Long-term stability of five atypical antipsychotics (risperidone, olanzapine, paliperidone, clozapine, quetiapine) and the antidepressant mirtazapine in human serum assessed by a validated SPE LC-MS/MS method.

Long-term sample stability of five atypical antipsychoticdrugs risperidone, paliperidone, clozapine, quetiapine and olanzapine and the antidepressant drug mirtazapine in serum was studied by use of a newly developed and validated analytical method based on solid-phase extraction and liquid chromatography-tandem mass spectrometry. Ascorbic acid was used as an antioxidative agent to stabilize olanzapine during storage and sample preparation. We assessed analyte stability on long-term storage in serum samples at 25°C, 5°C, -20°C and -80°C, and during five freeze-thaw cycles. Analytes were stable for 23 days at room temperature except for olanzapine and mirtazapine (17 days). All analytes were stable for at least 30 days at 5°C. All analytes were stable for 270 days at -20°C, except for paliperidone and mirtazapine with 60 days and 180 days, respectively. All analytes were stable for 270 days at -80°C. Furthermore, all analytes were stable for five freeze-thaw cycles. We recommend storage at -80°C when samples drawn for analysis of antipsychotic drugs are stored for more than 60 days, whereas a temperature of -20°C is sufficient for storage less than 60 days.

Transcriptome analysis to explore the mechanism of downregulated TNIK influencing the effect of risperidone.

Background: Risperidone is one of the most reliable and effective antipsychotics for schizophrenia treatment. However, the mechanism of action of risperidone is not yet fully understood. Traf2 and Nck-interacting protein kinase (TNIK), a schizophrenia susceptibility gene, is associated with risperidone treatment response. Our previous in vitro experiments confirmed that downregulated TNIK affected the effect of risperidone on downstream targets. However, the effect of downregulated TNIK on risperidone-induced molecular expression remains to be further explored. Methods: Transcriptome analysis was performed on U251 cells subjected to risperidone, TNIK siRNA, and no treatment, respectively. Compared to the no-treatment group, two groups of DEGs were screened out and then intersected with the schizophrenia-related genes to screen the cross-talk genes. Those DEGs were analyzed using GO and KEGG. STRING and Cytoscape were used to construct a protein-protein interaction (PPI) network for the cross-talk gene. Results: The results showed that the parathyroid hormone synthesis, secretion, and action were significantly enriched after risperidone treatment. Downregulated TNIK could have an impact on the collagen-containing extracellular matrix, signaling receptor activator activity, and PI3K-Akt signaling pathway. Interestingly, bone mineralization function and calcium signaling pathway were enriched in the cross-talk genes. Additionally, FGFR2, FGF1, and FGFR might be the potential targets for TNIK affecting the effects of risperidone. Conclusion: The study indicated that risperidone primarily influences functions and/or pathways associated with bone metabolism, potentially contributing to the adverse effect of osteoporosis. Our study may offer a novel perspective on investigating the mechanisms underlying the adverse effects of risperidone.

Evaluation of the Impact of the Addition of Atypical Antipsychotics to Continuous Infusion Propofol Therapy.

Purpose: The administration of sedatives to critically ill patients is a common practice in intensive care units (ICU) and has been associated with negative outcomes. To mitigate this, atypical antipsychotics are utilized as adjunctive therapy. This study aims to review and quantify overall effectiveness of the atypical antipsychotics quetiapine, risperidone, and olanzapine on reduction in the amount of continuous infusion propofol utilized in the ICU. Methods: This was an observational study that took place from February 27, 2021 to December 31, 2022. The primary outcome of this study was the percentage change in average propofol infusion rate (mcg/kg/min) from baseline to the greater than 24 to 48 hours period after atypical antipsychotic initiation. Secondary outcomes included ICU length of stay, duration of mechanical ventilation, QTc interval monitoring, and continuation of the antipsychotic without a valid indication. Descriptive statistics were utilized for the statistical analysis. Results: A total of 47 patients were included in the study. The average baseline propofol rate was 31 mcg/kg/min, which reduced 8.6% to 28.35 mcg/kg/min over the 0 to 24 hours period, was reduced by 19.4% compared to baseline to a rate of 25 mcg/kg/min during the greater than 24 to 48 hours period, and finally a percent reduction of 54.2% seen during the greater than 48 to 72 hours period to a rate of 14 mcg/kg/min. Conclusions: Patients who received an adjunctive antipsychotic saw resulting propofol rate reductions of 8.6% at 24 hours, 19.4% at 48 hours, and 54.2% at 72 hours. However, research on this topic should not end here, as further investigation with higher-level study design is needed to determine the true impact of these agents for this indication.

