Association of the Clinical Subtype and Etiology for Delirium with the Outcome after Risperidone Monotherapy in Patients Having Cancer.

Background Delirium is the most frequent psychiatric syndrome in patients with advanced cancer, but its management is complicated by its multifactorial pathology. In this study, we investigated the association of the clinical subtypes, possible etiologies, and reversibility of delirium in patients having cancer with risperidone monotherapy. Methods This study included 16 inpatients with advanced cancer who were consecutively referred to psychiatric consultation service or palliative care team and were diagnosed with delirium by a psychiatrist. These patients were assessed using the Delirium Rating Scale Revised 98 (DRS-R98) at baseline and on a follow up visit (seventh day). The etiologies of delirium were determined using the Delirium Etiology Checklist. Oral risperidone was given once a day (0.5 or 1 mg/day) with routine clinical management. A detailed examination of the association between each clinical factor and their reversibility after risperidone treatment was examined retrospectively. Results Of the 15 patients (mean age 64.1? 9.5 years) whose data were available, 53% had hyperactive delirium and 47% had mixed delirium, while no patient showed hypoactive delirium. The most frequent etiology of delirium was metabolic/endocrine disturbance, drug intoxication, and systemic infection. In 10 patients (67%), remission of delirium was achieved, according to the DRS-R98. Neither clinical subtypes nor possible etiologies were associated with delirium reversibility after risperidone treatment. Conclusions Risperidone monotherapy is effective for treating delirium in patients with advanced cancer.