Glutamatergic Modulation of Cocaine-related Deficits

Brief Summary

Cocaine dependence involves problematic neuroadaptations, such as heightened reactivity to cocaine cues, that may be responsive to pharmacological modulation of glutamatergic circuits. Despite promising preclinical findings with n-methyl-d-aspartate receptor (NMDAr) modulators, studies with human subjects have been unsuccessful to date. The purpose of this investigation is to examine the effects of the NMDAr antagonist ketamine, recently found to have potent therapeutic effects in humans, on cue-induced craving and impaired motivation for quitting cocaine in cocaine dependent participants, 24-hours post-infusion.

Intervention / Treatment

  • Ketamine 0.41 mg/kg (DRUG)
    52 minute iv infusion of ketamine 0.41 mg/kg
  • Ketamine 0.71 mg/kg (DRUG)
    52 minute iv infusion of ketamine 0.71 mg/kg. This dose follows K1 in all 3 orderings.
  • Lorazepam 2 mg (DRUG)
    52 minute infusion of lorazepam 2 mg. This serves as an active control.

Condition or Disease

  • Cocaine Dependence

Phase

  • Phase 2
  • Study Design

    Study type: INTERVENTIONAL
    Status: Completed
    Study results: No Results Available
    Age: 21 Years to 52 Years
    Enrollment: 8 (ACTUAL)
    Funded by: Other
    Allocation: Randomized
    Primary Purpose: Treatment

    Masking

    TRIPLE:
    • Participant
    • Investigator
    • Outcomes Assessor

    Clinical Trial Dates

    Start date: Feb 01, 2011
    Primary Completion: Mar 01, 2012 ACTUAL
    Completion Date: Mar 01, 2012 ACTUAL
    Study First Posted: Feb 13, 2013 ESTIMATED
    Results First Posted: Jun 27, 2016 ESTIMATED
    Last Updated: Apr 16, 2019

    Sponsors / Collaborators

    Responsible Party: N/A

    In this study, volunteers will undergo a 9 day inpatient trial during which they will receive three counter-balanced infusions (two doses of ketamine and a dose of lorazepam) on three separate days in a within-subject, double-blind, controlled design. Of the various glutamate antagonists available for human use, ketamine will be utilized because its safety profile, pharmacokinetics, and range of tolerable sub-anesthetic dosings have been very well studied. Also, ketamine has shown promise in managing opiate and alcohol use disorders in certain studies, and may therefore be the most likely glutamate antagonist to dampen cue reactivity and increase motivation in cocaine users. If ketamine significantly improves these deficits, this would suggest that the drug should be investigated further for potential utility as a treatment for cocaine dependence.

    Participant Groups

    • Ketamine 0.41 mg/kg infused over 52 min (K1)

    • Ketamine 0.71 mg/kg infused over 52 min (K2)

    • Lorazepam 2 mg infused over 52 minutes (LZP)

    Eligibility Criteria

    Sex: All
    Minimum Age: 21
    Maximum Age: 52
    Age Groups: Adult
    Healthy Volunteers: Yes

    Inclusion Criteria

    1. Active free-base cocaine dependence (at least 4 days of use over the past month, with at least 1 use per week); if the participant uses through another route (IN, IV), then the FB route is dominant (\> 80% of occasions).
    2. Physically healthy
    3. No adverse reactions to study medications
    4. 21-52 years of age
    5. Normal body weight
    6. Responsive to drug cues
    7. Capacity to consent

    Exclusion Criteria:

    1. Seeking treatment or abstinence
    2. DSM IV criteria for substance dependence (other than methamphetamine, cocaine, cannabis, or nicotine), or DSM IV criteria for abuse of ketamine or lorazepam
    3. DSM-IV criteria for other Axis I psychiatric illness that may make participation hazardous such as schizophrenia, schizoaffective disorder, psychosis NOS, MDD, psychosis secondary to substances, or bipolar disorder
    4. Delirium, Dementia, Amnesia, Cognitive Disorders, or dissociative disorders
    5. Current suicide risk or a history of suicide attempt within the past 2 years
    6. Current use of prescribed psychotropic medication
    7. Pregnancy, nursing, or had a baby within the past 6 mo.
    8. Heart disease as indicated by history, abnormal ECG, previous cardiac surgery.
    9. Unstable physical disorders which might make participation hazardous such as end-stage AIDS, hypertension (\>140/90), anemia, active hepatitis or other liver disease, or diabetes
    10. "Bad" reaction/experience with prior exposure to ketamine or lorazepam
    11. History of significant violence
    12. First degree relative with a psychotic disorder

    Primary Outcomes
    • Serial visual analogue scale (VAS) scores for craving elicited by cocaine cue: units on a scale (0-200), high is worse. Scores are obtained at baseline and at 24 hours after the infusion.

    • Motivation score obtained from the University of Rhode Island Change Assessment (URICA). Scores are obtained at baseline and at 24 hours after each infusion. The scores are 0-13, with higher scores indicating greater motivation. The analysis is within-subject. Scores included below are means; higher scores represent higher motivation to quit than do lower scores.

    More Details

    NCT Number: NCT01790490
    Other IDs: #6162
    Study URL: https://clinicaltrials.gov/study/NCT01790490
    Last updated: Sep 29, 2023