Possible toxic encephalopathy following high-dose intravenous haloperidol

OBJECTIVE: To describe a case of possible toxic encephalopathy in a surgical patient receiving high-dose intravenous haloperidol. CASE SUMMARY: A 54-year-old African-American man was admitted for spinal fusion. His medical history included bipolar disorder and a cerebrovascular accident. His recovery from surgery was complicated by the development of agitation, which was treated with increasing doses of intravenous haloperidol. An electroencephalogram was consistent with toxic encephalopathy. The patient's mental status returned to normal 8 days after discontinuation of haloperidol. DISCUSSION: High-dose intravenous haloperidol for severe agitation has been reported as an effective and safe treatment option for the hospitalized patient. We report the occurrence of toxic encephalopathy in a patient who received high-dose intravenous haloperidol. CONCLUSIONS: Caution should be used when high-dose intravenous haloperidol is used in an agitated patient. If the patient's clinical response is paradoxical to what is anticipated and the resulting agitation is mistakenly attributed to inadequate treatment, increasingly higher doses may only aid in the development of toxic encephalopathy.