This review is an update of a previous Cochrane review published in 2007. We searched up to 15 July 2015 in Cochrane Drugs and Alcohol Group Specialised Register (searched in CRSLive); the Cochrane Library (including the Cochrane Central Register of Controlled Trials (CENTRAL); the Database of Abstracts of Reviews of Effects (DARE)); PubMed; EMBASE; CINAHL and Web of Science. All searches included non-English language literature.
SELECTION CRITERIA: We used standard methodological procedures expected by Cochrane.
MAIN RESULTS: We included 14 studies (719 participants). The
antipsychotic drugs studied were
risperidone,
olanzapine,
quetiapine,
lamotrigine,
aripiprazol,
haloperidol and
reserpine. Comparing any
antipsychotic drugs versus placebo, we found that
antipsychotics reduced dropout: eight studies, 397 participants, risk ratio (RR) 0.75 (95% confidence interval (CI) 0.57 to 0.97), moderate quality of evidence. We found no significant differences for any of the other primary outcomes considered: number of participants using
cocaine during the treatment, two studies, 91 participants: RR 1.02 (95% CI 0.65 to 1.62); continuous abstinence, three studies, 139 participants: RR 1.30 (95% CI 0.73 to 2.32); side effects, six studies, 291 participants: RR 1.01 (95% CI 0.93 to 1.10); and craving, four studies, 240 participants: RR 0.13 (-1.08 to 1.35). For all of these comparisons we rated the quality of evidence as low.Comparisons of single
drug versus placebo or versus another
drug are conducted in few trials with small sample sizes, limiting the reliability of the results. Among these comparisons, only
quetiapine seemed to outperform placebo in reducing
cocaine use, measured by grams per week: mean difference (MD) -0.54 (95% CI -0.92 to -0.16), by US dollars spent per week: MD -53.80 (95% CI -97.85 to -9.75), and by craving: MD -1.23 (95% CI -2.19 to -0.27), but results came from one study with 60 participants.The major limitations of the studies were the high risk of attrition bias (40% of the included studies) and low quality of reporting, mainly for the risk of selection bias, performance and detection bias, that we rated as being at unclear risk for 75% to 80% of the studies. Furthermore, most of the included studies did not report results on important outcomes such as side effects, or use of
cocaine during treatment and craving, which prevented the possibility of including them in statistical synthesis.
AUTHORS' CONCLUSIONS: At present, there is no evidence supporting the clinical use of
antipsychotic medications in the treatment of
cocaine dependence, although results come from only 14 trials, with small sample sizes and moderate to low quality of evidence.