Risperidone-Induced Urinary Incontinence in Schizoaffective Disorder: A Case Report.

Risperidone is a widely used atypical antipsychotic known for its efficacy in managing various psychiatric conditions. However, it is not without adverse effects, and one such underreported side effect is that of urinary incontinence. This case report highlights the experience of a 59-year-old gentleman with a diagnosis of schizoaffective disorder who, after being admitted due to a relapse of his symptoms, developed urinary incontinence with risperidone. The patient's symptoms resolved upon the gradual reduction of the risperidone dose to 2 mg at bedtime. Urinary incontinence as a side effect of antipsychotics has been documented in children, especially in those with autism or developmental disorders, but there is limited research on its occurrence in adults. Urinary incontinence can have significant social and psychological impacts on patients, leading to feelings of embarrassment and social withdrawal. It can also contribute to treatment non-adherence leading to frequent relapses and exacerbations of psychiatric symptoms. In managing patients with risperidone-induced urinary incontinence, it is essential to explore medical causes thoroughly before considering medication changes. Behavioral modifications such as bladder training, biofeedback, and lifestyle modifications can also be effective in reducing the frequency of incontinence episodes. This case report emphasizes the importance of prompt identification and intervention to minimize the debilitating effects of urinary incontinence on patients with psychiatric conditions.

Comparative effect of atorvastatin and risperidone on modulation of TLR4/NF-κB/NOX-2 in a rat model of valproic acid-induced autism.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that is significantly increasing, resulting in severe distress. The approved treatment for ASD only partially improves the sympoms, but it does not entirely reverse the symptoms. Developing novel disease-modifying drugs is essential for the continuous improvement of ASD. Because of its pleiotropic effect, atorvastatin has been garnered attention for treating neuronal degeneration. The present study aimed to investigate the therapeutic effects of atorvastatin in autism and compare it with an approved autism drug (risperidone) through the impact of these drugs on TLR4/NF-κB/NOX-2 and the apoptotic pathway in a valproic acid (VPA) induced rat model of autism. METHODS: On gestational day 12.5, pregnant rats received a single IP injection of VPA (500 mg/kg), for VPA induced autism, risperidone and atorvastatin groups, or saline for control normal group. At postnatal day 21, male offsprings were randomly divided into four groups (n = 6): control, VPA induced autism, risperidone, and atorvastatin. Risperidone and atorvastatin were administered from postnatal day 21 to day 51. The study evaluated autism-like behaviors using the three-chamber test, the dark light test, and the open field test at the end of the study. Biochemical analysis of TLR4, NF-κB, NOX-2, and ROS using ELISA, RT-PCR, WB, histological examination with hematoxylin and eosin and immunohistochemical study of CAS-3 were performed. RESULTS: Male offspring of prenatal VPA-exposed female rats exhibited significant autism-like behaviors and elevated TLR4, NF-κB, NOX-2, ROS, and caspase-3 expression. Histological analysis revealed structural alterations. Both risperidone and atorvastatin effectively mitigated the behavioral, biochemical, and structural changes associated with VPA-induced rat model of autism. Notably, atorvastatin group showed a more significant improvement than risperidone group. CONCLUSIONS: The research results unequivocally demonstrated that atorvastatin can modulate VPA-induced autism by suppressing inflammation, oxidative stress, and apoptosis through TLR4/NF-κB/NOX-2 signaling pathway. Atorvastatin could be a potential treatment for ASD.

Metabolic Side Effects of Risperidone in Pediatric Patients with Neurological Disorders: A Prospective Cohort Study.

