• Proceedings of the PSK Conference
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• 2003.10b
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• pp.238.2-239
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• 2003

The purposes of this study were to evaluate the relationship between the genetic polymorphisms in CYP2D6*10 allele, MDR1 (exon 21 and 26) gene and risperidone pharmacokinetics in healthy male Korean subjects. A single dose of 2 mg risperidone tablet was given orally to 23 healthy male Korean volunteers. Blood samples were taken during the 12 hours after the dose. Serum concentrations of risperidone and 9-hydroxyrisperidone were measured using HPLC with UV detector. 23 subjects were genotyped for CYP2D6*10 allele, MDR1 G2677 T and C3435T by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). (omitted)

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.281-286
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• 1995

Objects : Manic phase of bipolar disorder is treated with a combination of mood stabilizer and antipsychotic drug, especially in the acute phase. Such combined treatment is often required for the clinical management of manic symptoms until therapeutic effects of mood stabilizer become evident. The present study was the first open trial to evaluate the efficacy of risperidone, and safety of the combination of mood stabilizer and risperidone in the treatment of acute manic patients. Method : This study was performed as an open clinical study. The subjects of this study were 42 patients who had been admitted with first manifestations or acute exacerbations of illness were selected, using DSM-III-R criteria for bipolar disorder, manic episode. Patients were rated using the the Brief Psychiatric Rating Scale (BPRS), Clinical Global Impression (CGI), Extrapyramidal Symptom Rating Scale(ESRS). Other adverse events were assessed by a symptom checklist and by observation by medical personnel. Vital signs were monitored in a standard way and electrocardiography, routine laboratory analysis were performed. Results : Thirty patients(67%) completed the 12-week trial period. The CGI showed a good therapeutic effect with a minimal incidence or severity of side effects. The majority of patients showed a continuos reduction in their BPRS scores. The extrapyramidal symptoms assessed on ESRS generally showed mild to moderate degree. laboratory porameters showed no significant changes during the course of treatment. Conclusion : The results of the study showed a good efficacy of the risperidone in manic patients and further controlled studies are warranted.

• Korean Journal of Biological Psychiatry
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• v.7 no.1
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• pp.99-106
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• 2000

Background : In spite of relative high risk of extrapyramidal side effect and tardive dyskinesia, it is common clinical practice to use antipyschotics in treatment of bipolar I disorder. But in Korea, there has been few study about clinical factors related with antipsychotics treatment in bipolar disorder patients. So the author studied about the clinical factors related with antipsychotics treatment in bipolar inpatients focusing on the comparison of risperidone and classical antipsychotics. Method : By reviewing medical record retrospectively, datas about patient-related, illness-related, and treatment-related clinical factors on antipsychotics use were collected. Association between antipsychotics dose and duration and clinical factors were analysed by statistical method. Results : Aggressive behavior was only statistically significant factor associated with antipsychotics use. And in the case of aggression, maintenance dose of risperidone was not changed(p=0.84), but dose of classical antipsychotics was increased significantly(p=0.005). Total hospital days and antipsychotics treatment duration showed no difference between risperidone and classical antipsychotics treatment groups. Conclusion : Clinical factors associated with antipsychotics use was aggressive behavior. In the case of aggression, risperidone required lesser dose increment compared with classical antipsychotics.

• Journal of Pharmaceutical Investigation
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• v.34 no.2
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• pp.139-145
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• 2004

The purpose of the present study was to evaluate the bioequivalence of two risperidone tablets, Risperdal (Janssen Korea Co., Ltd.) and Rispen (Myung In Pharm. Co., Ltd), according to the guidelines of Korea Food and Drug Administration (KFDA). The risperidone release from the two risperidone formulations in vitro was tested using KP VIII Apparatus II method with various of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, $23.33\;{\pm}2.10$ years in age and $69.24{\pm}8.05\;kg$ kg in body weight, were divided into two groups and a randomized $2\;{\times}\;2$ cross over study was employed. After one tablet containing 2 mg as risperidone was orally administered, blood was taken at predetermined time intervals and the concentrations of risperidone in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t$,$C_{max},\;and\;T_{max}$ were calculated and ANOVA test was utilized for the analysis of the parameters using logarithmically transformed $AUC_t$,$C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the Risperdal were 0.20, -1.29 and -11-09% for $AUC_t$,$C_{max},\;and\;T_{max}$, respectively There were no sequence effects two formulations in parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g.,$log(0.90){\sim}log(1.30)$ and $log(0.84){\sim}log(1.09)$ for$AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA guideline for the bioequivalence were satisfied, indicating Rispen tablet and Risperdal tablet were bioequivalent.

