Neuroleptic malignant syndrome is characterized by fever, muscular rigidity, labile blood pressure, altered mental status, decreased conscious level and autonomic dysfunction. Although potent neuroleptics (eg, haloperidol, fluphenazine) are more frequently associated with NMS, all antipsychotic agents may precipitate the syndrome. For example, these agents are prochlorperazine, promethazine , clozapine , risperidone .