Trial · NCT04791969

Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM

NCT04791969, Phase 2, Completed, Glenn-Milo Santos; results first posted 2025-10-27

3 sourcestrials-2026-11-12-0.4.0

Cite this record

ConductScience Library. Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM. Trials, record NCT04791969. Release trials-2026-11-12-0.4.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT04791969

On this page

Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM
NCT number: NCT04791969
Status: Completed
Phases: Phase 2
Enrollment: 60 participants, actual
Lead sponsor: Glenn-Milo Santos
Conditions: Methamphetamine Use Disorder
Interventions: Naltrexone Hydrochloride, Placebo, Ecological Momentary Intervention
First posted: 2021-03-10
Last updated: 2025-10-27
Results first posted: 2025-10-27
Limitations and caveats: Limitations include loss to follow-up in study participants, leading to a smaller number of observations analyzed than original number of participants enrolled.

Source ClinicalTrials.gov

Registered outcomes3

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Number of People With Meth-positive Urine Tests at Weekly Visits	Every week from week 1 to the end of treatment at 12 weeks	As measured by the count of participants with meth-positive urine tests.
Secondary	Mean in Sexual Risk Behaviors at Week 12	Past month behavior, measured at the end of treatment at 12 weeks	As measured by the mean number of sexual partners with whom they used meth, in the prior month, at week 12
Other	Adherent to PrEP or to Antiretroviral Medication	At the end of treatment at the 12-week visit	As measured by PrEP drug levels being detected in HIV negative participants (PrEP Adherent and viral suppression rates in HIV positive participants (Antiretroviral treatment adherent)

Source ClinicalTrials.gov

Outcomes3

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Number of People With Meth-positive Urine Tests at Weekly Visits	Every week from week 1 to the end of treatment at 12 weeks		Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Mean in Sexual Risk Behaviors at Week 12	Past month behavior, measured at the end of treatment at 12 weeks	Participants who completed sexual behavior questionnaire at final visit	number of meth-using male partners	MEAN
OTHER_PRE_SPECIFIED	Adherent to PrEP or to Antiretroviral Medication	At the end of treatment at the 12-week visit	Participants who are HIV-negative and who provided samples for PrEP drug levels testing at final visit, or participants who are living with HIV and provided samples for HIV viral load testing	Participants	COUNT_OF_PARTICIPANTS

Source ClinicalTrials.gov

Results by group28

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Units
Number of People With Meth-positive Urine Tests at Weekly Visits	Naltrexone With Ecological Momentary Intervention	Week 1	20	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Placebo With Ecological Momentary Intervention	Week 1	13	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Naltrexone With Ecological Momentary Intervention	Week 2	23	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Placebo With Ecological Momentary Intervention	Week 2	9	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Naltrexone With Ecological Momentary Intervention	Week 3	21	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Placebo With Ecological Momentary Intervention	Week 3	10	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Naltrexone With Ecological Momentary Intervention	Week 4	25	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Placebo With Ecological Momentary Intervention	Week 4	10	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Naltrexone With Ecological Momentary Intervention	Week 5	19	Participants
Number of People With Meth-positive Urine Tests at Weekly Visits	Placebo With Ecological Momentary Intervention	Week 5	8	Participants

1 to 10 of 28Source ClinicalTrials.gov

See all 28 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Naltrexone With Ecological Momentary Intervention	40
Overall Study	STARTED	Placebo With Ecological Momentary Intervention	20
Overall Study	COMPLETED	Naltrexone With Ecological Momentary Intervention	35
Overall Study	COMPLETED	Placebo With Ecological Momentary Intervention	11
Overall Study	NOT COMPLETED	Naltrexone With Ecological Momentary Intervention	5
Overall Study	NOT COMPLETED	Placebo With Ecological Momentary Intervention	9

Source ClinicalTrials.gov

Adverse events8

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Fatigue	General disorders	Naltrexone With Ecological Momentary Intervention	2	40	2
other	Fatigue	General disorders	Placebo With Ecological Momentary Intervention	0	20	0
other	Nausea	Gastrointestinal disorders	Naltrexone With Ecological Momentary Intervention	5	40	5
other	Nausea	Gastrointestinal disorders	Placebo With Ecological Momentary Intervention	0	20	0
serious	Post-obstructive renal failure	Renal and urinary disorders	Naltrexone With Ecological Momentary Intervention	1	40	1
serious	Post-obstructive renal failure	Renal and urinary disorders	Placebo With Ecological Momentary Intervention	0	20	0
serious	Hernia	Musculoskeletal and connective tissue disorders	Naltrexone With Ecological Momentary Intervention	1	40	1
serious	Hernia	Musculoskeletal and connective tissue disorders	Placebo With Ecological Momentary Intervention	0	20	0

Source ClinicalTrials.gov

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Naltrexone With Ecological Momentary Intervention	0	40
Total, all-cause mortality	Placebo With Ecological Momentary Intervention	0	20
Total, other adverse events	Naltrexone With Ecological Momentary Intervention	7	40
Total, other adverse events	Placebo With Ecological Momentary Intervention	0	20
Total, serious adverse events	Naltrexone With Ecological Momentary Intervention	2	40
Total, serious adverse events	Placebo With Ecological Momentary Intervention	0	20

Source ClinicalTrials.gov

Papers0

The papers the trial lists on ClinicalTrials.gov.

None in this release.

Grants1

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

Project	Title	Principal investigators	Organization	Funder	Fiscal years
R01DA053171	The ION+EMI Study: Intermittent Oral Naltrexone enhanced with an Ecological Momentary Intervention for Methamphetamine-using MSM	SANTOS, GLENN-MILO	UNIVERSITY OF CALIFORNIA, SAN FRANCISCO	NATIONAL INSTITUTE ON DRUG ABUSE	2021 to 2023

Source NIH RePORTER

Trial comparisons3

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
Naltrexone With Ecological Momentary Intervention vs Placebo With Ecological Momentary Intervention: Adherent to PrEP or to Antiretroviral Medication	Trial comparisons
Naltrexone With Ecological Momentary Intervention vs Placebo With Ecological Momentary Intervention: deaths from any cause	Trial comparisons
Naltrexone With Ecological Momentary Intervention vs Placebo With Ecological Momentary Intervention: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Source

Release: trials-2026-11-12-0.4.0
Release manifest SHA-256: 0f4a8d8c48aee2a7573ae0fa94ecbeab70c1adbe449bbc95c424bc7d3e97b9d4
Registry capture: 2026-11-12
Results copy, AACT: 2026-03-23
NIH clinical studies file: 2026-11-13

Source ClinicalTrials.gov

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNone stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

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