Intermittent Naltrexone Among Polysubstance Users (Project iN)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01723384
Recruitment Status : Completed
First Posted : November 7, 2012
Last Update Posted : December 16, 2014
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
Glenn-Milo Santos, University of California, San Francisco

November 2, 2012
November 7, 2012
December 16, 2014
May 2013
October 2014   (Final data collection date for primary outcome measure)
  • 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 ]
    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 ]
    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 ]
    Adherence to naltrexone and placebo, as determined via electronic monitoring device (WisePill) data, pill count, and self-report.
Same as current
Complete list of historical versions of study NCT01723384 on Archive Site
  • Methamphetamine use and drinking outcomes [ Time Frame: assess at baseline, month 1 and month 2 visits ]
  • Sexual Behaviors [ Time Frame: assessed at baseline, month 1 and 2 visits ]
Same as current
Not Provided
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Intermittent Naltrexone Among Polysubstance Users
Not Provided
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.
Not Provided
Phase 2
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
  • Methamphetamine
  • Alcohol
  • Drug: Intermittent Oral Naltrexone
  • Drug: Placebo
  • Active Comparator: Naltrexone
    Intermittent oral naltrexone to be taken on an as-needed basis for 8 weeks.
    Intervention: Drug: Intermittent Oral Naltrexone
  • Placebo Comparator: Placebo
    Intermittent oral placebo to be taken on an as-needed basis for 8 weeks
    Intervention: Drug: Placebo
Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
November 2014
October 2014   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  1. male gender or transgender male-to-female
  2. self-reported anal sex with men in the prior six months while under the influence of meth and/or alcohol
  3. self-reported meth use at least bi-weekly in the prior three months
  4. at least weekly binge drinking (five or more drinks on a single drinking session) in the prior three months

4) interested in reducing meth use and/or binge drinking 5) HIV-negative by rapid test or medical record of HIV infection 6) no current acute illnesses requiring prolonged medical care 7) no chronic illnesses that are likely to progress clinically during trial participation 8) able and willing to provide informed consent and adhere to visit schedule 9) age 18-70 years 10) baseline complete blood count (CBC), total protein, albumin, glucose, alkaline phosphatase, creatinine, blood urea nitrogen (BUN), and electrolytes without clinically significant abnormalities as determined by study clinician in conjunction with symptoms, physical exam, and medical history

Exclusion Criteria:

  1. any psychiatric (e.g., depression with suicidal ideation) or medical condition that would preclude safe participation in the protocol
  2. known allergy or previous adverse reaction to naltrexone
  3. current use of or dependence on any opioids or a known medical condition which currently requires or may likely require opioid analgesics
  4. opioid-positive urine test at enrollment
  5. current cluster of differentiation 4 (CD4) count < 200 cells/mm3
  6. moderate or severe liver disease (aspartate aminotransferase, alanine aminotransferase, or total bilirubin > 3 times upper limit of normal)
  7. impaired renal function (creatinine clearance < 60 ml/min)
  8. currently participating in another research study
  9. meth or alcohol dependence as determined by Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (SCID) criteria
  10. any condition that, in the principal investigator and/or study clinician's judgment interferes with safe participation or adherence to study procedures.
  11. unwillingness to provide minimum locator for information
  12. not having a cellular phone that can send or receive a text message
  13. plans to leave the Bay Area during study follow-up
  14. not comfortable speaking and reading English, enough to participate in a program in English
Sexes Eligible for Study: Male
18 Years to 70 Years   (Adult, Older Adult)
Contact information is only displayed when the study is recruiting subjects
United States
R36DA035109-01 ( U.S. NIH Grant/Contract )
Not Provided
Not Provided
Glenn-Milo Santos, University of California, San Francisco
University of California, San Francisco
National Institute on Drug Abuse (NIDA)
Principal Investigator: Glenn-Milo Santos, PhD University of California, San Francisco
Study Director: Jason Euren, MA San Francisco Department of Public Health
University of California, San Francisco
December 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP