Dose Of Risperidone Research Articles

Unidentified CYP2D6 genotype does not affect pharmacological treatment for patients with first episode psychosis.

Research on the pharmacogenetic influence of hepatic CYP450 enzyme 2D6 (CYP2D6) on metabolism of drugs for psychosis and associated outcome has been inconclusive. Some results suggest increased risk of adverse reactions in poor and intermediate metabolizers, while others find no relationship. However, retrospective designs may fail to account for the long-term pharmacological treatment of patients. Previous studies found that clinicians adapted risperidone dose successfully without knowledge of patient CYP2D6 phenotype. Here, we aimed to replicate the results of those studies in a Dutch cohort of patients with psychosis (N = 418) on pharmacological treatment. We compared chlorpromazine-equivalent dose between CYP2D6 metabolizer phenotypes and investigated which factors were associated with dosage. This was repeated in two smaller subsets; patients prescribed pharmacogenetics-actionable drugs according to published guidelines, and risperidone-only as done previously. We found no relationship between chlorpromazine-equivalent dose and phenotype in any sample (complete sample: p = 0.3, actionable-subset: p = 0.82, risperidone-only: p = 0.34). Only clozapine dose was weakly associated with CYP2D6 phenotype (p = 0.03). Clinicians were thus not intuitively adapting dose to CYP2D6 activity in this sample, nor was CYP2D6 activity associated with prescribed dose. Although the previous studies could not be replicated, this study may provide support for existing and future pharmacogenetic research.

Real world clinical outcomes of treatment of cannabis-induced psychosis and prevalence of cannabis-related primary psychosis: a retrospective study

BackgroundCurrent treatment of cannabis-induced psychosis (CIP) focus on the presenting symptoms of individual patient. Therefore, the objective of this study was to investigate the efficacy of pharmacological treatment for CIP in a retrospective manner.MethodsA retrospective chart review study was conducted at the Princess Mother National Institute on Drug Abuse Treatment (PMNIDAT), Thailand. Patients aged more than 12 years who met the International Classification of Disease-10 (ICD-10) criteria of CIP, had recorded of cannabis use in medical chart, and had positive urine test of cannabis on the first day of admission from October 2013 to September 2019 were enrolled. The primary outcome was the efficacy of pharmacological treatment of CIP. Brief Psychotic Rating Scale (BPRS) on the first day and weekly after receiving treatment were used to assess the primary outcome.ResultsFour hundred and three medical charts with diagnosis of CIP were enrolled into the study and only 317 charts were analyzed. Most of them were male with an average aged of 21.0 (19.0–24.0) years old. All of them used smoked cannabis from dried leaves and flowers of cannabis plant. The presented symptoms on admission were psychosis, mood symptoms, sleep problems, weight loss, and cognitive problems (100%, 64%, 61%, 11%, and 7%, respectively). Baseline BPRS score of the first day of admission was 55.2 ± 9.6. Majority of patients received antipsychotic (98.7%) followed by the combination of antipsychotics with benzodiazepines (34.5.%), antipsychotics with antidepressants (14.4%) and antipsychotics treatment with antidepressants and benzodiazepines (25.9%). Only few patients received antipsychotic monotherapy (17.9%). Risperidone was the most frequently prescribed antipsychotics (83.6%). Mean equivalence dose of risperidone was 8.0 ± 5.9 mg/day. The average hospital length of stay was 28 days (range 22-31). BPRS at 22 days significantly improved compared to the first day of admission (p < 0.001). Schizophrenia was diagnosed in 7% at 1.3 years of follow up.ConclusionAntipsychotics was still a key psychotropic drug for treatment of CIP. The symptoms were decreased rapidly and sustained among the treatment period. However, antidepressants and benzodiazepines were commonly used for treatment of other symptoms beyond psychosis.Trial registrationClinicalTrials.gov ID: NCT04945031 (Registration Date: 30 June, 2021).

