Treatment of Tardive Dystonia Induced by Antipsychotics, Old and New

Tardive dystonia is a serious extrapyramidal side effect emerging after long-term treatment with antipsychotics, frequently with a deteriorating course, and unsatisfactory treatment. Presently, clozapine is used for the cotreatment of tardive dystonia and psychosis, at the cost of serious side effects. Apart from clozapine, there have been case reports describing positive effects of quetiapine on dystonic symptoms. Aim of the present study was to demonstrate the ameliorating effects of quetiapine on dystonic symptoms, in a sample of patients suffering from antipsychotic-induced tardive dystonia.

Quetiapine was administered to 16 consecutively enrolled stabilized patients with psychotic or mood disorders and tardive dystonia, replacing the "offending drugs," over a 3-month cross-tapering period. Target dose of quetiapine was set according to the defined daily dose of the received antipsychotic(s) at baseline, as reviewed by the World Health Organization Center of Drug Statistics Methodology, aiming at both maintenance of psychosis control and reduction of dystonic symptoms.

Patients were found to have significant positive results in amelioration of dystonia (P < 0.001) over a 1-year period, without loss of antipsychotic efficacy. Reduction of dystonic symptoms with the use of quetiapine could be considered comparable with the positive effects of clozapine, with the additional advantage of relatively lacking serious side effects.

Quetiapine may represent a valuable therapeutic choice for the treatment of tardive dystonia.