Feasibility as Assessed by Number of Participants Enrolled
Time frame · Week 0
Enrollment will be assessed by the number of participants signing the informed consent.
Feasibility as Assessed by Number of Study Visits Attended
Time frame · From Week 1 to Week 6
There were 6 study visits planned.
Feasibility as Assessed by Retention as Indicated by Total Number of Completed Study Visits
Time frame · From Week 1 to Week 6
Retention will be assessed by the total number of completed study visits. A completed study visit is a visit in which the participant attended and received the study treatment.
Feasibility as Indicated by Overall Acceptability as Reported on the Satisfaction Survey
Time frame · Week 6
The Satisfaction Survey includes a 9-point likert scale that ranges from 1 to 9, with a higher score indicating greater acceptability.
Clinical Effect of Exenatide as Assessed by Number of Participants Who Self-reported Cocaine Use on 50% or More Days of the Week
Time frame · From Week 1 to Week 6
Timeline Followback (TLFB) administered once weekly.
Clinical Effect of Exenatide as Indicated by Number of Participants Who Reported a Reduction in Craving by Week 6 as Indicated by Cocaine Craving on the Brief Substance Craving Scale
Time frame · From Week 0 to Week 6
The brief substance craving scale (BSCS) is a 16-item, self-report instrument that assesses craving for cocaine and other substances of abuse over a 24 hour period. The domains of intensity, frequency, and duration are recorded on a five-point Likert scale. The range of scores for each domain is 0 to 4, and the total score is the sum of all three domains. The total score range is 0 to 12, and higher scores indicate higher craving (worse outcome.)
Clinical Effect of Exenatide as Assessed by Number of Participants Who Had a Decrease in Drug Demand by Week 6
Time frame · From Week 0 to Week 6
Drug demand will be measured by the computerized Cocaine Purchasing Task (CPT). The CPT asks participants how much cocaine they would purchase at the beginning of a hypothetical day as the cost of cocaine increases from $0 to $1,000. The CPT simulates changes in price and consumption of drug in order to assess demand curves associated with drug consumption. The CPT will assess both cocaine reward value as well as motivation to consume cocaine.
Clinical Effect of Exenatide as Assessed by Number of Participants Who Were Below the Clinical Range for Depression by Week 6 as Indicated by the Beck Depression Inventory
Time frame · Week 6
The Beck Depression Inventory score ranges from 0 to 63, with a higher score indicating greater depressive symptoms. The scores from each timepoint will be plotted as a trend line.
Clinical Effect of Exenatide as Indicated by Number of Participants Who Had an Increase in Positive Affect Symptoms by Week 6 as Indicated on the Positive/Negative Affect Schedule
Time frame · From Week 0 to Week 6
The Positive/Negative Affect Schedule is a 20-item questionnaire divided into 10 positive affect items and 10 negative affect items. The score for the positive affect items ranges from 10 to 50, with a higher score indicating higher levels of positive affect. The scores from each timepoint will be plotted as a trend line.
Clinical Effect of Exenatide as Indicated by Number of Participants Who Had a Decrease in Negative Affect Symptoms Indicated on the Positive/Negative Affect Schedule
Time frame · From Week 0 to Week 6
The Positive/Negative Affect Schedule is a 20-item questionnaire divided into 10 positive affect items and 10 negative affect items. The score for the negative affect items ranges from 10 to 50, with a lower score indicating lower levels of negative affect. The scores from each timepoint will be plotted as a trend line.