Haloperidol-induced neuroleptic malignant syndrome complicated by hyperosmolar hyperglycemic state.

Neuroleptic malignant syndrome (NMS) is a life-threatening neurologic emergency that may be caused by neuroleptic agents of any class. The association with hyperosmolar hyperglycemic state (HHS) is rare and carries a grave prognosis. We describe the case of a 25-year-old male patient with haloperidol-induced NMS complicated by HHS that culminated in the patient's death despite all treatment efforts. Physicians caring for diabetic psychiatric patients who are treated with neuroleptic agents should be aware of this association that may be prevented by tight glycemic control.