Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM
Public ClinicalTrials.gov record NCT04791969. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
The ION+EMI Study: Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is a double-blind, placebo-controlled phase 2b trial in which 54 MSM who use meth will be randomly assigned (2:1) to receive 12 weeks of as-needed intermittent oral naltrexone 50 mg enhanced with an EMA-informed EMI platform, or receive as-needed placebo with EMA-informed EMI. The 12-week treatment period is consistent with other pharmacotherapy trials for substance use disorders. The proposed sample size is also consistent with other phase 2b trials for substance use treatment. Upon enrollment, participants will complete daily EMA assessments and weekly visits for behavioral surveys and urine testing for meth metabolites, study drug dispensing and computer-based counseling for substance use. Safety laboratory assessments and vital signs will be completed monthly. Efficacy (Specific Aims 1-3) will be assessed upon trial completion as measured by proportion meth-positive urine samples; PrEP and ART adherence by drug levels and viral load testing; and sexual risk behavior data accounting for PrEP use and viral suppression.
Study identification
- NCT ID
- NCT04791969
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 60 participants
Conditions and interventions
Conditions
Interventions
- Naltrexone Hydrochloride Drug
- Placebo Drug
- Ecological Momentary Intervention Behavioral
Drug · Behavioral
Eligibility (public fields only)
- Age range
- 18 Years to 70 Years
- Sex
- Male
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Dec 13, 2021
- Primary completion
- Feb 29, 2024
- Completion
- Jun 30, 2024
- Last update posted
- Oct 26, 2025
2021 – 2024
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| San Francisco Department of Public Health | San Francisco | California | 94102 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04791969, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Oct 26, 2025 · Synced Sep 3, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04791969 live on ClinicalTrials.gov.