• Korean Journal of Biological Psychiatry
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• v.15 no.2
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• pp.101-109
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• 2008

Objectives : This study was conducted to examine the effects on food intake, body weight, and metabolic parameters by amisulpride administration in male and female mice, comparing the effects of risperidone and vehicle administration. Methods : Female and male C57BL/6 mice were grouped into low dose amisulpride(1.5mg/kg), high dose amisulpride(15mg/kg), risperidone(0.1mg/kg) and vehicle. Drugs were administered once daily through intraperitoneal injection over 21days. Body weight was measured weekly and food intake was measured daily. Levels of triglyceride, glucose, insulin and prolactin were determined at the end of experiment(on day 22). Results : In the female mice, low and high dose amisulpride as well as risperidone caused significant weight gains. But weight gains in amisulpride groups were numerically smaller than that of risperidone group. In male mice, only high dose amisulpride caused significant weight gain. Among weight gain groups, only weight gain of male mice with high dose amisulpride was significantly associated with increased food intake. Weight gain group in female mice did not show significant correlation with food intake. In male mice, both amisulpride groups showed significantly high plasma insulin levels compared to vehicle. In female and male mice, low and high dose amiulpride groups showed significant high plasma prolactin levels compared to vehicle. Triglyceride level were not significantly changed in all groups. Glucose level was changed significantly only in male risperidone group. Conclusions : Administration of amisulpride caused more significant weight gains in female and male mice than controls but changes of metabolic parameters were different according to sex of mice. Our results suggest that different mechanisms of amisulpiride are likely to affect weight gain between male and female mice.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.47-56
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• 2008

Risperidone is a widely prescribed atypical antipsychotic agent. Approved by the FDA as the first drug to treat irritability associated with autism in children, it is also used to treat tic disorder and Tourette's syndrome. Its adverse reactions related to dentistry include dry mouth, the mechanism of which is yet to be identified. The aim of this study is to identify, at the cellular level, how and to what extent risperidone affects intracellular free calcium concentration ($[Ca^{2+}]_i$), an primary intracellular factor in the regulation of fluid secretion in salivary gland cells. The human salivary gland cell line (HSG) was grown in MEM supplemented with 10% BCS. In order to measure $[Ca^{2+}]_i$, Fura-2/AM was loaded in the HSG, and fluorescence at 340 nm/380 nm excitation was measured in the 500 nm emission ratio. After every experiment, a calibration experiment was conducted in order to readjust the ratio to the actual $[Ca^{2+}]_i$. Changes in $[Ca^{2+}]_i$ were measured in the presence of carbachol, ATP and histamine. The researcher then explored how the pretreatment of risperidone affected such changes. Findings of this study include: 1. In HSG, $[Ca^{2+}]_i$ increased due to the addition of carbachol, ATP and histamine. The presence of risperidone inhibited the action of histamine on this process, while making little effect on that of carbachol and ATP. 2. A quantification of $[Ca^{2+}]_i$ in relation to histamine of different concentrations indicates that the effect of histamine was concentration dependent with an $EC_{50}$ of $3.3{\pm}0.5\;{\mu}M$. 3. The inhibitory effect of risperidone on histamine-induced $[Ca^{2+}]_i$ was concentration-dependent with an $IC_{50}$ of $104.4{\pm}14\;nM$. 4. Risperidone inhibits histamine-induced Ca2+ release from endoplasmic reticulum and influx of extracellular $Ca^{2+}$ in HSG cells(p<0.05).

• Korean Journal of Biological Psychiatry
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• v.4 no.2
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• pp.198-210
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• 1997

To examine the double-faced thymoleptic(antidepressant and antimanic) effects of risperidone in mood disorders, this article reviews the psychotropic-induced mania, thymoleptic effects of antipsychotics, therapeutic effects of risperidone and risperidone(RIS)-induced mania(RIM) in mood disorders, risk factors of RIM, possible neurochemical mechanism of these thymoleptic effects, pathophysiological and clinical significance of thymoleptic effects, and suggestive clinical guideline of RIS in mood disorders. RIS appeared effective for bipolar disorder at a lower dose than that recommended for schizophrenia, especially in the cases of maintenance of mood stabilizers, and gradual titration from low doses. Manic induction/exacerbation can occur by chance during RIS treatment in mood disorders, schizoaffective disorders, and schizophrenias. The possible risk factors for RIM are refractory mood disorder, especially in bipolar I disorder with poor initial response ; refractory schizoaffective disorders, especially in bipolar type with poor initial response ; refractory chronic schizophrenias, especially with initial responses ; psychotic features ; higher initial doses ; rapid titration ; combined therapy with antidepressants in refractory depression ; and RIS monotherapy in mania/hypomania. RIS is a drug that preferentially block 5-HT2 receptors. The effects of low dose are due mainly to the blockade of 5-HT2 receptors. There are more gradual increase in D2 blockade with increasing dose and this D2 blocking properties become apparent at higher doses. This may be related to a modulation of dopaminergic transmission by 5-HT2 antagonism at lower doses with the direct action of RIS on DA receptors coming into play at higher dose. The serotonergic antagonistic effect may be important for its effects on depressive symptoms. This, together with adequate blo-ckade of D2 receptors, may not necessarily lead to destabilization of mood disorder, but rather to more therapeutic effects. Therefore, this dose-receptor affinity relationship with both antidepressant and antimanic effects according to treatment duration can explain a continuum of antidepressant effect, antimanic effect, behavioral stimulation, and manic/hypomanic induction/exacerbation. It was the recognition of a useful psychiatric side effects by a thoughtful observer with fertile minds that led to their ultimate utilization as psychotropic drugs, i.e., phenothiazine, MAOI, TCA, and lithium. And, in vivo pharmacological challenge by novel psychotropics, as a neurochemical probe, with more specific actions is a useful tool to select pharmacologically homogeneous subgroup of the same phenotypical(clinical) condition, to further study the unknown underlying pathogenesis of various mental illnesses. Finally, RIS may be a useful alternative or adjunctive drug for patients with mood disorders without psychotic features or refractory to treatment with standard antipsychotic drugs. The more conservative doses(tirated slowly from 1-3 mg/d) of RIS, and maintenance of mood stabilizer in the cases with risk factors of RIM are recommended in mood disorder.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2125-2132
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• 2012

