Two Cases of Risperidone-Induced Mania in Schizophrenics / 신경정신의학

ABSTRACT

We report the first two cases of manic and hypomanic episodes respectively induced by risperidone treatment done to schizophrenics in Korea. One case was a 22-year-old woman with catatonic schizophrenia. Since 3 years ago, she had shown psychotic symptoms, but with was poor treatment compliance. She had mainly negative symptoms such as social withdrawal, decreased flood intake, mutism, and symptoms had been worsened since last 4-5 months. Prior to closed ward admission, she was prescribed 2mg/d of risperidone far a week at OPD. Two days after taking medicine totally 6-8mg, she revealed manic features. After hospitalization, risperidone was discontinued and then, lithium 900mg/d and high dosage of conventional antipsychotics(chlorpromazine 1200mg/d or haloperidol 20mg/d) were prescribed. About on the l0th day of hospitalization, there was limited improvement of her manic symptoms. The other case was a 29-year-old man with a 3-year history of paranoid schizophrenia. He was never exposed to antipsychotics before. His main symptoms were delusions of being poisoned and of persecution. His positive and also negative symptoms were alleviated by 38 days of risperidone 2mg/d trial. However, one week after dosage increment to 3mg/d, hypomanic symptoms appeared. Risperidone medication was discontinued and was replaced by chlorpromazine 300mg/d. The hypomanic episode was resolved over 5 days. In both of the two cases, manic episodes occurred by monotherapy of risperidone without mood stabilizer, and there were no history of substance abuse and other psychiatric disorders, family history of psychiatric disorders, and comorbid physical illnesses. It is hypothesized that the potent blockade effect on serotonin(5-HT2) receptor of risperidone causes antidepressant effect, as well as therapeutic effect for negative and affective symptoms in schizophrenia. Risperidone would induce manic or hypomanic features in schizophrenic patients. And there are few case reports of risperidone-induced mania or exacerbation of preexisting manic symptoms by risperidone treatment in mood disorder and schizoaffective disorder. Risperidone is being used more widely, even for obsessive-compulsive disorder and other psychiatric disorders. It is necessary for clinicians to recognize manic switch, one of psychiatric side effects by risperidon trial. It is recommended that the combination of mood stabilizer with risperidone or usage of the minimum effective dose of risperidone may bewefal especially in the patients with mood disorders or schizoaffective disorders. Clozapine which has mood-stabilizing properties is also beneficial in risk groups of risperidone-induced mania.