A Cochrane review included 7 studies with a total of 492 subjects. The studies differ for design, quality, characteristics of patients, services and treatments delivered. Drug counselling, cognitive behavior therapy, Twelve Step Facilitation, or individual psychotherapy were offered as ancillary interventions. There were no statistically significant results for dropouts but a trend favouring disulfiram compared to placebo or naltrexone (RR 0.82, 95% CI 0.66 to 1.03; 2 trials, n=87 and RR 0.67, 95% CI 0.45 to 1.01; 3 trials, n=131 respectively). For cocaine use, 1 out of 4 studies was in favour of disulfiram compared to placebo (number of weeks abstinence, WMD 4.50, 95% CI 2.93 to 6.07; n=20). No significant difference for cocaine use in comparison of disulfiram vs naltrexone was seen in the only study that considered this outcome. Disulfiram improved the abstinence of cocaine use compared to no pharmacological treatment in one trial with 90 participants (number of subjects achieving 3 or more weeks of consecutive abstinence, RR 1.88, 95% CI 1.09 to 3.23). The duration of the trials was 11 to 12 weeks. Adverse effects and the potential toxicity coming from the interaction between disulfiram and cocaine, were not studied.
Comment: The quality of evidence is downgraded by several shortcomings in study quality , by inconsistency (heterogeneity in interventions and outcomes), and by imprecise results (limited study size for each comparison) .