Polypharmacy and excessive dosing: psychiatrists' perceptions of antipsychotic drug prescription.

BACKGROUND Despite extensive research and recommendations regarding the optimal prescription of antipsychotic drugs, polypharmacy and excessive dosing still prevail. AIMS To identify the factors associated with the polypharmacy and excessive dosing phenomena. METHOD We studied 139 patients with schizophrenia, in 19 acute psychiatric units in Japanese hospitals, who were due to be discharged between October and December 2003. We examined patient characteristics, nurses' requests, and psychiatrists' characteristics and perceptions of prescribing practice and algorithms. RESULTS Polypharmacy and excessive dosing were observed in 96 cases. Logistic regression analysis revealed that the use of multiple medications and excessive dosing were influenced by the psychiatrist's scepticism towards the use of algorithms, nurses' requests for more drugs and the patient's clinical condition. CONCLUSIONS Educational interventions are necessary for psychiatrists and nurses to follow evidence-based guidelines or algorithms.