Skip to Main Content

RTI uses cookies to offer you the best experience online. By and clicking “accept” on this website, you opt in and you agree to the use of cookies. If you would like to know more about how RTI uses cookies and how to manage them please view our Privacy Policy here. You can “opt out” or change your mind by visiting: http://optout.aboutads.info/. Click “accept” to agree.

Accept
RTI International
  • About
    • Office Locations
    • Executive Leadership
    • Corporate Governance
    • Partner with Us
      • U.S. Government
      • Clients and Funding Agencies
      • Industry and Commercial Clients
      • Foundations and Associations
      • Bilateral Agencies and Multilateral Banks
      • Universities and Academic Research Institutions
      • Suppliers and Small Businesses
    • Commitment to Quality
      • RTI's Client Listening Program
    • Ethics and Human Research Protection
    • Living Our Mission
    • Veteran Opportunities at RTI

    About

  • Practice Areas
    • Health
      • Public Health and Well-Being
      • Health Care Transformation
      • Behavioral Health
      • Health Behavior Change
      • Precision Medicine
      • RTI Health Solutions (RTI-HS)
      • RTI Center for Community Health Evaluation and Economics Research
      • Health Equity
      • RTI Health Advance
    • Transformative Research Unit for Equity​
      • Equity Capacity Building Hub
      • Social and Economic Justice Research Collaborative
      • Narrative Research and Community Engagement Lab
    • Education and Workforce Development
      • Early Childhood
      • K-12 Education
      • Postsecondary Education
      • Career and Adult Education and Workforce Development
      • Education Policy, Systems, and Governance
      • Education Research Methodologies
      • Education Technologies
    • International Development
      • Energy for Development
      • Environment
      • Global Food Security, Agriculture, and Nutrition
      • Global Health
      • International Education
      • Monitoring, Evaluation, Research, Learning, and Adapting (MERLA)
      • Youth and Economic Opportunity
      • Building Resilience Against COVID-19 in Developing Countries
      • Water, Sanitation, and Hygiene (WASH)
      • RTI Center for Governance
    • Climate Change
      • Clean Energy Technology and Renewables
      • Climate Finance
      • Climate Justice and Equity
      • Climate Planning, Preparedness and Resilience
      • Climate Policy
      • Climate Vulnerability, Adaptation, and Mitigation
      • Economic Impacts of Climate Change
    • Water
      • Food-Energy-Water Nexus
      • Water Quality
      • WASH (Water, Sanitation, Hygiene)
      • Water Resources Management
    • Energy Research
      • Carbon Capture and Utilization
      • Biomass Conversion
      • Natural Gas
      • Energy Efficiency
      • Industrial Water
      • Syngas Processing
    • Environmental Sciences
      • Air Quality
      • RTI Center for Water Resources
      • Urban Sustainability
      • Toxics
      • Building Resiliency in the FEW Nexus
      • Climate Change Sciences and Analysis
      • Environmental Policy
      • Environmental Justice
      • Sustainable Materials & Waste Management Solutions
    • Justice Research and Policy
      • RTI Center for Community Safety and Crime Prevention
      • RTI Center for Policing Research and Investigative Science
      • Child Well-Being and Family Strengthening
      • RTI Center for Forensic Sciences
    • Food Security and Agriculture
      • Market Systems Strengthening
      • Food Safety
      • Food and Nutrition
      • Global Food Security, Agriculture, and Nutrition
      • Climate-Smart Agriculture
      • Agricultural Innovation
      • Obesity Prevention
    • Innovation Ecosystems
      • Innovation Advising
      • Innovation for Economic Growth
      • Innovation for Emerging and Developing Economies
      • Innovation for Organizations
      • Research, Technology, and Innovation Policy
      • Technology Acceleration
    • Military Support
      • Military Behavioral Health
      • Military Health and Human Performance
      • Military Sexual Assault, Harassment, and Domestic Violence Prevention
      • Wearable Sensor Technologies
      • Military Health System Transformation