Fluoxetine and tianeptine are commonly used as antidepressants (AD), and haloperidol and risperidone are widely used as antipsychotic drugs (APD), and it modulates various ion channels. TREK2 channel subfamily is very similar to physiological properties of TREK1 channel which can play important roles in the pathophysiology of mental disorders such as depression and schizophrenia, therefore, the pharmacological effect of psychiatric and depression drug on TREK2 channel may be similar to those of TREK1. Using the excised inside-out patch-clamp technique, we have examined the effects of APD and AD on cloned TREK2 channel expressed CHO cells. Fluoxetine (selective serotonin release inhibitor, SSRI) inhibited the TREK2 channel in a concentration-dependent manner ($IC_{50}$ $13{\mu}M$), whereas selective serotonin reuptake enhancer (SSRE) tianeptine increased without reducing the TREK2 channel activity. Haloperidol also inhibited the TREK2 channel in a concentration-dependent manner ($IC_{50}$ $44{\mu}M$), whereas even higher concentration ($100{\mu}M$) of risperidone did not completely inhibit on the activity. This study showed that TREK2 channel was preferentially blocked by fluoxetine rather than tianeptine, and inhibited by haloperidol rather than risperidone, suggesting differential effect of TREK2 channels by APD and AD may contribute to some mechanism of adverse side effects.

• Korean Journal of Biological Psychiatry
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• v.11 no.1
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• pp.61-63
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• 2004

We describe the case of a 73 year-old female patient, YSG, who initially presented with a manic episode without any previous psychiatric history and was later diagnosed as having a meningioma in the left frontal lobe. YSG's symptoms were characterized by hyperactivity, insomnia, aggressive behavior with an auditory hallucination. She showed no abnormal signs on a complete neurologic examination. A gadolinium-enhanced MRI study showed a huge, extra-axial mass with homogenous enhancement in the left high convexity of the frontal lobe. Her manic symptoms subsided after administration of risperidone 1mg and valproic acid 500mg daily, for three weeks without surgical resection of the tumor. These findings suggest that YSG's mania might have resulted from the left-sided frontal tumor, and that her symptoms were treated rapidly by small doses of risperidone combined with valproic acid. Medical staff who care for manic patients should be aware of this possibility of a organic lesion without evidence of neurologic disease.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.951-959
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• 2003

A series of typical (chlorpromazine, haloperidol and thioridazine) and atypical (risperidone, quetiapine, clozapine and olanzapine) antipsychotics were tested for effects on integrated bioenergetic functions of isolated rat liver mitochondria. Polarographic measurement of oxygen consumption in freshly isolated mitochondria showed that electron transfer activity at respiratory complex I is inhibited by chlorpromazine, haloperidol, risperidone, and quetiapine, but not by clozapine, olanzapine, or thioridazine. Chlorpromazine and thioridazine act as modest uncouplers of oxidative phosphorylation. The typical neuroleptics inhibited NADH-coenzyme Q reductase in freeze-thawed mitochondria, which is a direct measure of complex I enzyme activity. The inhibition of NADH-coenzyme Q reductase activity by the atypicals risperidone and quetiapine was 2-4 fold less than that for the typical neuroleptics. Clozapine and olanzapine had only slight effects on NADH-coenzyme Q reductase activity, even at 200 $\mu$ M. The relative potencies of these neuroleptic drugs as inhibitors of mitochondrial bioenergetic function is similar to their relative potencies as risk factors in the reported incidence of extrapyramidal symptoms, including tardive dyskinesia (TD). This suggests that compromised bioenergetic function may be involved in the cellular pathology underlying TD.