Ability of Aprepitant to Block Opioid Reward in Non-Dependent Opiate Abusers

Study Overview
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Brief Summary
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The objective of this study is to determine whether aprepitant blocks the opiate reward system in non-dependent opiate abusers, indicating its potential as a safe, non-addictive first line therapy for early heroin abuse.

Detailed Description
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This initial proof-of-concept study focuses on evaluating whether an NK1 antagonist, aprepitant, can block opiate reward in non-dependent opiate experienced volunteers in response to a standard opiate challenge. Sixty subjects will be included in a randomized controlled study. Following a training challenge session, they will receive 1 week treatment with aprepitant or matching placebo, followed by a challenge session during which subjective and physiological responses to the opiate partial agonist buprenorphine will be assessed.

Official Title
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Modulation of Opiate Reward by NK1 Antagonism: A Laboratory-Based Proof of Concept Study

Conditions
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Opioid-Related Disorders, Heroin Dependence, Substance-Related Disorders

Intervention / Treatment
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* Drug: aprepitant
* Drug: Pseudo-placebo - buprenorphine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 - 50 Current opiate use, without dependence Exclusion Criteria: Clinical diagnosis of opiate dependence Positive urine screen for opiates on day of challenge sessions Meet diagnostic criteria for any other substance abuse disorder except nicotine within the last 12 months. Any ongoing prescription medication other than oral contraceptives or hormone replacement Any serious medical condition which in the judgment of the investigators makes administration of opiates medically inappropriate.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Aprepitant | Drug: aprepitant<br>* Oral, 125 mg once daily for one week<br>* Other names: Emend;|
| Placebo Comparator: 2<br>Placebo | Drug: Pseudo-placebo - buprenorphine<br>* Randomized to receive either 8 mg sublingual tablets or 0.4 mg sublingual tablets<br>* Other names: Subutex;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome will be self-reported pleasurable opiate effect. |  | One week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The secondary outcome will be physiological opiate responses. |  | One week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heroin abuse, Opioids, Opiates, Substance abuse, Addiction