Effectiveness of anti-psychiatric treatment on visual and haptic perceptual disorder for a patient with Alzheimer’s disease: A case report

BACKGROUND Perception is frequently impaired in patients with Alzheimer’s disease (AD). Several patients exhibit visual or haptic hallucinations. CASE SUMMARY A 71-year-old Chinese man presented with visual and haptic hallucinations he had been experiencing for 2 weeks. The clinical manifestations were the feeling of insects crawling and biting the limbs and geison. He looked for the insects while itching and scratching, which led to skin breakage on the limbs. He was treated with topical and anti-allergic drugs in several dermatology departments without any significant improvement. After admission, the patient was administered risperidone (0.5 mg) and duloxetine (2 mg/day). One week later, the dose of risperidone was increased to 2 mg/day, and that of duloxetine was increased to 60 mg/day. After 2 weeks of treatment, the patient’s sensation of insects crawling and biting disappeared, and his mood stabilized. CONCLUSION This patient manifested psychiatric behavioral symptoms caused by AD brain atrophy. It was important to re-evaluate the patient’s cognitive-psychological status when the patient repeatedly went to the hospital for treatment. Follow-up attention to cognitive function and the consideration of perceptual deficits as early manifestations of AD should be considered.

Incidence of hypercholesterolaemia and hyperglycaemia in schizophrenic patients: Atypical antipsychotic medication and clinical variables

Background: Atypical or second-generation antipsychotic drugs commonly used in the management of schizophrenia include risperidone. Risperidone is linked to the incidence of metabolic syndrome-related adverse effects. Objective: This study aims to investigate the correlation between the administration of risperidone therapy and the incidence of metabolic syndrome in outpatients diagnosed with schizophrenia. This inquiry involves an examination of relevant laboratory parameters, specifically cholesterol, blood glucose, and haemoglobin A1c (HbA1C) levels, alongside an evaluation of pertinent clinical variables that may exert an influence. Methods: This study adopted a cross-sectional approach to receiving risperidone therapy for a minimum of three months at Grhasia Mental Hospital in Yogyakarta, Indonesia. Sampling was executed using an accidental sampling technique, targeting patients who met the predefined inclusion criteria. Results: The study enrolled a total of 97 participants, comprising 58 males and 39 females. Subsequent statistical analyses failed to demonstrate any statistically significant associations between hyperglycemia and various factors, including the risperidone regimen (p = 0.574), risperidone dosage (p = 0.619), and the duration of risperidone therapy (p = 1.000). Conclusion: Risperidone has a long-term risk of causing hyperglycemia in people with schizophrenia; consequently, blood glucose and HbA1C levels must be monitored on a regular basis.

Concurrent mood pathology in patients with autism spectrum disorder (ASD). A case report.

IntroductionMood disorders in patients with ASD (Autism Spectrum Disorder) have a significant impact on their well-being. Major depression and bipolar disorder are among the most common co-occurring psychiatric diagnoses in autism. Prevalence estimates range from 10-50% for depression and approximately 5% for bipolar disorder. These figures are markedly higher than those reported in the general population. The diagnosis of these disorders in patients with autism poses several challenges: mood problems may be “overshadowed” by the diagnosis itself, symptoms vary between individuals and may present “atypically” (psychomotor agitation, regression, reduced self-care, and severe irritability). The use of assessment tools based largely on criteria developed and validated in the general population is common.ObjectivesA case of a patient diagnosed with ASD and co-occurring mood disorder is presented followed by a theoretical review on the topic.MethodsA case is presented with a bibliographic review.Results A 20-year-old patient with a diagnosis of severe autism spectrum disorder was referred to the emergency department for behavioral disturbances based on episodes of heteroaggressiveness and self-aggressiveness, with a daily frequency, in the last 2 months. His parents attribute this decompensation to the introduction of Sertraline and changes in his routine, which has implied less stimulation. Having ruled out underlying organic pathology, given that her father refers to frequent episodes of crying and abandonment of leisure activities of his liking, we suspect a mood disorder. In hospitalization, Sertraline was withdrawn and Valproic Acid was introduced. Likewise, Risperidone dose was increased, already prescribed in outpatient care. Progressively, a notable improvement was observed.ConclusionsCurrent clinical recommendations on the use of selective serotonin reuptake inhibitors (SSRIs) for mood problems are largely based on evidence from typically developing groups. However, it has been shown that some individuals with autism show different neural responses to pharmacological challenge compared to neurotypical individuals. In addition, the use of SSRIs in ASD may result in increased adverse side effects, such as agitation, impulsivity, hyperactivity, stereotypy, and insomnia, and it has been suggested that they should therefore only be considered on a “case-by-case” basis. A systematic review reported that mood stabilizers (Lithium, Valproic Acid) are preferable to atypical antipsychotics, which are associated with a large number of side effects.Because of the lack of strong evidence on the efficacy of pharmacologic interventions and issues regarding safety and side effects, risperidone and aripiprazole are among the few medications approved by the FDA for the treatment of irritability in people with autism. More research aimed at effective medications to treat mood problems in ASD needs to be advocated.Disclosure of InterestNone Declared