Background/Objectives: Risperidone-related metabolic side effects in children have been primarily linked to variations between guideline-recommended and clinical treatment procedures. We explored the metabolic effects of risperidone administration in pediatric patients diagnosed with neurological disorders, thus evaluating its influence on metabolic indicators. Methods: This prospective cohort study gathered data from electronic health records, medical databases, and clinical reports. These data included patient demographics (e.g., age, sex, and body mass index) and information on risperidone use, including dosage, dosing frequency, and treatment duration. Additionally, laboratory tests were conducted at baseline and during treatment, along with other pertinent clinical variables. Result: A total of 52 eligible children (male; 73.1%) with neurological disorders treated with risperidone were included. The mean age was 13.4 ± 2.2 years. Risperidone was administered to 32.7% of patients for <2 years, 40.4% for 2-5 years, and 26.9% for 6-9 years, with a mean duration of 3.6 years. Most (53.8%) of the children experienced at least one metabolic side effect, with hyperlipidemia being the most common (34.6%). The median prolactin level increased slightly from 448.5 ng/mL at baseline to 479 ng/mL after 6-8 weeks. No significant associations were found between age, sex, duration of treatment, dosage form, dosing frequency, and hemoglobin A1c levels. Conclusion: Monitoring metabolic and anthropometric parameters in children receiving risperidone for neurological disorders is cardinal. Clinicians should consider individualized treatment plans, closely monitor metabolic markers, and address potential risks associated with long-term risperidone use in this vulnerable population.

Drug-Induced Gynecomastia: Data Mining and Analysis of the FDA Adverse Event Reporting System Database.

Purpose: Drug-induced gynecomastia significantly affects patient health and quality of life. This study aimed to perform an exploratory analysis of gynecomastia reports and the most commonly associated medications within the FAERS database. Patients and Methods: A comprehensive analysis of the FAERS from January 2004 to December 2023 was conducted. Disproportionality analysis and subsequent sensitivity analysis were performed to identify drugs potentially associated with gynecomastia, utilizing the reported odds ratio (ROR). Logistic regression analysis was employed to assess potential risk factors. The Weibull shape parameter (WSP) test was used to assess the time-to-onset characteristics of the top drugs associated with gynecomastia. Results: The study identified 30,265 cases of gynecomastia, primarily associated with nervous system drugs, accounting for 85.50% of cases. Notably, risperidone accounted for 80.81% of the total cases. Among the 165 agents with ≥ 5 cases of gynecomastia, the strongest signals were exhibited by risperidone (ROR 602.38, 95% CI 585.07-620.20), dutasteride (ROR 17.18, 95% CI 15.55-18.89), spironolactone (ROR 15.8, 95% CI 13.99-17.83), and paliperidone (ROR 7.16, 95% CI 6.55-7.84). In the sensitivity analysis of disproportionality, unexpected associations were observed, such as montelukast (n = 21, ROR 1.94, 95% CI 1.26-2.98). The logistic regression analysis indicated that the risk of risperidone-induced gynecomastia was significantly lower in adults compared to pediatric patients (OR 0.12, 95% CI 0.09-0.15) and in patients with higher body weight than in those with lower body weight (OR 5.24, 95% CI 3.62-7.76). The WSP test showed that gynecomastia induced by most of the top 10 common agents tends to occur in an early failure mode. Conclusion: The rankings and signal strengths of drugs associated with gynecomastia were extracted from the FAERS. The age distribution and time-to-onset distribution of the top 10 drugs linked to gynecomastia were investigated, which can facilitate accurate clinical recognition of drug-induced gynecomastia.

Successful Treatment of Risperidone-Induced Hypothermia With Aripiprazole: A Brief Case Report and a Literature Review.

Hypothermia, a potentially fatal condition, can result from various internal causes, including certain medications. Antipsychotics, in particular, are associated with hypothermia, typically emerging 7-10 days after dosage adjustments. Here, we report the case of a 68-year-old male with a history of cerebral palsy, bipolar disorder, and paranoid schizophrenia who was admitted due to poor oral intake and was found to have persistent hypothermia despite active external rewarming. After substituting risperidone with aripiprazole, his temperature normalized, and he experienced no further hypothermic episodes.  Antipsychotic-induced hypothermia should be considered in patients on these medications who present with non-specific symptoms. Regular monitoring of temperature and vital signs is crucial for early detection and management.

Risperidone-induced bioenergetic disruption in the isolated human peripheral blood monocytes.

