oslo, Norway 11Faculty for Health Science, Oslo Metropolitan University, Pilestredet 32, 0167 Oslo, Norway BackgroundCompare 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). MethodsWe 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 had completed detoxification and received at least one dose of study medication. ResultsOf 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 to the BP-NLX group (HR 0.46; 95% CI 0.28-0.76; p=.002, and HR 0.11; 95% CI 0.04-0.29; p<.001, respectively) and (HR 0.15, 0.09-0.27; p<.001 and HR 0.05, 0.03-0.09; p<0.001, respectively). There was a stable low risk of relapse among participants receiving XR-NTX in follow-up. ConclusionCompared 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. Our data support XR-NTX as a first line treatment option for patients with opioid addiction both in short and longer-term treatment. 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 contradicts previous data from the X:BOT study, showing no significant difference in relapse risk between the groups in a 6 months RCT.