Clozapine Treatment for Neuroleptic-Induced Tardive Dyskinesia, Parkinsonism, and Chronic Akathisia in Schizophrenic Patients

Background: Previous studies on the use of clozapine in neuroleptic-resistant chronic schizophrenic patients have demonstrated positive effects on tardive dyskinesia but were less conclusive about chronic akathisia and parkinsonism. The aim of the present study was to investigate the short-term (18 weeks) efficacy of clozapine in neuroleptic-resistant chronic schizophrenic patients with coexisting tardive dyskinesia, chronic akathisia, and parkinsonism.

Method: Twenty chronic, neuroleptic-resistant schizophrenic patients with coexisting tardive dyskinesia, parkinsonism, and chronic akathisia were treated with clozapine. Assessment of tardive dyskinesia, parkinsonism, and chronic akathisia was made once weekly for 18 weeks with the Abnormal Involuntary Movement Scale (AIMS), Simpson-Angus Rating Scale for Extrapyramidal Side Effects, and Barnes Rating Scale for Drug-Induced Akathisia (BAS).

Results: At the end of 18 weeks of clozapine treatment, improvement rates were 74% for tardive dyskinesia, 69% for parkinsonism, and 78% for chronic akathisia. A statistically significant reduction in the scores on the AIMS and Simpson-Angus Scale was achieved at Week 5 and on the BAS at Week 6 (p<.0001).

Conclusion: Relatively low doses of clozapine are effective for the treatment of neuroleptic-induced extrapyramidal syndromes in neuroleptic-resistant chronic schizophrenic patients. The relief of tardive dyskinesia, parkinsonism, and chronic akathisia in this group of patients occurs more rapidly than the reduction in psychotic symptoms. Disturbing, long-term extrapyramidal syndromes in chronic schizophrenic patients should be considered an indication for clozapine treatment.