Risperidone (RIS) is a widely used antipsychotic drug with reported alteration in immune response. The current study investigated mitochondrial disruption as the underlying mechanism of RIS-induced immunotoxicity in isolated human peripheral blood monocytes (hPBM). RIS was cytotoxic to hPBM in exposure duration and concentration-dependent patterns. Functionally, RIS was shown to increase the release of IL-6, TNF-α, and IL-8 with a decrease in test particle phagocytosis in concertation and exposure time-based patterns. It was found that RIS decreased ATP production in isolated monocytes' mitochondria, with an estimated EC50 of around 70 µM after 24 h with parallel inhibition of mitochondrial complexes I and III activities and decreased mitochondrial membrane potential and oxygen consumption rates with increased lactate production from by the treated cells in comparison to controls. Structurally, RIS in 100 µM concentration significantly increased the mitochondrial membrane fluidity with significant increase in increased unsaturated/saturated fatty acids ratios of the mitochondrial membranes of the treated cells. Interestingly, water-soluble CoQ10 formulation significantly decreased the cytotoxic effect of RIS and improved the phagocytic activity of RIS-treated cells. To conclude, the current data suggests mitochondrial disruption as the underlying mechanism of RIS-induced immunotoxicity with shown protective effect of water-soluble CoQ10 formulation.

Elucidating of the metabolic impact of risperidone on brain microvascular endothelial cells using untargeted metabolomics-based LC-MS.

Risperidone is useful for the treatment of schizophrenia symptoms; however, it also has side effects, and an overdose can be harmful. The metabolic effects of risperidone at high therapeutic doses and its metabolites have not been elucidated. Endogenous cellular metabolites may be comprehensively analyzed using untargeted metabolomics-based liquid chromatography-mass spectrometry (LC-MS), which can reveal changes in cell regulation and metabolic pathways. By identifying the metabolites and pathway changes using a nontargeted metabolomics-based LC-MS approach, we aimed to shed light on the potential toxicological effects of high-dose risperidone on brain microvascular endothelial cells (MVECs) associated with the human blood brain barrier. A total of 42 metabolites were selected as significant putative metabolites of the toxicological response of high-dose risperidone in MVECs. Six highly correlated pathways were identified, including those involving diacylglycerol, fatty acid, ceramide, glycerophospholipid, amino acid, and tricarboxylic acid metabolism. We demonstrated that methods focused on metabolomics are useful for identifying metabolites that may be used to clarify the mechanism of drug-induced toxicity.

Association of new-onset diabetes mellitus in adults with schizophrenia treated with clozapine versus patients treated with olanzapine, risperidone, or quetiapine: A systematic review and meta-analysis.

INTRODUCTION: Many articles suggest that clozapine was strongly associated with a higher incidence of new-onset diabetes mellitus, and the issue has remained unsettled. Many articles have compared clozapine with FGAs, but few have compared clozapine with SGAs. We aimed to compare the risk of new-onset diabetes mellitus in adults with schizophrenia treated with clozapine and other SGAs. METHODS: We conducted a comprehensive search of databases from their inception up until August 26, 2023. The specific databases include PubMed, Embase and others. We included non-randomized controlled trials involving the use of SGAs such as clozapine, olanzapine, risperidone, quetiapine, amisulpride, and zotepine, with a focus on new-onset diabetes mellitus as an outcome. We utilized odds ratio with 95 % credible intervals (95 % CI) as our effect size measures. The study protocol is registered with PROSPERO, number CRD42024511280. RESULTS: We included 7 studies with sufficient data to include in the meta-analysis. A total of eight studies with 641,48 participants met the eligibility criteria. The OR of the incidence rates of new-onset diabetes between clozapine and olanzapine was 0.95 (95 % CI:[0.82-1.09]), between clozapine and risperidone was 1.25 (95 % CI: [1.09-1.44]), between clozapine and quetiapine was 1.44 (95 % CI: [0.92-2.25]). CONCLUSION: In patients with schizophrenia, clozapine has been found to have a higher rate of new-onset diabetes mellitus compared to risperidone. However, there was no significant difference in incidence rate between clozapine versus olanzapine and quetiapine. These findings can assist clinicians in balancing the risks and benefits of those drugs.

Quantification of Microsphere Drug Release by Fluorescence Imaging with the FRET System.

