Topiramate impairs cognitive function in methadone-maintained individuals with concurrent cocaine dependence

Neurovascular effects of cocaine: relevance to addiction

Cocaine is a highly addictive drug, and its use is associated with adverse medical consequences such as cerebrovascular accidents that result in debilitating neurological complications. Indeed, brain imaging studies have reported severe reductions in cerebral blood flow (CBF) in cocaine misusers when compared to the brains of healthy non-drug using controls. Such CBF deficits are likely to disrupt neuro-vascular interaction and contribute to changes in brain function. This review aims to provide an overview of cocaine-induced CBF changes and its implication to brain function and to cocaine addiction, including its effects on tissue metabolism and neuronal activity. Finally, we discuss implications for future research, including targeted pharmacological interventions and neuromodulation to limit cocaine use and mitigate the negative impacts.

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 P > 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 (P>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.

Efficacy and safety of adjunctive topiramate for schizophrenia: a meta-analysis of randomized controlled trials

OBJECTIVE

To systematically examine the randomized controlled trial (RCT) evidence regarding efficacy and tolerability of topiramate cotreatment with antipsychotics in schizophrenia-spectrum disorders.

METHODS

Random-effects meta-analysis of RCTs of topiramate cotreatment with antipsychotics vs. placebo/ongoing antipsychotic treatment in schizophrenia-spectrum disorders. Standardized or weighted mean difference (SMD/WMD), risk ratio (RR) ±95% confidence intervals (CIs), and number needed to harm (NNH) were calculated.

RESULTS

Across 16 RCTs (n = 934, duration = 11.8 ± 5.6 weeks), topiramate outperformed the comparator regarding change/endpoint of total (SMD: -0.58, 95% CI: -0.82, -0.35, P < 0.00001), positive (SMD: -0.37, 95% CI: -0.61, -0.14, P = 0.002), negative (SMD: -0.58, 95% CI: -0.87, -0.29, P < 0.0001), and general symptoms (SMD: -0.68, 95% CI: -0.95, -0.40, P < 0.00001). Furthermore, topiramate was superior regarding body weight (WMD: -2.75 kg, 95% CI: -4.03, -1.47, P < 0.0001), body mass index (BMI) (WMD: -1.77, 95% CI: -2.38, -1.15, P < 0.00001), triglycerides (P = 0.006), and insulin levels (P < 0.00001). Superiority regarding psychopathology and body weight/BMI was consistent across Chinese/Asian and Western RCTs, double-blind and open designs, clozapine and non-clozapine cotreatment, augmentation and co-initiation RCTs, and higher and lower quality RCTs. In meta-regression analyses, topiramate's efficacy for total symptoms was moderated by shorter illness duration (P = 0.047), while weight loss was greater in prevention/co-initiation vs. intervention/augmentation RCTs (-4.11 kg, 95% CI: -6.70, -1.52 vs. -1.41 kg, 95% CI: -2.23, -0.59, P < 0.001). All-cause discontinuation was similar between topiramate and comparators (RR: 1.28, 95% CI: 0.91, 1.81, P = 0.16). While topiramate led to more concentration/attention difficulties (P = 0.03, NNH = 8, 95% CI=4-25), psychomotor slowing (P = 0.02, NNH = 7, 95% CI = 4-25), and paresthesia (P = 0.05, NNH = 2, 95% CI = 4-33), it led to less ≥7% weight gain (P = 0.0001, NNH = 2, 95% CI = 2-3) and constipation (P = 0.04, NNH = 9, 95% CI = 5-100) than the comparator.

CONCLUSIONS

These results indicate that adjunctive topiramate to antipsychotics is an effective and safe treatment choice for symptomatic improvement and weight reduction in patients with schizophrenia-spectrum disorders.