Why do physicians switch from one antipsychotic agent to another? The "physician drug stereotype"

There is a lack of research on why physicians select a certain drug in an individual case and not another available alternative, although this drug selection process is important for quality assurance and cost control. Four hundred ninety-five psychiatrists documented in a standardized form patient and illness characteristics of 1711 schizophrenic outpatients who were switched for individual clinical reasons from an ongoing neuroleptic treatment to olanzapine, and of another 1654 schizophrenic outpatients whose present neuroleptic medication was continued. Physicians also filled in the "Reason for Treatment Selection Questionnaire." Patients who were switched to olanzapine were more ill and showed more preexisting extrapyramidal symptoms and less patient compliance. Reasons of psychiatrists to switch to olanzapine were the expectation of better efficacy and tolerability of the present treatment and patient preferences to continue with the present medication. The price of olanzapine is seen as a reason not to select olanzapine but has no effect on the treatment decision. The "physician drug stereotype" of olanzapine corresponds with clinical data on the efficacy and tolerability of olanzapine. The data show that medical decisions about drug selection are multidimensional, integrating knowledge about the clinical properties of the drug, personal experiences and information about the individual case. The Reason for Treatment Selection Questionnaire is an instrument that allows to objectively assess important aspects of medical decision making, to generate psychological drug profile, and to understand why physicians prefer one drug over alternatives.