Evaluating Buspirone to Treat Opioid Withdrawal

April 27, 2026 updated by: University of Maryland, Baltimore

Evaluating a Mechanistically-Supported Pharmacotherapy to Treat Opioid Withdrawal

The investigators propose a rigorous, Phase II, three-group, placebo-controlled double-blind randomized controlled trial (RCT) to evaluate the efficacy of buspirone for both withdrawal and craving among individuals with opioid use disorder (OUD) undergoing a standardized stepwise taper. During this 10 to 12-day residential study, participants with OUD will be enrolled, stabilized on a short-acting opioid, undergo an opioid stepwise taper, and complete a post-taper observation period where participants will have the opportunity to initiate long-term buprenorphine or extended-release naltrexone.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This R01 will conduct a rigorous and appropriately powered randomized clinical trial to evaluate the efficacy of buspirone to decrease opioid withdrawal and craving, improve treatment retention and decrease rates of relapse. The use of buspirone for opioid use disorder (OUD) is mechanistically-supported and has demonstrated initial efficacy in small clinical trials including mostly male samples. Since the latest promising results were published 15 years ago, buspirone has yet to be evaluated in a rigorous and appropriately representative and powered randomized clinical trial. Buspirone stands to provide immediate aid to unmet treatment needs among individuals with OUD because it is FDA-approved and generically available. The investigators have designed a Phase-II, three-group, double-blind, placebo controlled evaluation of buspirone for opioid withdrawal and craving during a residential stepwise opioid taper. The study will take place in a clinical research unit over 10-12 days where participants will undergo a short-term stabilization period, an opioid taper, and a post-taper observation period where participants will initiate extended release naltrexone (XR-NTX) or buprenorphine or will receive a referral to a treatment program of the participants' choice. One hundred participants with OUD and interested in completing a residential opioid taper will be enrolled and randomized to one of three conditions: (1) an opioid stepwise taper with placebo (control), (2) an opioid stepwise taper with lofexidine (positive control), and (3) an opioid stepwise taper with buspirone (experimental). Based on previous retention rates, the investigators anticipate completing 90 participants (n=30/condition). Withdrawal and tonic craving will be collected daily throughout the course of the study using standardized questionnaires. Acute craving will be assessed in a cue-induced craving task, which was developed by Co-I Huhn, once during the residential phase and once during the outpatient phase. Finally, the safety and acceptability by the study participants will be assessed through Adverse Events (AEs), abnormal ECGs, acceptability scores, and negative comments.

The Primary Aim will compare the changes in opioid withdrawal across the three conditions. The investigators hypothesize that the opioid taper + buspirone and opioid taper + lofexidine will significantly decrease withdrawal (SOWS, COWS) relative to opioid taper alone.

Secondary Aim 1 will compare changes in craving across the three conditions. The investigators hypothesize that individuals will have significantly lower tonic and cue-induced craving scores when the individuals are actively receiving opioid taper + buspirone relative to opioid taper alone and opioid taper + buspirone. Individuals who receive opioid taper + lofexidine will have significantly lower craving following cue-induced craving + stress tasks compared to opioid taper alone and opioid taper + buspirone conditions. Secondary Aim 2 will compare the safety and acceptability by the participants in the three conditions. The investigators hypothesize that buspirone will produce the fewest adverse events and instances of negative qualitative feedback and the greatest acceptability scores, followed by opioid taper + lofexidine. Opioid taper alone is expected to produce the highest number of adverse events and the lowest acceptability.

The Exploratory Aim will compare the changes in anxiety and acute stress response across the three conditions. The investigators offer no hypothesis on this aim.