Accurately measuring drug and its release kinetics in both in vitro and in vivo environments is crucial for enhancing therapeutic effectiveness while minimizing potential side effects. Nevertheless, the real-time visualization of drug release from microspheres to monitor potential overdoses remains a challenge. The primary objective of this investigation was to employ fluorescence imaging for the real-time monitoring of drug release from microspheres in vitro, thereby simplifying the laborious analysis associated with the detection of drug release. Two distinct varieties of microspheres were fabricated, each encapsulating different drugs within PLGA polymers. Cy5 was selected as the donor, and Cy7 was selected as the acceptor for visualization and quantification of the facilitated microsphere drug release through the application of the fluorescence resonance energy transfer (FRET) principle. The findings from the in vitro experiments indicate a correlation between the FRET fluorescence alterations and the drug release profiles of the microspheres.

Risperidone Pellets, Pycnogenol®, and Glucomannan Gummy Formulation for Managing Weight Gain and ADHD in Autistic Children.

Gummy formulations are defined as gradually or slowly released solid oral dosage forms. Risperidone is an atypical antipsychotic medication used to treat schizophrenia and autism-related irritability. This study presents the development of visually appealing, patient-tailored medicated gummies that act as a novel pharmaceutical form of Risperidone for pediatrics. In this study, two gummy bases were used, one containing Glucomannan and the other containing Gelatin as a gelling agent, where these gummy bases were loaded with coated Risperidone pellets with a controlled release layer. The final products were evaluated for their pH, viscosity, content uniformity, drug content, and dissolution profile. Both formulas showed proper rheology and met content and weight uniformity standards. The release rates for F1 and F2 in the acidic media were 25% and 11%, respectively, after 2 h. At the same time, a full-release profile for Risperidone was noticed in both formulae at pH 6.8 where the release lasts for 24 h. It can be concluded that the chewable semi-solid dosages (gummies) filled with coated pellets are suitable for pediatric patients since pediatrics have drug-related problems which can be solved using high gastro-resistance coated pellets, which also shows a proper release profile for the drug.

ß-Adrenoceptor blockade can augment the torsadogenic action of risperidone.

Risperidone is a second-generation antipsychotic for treating schizophrenia and bipolar disorder. It can potently inhibit IKr, but is classified into conditional risk for torsade de pointes (TdP) by CredibleMeds®. Our previous studies using chronic atrioventricular block dogs showed that risperidone alone did not induce TdP, and that dl-sotalol (ß-adrenoceptor blockade plus IKr inhibition) induced TdP three times more frequently than d-sotalol (IKr inhibition alone). Since risperidone can block α1-adrenoceptor and decrease blood pressure, the resulting reflex-mediated increase of sympathetic tone on ß-adrenoceptor might protect the heart from its IKr inhibition-associated TdP. To validate this hypothesis, risperidone was administered to chronic atrioventricular block dogs after ß-adrenoceptor blocker atenolol infusion with monitoring J-Tpeak and Tpeak-Tend, which are proarrhythmic surrogate markers of "substrate" and "trigger" toward TdP, respectively. Atenolol alone induced TdP in 1 out of 5 dogs; moreover, an additional infusion of risperidone induced TdP in 3 out of 4 dogs. Risperidone prolonged QT interval, J-Tpeak and Tpeak-Tend in animals that induced TdP. These findings indicate that ß-adrenoceptor blockade can diminish repolarization reserve to augment risperidone's torsadogenic potential, thus advising caution when using ß-adrenoceptor blockers in patients with IKr inhibition-linked labile repolarization.

Novel dissolution methods for drug release testing of Long-Acting injectables.

Long-acting parenteral drug products are a popular choice for therapeutic areas requiring long term treatment. These products range from dispersed systems such as drug suspensions and polymeric microspheres to in situ forming polymeric implants. The lack of reliable drug release testing methods for these drug products not only impedes the development of new drug products but also affects generic drug development. Current release methods suffer from a range of problems such as high variability, poor reproducibility, poor discriminatory ability, lack of depot-like structure formation (that could mimic the in vivo situation). Moreover, shorter duration (less than a week) of release renders them unsuitable for in vitro-in vivo correlations (IVIVCs). To overcome these issues, novel adapters were developed for both USP-type-II & IV apparatus. These adapters were validated and assessed using the long-acting injectable (LAI) suspension drug product Depo Provera 150® as well as its Q1/Q2 equivalents. For USP-type-IV apparatus, two open adapter designs (conical and ellipsoidal shaped cavity with volume capacities of 50 µl and 1 ml, respectively) were developed. A closed conical adapter design with a volume capacity of 0.05 ml was developed for USP apparatus type-II. All three novel adapter designs effectively retained the suspensions, achieved release durations of 3-6 weeks with good reproducibility, minimal variability (RSD≤5%) and had good discriminatory ability. Based on this, the adapter-based dissolution methods were deemed suitable for IVIVC development of long-acting injectables. A successful Level A IVIVC was developed for Depo SubQ Provera 104® and its Q1Q2 equivalents using USP apparatus type IV with a conical adapter design. The closed adapter design for apparatus type-II was also investigated for suitability with risperidone in situ forming implants. The adapter was able to securely retain and maintain the shape of the in situ forming implants and resulted in release profiles of up to one month with good discriminatory ability and low standard error (RSD≤5%). These novel adapters hold promise of wide use for in vitro release testing of different long-acting parenteral drug products.

