title: Efficacy and tolerability of histamine-2 receptor antagonist adjunction of antipsychotic treatment in schizophrenia: a meta-analysis of randomized placebo-controlled trials.
abstract: BACKGROUND
  No comprehensive meta-analysis has been performed concerning the efficacy and tolerability of adjunctive therapy with histamine-2 receptor antagonists (H2R-ANTs) in schizophrenia patients who were treated with antipsychotics.
  
  
  METHODS
  Risk ratios, standardized mean differences (SMD), and 95% confidence intervals were calculated.
  
  
  RESULTS
  We included 8 double-blinded, randomized placebo-controlled trials (RCTs) (n=418) that met the inclusion criteria (famotidine: N=3, n=74; nizatidine: N=4, n=292; ranitidine: N=1, n=52). Pooled H2R-ANTs were not different from placebo with regard to reduction in overall symptoms and body weight. However, pooled H2R-ANTs resulted in lower body mass index (BMI) than placebo (SMD=-0.68). Moreover, nizatidine was associated with an increase in plasma leptin levels (SMD=-1.14). There were no significant differences in the discontinuation rates due to all-cause, side effects, and inefficacy between pooled H2R-ANTs and placebo. However, nizatidine produced more depression and dry mouth than placebo.
  
  
  CONCLUSIONS
  H2R-ANT adjunctive therapy did not improve overall symptoms. To clarify the opposite results between body weight and BMI, future research should investigate long-term efficacy and generate more safety data by using larger samples.
authors.affiliation: Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kishi
authors.affiliation: Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Iwata
mesh_terms: D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006633:Histamine Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D006633:Histamine Antagonists