Interaction between baseline BMI and baseline disease severity predicts greater improvement in negative symptoms in first-episode schizophrenia.

Several studies have reported that baseline symptom severity in patients with schizophrenia (SCZ) is associated with the efficacy of antipsychotic medication. Overweight/obesity is common in SCZ and has also been reported to be correlated with therapeutic response to antipsychotics. This study aimed to evaluate whether baseline body mass index (BMI) and disease severity were associated with improvements in negative symptoms in patients with first-episode and medication-naïve (FEMN) SCZ. A total of 241 FEMN patients were recruited in this study and treated with oral risperidone over 3months. Clinical symptoms were measured by the Positive and Negative Syndrome Scale (PANSS) and BMI was assessed at baseline and 3-month follow-up. We found that baseline BMI was correlated with the baseline severity of symptoms. Baseline BMI or baseline disease severity was associated with improvement in negative symptoms after 3months of treatment. Linear regression analysis indicated that the interaction of BMI and disease severity at baseline was associated with improvement in negative symptoms in the early stage of SCZ after controlling for sex, age, and dose of risperidone. Our study suggests that the interaction of baseline BMI and disease severity may play a role in predicting negative symptom improvement after 3months of risperidone treatment.

Atypical antipsychotic-induced neuroleptic malignant syndrome

The rare neuroleptic malignant syndrome (NMS) is associated with early mortality of &gt;30%. Better supportive care has reduced mortality to &lt;10%. Atypical antipsychotics such as clozapine and risperidone are associated with an atypical but potentially lethal, NMS. A 22-year-old male developed NMS after being treated with clozapine and risperidone for aggression associated with mental retardation for about 8 years. For the past 1 year, the dose of clozapine was 200 mg/day and the dose of risperidone was 8 mg/day. The patient presented with symptoms of hyperthermia, perspiration, neck rigidity, and tonic posturing of all four limbs with tongue bite and frothing from the mouth. On examination, the patient’s Glasgow coma Scale was E3V1M4. He was intubated and given antibiotics, antiepileptic, tablet bromocriptine 2.5 mg (1-1-1-1), and other supportive treatment. The patient showed improvement in 10 days. Knowledge of diagnostic features, risk factors, treatment modalities, and differential diagnosis of NMS is essential. Early diagnosis and prompt treatment can reduce mortality and morbidity significantly.

Risperidone ISM®: review and update of its usefulness in all phases of schizophrenia.

