Anticholinergic medication for neuroleptic-induced tardive dyskinesia

Neuroleptic medication is used extensively to treat people with chronic mental illnesses. However, it is associated with a wide range of adverse effects, including movement disorders. Because of this, many acutely psychotic patients being treated with neuroleptic medication also receive anticholinergic drugs in order to reduce some of the associated movement side-effects.

To determine whether the use or the withdrawal of anticholinergic drugs (benzhexol or benztropine or biperiden or orphenadrine or procyclidine or scopolamine or trihexylphenidyl) were clinically effective for the treatment of people with both neuroleptic-induced TD and schizophrenia or other chronic mental illnesses.

Electronic searches of Biological Abstracts (1982-1995), Cochrane Schizophrenia Group's Register of trials (1995), EMBASE (1980-1995), LILACS (1982-1996), MEDLINE (1966-1995), PsycLIT (1974-1995), and SCISEARCH (1995) were undertaken. References of all identified studies were searched for further trial citations. Principle authors of trials were contacted.

Reports identified in the search were included 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 an anticholinergic agent or to a placebo (or no intervention).

No data could be extracted from the seven randomised controlled trials identified.

No data were synthesized. The authors have been contacted to provide the relevant information. Two studies were excluded because no data are available and six others are still awaiting further information from the authors.

Based on currently available information, no confident statement can be made about the effectiveness of anticholinergics to treat people with neuroleptic-induced tardive dyskinesia. The same applies for the withdrawal of such medications. Whether the withdrawal of anticholinergics may benefit people with neuroleptic-induced TD, this should be evaluated in a parallel-group, placebo-controlled randomised trial, with adequate sample size and at least 6 weeks of follow up.