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Olanzapine vs haloperidol: treating delirium in a critical care setting



To compare the safety and estimate the response profile of olanzapine, a second-generation antipsychotic, to haloperidol in the treatment of delirium in the critical care setting.


Prospective randomized trial


Tertiary care university affiliated critical care unit.


All admissions to a medical and surgical intensive care unit with a diagnosis of delirium.


Patients were randomized to receive either enteral olanzapine or haloperidol.


Patient’s delirium severity and benzodiazepine use were monitored over 5 days after the diagnosis of delirium.

Main results

Delirium Index decreased over time in both groups, as did the administered dose of benzodiazepines. Clinical improvement was similar in both treatment arms. No side effects were noted in the olanzapine group, whereas the use of haloperidol was associated with extrapyramidal side effects.


Olanzapine is a safe alternative to haloperidol in delirious critical care patients, and may be of particular interest in patients in whom haloperidol is contraindicated.

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Support for this study was generously provided by a (peer-reviewed) grant from the Zyprexa fund, Eli-Lilly, North America.

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Correspondence to Yoanna K. Skrobik.

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Skrobik, Y.K., Bergeron, N., Dumont, M. et al. Olanzapine vs haloperidol: treating delirium in a critical care setting. Intensive Care Med 30, 444–449 (2004).

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  • Delirium
  • Therapy
  • Critical care
  • Olanzapine
  • Haloperidol
  • Parkinson’s disease