• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.153-155
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• 2001

There had been few reports of arachnoid cyst accompanying psychiatric disturbance and no report treated with low-dose risperidone administration. We report a patient, developed first-transient psychotic episode considered to be provoked by an arachnoid cyst, responsive to risperidone, which was found in the middle cranial fossa as follows. A 57-year-old man was admitted by suddenly developed headache, auditory hallucination, delusion of persecution and, an arachnoid cyst in the anteromedial aspect of middle cranial fossa was found on MRI after admission. The psychotic episode was first to him and he was also negative to other clinical evaluation including endocrine abnormality, his psychotic symtom was suspected to be induced by arachnoid cyst and was well controlled to low-dose risperidone administration. He left hospital free from psychotic symptoms on 14 hospital days.

• 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.5 no.1
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• pp.138-141
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• 1998

Neuroleptic malignant syndrome (NMS) is an uncommon but potentially fatal idiosyncratic reaction to neuroleptics, characterized by muscular rigidity, fever, autonomic dysfunction, and altered consciousness. The major theories to explain NMS is central dopaminergic blockade, but it is unclear. Risperidone is a new antipsychotic drug, a benzisoxazole derivative that blocks dopamine $D_2$ receptor and serotonin type 2 receptor. The comparatively greater serotonin-blocking activity is believed to give risperidone the specific property of not causing any more extrapyramidal side effects than conventional antipsychotics at the optimal dose of 4-8mg/day. It is postulated that risperidone is unlikely to cause NMS. Here, we report a case of risperidone induced neuroleptic malignant syndrome.

• Korean Journal of Biological Psychiatry
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• v.10 no.2
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• pp.141-146
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• 2003

Objective:To find out the optimal assessment that can relieve amenorrhea associated with risperidone. Methods:Sixteen female outpatients who have taken risperidone for more than 3 months reported voluntarily amenorrhea during Nov 2001 to May 2002. Since the reports of the amenorrhea, the resolution of amenorrhea has been prospectively followed during the next six months. The dosage of risperidone was reduced or discontinued in nine of sixteen patients, while risperidone was switched to olanzapine or quetiapine in other 7 patients according to the clinician's decision. Results:Fourteen of 16 patients showed higher levels of prolactin than normal level. Five patients of the risperidone-reduction group recovered from the amenorrhea while all subjects of the drug-switch group recovered. The resolved patients of the former group recovered from amenorrhea in the dosage below 3mg per day of risperidone. Two patients of the risperidone-reduction group were dropped out during the reduction. Conclusion:These findings suggest that risperidone-induced amenorrhea may be alleviated by reducing dosage to less 3mg per day(including discontinuation) or by switching to other antipsychotic drugs. Whether we would choose which method depends on patient's clinical status, diagnosis, and dose of medication and so on.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.198-205
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• 2000

Objectives : Risperidone and clozapine belong to a new generation of antipsychotics that are reportedly more effective and better tolerated than conventional neuroleptics. However, each of these agents costs far more per unit than conventional neuroleptics. The purpose of our retrospective study was to ascertain the total cost and effectiveness of treatment before and after administration of risperidone and clozapine in "revolving door" schizophrenia patients. Method : Data collected on revolving door schizophrenics for 2 years before clozapine and risperidone treatment and for at least 2 years after clozapine and risperidone treatment. Direct cost of inpatient and outpatient treatment was measured. Effectiveness was scaled as "years of mild disability gained". Result : Both risperidone and cloazpine result in higher costs and additional benefits to patients, for example, increased mild disability, reduced number of relapse, and reduced hospital length-of-stay. An ICER of risperidone was less than Rc and ICER of clozapine was greater than Rc. According to decision-analytic this model, risperidone had favorable cost-effectiveness ratios relative to clozapine. Conclusion : We have assumed that risperidone is more cost-effective than clozapine.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.191-197
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• 2000

Objectives : Risperidone is a new antipsychotic drug developed to overcome the therapeutic limitation of conventional antipsychotics. It responses to negative as well as positive symptoms by blocking both dopaminergic and serotonergic receptors, causing no significant side effects such as agranulocytosis and seizure. It is, however, not known whether it induces any serious cardiovascular side effects as evoked by other conventional antipsychotic drugs. The aims of this study were to evaluate the effect of risperidone on cardiovascular function, and to discuss the factors affecting the cardiovascular function. Methods : For 42 patients(22 males and 20 females) diagnosed as schizophrenia, schizophreniform disorder or schizoaffective disorder according to the DSM-IV classification, the cardiovascular fuctions such as heart rate, systolic and diastolic blood pressure, PR interval, QRS interval and QT interval were successively checked before and after 2 weeks and 4 weeks risperidone administration. Furthermore, variables such as body weight, Brief Psychiatric Rating Scale(BPRS), Clinical Global Impression(CGI), Extrapyramidal Symptom Rating Scale(ESRS), Anticholinergic Rating Scale(ARS), serum cholesterol level, serum triglyceride level, serum high-density-lipoprotein level, serum WBC, serum Hb, serum platelet level, prothrombin time and partial thromboplastin time were also analyzed before and after 2 weeks and 4 weeks risperidone administration. Results : 1) Risperidone treatment resulted in a significantly decreased heart rate and increased QT interval after 4 weeks administration(p<0.005 respectively). 2) The scores of BPRS and CGI were significantly decreased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). The scores of ESRS and ASRS were significantly increased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). 3) There were positive correlations between heart rate after 4 weeks and total dose(P<0.05). Blood pressure was significantly(p<0.05) correlated with sex(higher in male) and significantly(p<0.05) positive correlated with body weight. QT interval was significantly(p<0.05) correlated with sex(longer in female) and smoking history(shorter in smokers). Conclusions : Risperidone could induce significant change in heart rate and Q-T interval. Therefore, the cardiovascular safety for risperidone should be reconsidered according to the duration and dosage increase.

