Novel antipsychotics and acute dystonic reactions.

The growing use of atypical antipsychotics has led to a decrease of acute dystonic reactions (ADR). To evaluate the prevalence of ADR, we recorded all ADR occurring in a population of patients consecutively admitted to a psychiatric intensive care unit. Among 1337 cases treated with antipsychotics, we observed 41 cases (3.1%) affected by ADR. At discharge, mean chlorpromazine-equivalent daily dose was 465.8 (+/-421.5) mg, while 39 cases (3.0%), all treated with typical neuroleptics, received anticholinergics. During hospitalization, 15 cases received quetiapine, 19 sertindole, 95 olanzapine, 142 clozapine, 495 risperidone and 561 typical neuroleptics. Four ADR occurred among the cases treated with risperidone monotherapy, and 4 occurred in risperidone-treated patients after emergency parenteral treatment with typical neuroleptics. In these last 4 cases, temporal relationship suggested that typical neuroleptics had caused ADR. One ADR occurred in a patient treated with olanzapine and 1 ADR in a patient treated with quetiapine. Among cases assuming typical neuroleptics, 32 ADR occurred. The difference between typical and atypical neuroleptics is highly significant (chi2 = 27.756; d.f. = 1; p = 0.000). Atypical antipsychotics carry a minimal risk of ADR.