Neuroleptic malignant syndrome associated with olanzapine.

OBJECTIVE: The aim of the present paper is to report a case of Neuroleptic Malignant Syndrome (NMS) occurring 2 days after olanzapine was added to the treatment regimen of an elderly patient with Schizoaffective Disorder. The patient had a previous history of NMS associated with risperidone. CLINICAL PICTURE: Two days after commencement of olanzapine, the patient presented in a stuporous state with dysarthria and increased muscle tone with cogwheeling. His level of consciousness fluctuated over the following 24 h with worsening rigidity, the onset of a mild fever, tachycardia and elevated blood pressure. Biochemical screening revealed markedly elevated creatine kinase. TREATMENT: Olanzapine was ceased and intravenous fluid replacement commenced. Hourly physical observations were instigated, as was regular serum monitoring of creatine kinase level. OUTCOME: Over the subsequent 48 h, there was gradual clinical improvement with resolution of dysarthria, ataxia, rigidity and fever. The patient was returned to the psychiatric ward 3 days after his admission to the medical ward.
CONCLUSIONS: Olanzapine therapy can be associated with NMS. To our knowledge, there are no previous reports of this in the literature.