A case of risperidone-associated neuroleptic malignant syndrome in a patient receiving long-term haloperidol treatment

We report a case of risperidone-associated neuroleptic malignant syndrome. A 53-year-old gentleman with mental retardation, psychosis and hypertension who was on long term haloperidol, lorazepam and atenolol treatment presented to the Department of Emergency Medicine of the Singapore General Hospital with hyperthermia, generalised rigidity, impaired consciousness and diaphoresis five weeks after adding on risperidone. Biochemical investigations revealed hyponatremia, raised creatine kinase levels and myoglobinuria. Chest X-ray showed consolidative changes in the right upper and middle zones and left middle zone. He was diagnosed as neuroleptic malignant syndrome with rhabdomyolysis, and aspiration pneumonia. He was discharged well after 13 days. (Hong Kong j.emerg.med. 2010;17:285-288)