    Practice Areas

  • Services + Capabilities
    • Surveys and Data Collection
      • Survey Design
      • Instrument Development
      • Survey Methodologies
      • Data Collection
      • Establishment Surveys
      • Health Registries
      • Data Analysis and Reporting
      • Research Operations Center
    • Statistics and Data Science
      • Survey Statistics
      • Environmental Statistics
      • Coordinating Centers for Multisite Studies
      • Analysis and Design of Complex Data
      • Biostatistics
      • RTI Center for Data Science
    • Evaluation, Assessment and Analysis
      • Evaluation Design and Execution
      • Advanced Qualitative, Quantitative, and Mixed Methods
      • Evaluation, Monitoring, and Assessment
      • Economic Analysis
      • Evaluating Communication Interventions and Campaigns
      • Evidence Synthesis for Policy and Practice
      • Risk Assessment and Prediction
    • Program Design and Implementation
      • Systems Strengthening and Scaling
      • Capacity Assessment and Building
      • Policy Reform Support
      • Curriculum and Teacher Professional Development
      • Interventions and Prevention Programs
      • Implementation Science
    • Digital Solutions for Social Impact
      • Human-Centered Design of Digital Solutions
      • Digital Product Development
      • Digital Communication Campaigns
      • Digital Data Analytics
    • Research Technologies
      • Survey Technologies
      • Data Management and Decision Support Systems
      • Geospatial Science, Technology, and Visualization
      • ICT for Limited-Resource Settings
      • Mobile Applications
      • Web Applications
      • Bioinformatics
      • Interactive Computing
    • Drug Discovery and Development
      • Medicinal Chemistry
      • Molecular Design and Cheminformatics
      • Behavioral Pharmacology
      • Drug Metabolism and Pharmacokinetics (DMPK)
      • In Vitro Pharmacology, Bioassay Development, and High-Throughput Screening (HTS)
      • Isotope Labeling
      • Regulatory Consulting and Support for Medical Products
    • Analytical Laboratory Sciences
      • Bioanalytical and Toxicology Research
      • Forensic Sciences
      • Physicochemical Characterizations
      • Metabolomics
      • Proficiency Testing and Reference Materials
      • Microbiology
      • Analytical Chemistry and Pharmaceutics
    • Engineering & Technology R&D
      • Biomedical Technologies
      • Decarbonization Sciences
      • Environmental Exposure & Protection
      • Materials & Environment
      • Sustainable Energy Solutions

    Services + Capabilities

  • Centers
    • RTI Center for Advanced Methods Development
    • RTI Center for Communication Science
      • Communication Research
      • Communication Design
      • Communication Delivery
    • RTI Center for Data Science
    • RTI Center for Education Services
      • Teaching and Learning
      • Education Leadership
      • Peer Learning Networks
      • Strategic Consulting
    • RTI Center for Forensic Sciences
    • RTI Center for Global Noncommunicable Diseases
      • Program Financing & Economics for NCDs
      • Health Systems Strengthening for NCDs
      • Communication Science and Behavior Change for NCDs
      • Implementation Science for NCDs
    • RTI GenOmics, Bioinformatics, and Translational Research Center
      • Disability Studies
      • Ethics
      • Newborn Screening
    • RTI Center for Water Resources
      • Water Resources Sectors
      • Water Resources Services
      • Water Resources Tools
    • RTI Center for Governance
    • RTI Global Gender Center
    • North Carolina Center for Optimizing Military Performance
    • NCCU-RTI Center for Applied Research in Environmental Sciences
    • RTI Center for Climate Solutions

    Centers

  • Impact
    • Newsroom
    • Insights Blog
    • Events
    • Publications
    • RTI Press
      • About the RTI Press
      • Instructions for Authors
      • RTI Press Collections
    • Projects
    • Global Reach
      • Asia
      • Eastern Europe and Central Asia
      • RTI International India
      • Africa
      • Middle East and North Africa (MENA)
      • Latin America and the Caribbean (LAC)

    Impact

  • Experts
    • Our Experts
    • In-Depth With Our Experts
    • Related News
    • Experts In the Media
    • RTI Fellow Program

    Experts

  • Emerging Issues
    • COVID-19 Research
    • Artificial Intelligence
    • Global Health Security
    • Cannabis Research
    • Opioid Research
      • Interventions for Opioid Use Disorders
      • Preventing Opioid Misuse and Overdose
      • Treating Opioid Use Disorders
    • Policing Research and Investigative Science
    • Drone Research and Application
    • E-cigarette Research
    • Zika Virus Research
    • Integrated Governance

    Emerging Issues

  • COVID-19 Research + Response
  • Global Reach
  • Insights Blog
  • Newsroom
  • RTI Press
  • Publications
  • Partner With Us
  • Careers
  • Facebook IconTwitter IconInstagram IconYouTube IconLinkedin Icon
  • Home
  • Impact
  • Publications
  • Extended-release injectable naltrexone (XR-NTX)

Extended-release injectable naltrexone (XR-NTX)

A response to clinical issues raised by Brewer and Streel

Jarvis, B. P., Holtyn, A. F., Subramaniam, S., Tompkins, D. A., Oga, E. A., Bigelow, G., & Silverman, K. (2019). Extended-release injectable naltrexone (XR-NTX): A response to clinical issues raised by Brewer and Streel. Addiction, 114(1), 189-190. https://doi.org/10.1111/add.14462, https://doi.org/10.1111/add.14462