Sex difference alters the behavioral and cognitive performance in a rat model of schizophrenia induced by sub-chronic ketamine.

Schizophrenia is a complex neuropsychiatric disorder with positive, negative, and cognitive symptoms. In rats, sub-chronic administration of ketamine is used for the induction of schizophrenia model. Increased locomotor activity is one of the most important features of psychotic-like symptoms in rodents. On the other hand, risperidone is a potent antipsychotic medication that is approved for the treatment of schizophrenia and bipolar disorder. In the present research, we aimed to investigate the effect of sub-chronic treatment of ketamine on cognitive and behavioral functions, and brain-derived neurotrophic factor (BDNF) expression level in the prefrontal cortex. Also, we assessed the efficacy of risperidone on cognitive and behavioral impairments induced by ketamine. Possible sex differences were also measured. Ketamine was intraperitoneally injected at the dose of 30 mg/kg for five consecutive days. Risperidone was also intraperitoneally injected at the dose of 2 mg/kg. Novel object recognition memory, pain threshold, locomotor activity, rearing behavior, and BDNF level were evaluated. The results showed that ketamine injection for five consecutive days impaired the acquisition of long-term recognition memory and decreased BDNF level in the prefrontal cortex in both sexes. Also, it decreased pain threshold in females, increased rearing behavior in males, and induced hyperlocomotion with greater effect in females. On the other hand, risperidone restored or attenuated the effect of ketamine on all the behavioral effects and BDNF level. In conclusion, we suggested that there were sex differences in the effects of ketamine on pain perception, locomotion, and rearing behavior in a rat model of schizophrenia.

The antipsychotic potential of Salix Mucronata on ketamine-induced rats.

Salix mucronata is one of the herbal plants offered by the traditional health practitioners in KwaZulu-Natal, South Africa for the treatment of schizophrenia. This study aimed to investigate the effects of repeated administration of ketamine on social interaction, novelty and motivation in adult, male Sprague Dawley rats. It also aimed to investigate the potential of risperidone and the herbal extract of S. mucronata to reverse impairments that are induced by ketamine. Experimental rats (n=45) received a dose of ketamine at 30 mg/kg via intraperitoneal injection for 5 consecutive days. They were then allocated into their respective treatment groups and given risperidone (APD) and the herbal extract of S. mucronata (TM) at doses of 6 mg/kg and 5 mg/kg, respectively, for 7 consecutive days. Social behaviour was tested using the 3-chambered sociability test, and anhedonia was tested using the sucrose preference test. Ketamine induction elicited social withdrawal and reduced social novelty which were later successfully reversed by risperidone and S. mucronata. The rats showed reduced preference to sucrose post-induction and post-treatment. Ketamine and mild stress caused by scruff restraint elicited reduced weight gain for the animals. No differences were noted on brain mass between controls and experimental groups and also between risperidone and S. mucronata groups. However, reduced brain volume was noted in experimental groups. Dopamine and acetylcholine concentration levels were high in groups which received risperidone and S. mucronata. These findings highlight that the antipsychotic potential of S. mucronata is similar to risperidone.

Protective Effect of Hyperprolactinemia on Oxidative Stress in Patients with Psychotic Disorder on Atypical Antipsychotics Risperidone and Paliperidone: A Cross-Sectional Study.

