Patterns of prescription of four major antipsychotics: a retrospective study based on medical records of psychiatric inpatients.

PURPOSE

(1) To identify factors associated with the choice among the three atypical antipsychotics available in France (amisulpride, olanzapine, risperidone) and the typical antipsychotic of reference: (haloperidol), (2) to compare psychotropic co-prescription rates according to antipsychotic.

METHODS

All antipsychotic prescriptions including at least one of the four antipsychotics (n=421) for all inpatients (n=372) hospitalized 24 hours or more in the 6 months previous to the start of the study were included (2003). Data were obtained from medical records and psychiatrist interviews. Of the prescriptions, 13.3% included amisulpride, 39.4% olanzapine, 27.3% risperidone, and 20.0% haloperidol. Mean dosages were 142 mg (amisulpride), 15 mg (olanzapine), 4.5 mg (risperidone), and 19.5 mg (haloperidol).

RESULTS

Differences between antipsychotics were observed in relation to patients' age (younger patients prescribed amisulpride and olanzapine, p=0.04), diagnoses (affective disorders more frequently prescribed olanzapine and risperidone, p=0.005), and mode of hospitalization (admissions under constraint more frequently prescribed haloperidol, p<0.001). Antidepressant and anxiolytic-hypnotic co-prescription rates were lower with haloperidol than with atypicals. Mood-stabilizer co-prescription rates were higher for olanzapine and risperidone than for haloperidol and amisulpride. Anticholinergic co-prescription was higher with haloperidol than with atypicals (p<0.001).

CONCLUSIONS

Haloperidol was prescribed to a minority and targeted male patients hospitalized under constraint, using high dosages. Type and rate of co-prescriptions varied considerably between haloperidol and atypicals.