Copy citation

Abstract

We appreciate the letter by Brewer and Streel expanding on clinical issues reported in our recent review on extended-release injectable naltrexone (XR-NTX).1 As stated in our methods, we intentionally focused on studies using XR-NTX and did not consider studies on other long-acting NTX formulations. Induction procedures for other long-acting NTX formulations, if more successful than those described in our review, could be investigated for their utility in increasing XR-NTX induction. However, the authors’ claim that 100% intent-to-treat induction rates for implantable NTX have been routinely achieved for thousands of patients is not supported by the cited reports. Two of these reported induction onto oral NTX.2,3 The other4 was a retrospective report of two cohorts, which were both comprised of patients who had previously received implantable NTX; induction rates were not reported. We described induction procedures as “rapid” because these involved XR-NTX administration before the manufacturer-recommended 7 to 10 days of opioid abstinence.5 In our search, we did not identify any published studies investigating shorter XR-NTX inductions within 24 hours. The suggestion by Brewer and Streel that induction to XR-NTX can routinely be easy and rapid is out of touch with broad experience to the contrary. For example, a recent multisite clinical trial6 that was included in our review from the U.S. National Drug Abuse Treatment Clinical TrialsThis article is protected by copyright. All rights reserved.Network referred to the relative difficulty of beginning XR-NTX versus sublingual buprenorphine-naloxone (significant at p < .0001) as “a substantial induction hurdle.”Regarding our decision to report urinalysis data, we agree that, while guidelines are available,7 there is no single standard for the selection of primary outcome measures for clinical trials evaluating medications for opioid use disorder.8 We chose to measure opioid use as the percentage of urine samples negative for opioids because this is nearly universally collected in clinical trials and provides an objective measures of recent opioid use. Several of the clinical trials included in our review used other opioid use outcomes (e.g., relapse, self-reported opioid-free days). We reported these findings and considered them in our conclusions on XR-NTX’s efficacy and effectiveness. Brewer and Streel’s statement that opioid use during XR-NTX blockade might constitute a “neuropharmacological abstinence” is valid but of unclear relevance. When adhered to, XR-NTX affords protection from overdose and agonist effects that might interfere with normal activities (e.g., driving, working, taking care of children), but opioid use can still have considerable negative impacts when taken under XR-NTX blockade (e.g., spread of HIV/HCV, infection, exposure to legal consequences, financial problems). These consequences should be emphasized, even if further evidence confirms an extinction-based mechanism for XR-NTX’s effectiveness.9Our statement that XR-NTX’s therapeutic effects on opioid use do not persist once discontinued was based on a large 24-week multi-site randomized controlled trial with follow up at 52 and 78 weeks.10 This finding and our statement are consistent with the chronic, relapsing nature of opioid use disorder and mirror the much larger literature on the effects of adherence to methadone and buprenorphine on opioid use.11 Rather than obscuring the clinical effects of XR-NTX, as suggested by Brewer and Streel, we believe this finding highlights the critical role that medication adherence and treatment retention play in promoting long-term remission and preventing relapse to opioid use.

Download/Explore
Share
  • Share on Facebook
  • Share on Twitter
  • Share on Linkedin
  • Email

Publications Info

To contact an RTI author, request a report, or for additional information about publications by our experts, send us your request.

  • +1 919 541 8787
  • publications@rti.org

Meet the Experts

View All Experts
Emmanuel Oga

Emmanuel Oga

Recent Publications

OCCASIONAL PAPER

Bringing an equity-centered framework to research

OCCASIONAL PAPER

The Preschool Entitlement

OCCASIONAL PAPER

Culturally informed community engagement

Article

Does the relationship between alcohol retail environment and alcohol outcomes vary by depressive symptoms? Findings from a US Survey of Black, Hispanic and White drinkers

RTI Logo
Partner With Us
  • US Government
  • Commercial
  • Foundations & Associations
  • Multilateral Donors
  • Universities
  • Suppliers
Site
  • Privacy Policy
  • Security Policy
  • Site Map
  • Terms of Use
  • Accessibility
  • Contact Us
Contact Us
Facebook Icon Twitter Icon Instagram Icon YouTube Icon Linkedin Icon
delivering the promise of science
for global good
RTI Health Solutions RTI Innovation Advisors RTI Health Advance

© 2023 RTI International. RTI International is a trade name of Research Triangle Institute. RTI and the RTI logo are U.S. registered trademarks of Research Triangle Institute.