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RecruitingAccepts healthy volunteersPhase 2/Phase 3

Naltrexone for Overdose Prevention

University of California, San Francisco · with National Institute on Drug Abuse (NIDA) · NCT06633900

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Opens the official ClinicalTrials.gov record, with the study team’s contacts. Bored Studies doesn’t enroll anyone.

Key facts

Compensation
Not posted. Ask the study team before screening.
Who can join
Ages 18+ · All sexes
Healthy volunteers
Accepted
Study type
Interventional · Phase 2, Phase 3
Target enrollment
100
US sites recruiting
1
Study start
April 10, 2025
Record last updated
June 9, 2026

Status re-checked against ClinicalTrials.gov within the last 12 hours.

What the study is about

The goal of this clinical trial is to see if an injectable medicine called naltrexone can prevent fentanyl overdose deaths in people who use other drugs (cocaine, methamphetamine). The main questions it aims to answer are:

What are the challenges for implementing naltrexone as an overdose prevention strategy?

Are injections of naltrexone effective for opioid overdose prevention among people who use stimulants?

How often are people who use stimulants and do not intentionally use opioids unintentionally exposed to opioids?

Researchers will compare participants to receive the study medication to the usual care group to see if one group experiences fewer opioid overdose events than the other.

Participants will be randomized to either receive a monthly injection of naltrexone over six months, or receive usual care. Usual care includes harm reduction supplies. Laboratory procedures will include the collection of urine, blood, and hair samples for various safety and outcome measure testing.

Being studied: IM naltrexone; Usual Care

Conditions: Overdose Accidental

Eligibility criteria

Copied from the official record. The study team makes the final decision at screening.

Show full criteria

Inclusion Criteria

  • at-risk for HIV or living with HIV
  • stimulant use disorder (by DSM-V) or positive urine drug test for cocaine, amphetamine, or methamphetamine in last 6 months AND report at least 10 days of stimulant use/month,
  • able to provide informed consent,
  • English-speaking,
  • age 18 years old or greater.

Exclusion Criteria

  • prescribed or non-prescribed opioid use (including newly diagnosed opioid use disorder by DSM-V),
  • receipt of long-acting injectable naltrexone for other indications in past 30 days,
  • planned surgery in next 6 months,
  • moderate, severe or chronic liver disease (AST, ALT ≥ 5 times the upper limit of normal or symptoms of current liver disease),
  • persons who are pregnant or breastfeeding,
  • increased risk of bleeding (thrombocytopenia \<50 x 109/L, coagulopathy, or therapeutic anticoagulation),
  • known hypersensitivity to naltrexone or its diluents, or
  • any other reason (e.g. comorbid medical conditions, adherence concerns, lack of interest in naltrexone, etc.) that judged by the study team's discretion, would impede the participant from successfully completing the trial.

Recruiting US locations

  • Center on Substance Use and Health

    San Francisco, CA 94102

    Site contact: John Walker, RN, FNP-C · 628-217-6227 · john.e.walker@sfdph.org

Study contacts (from the official record)

  • Ayesha Appa, MD · 628-206-7839 · ayesha.appa@ucsf.edu
  • Xochitl Luna Marti, MPH · 628-217-6235 · xochitl.lunamarti@sfdph.org
All healthy volunteers studies in California →
Naltrexone for Overdose Prevention (NCT06633900) | Bored Studies