• Korean Journal of Biological Psychiatry
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• v.10 no.2
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• pp.177-185
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• 2003

Object:We investigated the relationship between prolactin response to antipsychotics and clinical courses of psychotic symptoms and DAT gene polymorphisms. Method:Twenty-four acute psychotic inpatients completed the 12-week trial of risperidone. Serum prolactin, BPRS, ESRS and hyperprolactinemia-related symptoms were measured at baseline, 2, 4, 8 and 12 weeks after medication. The DAT gene polymorphisms were analyzed. Results:The serum prolactin was significantly increased over time. According to the prolactin level at 2-week, the subjects were divided into the severe group(serum prolactin>60ng/mL, N=15) and the mild group (serum prolactin<60ng/mL, N=9). The prolactin levels of the mild group didn't increase beyond 60ng/mL throughout 12 weeks. Severe group had slower decrement of BPRS scores than those of mild group. Six females in severe group complained of irregular menstruations, but no female in mild group. Most patients had 10 allele of DAT gene. Conclusion:This study suggests that the magnitude of prolactin elevation at the 2-week of risperidone medication is correlated with severity of hyperprolactinemia throughout treatments. Our results did not show the relationship between prolactin responses and DAT gene polymorphisms.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.24 no.3
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• pp.164-169
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• 2013

Objectives : We assessed the availability of Aberrant Behavior Checklist (ABC) for the evaluation of the pharmacological effect in autistic disorder. Methods : A retrospective review of the medical records of 27 children with autistic disorder, who visited the department of child and adolescent psychiatry of Kyungpook National University Hospital, from October 2011 to February 2013, was conducted. After treatment with risperidone, changes in the severity and improvement of symptoms were measured using ABC at the baseline, 2nd visit and 3rd visit, respectively. Results : The mean daily dose of risperidone increased from $0.66{\pm}0.27mg$ (baseline, initial dose) to $1.02{\pm}0.50mg$, 2nd visit, and $1.19{\pm}0.50mg$, 3rd visit. According to ABC, irritability, lethargy, hyperactivity, and inappropriate speech subscale scores decreased significantly from the baseline to 2nd visit. Irritability and Hyperactivity subscale scores decreased significantly from the 2nd to 3rd visit. All subscales and total scores of ABC decreased significantly from the baseline to 3rd visit. Conclusion : The results of this study suggest that ABC can be used as an efficient tool to measure the symptoms of autistic disorder and to evaluate the medication effect on continuous treatment.

• Korean Journal of Biological Psychiatry
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• v.7 no.1
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• pp.14-20
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• 2000

Recently atypical antipsychotics have been used as first line agent in the treatment of schizophrenia, and also played a significant role in the treatment of many kinds of psychiatric disorders. The pharmacokinetic and pharmacodynamic properties of these newer antipsychotics are well known through preclinical and early clinical trials. However, it is important to note the limitations of the results due to its relatively short experience. Clozapine is eliminated principally by the hepatic P450 1A2 and 3A4 cytochrome enzymes. 1A2 inducers such as carbamazepine and smoking can reduce its half-life, while 1A2 inhibitors such as SSRIs, especially fluvoxamine can increase its duration of action. Carbamazepine should be avoided in a patient on clozapine because of carbamazepine's potential effects on bone marrow. Benzodiazepines tend to increase the chances of sedation, delirium and respiratory depression. Risperidone is metabolized to 9-hydroxyriperidone by the hepatic P450 2D6 cytochrome enzymes. Fluoxetine and paroxetine, 2D6 inhibitors interfere with metabolism, but 9-hydroxyrisperidone has similar biological activity as parental drug, so it has little affect on the outcome. Olanzapine shows minimal capacity to inhibit cytochrome P450 isoenzymes and shows minimal chance of drug interaction. It is eliminated principally by the hepatic P450 1A2 and 2D6 cytochrome enzymes.

• Korean Journal of Biological Psychiatry
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• v.7 no.1
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• pp.74-79
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• 2000

Objectives : The dopamine-blocking effects and the associated side effects(amenorrhea, lactation, sexual dysfunction) of classical antipsychotics in schizophrenic patients have been studied for a long time. The purpose of this study was to find out these effects of new antipsychotics(risperidone, olanzapine) in schizophrenic patients treated with clinically relevant doses. Method : Plasma levels of both prolactin and testosterone were measured in 91 schizophrenic patients(28 taking haloperidol, 4-20mg/day ; 31 taking risperidone, 2-6mg/day ; 32 taking olanzapine, 5-20mg/day). Results : In male schizophrenic patients, the prolactin levels of risperidone group($76.44{\pm}38.85ng/ml$) and haloperidol group($60.26{\pm}20.74ng/ml$) had no significant difference, but were significantly higher than that of olanzapine($26.90{\pm}5.36ng/ml$). In female, the prolactin level of olanzapine group($36.66{\pm}17.55$) was significantly lower than those of risperidone($121.7{\pm}48.33$) and haloperidol group($161.66{\pm}37.53$). And prolactin level of risperidone group was lower than that of haloperidol group. While the testosterone plasma level of risperidone, haloperidol and olanzapine in both male and female schizophrenic patients had no significant difference. Conclusions : At doses known to be effective in popular clinical setting, prolactin level in patients taking risperidone was higher than that of haloperidol, while olanzapine showed no significant difference in terms of prolactin plasma level from haloperidol. New antipsychotics may not influence the testosterone plasma level.