One of the most important challenges in the management of patients with schizophrenia is to ensure adherence to antipsychotic treatment. The contribution of long-acting injectables (LAI) is undeniable in this matter, but there are still some unmet medical needs not covered by these drugs (e.g. quick onset of action for patients with acute exacerbation of schizophrenia). This article summarises the pharmacokinetics, efficacy and safety of Risperidone ISM (in situ microparticles). The aim of this review is to provide information about the potential uses of this new LAI formulation of risperidone for the treatment of schizophrenia, contextualising and diving into the published evidence. Risperidone ISM shows a rapid release which allows achieving within 12 h risperidone active moiety levels similar to those observed in the steady-state for oral risperidone treatment, achieving a mean average concentration of 38.63 ng/mL. The plasma concentration of active moiety achieved by Risperidone ISM comes with a predictable dopamine D2 receptor occupancy above 65% throughout the 28-day dosing period, which is accepted as a threshold for the efficacy of the antipsychotic treatment. This can be associated with the positive efficacy findings throughout its clinical development. In the short term, it provides an early and progressive reduction of symptoms in adult patients with acute exacerbation of schizophrenia without the need for loading doses or oral risperidone supplementation, which could contribute to reinforcing the therapeutic alliance between the patient and the psychiatrist. In addition, long-term treatment was effective, safe and well tolerated regardless of the initial disease severity or whether patients were previously treated with Risperidone ISM during an acute exacerbation or switched from stable doses of oral risperidone. Improvement and maintenance of personal and social functioning and health-related quality of life were observed in each setting, respectively. All these findings endorse Risperidone ISM as a useful and valuable treatment for the acute and maintenance management of patients with schizophrenia.

Hyponatremia in the Elderly Induced by Risperidone: A Case Report

Hyponatremia due to risperidone is a rare complication that can be associated with drowsiness, confusion to coma and seizures. We report a case of a 92-year-old female with delirium combined with pulmonary infection who developed severe hyponatremia after 30 days of risperidone treatment, and the patient’s blood sodium gradually increased to normal after administration of concentrated sodium chloride, tolvaptan and gradual reduction of risperidone dosage until discontinuation. Through clinical observation, the mechanism of hyponatremia caused by risperidone is related to the Syndrome of Inappropriate Antidiuretic Hormone (SIADH).

Delusional infestation treated with risperidone: a series of27 patients.

Patients with delusional infestation (DI) frequently refuse to be treated with psychoactive drugs. In the past, pimozide was commonly used as a first-line agent but is now prescribed more rarely. Risperidone was first used to treat DI in 1995. A recent review identified 12 studies that evaluated the use of risperidone in 43 patients with DI. To study the characteristics of and therapeutic results in patients with DI treated with risperidone at a university medical centre in São Paulo, Brazil. We performed a retrospective study of patients with DI treated with risperidone at a dermatological university clinic since 2016. Records were reviewed for personal data and findings related to treatment. Twenty-seven patients were studied (20 women and 7 men). The maintenance dose of risperidone varied from 1 mg three times weekly to 8 mg daily. Control of symptoms was achieved in the majority of patients. A reduction in dosage due to side-effects was seen in four patients; risperidone had to be switched to another antipsychotic in three cases, despite a good response. Only one patient did not respond to risperidone. Risperidone is an effective, well-tolerated and safe treatment for delusional parasitosis. Adequate follow-up is mandatory in order to obtain long-term control of symptoms.

Low Dose Risperidone Prophylaxis for The Prevention of Delirium in The Intensive Care Unit: A Randomized, Placebo Controlled Trial

Background Delirium is common among patients in intensive care units. Antipsychotics have been shown to reduce the incidence of delirium in post-operative patients. We set out to compare the efficacy of risperidone to placebo in preventing delirium in critically ill patients admitted to a medical ICU. Methods This double-blind, randomised controlled trial compared prophylactic low-dose risperidone to placebo in critically ill patients. Patients were screened daily for delirium using a validated screening tool (CAM-ICU), and the incidence of delirium was compared between groups. Results Forty-five patients were recruited. Baseline demographic characteristics, diagnosis and severity of illness were not statistically significantly different between groups. There was no significant difference in the incidence of delirium, adverse events or complications. Conclusion In this study, low-dose risperidone did not prevent the incidence of delirium. As delirium is a heterogeneous syndrome, a single intervention may not be effective across subtypes and aetiologies (ISRCTN17375500) Key Message Prophylactic risperidone did not reduce the incidence of delirium in ICU patients in this small study. As delirium is a heterogeneous syndrome, a single intervention may not be effective across subtypes and aetiologies.

Budget Impact Analysis of Risperidone Use and Adverse Event Monitoring in Autism Spectrum Disorder in Brazil: Assessment of Theoretical Versus Real Data.

Risperidone is used in autism spectrum disorder (ASD) to manage aggressive behavior. Budget impact analysis (BIA) assists managers in promoting more sustainable health systems; however, it is unclear whether BIAs underestimate or overestimate the estimates derived from real-world data. This study aimed to compare the estimated BIA values of risperidone use and the monitoring of adverse events in ASD using theoretical and real data. Analyses were conducted based on the clinical protocol and the Brazilian therapeutic guidelines for ASD. The perspective adopted was that of the Unified Health System (SUS), considering a time horizon of 5 years. Three possible scenarios were considered based on the maximum daily dose of risperidone. Expenses related to the acquisition of risperidone and the monitoring of adverse events were taken into account using health databases in Brazil. For the calculation based on theoretical data, the prevalence of ASD was estimated using information from the scientific literature and the Brazilian demographic census. The model calculated from real data was obtained by analyzing the linear trend of the number of users assisted in the SUS from 2017 to 2021. The population estimated by the theoretical model compared with the model calculated from the real data was higher. Likewise, the 5-year budgetary impact of the theoretical model versus the model calculated from the real data was higher, with statistical significance in all scenarios (p<0.001). In the real data model, the most economically advantageous scenarios were Scenario 1 for children (International dollars [I$]7,630,040.73) and Scenario 3 for adults (I$60,329,288.17). Estimated expenditures for monitoring adverse events ranged from 17 to 74% in children and from 50% to 63% in adults. The data revealed significant differences in population and cost estimation between theoretical data and real-world data. The expenses associated with monitoring adverse events represented a substantial expenditure estimate for the SUS.

The effect of risperidone on behavioral reactions and gene expression of pro- and anti-inflammatory cytokines in neuropathic pain model induced by chronic constriction injury of the sciatic nerve in rat.

Neuropathic pain results from lesions or diseases affecting the somatosensory system. The management of a patient with chronic neuropathic pain remains a challenge several studies report the analgesic effect of serotonin receptor antagonists in different models of experimental pain. The present study was designed to study the effect of systemic administration of risperidone, on behavioral scores of neuropathic pains in chronic constriction (CCI) model in rats. Inducing neuropathic pain with the CCI model which causes heat hyperalgesia, heat, and mechanical allodynia was performed on rats, and then, in two phases, risperidone effect was determined. In the acute phase, risperidone 1, 2, 4mg was administered for three groups half an hour before behavioral tests on the 7th, 14th, and 21st day after surgery, and in the chronic phase, risperidone 1, 2, and 4mg was administered for three different groups from the 1st to 14th days after surgery than on 14th-day behavioral scores were performed. For gene expression analysis, samples are taken from spinal cord tissues in lumbar segments. This study shows chronic administration of risperidone as an antipsychotic drug was effective on heat hyperalgesia and allodynia. However, only the max dosage (4mg) of risperidone showed meaningful improvement in increasing mechanical allodynia. However, acute administering of risperidone did not show any meaningful changes in behavioral tests on neuropathic pain induced by chronic constriction injury of the sciatic nerve in rats. In addition, gene expression results showed an increase in IL-4 and IL-10 gene expression in the risperidone group compared to the sham group. This study suggests the helpful preventive effects of risperidone in developing and increasing neuropathic pain, but it does not have any instant effect.

