Using naltrexone injections to prevent overdose deaths in stimulant users

Extended-Release Naltrexone as Opioid Overdose Pre-Exposure Prophylaxis (PrEP) in People Using Stimulants Living With or At Risk of HIV

Phase2; Phase3 Interventional University of California, San Francisco · NCT06633900

This study is testing if monthly naltrexone injections can help prevent overdose deaths from fentanyl in people who use stimulants like cocaine and methamphetamine.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of California, San Francisco Academic / other
Locations1 site (San Francisco, California)
Trial IDNCT06633900 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates the effectiveness of injectable naltrexone in preventing fentanyl overdose deaths among individuals who use stimulants like cocaine and methamphetamine. Participants will be randomly assigned to receive either monthly naltrexone injections or usual care, which includes harm reduction supplies. The study will assess the feasibility, acceptability, and preliminary effectiveness of naltrexone, alongside collecting data on opioid exposure in this population. Monthly assessments will track participants' exposure to opioids and adherence to the treatment over a 24-week period.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 18 and older who are at risk for HIV or living with HIV and have a stimulant use disorder.

Not a fit: Patients who are currently using opioids or have a recent history of opioid use disorder will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly reduce the risk of opioid overdose deaths among stimulant users.

How similar studies have performed: While the use of naltrexone for opioid overdose prevention is a novel approach, similar studies have shown promise in addressing overdose risks in different populations.

Eligibility criteria

Show full inclusion / exclusion criteria
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), or
7. known hypersensitivity to naltrexone or its diluents.

Where this trial is running

San Francisco, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Overdose Accidentalstimulantscocainemethamphetamineoverdose preventionnaltrexonefentanyl exposure
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.