Neuroleptic Malignant Syndrome After Addition of Haloperidol to Atypical Antipsychotic

Ms. A was a 29-year-old black woman with a 10-year history of schizophrenia who was brought to the emergency room in the midst of an acute psychotic episode. Before 1997 she had received thiothixene, haloperidol, and fluphenazine decanoate. In 1997, she had started taking olanzapine, 10 mg/day, with good response for over 2 years. She relapsed in 1999, apparently from lowering her olanzapine dose from 10 to 5 mg/day. During this episode, as in previous ones, her acute symptoms were characterized by delusions and disorganization but no motor phenomena such as catatonia. In the emergency room, her olanzapine regimen was restarted at 10 mg/day, with lorazepam given as needed. When her acute symptoms did not improve within 24 hours, oral and intramuscular haloperidol was added to her regimen. Over the next 48 hours, Ms. A received a total of 23 mg of oral and intramuscular haloperidol.

The next day, there was an abrupt deterioration in Ms. A’s mental and physical status. She appeared disoriented and mute. The results of physical and laboratory tests included muscle rigidity, fever, incontinence, hypertension, leukocytosis, and an elevated creatine phosphokinase level. She was diagnosed with neuroleptic malignant syndrome and transferred to an intensive care unit, where she had a stormy course of illness with multiple complications, including deep vein thrombosis, aspiration pneumonia, and sepsis. It took her over 3 months to recover. On follow-up, her schizophrenia was reasonably stable with 10 mg/day of olanzapine. She has not had any signs of extrapyramidal symptoms or recurrence of neuroleptic malignant syndrome.