Conditions: Cocaine Abuse
Keywords: Aripiprazole Cocaine abuse
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 26
Healthy volunteers: yes

Brief summary:
The purpose of this study is to investigate whether aripiprazole will decrease cocaine self-administration, subjective effects and cravings compared to placebo.

Detailed description:
Despite the recent increase in data about cocaine's basic neurochemical mechanisms of action, progress towards the development of an effective pharmacological treatment for cocaine abuse has been disappointing. We are proposing to use our laboratory model of repeated dose cocaine self-administration to assess the potential efficacy of the novel antipsychotic, aripiprazole. Aripiprazole is a partial agonist at both the dopamine D2 receptor and at the serotonin 5HT1a receptor, while antagonizing the 5HT2a receptor. By functioning as a partial D2 agonist, aripiprazole is hypothesized to function as a D2 antagonist during hypodopaminergic states, such as during cocaine use, while functioning as a D2 agonist during hypodopaminergic states, such as during cocaine withdrawal. This 42-day, outpatient/inpatient/outpatient/inpatient protocol will evaluate the effects of aripiprazole maintenance (0, 15 mg/day) on cocaine craving, subjective effects, and self-administration using a within-subjects design. Non-treatment seeking cocaine abusers will be maintained outpatient for 16 days of dose maintenance prior to inpatient cocaine self-administration sessions. During the inpatient phases, volunteers will live on a hospital clinical research unit and will participate in laboratory sessions in which they will have the opportunity to choose between repeated doses of smoked cocaine and $5. In addition to measuring their cocaine self-administration, we will measure the cardiovascular and subjective effects of cocaine under each aripiprazole maintenance condition.

Arms:
arm 1: Aripiprazole (15 mg/day) in conjunction with a smoked cocaine dose-response curve (0, 12, 25, 50 mg). arm 2: Placebo (0 mg/day) in conjunction with a smoked cocaine dose-response curve (0, 12, 25, 50 mg)

Interventions: intervention 1: Aripiprazole + Cocaine intervention 2: Placebo + Cocaine
Intervention descriptions: intervention 1: Participants received aripiprazole (15mg/day) in conjunction with a dose-response of cocaine (0, 12, 25, 50 mg). intervention 2: Placebo (0 mg/day) in conjunction with a dose-response of cocaine (0, 12, 25, 50 mg).

Protocol document: