Recruiting
Phase 2
Phase 3

Naltrexone

Sponsor:

UCLA

Code:

NCT06633900

Conditions

Overdose Accidental

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

IM naltrexone

Usual Care

Study Details

Brief summary:

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.

Conditions

Overdose Accidental

Study ID

NCT06633900

Start date

Apr 10, 2025

Status verified date

Jun, 2026

Completion date

Apr 15, 2027

Anticipated

Primary completion date

Apr 15, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

1. at-risk for HIV or living with HIV
2. 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,
3. able to provide informed consent,
4. English-speaking,
5. age 18 years old or greater.

Exclusion Criteria:

1. prescribed or non-prescribed opioid use (including newly diagnosed opioid use disorder by DSM-V),
2. receipt of long-acting injectable naltrexone for other indications in past 30 days,
3. planned surgery in next 6 months,
4. moderate, severe or chronic liver disease (AST, ALT ≥ 5 times the upper limit of normal or symptoms of current liver disease),
5. persons who are pregnant or breastfeeding,
6. increased risk of bleeding (thrombocytopenia <50 x 109/L, coagulopathy, or therapeutic anticoagulation),
7. known hypersensitivity to naltrexone or its diluents, or
8. 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.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Intervention

Participants assigned to the intervention arm will receive naltrexone injections once a month over 6 months. The naltrexone injection (380mg) will be administered every 4 weeks in the ventrogluteal location.

active comparator: Control

Participants in the control arm will receive usual care.

Interventions

IM naltrexone

The study drug is an intramuscular injection of naltrexone (380mg), administered every 4 weeks via an injection in the ventrogluteal region.

Usual Care

Participants assigned to usual care will receive a harm reduction bundle in clinic. It will include the following components: 1) intranasal naloxone 4mg x 2, 2) participant choice of safer consumption kits based on substances and route used (specific materials for inhaled use vs. injecting, based on common use practices in the region), 3) fentanyl test kits with 2 lateral flow assays per package along with instructions to minimize false positive results, and 4) information about universal overdose precautions (behavioral modifications to optimize safety like using in the presence of others, use a test dose of new substances, etc.)

Primary outcome measure

  • Acceptability [ Time Frame: 6 months ]

Central Contacts and Locations

Central contacts

Ayesha Appa, MD

628-206-7839ayesha.appa@ucsf.edu

Xochitl Luna Marti, MPH

628-217-6235xochitl.lunamarti@sfdph.org

Locations

Center on Substance Use and Health

Recruiting

San Francisco, California, United States, 94102

Contacts

John Walker, RN, FNP-C

628-217-6227john.e.walker@sfdph.org

Xochitl Luna Marti, MPH

628-217-6235xochitl.lunamarti@sfdph.org

Principal Investigator:

Ayesha Appa, MD

More Information

Sponsor

University of California, San Francisco

Last update posted

Jun 9, 2026

Last verified

Jun, 2026

Keywords

  • stimulants
  • cocaine
  • methamphetamine
  • overdose prevention
  • naltrexone
  • fentanyl exposure

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of California, San Francisco on 2026-06-09.