Several studies indicate the impact of antipsychotics like risperidone and paliperidone on oxidative stress parameters, yet data remain inconsistent. We investigated the link between these medications, hyperprolactinemia (HPRL), and oxidative stress. This study was conducted at the Psychiatry Clinic, University Clinical Center, Kragujevac, between November 2022 and August 2023. Inclusion criteria comprised diagnosed psychotic disorders from the ICD-10-based F20-F29 spectrum and clinical stability on risperidone/paliperidone for ≥12 weeks with no recent dose adjustments. Exclusion criteria included pregnancy, breastfeeding, relevant medical conditions, or co-therapy with prolactin-secreting drugs. Data encompassed drug choice, administration method, therapy duration, and daily dose. Prolactin (PRL) levels, oxidative stress parameters (TBARS, H2O2, O2-, NO2-), and antioxidant system (CAT, GSH, SOD) were assessed. Of 155 subjects, women exhibited significantly higher PRL levels (p < 0.001) and symptomatic HPRL (p < 0.001). Drug choice and regimen significantly influenced TBARS (p < 0.001), NO2- (p < 0.001), O2- (p = 0.002), CAT (p = 0.04), and GSH (p < 0.001) levels. NO2- levels were affected by drug dose (p = 0.038). TBARS (p < 0.001), O2- (p < 0.001), and SOD (p = 0.022) inversely correlated with PRL levels, suggesting PRL's protective role against oxidative stress. The female sex association with higher PRL levels implies additional factors influencing PRL's antioxidant role. Antipsychotic choice and dosage impact PRL and oxidative stress markers, necessitating further exploration.

Physiologically-Based Pharmacokinetic Modeling and In Vitro-In Vivo Correlation of TV-46000 (Risperidone LAI): Prediction from Dog to Human.

The interest in the development and therapeutic application of long-acting injectable products for chronic or long-term treatments has experienced exponential growth in recent decades. TV-46000 (Uzedy, Teva) is a long-acting subcutaneous (sc) injectable formulation of risperidone, approved for the treatment of schizophrenia in adults. Following sc injection, the copolymers together with risperidone precipitate to form a sc depot under the skin to deliver therapeutic levels of risperidone over a prolonged period of either 1 month or 2 months, depending upon the dose. This work presents the strategy and the results of the physiologically-based pharmacokinetic (PBPK) modeling and establishing of in vitro-in vivo correlation (IVIVC) for the prediction of TV-46000 pharmacokinetic profile in humans, using in vitro release, intravenous (iv), and sc single-dose pharmacokinetic data in beagle dogs. The resulting simulated TV-46000 PK profile in humans showed that the shape of the predicted risperidone and its active metabolite 9-OH-risperidone PK profiles was different from the observed one, thus suggesting that the TV-46000 release profile was species-dependent and cannot be directly extrapolated from dog to human. In conclusion, while level A IVIVC cannot be claimed, this work combining PBPK and IVIVC modeling represents an interesting alternative approach for complex injectable formulations where classical methods are not applicable.

Assessing the Clinical Efficacy of Therapeutic Drug Monitoring for Risperidone and Paliperidone in Patients with Schizophrenia: Insights from a Clinical Data Warehouse.

This study investigated the usage patterns and impact of therapeutic drug monitoring (TDM) for risperidone and paliperidone in patients diagnosed with schizophrenia, utilizing retrospective real-world data sourced from a single center's Clinical Data Warehouse. Our study cohort comprised patients diagnosed with schizophrenia undergoing treatment with either risperidone or paliperidone. Data on demographic characteristics, comorbidities, medication utilization, and clinical outcomes were collected. Patients were categorized into two groups: those undergoing TDM and those not undergoing TDM. Additionally, within the TDM group, patients were further stratified based on their risperidone and paliperidone concentrations relative to the reference range. The findings revealed that patients in the TDM group received higher risperidone and paliperidone doses (320 mg/day and 252 mg/day, p = 0.0045) compared to their non-TDM counterparts. Nevertheless, no significant disparities were observed in hospitalization rates, duration of hospital stays, or compliance between the two groups (p = 0.9082, 0.5861, 0.7516, respectively). Subgroup analysis within the TDM cohort exhibited no notable distinctions in clinical outcomes between patients with concentrations within or surpassing the reference range. Despite the possibility of a selection bias in assigning patients to the groups, this study provides a comprehensive analysis of TDM utilization and its ramifications on schizophrenia treatment outcomes.