Reinforcing Effects of Cocaine During Phendimetrazine Maintenance

• Phendimetrazine (Drug), also known as Bontril: Phendimetrazine will be administered in divided doses twice daily.
• Cocaine (Drug): Intranasal cocaine will be administered during experimental sessions.
• Placebo (Drug): Placebo capsules will contain only cornstarch.

Primary outcomes

• Number of Times Cocaine Was Selected in the Presence of a Monetary Reward Alternative [After at least seven days of maintenance placebo or target phendimetrazine dose]: 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.

Sex: All, ages: 18 Years to 55 Years, accepts healthy volunteers

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

Participant flow

Outcome results

• Number of Times Cocaine Was Selected in the Presence of a Monetary Reward Alternative (Primary), Mean, Cocaine Choices: Placebo .34 +/- .34; Phendimetrazine .24 +/- .15

Adverse events

Time frame: Approximately 1 month of inpatient admission

• Study Protocol and Statistical Analysis Plan (PDF, 2015-07-02)

NIH grants: R01DA036553