Efficacy of low-dose risperidone in combination with sertraline in first-episode drug-naïve patients with schizophrenia: a randomized controlled open-label study

ObjectiveDespite advances in pharmacology, the treatment of schizophrenia (SZ) remains a challenge due to relapse after antipsychotic discontinuation and multiple adverse effects of antipsychotics. We hypothesized that a low dose of risperidone in combination with sertraline would reduce serious adverse effects without decreasing treatment response. This study aimed to examine the efficacy, safety, and tolerability of low-dose risperidone combined with sertraline to reduce risperidone dose and serious adverse effects in first-episode and medication-naive (FEMN) SZ patients.MethodsA total of 230 patients with FEMN SZ were randomly assigned to receive low-dose risperidone in combination with sertraline (RS group) or regular-dose risperidone (control group). The Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale (HAMD), and Personal and Social Performance Scale (PSP) were assessed at baseline and the end of the first, second, third, and sixth months. In addition, serum prolactin levels and extrapyramidal symptoms were measured at baseline and follow-up.ResultsRepeated measures ANCOVA showed significant interaction effects of treatment by time on psychotic symptoms, as well as HAMD, PSP scores, prolactin levels, and extrapyramidal symptoms (all p < 0.05). Compared with the control group, the RS group had greater decreases in PANSS total score and its subscores and HAMD score (all p < 0.01) and a greater increase in PSP total score (p < 0.01). Notably, side effects were lower in the RS group relative to the control group. Improvements in HAMD and PANSS total scores, changes in prolactin levels and gender predicted improvements in PSP from baseline to month 6.ConclusionsOur study suggests that low-dose risperidone in combination with sertraline was more effective for psychotic symptoms and psychosocial functioning, with significantly fewer adverse effects in patients with FEMN SZ.Trial registration number: ClinicalTrials.gov, NCT04076371

New-Onset Psychosis in the Context of COVID-19 Infection: An Illustrative Case and Literature Review.

Infection with COVID-19 virus can result in a wide array of neuropsychiatric symptoms, such as anxiety, depression, psychosis, and delirium. Complications can occur even in the absence of a severe respiratory illness. To recognize patterns in the presentation and treatment of patients with psychosis in the context of COVID-19 infection to help inform clinicians who directly care for these patients. In this case report and literature review, the authors first present a case of a 70-year-old female who developed new-onset psychosis in the context of mild infection with COVID-19. The authors then review the literature to present case reports that describe patients similar to the female patient presented. The patient presented in the case report showed improved psychotic symptoms after 3 days of receiving a very low dose of risperidone. Of the case reports reviewed, more than half of the patients presented showed improvement of psychotic symptoms on low or very low doses of antipsychotics. This review shows the necessity of additional research on psychosis due to COVID-19 in order to better understand the course of illnesses and the most effective treatment.

Rifampin – Risperidone and Divalproex Drug-drug Interaction: A Case Report

Rifampin is a potent hepatic cytochrome enzyme inducer, promoting the metabolism of many drugs. Here, we describe a case wherein rifampin-induced drug interactions affected the clinical improvement of a patient on psychiatric drugs for bipolar disorder. He was administered divalproex, risperidone, quetiapine, and clonazepam, along with anti-tuberculosis drugs HERZ, containing 600 mg rifampin. Despite taking 900 mg/day divalproex, his serum valproate levels were below 2 μg/ml, and his manic symptom persisted. Therefore, the antipsychotic risperidone (5 mg) was replaced with olanzapine (20 mg). Following this, his manic symptoms improved rapidly. Rifampin is a potent CYP3A and CYP2D6 inducer and is known to significantly reduce serum risperidone levels. Thus, even a high dose of risperidone did not induce a significant clinical effect, which was observed immediately after replacing with olanzapine. Therefore, drug interactions may have had a significant effect on clinical outcomes. Clinicians should be cognizant of drug interactions when treating psychiatric patients on rifampin therapy. The case has been sufficiently revised to protect the patient's personal information.

