Prevalence and severity of akathisia in patients on clozapine.

The atypical antipsychotic clozapine is reported to have unique therapeutic effects and to produce minimal extrapyramidal side effects. However, in a blind survey, akathisia was observed to be similar in prevalence and severity in patients treated with clozapine and those receiving standard neuroleptic antipsychotic drugs. In addition, as with standard antipsychotic drugs, the presence of akathisia in patients receiving clozapine was associated with a worse overall clinical outcome. The results suggest that akathisia may be a common side effect of all antipsychotic drugs, that akathisia may be produced by a mechanism distinct from other locomotor effects of these medications, and that patients receiving clozapine, like patients receiving standard antipsychotic drugs, should be monitored for akathisia.