A multi-site, double-blind, placebo-controlled pilot clinical trial to evaluate the efficacy of buspirone as a relapse-prevention treatment for cocaine dependence

Objective—To evaluate the potential efficacy of buspirone as a relapse-prevention treatment for cocaine dependence. Method—A randomized, double-blind, placebo-controlled, 16-week pilot trial conducted at six clinical sites between August 2012 and June 2013. Adult crack cocaine users meeting DSM-IVTR criteria for current cocaine dependence scheduled to be in inpatient/residential substance use disorder (SUD) treatment for 12–19 days when randomized, and planning to enroll in local outpatient treatment through the end of the active treatment phase were randomized to buspirone titrated to 60 mg/day (n=35) or to placebo (n=27). All participants received psychosocial treatment as usually provided by the SUD treatment programs in which they were enrolled. Outcome measures included maximum days of continuous cocaine abstinence (primary), proportion of cocaine use days, and days-to-first-cocaine-use during the outpatient treatment phase (study weeks 4–15) as assessed by self-report and urine drug screens. Results—There were no significant treatment effects on maximum continuous days of cocaine abstinence or days to first cocaine use. In the females (n=23), there was a significant treatment-bytime interaction effect (X2 (1)=6.06, p=.01), reflecting an increase in cocaine use by the buspirone, relative to placebo, participants early in the outpatient treatment phase. A similar effect was not detected in the male participants (n=39; X2 (1)=0.14, p=.70). Conclusions—The results suggest that buspirone is unlikely to have a beneficial effect on preventing relapse to cocaine use and that buspirone for cocaine-dependent women may worsen their cocaine-use outcomes. Trial Registration—Clinical Trials.gov http://www.clinicaltrials.gov; Identifier: NCT0164115