Delirium is an organic psychiatric syndrome characterized by fluctuating consciousness and impairment in perception, cognition and behavior. In hospitalized elderly, the prevalence of delirium ranges from 10% to 40%. If untreated, delirium is associated with significant morbidity and mortality. Treatment of delirium consists of identifying and managing underlying medical abnormalities and the associated psychiatric symptoms. Conventional antipsychotics have been the mainstay of treatment of agitation and psychosis associated with delirium; but their use is limited in terms of EPS side effects. Second-generation antipsychotic agents have been reported to have a lower incidence of extrapyramidal side effects and tardive dyskinesia which has resulted in their increased use in the treatment of delirious patients. However, there is still no consensus regarding standard pharmacologic treatment of this syndrome that takes use of second-generation antipsychotic agents into account.

Risperidone and zotepine have a lower incidence of EPS and are effective in treating disturbing psychotic behaviors. We hope to compare the efficacy and safety of risperidone and zotepine in the treatment of delirium and the correlation between the severity of delirium with autonomic dysfunction.