An open trial of olanzapine for the treatment of delirium in hospitalized cancer patients.

We conducted an open, prospective trial of olanzapine for the treatment of delirium in a sample of 79 hospitalized cancer patients. Patients all met DSM-IV criteria for a diagnosis of delirium and were rated systematically with the Memorial Delirium Assessment Scale (MDAS) as a measure of delirium severity, phenomenology, and resolution, over the course of a 7-day treatment period. Sociodemographic and medical variables and measures of physical performance status and drug-related side effects were collected. Fifty-seven patients (76%) had complete resolution of their delirium on olanzapine therapy. No patients experienced extrapyramidal side effects; however, 30% experienced sedation (usually not severe enough to interrupt treatment). Several factors were found to be significantly associated with poorer response to olanzapine treatment for delirium, including age >70 years, history of dementia, central nervous system spread of cancer and hypoxia as delirium etiologies, "hypoactive" delirium, and delirium of "severe" intensity (i.e., MDAS >23). A logistic-regression model suggests that age >70 years is the most powerful predictor of poorer response to olanzapine treatment for delirium (odds ratio, 171.5). Olanzapine appears to be a clinically efficacious and safe drug for the treatment of the symptoms of delirium in the hospitalized medically ill.