title: Gamma-aminobutyric acid agonists for neuroleptic-induced tardive dyskinesia.
abstract: BACKGROUND
  Chronic antipsychotic drug treatment may cause tardive dyskinesia (TD), a long-term movement disorder. Gamma-aminobutyric acid (GABA) agonist drugs, which have intense sedative properties and may exacerbate psychotic symptoms, have been used to treat TD.
  
  
  OBJECTIVE
  To determine the clinical effects of GABA agonist drugs (baclofen, gamma-vinyl-GABA, gamma-acetylenic-GABA, progabide, muscimol, sodium valproate and tetrahydroisoxazolopyridine (THIP) for people with schizophrenia or other chronic mental illnesses who also developed neuroleptic-induced tardive dyskinesia.
  
  
  METHODS
  We updated the previous Cochrane review by searching the Cochrane Schizophrenia Group Register (June 2010).
  
  
  METHODS
  We included reports if they were controlled trials dealing with people with neuroleptic-induced TD and schizophrenia or other chronic mental illness who had been randomly allocated to either non-benzodiazepine GABA agonist drugs with placebo or no intervention.
  
  
  METHODS
  Working independently, we selected and critically appraised studies, extracted data and analysed on an intention-to-treat basis. Where possible and appropriate we calculated risk ratios (RR) and their 95% confidence intervals (CI) with the number needed to treat (NNT). For continuous data we calculated mean differences (MD).
  
  
  RESULTS
  We identified eight small poorly reported studies for inclusion. For the outcome of 'no clinically important improvement in tardive dyskinesia' GABA agonist drugs were not clearly better than placebo (n = 108, 3 RCTs, RR 0.83 CI 0.6 to 1.1). Deterioration in mental state was more likely to occur in people receiving GABA medication (n = 95, 4 RCTs, RR 2.47 CI 1.1 to 5.4), but this effect was influenced by the decision to assign a negative outcome to those who left early before the end of the study. A greater proportion of people allocated GABA medication may fail to complete the trial compared with those allocated placebo (20% versus 9%), but this difference was not statistically significant (n = 136, 5 RCTs, RR 1.99 CI 0.8 to 4.7). There is a suggestion of an increase in ataxia (loss of power of muscular coordination) for both baclofen and sodium valproate (n = 95, 2 RCTs, RR 3.26 CI 0.4 to 30.2), and in sedation (n = 113, 3 RCTs, RR 2.12 CI 0.8 to 5.4) compared with placebo, but this was not significant. Withdrawal of tetrahydroisoxazolopyridine (THIP) may cause seizures.
  
  
  CONCLUSIONS
  Evidence of the effects of baclofen, progabide, sodium valproate, or THIP for people with antipsychotic-induced TD is inconclusive and unconvincing. Any possible benefits are likely to be outweighed by the adverse effects associated with their use.
authors.affiliation: Faculty of Medicine, Damascus University, Damascus, Syrian Arab Republic.
authors.forename: Samer
authors.initials: S
authors.lastname: Alabed
authors.forename: Youssef
authors.initials: Y
authors.lastname: Latifeh
authors.forename: Husam Aldeen
authors.initials: HA
authors.lastname: Mohammad
authors.forename: Abdullah
authors.initials: A
authors.lastname: Rifai
mesh_terms: D014150:Antipsychotic Agents / Q000009:adverse effects; D004409:Dyskinesia, Drug-Induced / Q000188:drug therapy* / Q000209:etiology; D018755:GABA Agonists / Q000627:therapeutic use*; D006801:Humans; D016032:Randomized Controlled Trials as Topic
chemical_list: D014150:Antipsychotic Agents; D018755:GABA Agonists