Previous studies of prescribing in psychiatric services have identified the relatively frequent use of combined antipsychotics in schizophrenia.

– To analyze the proportion of patients treated with more than one antipsychotic;

– to study clinical as sociodemographic variables associated with types of prescription.

Retrospective descriptive study of treatment prescribed to psychiatric inpatients treated in an acute care unit of Psychiatry Service in a large teaching hospital during a period of 3 years. Consecutively admitted inpatients receiving concurrent antipsychotics were compared with those treated with a single antipsychotic. Prescription drug records at discharging were revised, n = 263.

From the total sample, 61% received more than one antipsychotic. The most common types of combinations were atypical plus a typical antipsychotic followed by two atypical antipsychotics, being less frequent combination of three or more antipsychotics. There were 19 different drug combinations. Concurrent antipsychotics were most frequently prescribed in schizophrenia and schizoaffective disorder. Patients with more previous episodes of illness received more frequently concurrent antipsychotics than patients with low number of previous episodes of illness (P < 0.03). Patients with longer time of hospitalization, and age between 30 and 50 years were treated more frequently with several antipsychotics. Analysis with other variables is presented in the study.

There is a significant difference in the strategies of treatment with antipsychotics depending on diagnosis and number of previous episodes of illness. The concurrent use of multiple antipsychotics in psychiatric inpatients appears to be a response to treatment resistance and is frequent in schizophrenic patients.

The authors have not supplied their declaration of competing interest.