Risperidoneへのparoxetineの追加投与により悪性症候群を呈した1例

Neuroleptic Malignant Syndrome induced by Concomitance of Paroxetine with Risperidone: A case report

【抄録】　Risperidoneを投与中の被害妄想，抑うつ，身体症状への強迫的こだわりなどの症状を持つ分裂感情障害患者に対しparoxetineを追加投与したところ悪性症候群（NMS）を呈した例を経験した。本例のNMSの発症に影響を及ぼしたメカニズムとしてセロトニン・ドパミン系間の薬力学的相互作用およびシトクロームP450を介した薬物動態学的相互作用の観点から考察を加え，risperidoneへのparoxetineの追加投与がNMSの発症に重大な影響を与えたと推定した。

　Risperidone. one of the widely employed serotonin-dopamine antagonists, is known to have a lower potential of inducing neuroleptic malignant syndrome (NMS), although some cases taking risperidone are reported to develop NMS. We encountered a patient with schizoaffective disorder who suffered from NMS while taking paroxetine (10 mg) added to risperidone (4mg). The patient was treated effectively with dantrolene and bromocriptine. We suspected a pharmacodynamic drug interaction between the serotonin and dopamine systems (the dopamine receptor blockade activity of risperidone and the serotonin reuptake inhibition activity of paroxetine may have induced a dopamine/serotonin imbalance condition). We also suspected that a pharmacokinetic drug interaction in metabolism through cytochrome P 450 (CYP) (CYP 2 D 6 inhibition activity of paroxetine may have increased the concentration of risperidone) have had a serious influence on the onset of NMS.