Reinforcing Effects of Cocaine During Phendimetrazine Maintenance

Study Overview
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Brief Summary
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This study will determine the initial efficacy of phendimetrazine as a pharmacotherapy for cocaine dependence. A rigorous, inpatient human laboratory study will be conducted in which the subjective, physiological and reinforcing effects of cocaine are evaluated during maintenance on placebo and phendimetrazine.

Official Title
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Behavioral Effects of Drugs (Inpatient): 31 (Cocaine and Phendimetrazine)

Conditions
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Cocaine Use Disorder

Intervention / Treatment
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* Drug: Phendimetrazine
* Drug: Cocaine
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Recent cocaine use Exclusion Criteria: Abnormal screening outcome (e.g., ECG, blood chemistry result) that study physicians deem clinically significant Current or past histories of substance abuse or dependence that are deemed by the study physicians to interfere with study completion History of serious physical disease, current physical disease, impaired cardiovascular functioning, chronic obstructive pulmonary disease, history of seizure or current or past histories of serious psychiatric disorder that in the opinion of the study physician would interfere with study participation will be excluded from participation Females not currently using effective birth control Contraindications to cocaine or phendimetrazine

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Subjects will be maintained on oral placebo, administered twice daily for approximately two weeks. Cocaine will be administered acutely during placebo maintenance. Placebo will be administered acutely during placebo maintenance. | Drug: Cocaine<br>* Intranasal cocaine will be administered during experimental sessions.<br>Drug: Placebo<br>* Placebo capsules will contain only cornstarch.<br>|
| Experimental: Phendimetrazine<br>Subjects will be maintained on oral phendimetrazine (up to 210 mg/day) administered twice daily for approximately two weeks. Cocaine will be administered acutely during placebo maintenance. Placebo will be administered acutely during placebo maintenance. | Drug: Phendimetrazine<br>* Phendimetrazine will be administered in divided doses twice daily.<br>* Other names: Bontril;Drug: Cocaine<br>* Intranasal cocaine will be administered during experimental sessions.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Times Cocaine Was Selected in the Presence of a Monetary Reward Alternative | The reinforcing effects of cocaine were determined using a modified progressive ratio procedure in which subjects made 10 choices between a portion of each available cocaine dose and money (US$0.25). Reinforcing effects are measured for each cocaine dose during both phendimetrazine and placebo maintenance. | After at least seven days of maintenance placebo or target phendimetrazine dose |