Aim This study tested three dopaminergic medications against a common unmatched placebo condition: hydergine 1 mg three times daily (n = 15); levodopa/carbidopa 25/100 mg three times daily (n = 15); cabergoline 0.5 mg per week (n = 15); and placebo three times daily (n = 15) as potential pharmacotherapies for cocaine dependence.
Design The four-parallel group, Cocaine Rapid Efficacy Screening Trial (CREST) design featured a 2-week baseline period followed by randomization to an 8-week medication condition that included 1 hour per week of cognitive behavioral drug counseling. A safety evaluation was conducted 4 weeks after termination.
Measures Outcomes included cocaine metabolites measured in urine, retention and self-reports for drug use, cocaine craving, clinical improvement, mood and HIV risk behaviors.
Results Participants assigned to receive cabergoline provided more urine samples negative for cocaine metabolites (42.4%) than those assigned to receive placebo (25.0%), a statistically significant difference after controlling for baseline differences in self-reported cocaine use (F = 2.95, df = 3; P = 0.05). Cabergoline-treated participants demonstrated a significant improvement over placebo from baseline to week 8 when measured using the Addiction Severity Index (ASI) employment subscale (overall change = − 0.09, SD = 0.10, t = 2.36, P < 0.05). Safety and adverse event measures showed similar rates and types of complaints by treatment condition.
Conclusions These results, combined with the apparent safety of cabergoline when used with this population, provide empirical support for conducting a larger study of the medication.