Reduction in neuroleptic-induced movement disorders after a switch to quetiapine in patients with schizophrenia

Background: Persistent neuroleptic-induced movement disorders limit effective pharmacological management of psychotic disorders. Although antipsychotic switching is a common strategy for managing extrapyramidal side effects (EPS), there is insufficient empirical support to guide the clinician. We designed the present study to examine whether patients with preexisting EPS switched to quetiapine would show greater reduction in EPS compared with control patients. Methods: Twenty-two patients with schizophrenia meeting clinical criteria for tardive dyskinesia or coexisting parkinsonism were randomized either to switch from their current antipsychotic to quetiapine (n = 13) or to remain on their current treatment (n = 9). A battery of standard clinical assessments for EPS along with electromechanical instrumental measures was administered before randomization and again 1 and 3 months postrandomization. Results: We observed significant reduction in parkinsonism (P < 0.001) and akathisia (P = 0.02) based on clinical assessments and dyskinesia (P < 0.05) based on instrumental assessment for the quetiapine group. Subjects remaining on current treatment exhibited an increase in rigidity (P < 0.05) based on instrumental measures. Conclusions: These findings support the switching to quetiapine in the management of preexisting neuroleptic-induced extrapyramidal side effects.