NEUROLEPTIC MALIGNANT SYNDROME WITH RISPERIDONE

Neuroleptic malignant syndrome is thought to be a result of dopamine D -2 receptor blockade in the striatum of the basal ganglia. Risperidone , a benzisoxazole derivative antipsychotic, has high serotonin 5-HT2 r eceptor blockade and dose-related D-2 receptor blockade. The high rati o is believed to impart the low frequency of extrapyramidal symptoms w ith risperidone at low dosages. With this low frequency of extrapyrami dal symptoms, it was thought the frequency of neuroleptic malignant sy ndrome might also be lowered. A 73-year-old woman developed neurolepti c malignant syndrome after monotherapy with risperidone. The syndrome reversed after discontinuing risperidone and starting treatment with d antrolene and bromocriptine. It appears that the protection from extra pyramidal side effects observed with risperidone does not ensure prote ction from neuroleptic malignant syndrome.