Benzodiazepines for neuroleptic-induced tardive dyskinesia

Tardive dyskinesia (TD) is a potentially disfiguring movement disorder of the orofacial region often caused by the use of neuroleptic drugs. A wide range of strategies have been used to help manage tardive dyskinesia and, for those who are unable to have their antipsychotic medication stopped or substantially changed, the benzodiazepine group of drugs has been suggested as a useful adjunctive treatment.

To determine the effects of benzodiazepines for people with neuroleptic-induced tardive dyskinesia and schizophrenia or other chronic mental illnesses.

Electronic searches of Biological Abstracts (1982-2002), the Cochrane Schizophrenia Group's Register of trials (February 2002), EMBASE (1980-2002), LILACS (1982-2002), MEDLINE (1966-2002), PsycLIT (1974-2002), SCISEARCH (2002), hand searching the references of all identified studies and contacting the first author of each included trial.

All randomised clinical studies focusing on people with both schizophrenia or other chronic mental illnesses and neuroleptic-induced tardive dyskinesia and comparing benzodiazepines with placebo or no intervention.

Studies were reliably selected, quality assessed and data extracted. Data were excluded where more than 50% of participants in any group were lost to follow up. For binary outcomes a fixed effects risk ratio (RR) and its 95% confidence interval (CI) was calculated. Where possible, the weighted number needed to treat/harm statistic (NNT/H), and its 95% confidence interval (CI), was also calculated. For continuous outcomes, endpoint data were preferred to change data. Non-skewed data from valid scales were synthesised using a weighted mean difference (WMD). If statistical heterogeneity was found by Mantel-Haenszel chi-square test, random effects models were used.

Two small trials (total n=32) were included. Using benzodiazepines as adjunctive treatment did not result in any clear changes for a series of tardive dyskinesia medium term outcomes (RR not improved to a clinically important extent 1.08 CI 0.57 to 2.05, n=30, 2 RCTs; RR not improved at all 1.19 CI 0.3 to 5.3, n=30, 2 RCTs; RR deterioration 1.85 CI 0.3 to 10.1, n=30, 2 RCTs). Adverse effects were not reported.

The 2002 update has added almost no extra data. This is clearly not an area of active research. Benzodiazepines may have something to contribute to the care of people with tardive dyskinesia but the use of this group of compounds should be considered experimental. Large definitive studies are indicated.