This study will determine whether buspirone is an effective medication for treating opioid withdrawal and craving. This study will demonstrate the utility of using mechanistically supported medications to treat opioid withdrawal symptoms. If proven to have a positive impact on OUD and related sequelae, these data would support additional research evaluating the benefits of buspirone in other short -and long-term treatment settings for opioid use disorder. Further, this medication should be evaluated among chronic pain patients interested in tapering off of opioids but requiring additional therapeutic support to address acute and protracted withdrawal. The re-purposing of buspirone to treat OUD could occur rapidly and offers a safe pharmacotherapy for individuals requiring additional support for OUD.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Recruiting
        • Kahlert Institute for Addictino Medicin
        • Contact:
        • Principal Investigator:
          • Cecilia Bergeria, Ph.D.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 18-75
  • Opioid positive urine sample
  • Current moderate-severe opioid use disorder with evidence of physical dependence
  • Interested in undergoing opioid detoxification

Exclusion Criteria:

  • Being pregnant or breastfeeding
  • Enrolled in methadone or buprenorphine maintenance treatment
  • Allergic to study medication or taking medications that are contraindicated with study medication (e.g., CYP3A4 inhibitors or inducers and/or monoamine oxidase (MAO) inhibitors)
  • Significant mental health or physical disorder, or life circumstance, that is expected to interfere with study participation (detailed further in protection of human subjects form).
  • Hypotension and/or prolonged QTc interval

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: opioid stepwise taper + buspirone
up to 45mg/day buspirone during the opioid stepwise taper
Drug: Buspirone
Buspirone administration begins 2 days prior to opioid taper (study day -2) and continues until the second day of the post-taper observation phase (study day 7).
Active Comparator: opioid stepwise taper + lofexidine
up to 2.16mg/day lofexidine during the opioid stepwise taper
Drug: Lofexidine
Lofexidine administration begins 2 days prior to opioid taper (study day -2) and continues until the second day of the post-taper observation phase (study day 7).
Placebo Comparator: opioid stepwise taper + placebo
placebo during the opioid stepwise taper
Drug: Placebo
Participants administration begins 2 days prior to opioid taper (study day -2) and continues until the second day of the post-taper observation phase (study day 7).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Opioid Withdrawal as assessed by the Subjective Opiate Withdrawal Scale (SOWS)
Time Frame: Days -2 to 8
Opioid withdrawal severity will be measured with the Subjective Opiate Withdrawal Scale (SOWS) and will be computed as a daily peak total SOWS score for study days -2 to 8. The SOWS consists of 16 opioid withdrawal symptoms that are assessed for severity on a scale from 0-4 ("Not at all" to "Extremely"). Total scores range from 0-64 where a score between 0-10 is considered mild, between 11-20 is considered moderate, and greater than 21 is considered severe.
Days -2 to 8

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in tonic craving scores
Time Frame: Days -2 to 8
Craving will be measured by tonic craving will be computed as daily peak total craving scores. The tonic craving assessment consists of 5 items related to craving that are completed on a visual analog scale (VAS) where 0 = not at all and 100 = A lot.
Days -2 to 8
Change in cue-induced craving scores
Time Frame: Days -2 to 8
Cue-induced craving will be computed as total craving scores before and after the craving task. The craving assessment consists of 5 items related to craving that are completed on a visual analog scale (VAS) where 0 = not at all and 100 = A lot.
Days -2 to 8
Change in stress-induced craving scores
Time Frame: Days -2 to 8
Stress-induced craving will be computed as total craving scores before and after stress/craving task. The craving assessment consists of 5 items related to craving that are completed on a visual analog scale (VAS) where 0 = not at all and 100 = A lot.
Days -2 to 8
Frequency of Adverse Events
Time Frame: Up to day 8
Safety will be assessed with the number of adverse events per treatment condition not including unrelated adverse events.
Up to day 8
Frequency of QTc Interval Prolongation
Time Frame: Up to day 8
Corrected QT (QTc) interval prolongation frequency will be compared across conditions. QTc interval is considered prolonged if >440 ms among male participants and >460 ms among female participants.
Up to day 8
Acceptability of buspirone for opioid withdrawal and craving
Time Frame: Up to day 8
Acceptability will be measured by acceptability questionnaires completed at discharge and will be computed as the average acceptability score. Scores range from 0-10, where 0 reflects no acceptability and 10 reflects high acceptability.
Up to day 8

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Maryland, Baltimore

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Cecilia Bergeria, Ph.D., Johns Hopkins University

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 15, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 18, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 19, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 23, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB00315529

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

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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