Incidence of extrapyramidal symptoms during treatment with olanzapine, haloperidol and risperidone: results of an observational study (EFESO study)

Abstract

Objectives: To analyze the incidence of extrapyramidal symptoms (EPS) and the concomitant use of anticholinergic drugs in outpatients diagnosed of schizophrenia treated with olanzapine (OLZ) in comparison with haloperidol (HAL) and risperidone (RIS) under routine clinical practice conditions.

Material and methods: The analysis was carried out on the basis of the information obtained in the EFESO study, an observational, prospective study carried out in outpatients diagnosed of schizophrenia and treated with olanzapine compared to other antipsychotic agents used in the clinical practice. The incidence of EPS in the OLZ treated group compared to the haloperidol and risperidone treatment groups in which over 100 patients were included is analyzed in the present work. The study duration was 6 months and the data were collected by 293 psychiatrists from mental health care areas.

Results: The percentage of patients who presented at least one adverse event (AE) (p≤ 0.001) was less in the OLZ groups (47.8%) compared to those of the HAL (79.8%) and RIS (57.2%) subgroups. A lower percentage of patients treated with OLZ (36.9%) presented EPS in comparison to the RIS (49.6%) and HAL (76%) subgroups (p≤ 0.001). A lower rate of patients from the OLZ group (10.2%) received anticholinergic treatments compared to the RIS (19.9%) and HAL (44%) subgroups (p< 0.001 in both cases).

Conclusions: OLZ-treated patients presented a lower incidence of EPS and required less anticholinergic treatment than the HAL and RIS treated patients. These results, obtained in naturalistic conditions, coincide with the conclusions reached in randomized clinical trials carried out prior to the marketing of OLZ.