Aprepitant Effects in Intravenous Heroin Dependence

Study Overview
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Brief Summary
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Current treatments for opioid addiction would benefit by the addition of a non-opioid based treatment medication. Recent behavioral studies have shown that the neurokinin-1 (NK1) receptor is involved in opioid reward and withdrawal. This study proposes to study a potential non-opioid treatment, the clinically available, FDA approved, NK1 antagonist aprepitant, in opioid addicted patients. Based on the unique behavioral and pharmacological characteristics of opioid addiction, and what is known of the currently employed treatments, the investigators propose that the therapeutic mechanism of any potential opioid addiction treatment medication must include the ability to reduce opioid withdrawal. This is of particular importance during treatment initiation (eg. detoxification). In addition, for long-term treatment and relapse prevention, it is important to manage drug craving and inhibit the rewarding effects of opioids if patients do experience a slip. Therefore, the investigators propose to study aprepitant using human models of opioid withdrawal, craving and acute opioid reward and reinforcement. The investigators will also include a neuro-economics choice procedure paradigm.

Official Title
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Clinical Laboratory Evaluations of Aprepitant for the Treatment of Opioid Dependence: Inpatient Test

Conditions
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Opioid Dependence

Intervention / Treatment
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* Drug: Aprepitant
* Drug: Placebo pill


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female subjects ranging in age from 18-55 years who are currently opioid dependent based on meeting DSM-IV criteria for dependence on heroin and who are either treatment or non-treatment seeking individuals. Use of intravenous heroin daily for a minimum of 45 days prior to study entry. Urine sample (+) for opioids and prior experience with i.v. drug injection. Female subjects who are not of childbearing potential, (i.e. post-hysterectomy, or two years post-menopausal) or who are of childbearing potential but will either abstain from heterosexual intercourse and/or practice a medically accepted form of contraception for the study duration. Subjects who have experienced significant opioid withdrawal and are familiar with its effects. Subjects who are willing to follow the protocol requirements, including methadone and study medication schedules, as evidenced by written informed consent and an ability to read, understand, and complete the study questionnaires. Exclusion Criteria: Subjects with any significant current axis-1 psychiatric problems, other than those related to drug abuse and opioid dependence, based on a structured psychiatric interview, SCID or MINI, during the screening process. Subjects undergoing active treatment for any illness other than chronic stable medical conditions (Patients with HIV and/or taking anti-viral HIV medication without a manifestation of AIDS symptoms are allowed). Subjects with clinically significant abnormal findings as determined by medical history, physical examination, vital signs (blood pressure, heart rate, and respiration rate), 02 saturation measure,12-lead ECG, clinical laboratory tests (CBC, chemistry panel), urine drug screen, alcohol breath test, and urine pregnancy test (for females of childbearing potential only). Subjects who have any acute organ dysfunction or serious unstable disease states including symptomatic heart, renal or liver disease, COPD, sleep apnea, or encephalitis. Subjects with 02 saturation below 90% at screening. Subjects taking any concomitant medications (prescription and over-the-counter therapy) including psychotropic medications for the treatment of current major depression, schizophrenia, or mood disorders, as well as medications contraindicated for use with morphine, naltrexone, aprepitant, or methadone. Subjects who have received any investigational drug or treatment within the thirty (30) days preceding administration of study medication. Females who are nursing, pregnant (as confirmed by a positive urine pregnancy test), or at risk of becoming pregnant. Subjects allergic or intolerant to morphine, methadone, naloxone, or aprepitant.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Aprepitant 125 mg<br>Day Number Dose Procedure Day 0 Aprepitant 125mg Admitting Medication Treatment Day 1 Aprepitant 125mg Saline-Saline Day 2 Aprepitant 125mg Morphine-Morphine Day 3 Aprepitant 125mg Saline-Morphine Day 4 Aprepitant 125mg Naloxone-Morphine and Discharge | Drug: Aprepitant<br>* Aprepitant 125 mg oral tablets<br>* Other names: Brand name: Emend;|
| Placebo Comparator: Placebo<br>Day Number Dose Procedure Day 0 placebo Admitting Medication Treatment Day 1 placebo Saline-Saline Day 2 placebo Morphine-Morphine Day 3 placebo Saline-Morphine Day 4 placebo Naloxone-Morphine and Discharge | Drug: Placebo pill<br>* Placebo oral pill- inactive compound<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioid Withdrawal | On the 4 dosing days, opioid withdrawal will be measured using the Clinical Opiate Withdrawal Scale (COWS) and the Subjective Opioid Withdrawal Scale (SOWS) at the following time points: 30 minutes pre-medication, 150 minutes post medication, 15 minutes post-challenge drug administration, 1 hour post- challenge drug administration, 2 hours post challenge drug administration and 3.5 hours post challenge drug administration | 30 minutes pre-medication, 150 minutes post medication, 15 minutes post-challenge drug administration, 1 hour post- challenge drug administration, 2 hours post challenge drug administration and 3.5 hours post challenge drug administration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioid Intoxication | On the 4 dosing days, opioid intoxication will be measured using the Visual Anaglog Scale (VAS)at the following time points: 30 minutes pre-medication, 150 minutes post medication, 15 minutes post-challenge drug administration, 1 hour post- challenge drug administration, 2 hours post challenge drug administration and 3.5 hours post challenge drug administration | 30 minutes pre-medication, 150 minutes post medication, 15 minutes post-challenge drug administration, 1 hour post- challenge drug administration, 2 hours post challenge drug administration and 3.5 hours post challenge drug administration | 
| Neuro-economic Choice Procedure | A neuro-economics collaborative team will perform a neuro-economic choice paradigm procedure at 45 minutes post challenge drug dosing to determine the relative proportion and amount of a further dose of drug at 3.5 hours post challenge drug administration versus receipt of a variable amount of money | 45 minutes post challenge drug dosing | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Aprepitant, Intravenous heroin dependence