Topiramate for the Treatment of Dually Dependent on Opiates and Cocaine: A Single-center Placebo-controlled Trial.

Background: Topiramate facilitates gamma aminobutyric acid (GABA) transference and an ideal candidate for reducing cocaine use in methadone patients. The present study evaluated topiramate in Dual dependence on opiate and cocaine.

Methods: This placebo-controlled study (Clinical Trial Registration Code: TCTR20170201001) conducted during the period 2013-2014, Cocaine-dependent individuals maintained on methadone (n=50) were randomized to receive topiramate or identical placebo capsules. Participants' dosage ranged between 25-300 mg/day (12 wk) in escalating doses. Methadone Doses started at 30 mg/day (median 100 mg/day; range 20 -140 mg/day). In addition, all subjects received brief behavioral compliance enhancement treatment (BBCET). The data were analyzed by Chi-square Test, generalized estimating equations (GEE) models, linear mixed effects (LME) model and Analysis of covariance (ANCOVA). Primary outcome measures included twelve weekly urine drug screens (cocaine abstinence, detection of benzoylecgonine) and treatment retention. Secondary outcome measures included correlation between cocaine craving with cocaine urine samples and Side effects of depression.

Results: Topiramate was not better than placebo in reducing cocaine use. The secondary outcome showed that Topiramate was better than placebo in reducing cocaine craving. The mean [99% confidence interval (CI)] scores of cocaine craving were 24.31 (18.61-30.01) in experimental group and 21.84 (16.86-26.81) in control group (all > 0.01). Retention and correlation between cocaine craving and cocaine urine samples were not significantly different between the groups. Topiramate usage was not associated with increase in depression symptoms as a side effect (>0.05).

Conclusion: The efficacy of topiramate in cocaine treatment is limited and needs the similar controlled clinical trials and can be used as a complementary intervention.