Efficacy for Psychopathology and Body Weight and Safety of Topiramate-Antipsychotic Cotreatment in Patients With Schizophrenia Spectrum Disorders: Results From a Meta-Analysis of Randomized Controlled Trials.

Abstract

To meta-analyze the efficacy and tolerability of topiramate-antipsychotic cotreatment in schizophrenia. PubMed/MEDLINE database were searched until September 5, 2015, using the keywords topiramate AND antipsych* OR neurolept* OR specific antipsychotic names. Randomized controlled trials (RCTs) of topiramate-antipsychotic cotreatment versus placebo and ongoing antipsychotic treatment in patients with schizophrenia spectrum disorders were included. Two evaluators extracted data. Standardized mean difference (SMD), weighted mean difference (WMD), and risk ratio (RR) ± 95% CIs were calculated. In 8 RCTs, lasting a mean ± SD of 13.6 ± 4.9 weeks, 439 patients were randomized to topiramate (100-400 mg/d) versus placebo (trials = 7) or ongoing antipsychotic treatment (trial = 1). Topiramate outperformed the comparator regarding total psychopathology (trials = 6, n = 269, SMD = -0.57 [95% CI, -1.01 to -0.14], P = .01), positive symptoms (trials = 4, n = 190, SMD = -0.56 [95% CI, -1.0 to -0.11], P = .01), negative symptoms (trials = 4, n = 190, SMD = -0.62 [95% CI, -1.13 to -0.10], P = .02) general psychopathology (trials = 3, n = 179, SMD = -0.69 [95% CI, -1.27 to -0.11], P = .02), body weight (trials = 7, n = 327, WMD = -3.14 kg [95% CI, -5.55 to -0.73], P = .01), and body mass index (BMI) (trials = 4, n = 198, WMD = -1.80 [95% CI, -2.77 to -0.84], P = .0003). Topiramate's efficacy for total psychopathology and weight reduction effects were not mediated/moderated by trial duration, topiramate dose, sex, age, inpatient status, baseline Positive and Negative Syndrome Scale, or baseline BMI. Conversely, clozapine-topiramate cotreatment moderated greater efficacy, but less weight loss, compared to topiramate-nonclozapine antipsychotic combinations. All-cause discontinuation was similar between topiramate and control groups (trials = 7, RR = 1.24 [95% CI, 0.76 to 2.02], P = .39). Topiramate trended only toward more paresthesia than placebo (trials = 4, RR = 2.03 [95 % CI, 0.99 to 4.18], P = .05). Topiramate-antipsychotic cotreatment significantly reduced total, positive, negative, and general psychopathology and weight/BMI in patients with schizophrenia spectrum disorder while being well tolerated. However, larger studies are needed to confirm and extend these findings.