Assessing a Clinically-meaningful Opioid Withdrawal Phenotype

September 5, 2025 updated by: University of Maryland, Baltimore
Evaluate individual differences in the expression of opioid withdrawal symptoms in persons with opioid use disorder (OUD) while completing a clinically-indicated medication taper.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Individuals who have opioid use disorder and are interested in being tapered off of opioids will be admitted to a residential research unit for an 11-day period. All participants will be maintained on morphine for 5 days. During this period participants will complete 2 sessions (on two different days) wherein participants will receive an intramuscular injection of naloxone to precipitate a short withdrawal syndrome. Participants will take a capsule prior to both sessions that will contain either placebo or the opioid withdrawal medication lofexidine. Beginning on day 6 participants will be tapered off of morphine using lofexidine (as clinically indicated). At the end of the study all participants will be able to transition to buprenorphine maintenance or receive oral naltrexone and an injection of Vivitrol (extended release naltrexone), consistent with standard of care practices. Investigators will collect a variety of biological samples and questionnaire ratings during the study and primary outcomes will be measures of withdrawal collected throughout the study. Investigators will use these data to learn more about why individuals express opioid withdrawal symptoms differently, which will help inform how to change current treatment practices to be more effective for persons with OUD.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21201
        • Recruiting
        • University of Maryland
        • Principal Investigator:
          • Kelly E Dunn, PhD, MBA
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18 years - 65 year old
  • Opioid-positive urine sample
  • Current opioid use disorder with evidence of physical dependence
  • Interest in undergoing opioid taper

Exclusion Criteria:

  • Evidence of physical dependence on alcohol or benzodiazepines that requires medical intervention
  • Being pregnant or breastfeeding
  • Enrolled in methadone or buprenorphine maintenance treatment
  • Clinically significant hypotension (<90/60mmHg) or bradycardia (<45bpm)
  • History of myocardial infarction
  • Subjects who are positive for hepatitis B surface antigen and/or hepatitis C antibody with liver function tests outside the normal range (persons with a positive hepatitis C antibody and normal liver functions tests are NOT excluded from the study)
  • Significant mental health or physical disorder, or life circumstances, that is expected to interfere with study participation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Within-subject design
All participants will undergo the same study design, which includes hydromorphone stabilization (days 1-5), two naloxone challenges (scheduled during morphine stabilization), lofexidine-assisted taper (days 6-10), and transition to aftercare (day 11).
Drug: Lofexidine
Oral Lofexidine dosed per FDA label (4 times daily) on days 6 through 10.
Drug: Hydromorphone
Up to 120mg oral per day in q4 dosing to manage withdrawal
Drug: Naloxone + lofexidine pretreatment
0.2-0.4mg naloxone injection during the Naloxone challenge + pretreatment with oral lofexidine (25% of max daily dose scheduled during lofexidine taper)
Drug: Naloxone + placebo pretreatment
0.2-0.4mg naloxone injection during the Naloxone challenge

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Withdrawal severity during lofexidine taper
Time Frame: Days 6 through 10
Withdrawal severity as assessed by the Subjective Opioid Withdrawal Scale. (The score range is 0 through 64) with higher score indicating more severe withdrawal.
Days 6 through 10
Withdrawal severity during naloxone challenge
Time Frame: Days 1 through 5
Withdrawal severity as assessed by the Subjective Opioid Withdrawal scale scores (The range is 0 through 64) with higher score indicating more severe withdrawal. Collected during two naloxone challenges (pretreatment with lofexidine and pretreatment with placebo).
Days 1 through 5

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Maryland, Baltimore

Collaborators

National Institute on Drug Abuse (NIDA)

Investigators

  • Principal Investigator: Kelly E Dunn, Ph.D, M.B.A., University of Maryland

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 1, 2021

Primary Completion (Estimated)

November 30, 2026

Study Completion (Estimated)

February 28, 2027

Study Registration Dates

First Submitted

August 24, 2021

First Submitted That Met QC Criteria

August 24, 2021

First Posted (Actual)

August 31, 2021

Study Record Updates

Last Update Posted (Estimated)

September 12, 2025

Last Update Submitted That Met QC Criteria

September 5, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB00279895
  • 1R01DA052937 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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