Do differences in atypical antipsychotics matter in routine practice? Medication switch from olanzapine and risperidone to amisulpride.

Atypical antipsychotics are often addressed as one class of drugs, although there are marked differences in their pharmacological profiles. It is unknown how this is seen by practitioners and to what extent they differentiate between the various atypical compounds. In a drug utilization study, 472 schizophrenic outpatients who were switched for individual reasons from either olanzapine or risperidone to amisulpride were monitored. Data on patients, illness and treatment as well as on reasons to switch were collected. The reasons to switch from olanzapine to amisulpride were preferably 'weight gain' (72.6% of the physicians), or the 'expectancy of less weight gain with amisulpride' (84.1%) and 'patient request' (60.2%). Specific reasons to switch from risperidone were 'extrapyramidal symptoms' (58.5%), or the 'expectancy of few extrapyramidal symptoms with amisulpride' (82.5%). In conclusion, this study confirms that physicians do not consider 'atypical antipsychotics' as one homogeneous class of drugs but make differences that reflect the specific pharmacological profiles of the respective drugs.