Neuroleptic malignant syndrome associated with olanzapine

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.

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.

Olanzapine was ceased and intravenous fluid replacement commenced. Hourly physical observations were instigated, as was regular serum monitoring of creatine kinase level.

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.

Olanzapine therapy can be associated with NMS. To our knowledge, there are no previous reports of this in the literature.