Atypical antipsychotic-induced neuroleptic malignant syndrome

Abstract

The rare neuroleptic malignant syndrome (NMS) is associated with early mortality of >30%. Better supportive care has reduced mortality to <10%. Atypical antipsychotics such as clozapine and risperidone are associated with an atypical but potentially lethal, NMS. A 22-year-old male developed NMS after being treated with clozapine and risperidone for aggression associated with mental retardation for about 8 years. For the past 1 year, the dose of clozapine was 200 mg/day and the dose of risperidone was 8 mg/day. The patient presented with symptoms of hyperthermia, perspiration, neck rigidity, and tonic posturing of all four limbs with tongue bite and frothing from the mouth. On examination, the patient’s Glasgow coma Scale was E3V1M4. He was intubated and given antibiotics, antiepileptic, tablet bromocriptine 2.5 mg (1-1-1-1), and other supportive treatment. The patient showed improvement in 10 days. Knowledge of diagnostic features, risk factors, treatment modalities, and differential diagnosis of NMS is essential. Early diagnosis and prompt treatment can reduce mortality and morbidity significantly.