Intermittent Naltrexone Among Polysubstance Users (Project iN)
Naltrexone, a µ-opioid receptor antagonist, is a promising agent for methamphetamine-using and binge-drinking men who have sex with men (MSM). Naltrexone has shown efficacy in reducing relapse to amphetamines and is FDA-approved for alcohol dependence. Oral naltrexone is inexpensive and has few toxicities but the standard daily regimen for naltrexone is problematic as patients forget to take the medication. Given the challenges in daily dosing, alternate regimen schedules have been proposed to increase efficacy and expand the population that may benefit from this pharmacologic agent. One approach is intermittent targeted administration of naltrexone, whereby individuals take the medication as-needed in anticipation of substance use or during periods of craving. Administration of naltrexone prior to exposure to amphetamines significantly attenuates craving and targeted naltrexone has shown efficacy in reducing heavy alcohol use. However, there have been no studies assessing intermittent targeted dosing of naltrexone among methamphetamine-using and binge-drinking MSM. Polysubstance use patterns are common among MSM, and studies among those who abuse more than one substance are urgently needed. The aims of this study are to determine whether targeted dosing of naltrexone is feasible, tolerable and acceptable among non-dependent methamphetamine-using and binge-drinking MSM.
Drug: Intermittent Oral Naltrexone
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
- Feasibility [ Time Frame: proportions eligible and enrolled assessed on ongoing basis throughout the study, proportion of visits completed assessed bi-weekly for each participant; overall retention assessed over 2 month follow-up for each participant ] [ Designated as safety issue: No ]Proportion of persons screened who are eligible and enrolled; proportion of scheduled study visits completed; final retention by study arm.
- Tolerability [ Time Frame: at each bi-weekly visit throughout the 2 month follow-up for each participant ] [ Designated as safety issue: Yes ]Comparison of adverse events in the naltrexone and placebo arms.
- Acceptability [ Time Frame: adherence assessed daily through electronic monitoring, pill count and self-report assessed at bi-weekly visits over the course of 2 month follow-up ] [ Designated as safety issue: No ]Adherence to naltrexone and placebo, as determined via electronic monitoring device (WisePill) data, pill count, and self-report.
- Methamphetamine use and drinking outcomes [ Time Frame: assess at baseline, month 1 and month 2 visits ] [ Designated as safety issue: No ]
- Sexual Behaviors [ Time Frame: assessed at baseline, month 1 and 2 visits ] [ Designated as safety issue: No ]
|Study Start Date:||May 2013|
|Study Completion Date:||November 2014|
|Primary Completion Date:||October 2014 (Final data collection date for primary outcome measure)|
Active Comparator: Naltrexone
Intermittent oral naltrexone to be taken on an as-needed basis for 8 weeks.
|Drug: Intermittent Oral Naltrexone|
Placebo Comparator: Placebo
Intermittent oral placebo to be taken on an as-needed basis for 8 weeks
Please refer to this study by its ClinicalTrials.gov identifier: NCT01723384
|United States, California|
|San Francisco Department of Public Health, Substance Use Research Unit|
|San Francisco, California, United States, 94102|
|Principal Investigator:||Glenn-Milo Santos, PhD||University of California, San Francisco|
|Study Director:||Jason Euren, MA||San Francisco Department of Public Health|