Priapism Associated With the Addition of Hydroxyzine to Risperidone: A Case Report

Background: Hydroxyzine hydrochloride is a piperazine derivative antihistamine that is used in the treatment of anxiety. Its tendency to cause somnolence makes it an attractive option for patients with anxiety-induced insomnia. Despite its antihistamine activity, hydroxyzine is noted to have alpha-adrenergic antagonism activity. Other alpha-adrenergic inhibitors have been implicated in medication-induced priapism, including risperidone. Risperidone is a second-generation antipsychotic that primarily blocks serotonin and dopamine receptors, while also inhibiting alpha-1 and alpha-2 receptors with high affinity. Objective: We report a case of a first-of-its-kind case report of a patient who was stable on risperidone and presented with priapism after taking hydroxyzine nightly for the previous 10 days. Results: A 35-year-old male with a past psychiatric history of depression, generalized anxiety disorder, schizoaffective disorder, presented to the emergency department with priapism for 15 hours that required intracaveronsal phenylephrine hydrochloride and manual drainage to achieve detumescence. The patient was on a stable dose risperidone but reported taking hydroxyzine 50 mg nightly for anxiety and insomnia 10 days prior to emergency department admission. Upon resolution of the priapism, the patient stopped hydroxyzine, but continued risperidone. The patient had another prolonged erection 10 days after stopping hydroxyzine; however, he reported that it resolved spontaneously without intervention after 4 hours. Conclusion: This case report demonstrates the risk of addition of hydroxyzine to antipsychotics which can result in an increased risk of priapism or prolonged episodes.

Risperidone-induced respiratory depression in a neonate through breast milk.

Risperidone is commonly used in postnatal mothers for depression and psychotic symptoms in spite of little data on its safety profile in neonates. It is reported previously that 6 mg/day can be used in mothers without having any untoward in breastfed neonates. Excretion of risperidone is dependent on the enzyme CYP2D6 whose activity varies as per individual phenotype. Maximum therapeutic levels are achieved at 2 h of administration of the drug. We are reporting a case of preterm breastfed neonate who presented with respiratory depression twice due to risperidone usage in its mother. This is the first reported case where 1 mg/day dosage of risperidone in nursing mother was associated with acute adverse effects such as respiratory depression in her neonate. The Naranjo Adverse Drug Reaction Probability Assessment Scale scored to 8 which suggests probable relation between the drug and its reaction in neonates. It underscores cautious use in mothers and close monitoring of neonates when risperidone is prescribed irrespective of dosage.

Effect of risperidone on morphine-induced conditioned place preference and dopamine receptor D2 gene expression in male rat hippocampus.

Previous studies suggest the possible effect of risperidone on brain reward system and D1 and D2 dopamine receptors' involvement in morphine-induced conditioned place preference (CPP). The present study was designed to investigate the effect of risperidone as an atypical antipsychotic drug on morphine-induced CPP and D2-like dopamine receptor gene expression in rat. An unbiased CPP paradigm was used to study the effect of risperidone. Intraperitoneal (i.p.) injection of risperidone (1, 2, and 4mg/kg) was performed 30min before the morphine (10mg/kg, i.p.) injection and just after the rat was placed in the CPP box. The open field test was used to assay the locomotor activity of animal. The gene expression of D2 dopamine receptor in hippocampus was measured by real-time PCR technique. The hippocampi of rats were also used for histology evaluation. Morphine-produced (10mg/kg) CPP and morphine-induced CPP were reversed only by the administration of a low dose of risperidone (1mg/kg). Low dose of risperidone (1mg/kg) showed no effect on locomotor activity but a higher dose of risperidone (2 and 4mg/kg) decreased locomotor activity. Real-time PCR data analysis revealed that the gene expression of D2 dopamine receptor had significant difference between morphine and a 1mg/kg dose of risperidone. Moreover, in histological evaluation, apoptosis was observed in the morphine group, whereas there was no evidence of apoptosis in the risperidone-treated groups. Our results suggest that risperidone (1mg/kg) reverses the morphine-induced CPP and may reduce the rewarding properties of morphine. It is also demonstrated that risperidone decreases the expression of D2 receptor in rat hippocampus. Therefore, risperidone can be considered potential adjunct therapy in morphine dependence.

High Dose Risperidone Intoxication in a Patient with Autism Spectrum Disorder

High Dose Risperidone Intoxication in a Patient with Autism Spectrum Disorder