A Comparative Study of Short Term Efficacy of Aripiprazole and Risperidone in Schizophrenia

Population Pharmacodynamic Models of Risperidone on PANSS Total Scores and Prolactin Levels in Schizophrenia

Currently, research predominantly focuses on evaluating clinical effects at specific time points while neglecting underlying patterns within the treatment process. This study aims to analyze the dynamic alterations in PANSS total scores and prolactin levels in patients with schizophrenia treated with risperidone, along with the influencing covariates. Using data from an 8-week randomized, double-blind, multicenter clinical trial, a population pharmacodynamic model was established for the PANSS total scores of and prolactin levels in patients treated with risperidone. The base model employed was the Emax model. Covariate selection was conducted using a stepwise forward inclusion and backward elimination approach. A total of 144 patients were included in this analysis, with 807 PANSS total scores and 531 prolactin concentration values. The PANSS total scores of the patients treated with risperidone decreased over time, fitting a proportionally parameterized sigmoid Emax model with covariates including baseline score, course of the disease, gender, plasma calcium ions, and lactate dehydrogenase levels. The increase in prolactin levels conformed to the ordinary Emax model, with covariates encompassing course of the disease, gender, weight, red blood cell count, and triglyceride levels. The impacts of the baseline scores and the course of the disease on the reduction of the PANSS scores, as well as the influence of gender on the elevation of prolactin levels, each exceeded 20%. This study provides valuable quantitative data regarding PANSS total scores and prolactin levels among patients undergoing risperidone treatment across various physiological conditions.

Temporal trends in antipsychotic prescriptions for pediatric patients using an administrative hospital database in Japan: a retrospective study

BACKGROUND

Schizophrenia is a psychiatric disorder characterized by hallucinations, delusions, and other symptoms. Although treatment guidelines for schizophrenia have been established in Japan, drugs are not recommended for pediatric schizophrenia. Additionally, the temporal trends in prescribing antipsychotics for pediatric patients with schizophrenia are unclear. Therefore, we aimed to clarify the trends in antipsychotic prescriptions for Japanese pediatric outpatients from 2015 to 2022.

METHODS

Administrative data (as of November 2023) of Japanese pediatric outpatients with schizophrenia aged 0-18 years who visited acute-care diagnosis procedure combination hospitals between January 1, 2015, and December 31, 2022, were included in this study. The target drugs for schizophrenia were all indicated for treating schizophrenia and marketed in Japan as of December 2022. Annual prescription trends for antipsychotics during this period were calculated based on their proportions. The Cochran-Armitage trend test was used to evaluate the proportion of prescriptions for each antipsychotic.

RESULTS

The main drugs prescribed for these patients were aripiprazole and risperidone. Among male patients, the proportion of prescriptions for aripiprazole increased significantly from 21.2% in 2015 to 35.9% in 2022, whereas that for risperidone decreased significantly from 47.9% in 2015 to 36.7% in 2022 (both P < 0.001). Among female patients, the proportion of prescriptions for aripiprazole increased significantly from 21.6% in 2015 to 35.6% in 2022, whereas that for risperidone decreased significantly from 38.6% in 2015 to 24.8% in 2022 (both P < 0.001).

CONCLUSIONS

Aripiprazole and risperidone were primarily prescribed for pediatric schizophrenia in Japan during the study period. Additionally, the proportion of aripiprazole prescriptions increased over time.

Quetiapine Ameliorates MIA-Induced Impairment of Sensorimotor Gating: Focus on Neuron-Microglia Communication and the Inflammatory Response in the Frontal Cortex of Adult Offspring of Wistar Rats

The maternal immune activation produced by the systemic administration of lipopolysaccharide (LPS) in rats provides valuable insights into the basis of behavioural schizophrenia-like disturbances and biochemical changes in the brains of the offspring, such as microglial activation. Regarding therapy, antipsychotics continually constitute the cornerstone of schizophrenia treatment. To their various efficacy and side effects, as well as not fully recognised mechanisms of action, further characteristics have been suggested, including an anti-inflammatory action via the impact on neuron–microglia axes responsible for inhibition of microglial activation. Therefore, in the present study, we sought to determine whether chronic treatment with chlorpromazine, quetiapine or aripiprazole could influence schizophrenia-like behavioural disturbances at the level of sensorimotor gating in male offspring prenatally exposed to LPS. Simultaneously, we wanted to explore if the chosen antipsychotics display a positive impact on the neuroimmunological parameters in the brains of these adult animals with a special focus on the ligand-receptor axes controlling neuron–microglia communication as well as pro- and anti-inflammatory factors related to the microglial activity. The results of our research revealed the beneficial effect of quetiapine on deficits in sensorimotor gating observed in prenatally LPS-exposed offspring. In terms of axes controlling neuron–microglia communication and markers of microglial reactivity, we observed a subtle impact of quetiapine on hippocampal Cx3cl1 and Cx3cr1 levels, as well as cortical Cd68 expression. Hence, further research is required to fully define and explain the involvement of quetiapine and other antipsychotics in Cx3cl1-Cx3cr1 and/or Cd200-Cd200r axes modulation and inflammatory processes in the LPS-based model of schizophrenia-like disturbances.

Bioequivalence of 2 Aripiprazole Orally Disintegrating Tablets in Healthy Chinese Volunteers Under Fasting and Fed Conditions

To assess the bioequivalence of 2 formulations of aripiprazole orally disintegrating tablets and to monitor their safety and tolerability in Chinese subjects, a single-site, open-label, randomized, 2-preparation, single-dose, 2-period crossover design was conducted. All 60 subjects were randomly divided into the fasting group and the fed group. Blood samples were collected at scheduled times after a single oral dose of orodispersible tablets containing 10 mg of aripiprazole. In the fasting state, the geometric mean ratios (90% confidence intervals [CIs]) of the test/reference formulation were 92.22%-100.20% for the area under the concentration-time curve (AUC) from time zero to the last measured concentration (AUC_0-t ), 91.73%-100.14% for the AUC from administration to infinite time (AUC_0-∞ ), and 98.52%-112.52% for the maximum plasma concentration (C_max ). In the fed state, AUC_0-t , AUC_0-∞ , and C_max were 92.23%-100.20%, 91.73%-100.14%, and 95.91%-105.13%, respectively. The 90%CIs of the test/reference AUC ratio and C_max ratio were within the acceptance range of 80.00%-125.00% for bioequivalence. Neither the maximum peak plasma concentration (t_max ) nor the terminal elimination half-life (t_1/2 ) showed any significant difference. No serious adverse events) were encountered during the study. The test and reference formulations were bioequivalent under both fasting and fed conditions and were found to be safe and tolerated.

The Schizophrenia Susceptibility Gene OPCML Regulates Spine Maturation and Cognitive Behaviors through Eph-Cofilin Signaling

Previous genetic and biological evidence converge on the involvement of synaptic dysfunction in schizophrenia, and OPCML, encoding a synaptic membrane protein, is reported to be genetically associated with schizophrenia. However, its role in the pathophysiology of schizophrenia remains largely unknown. Here, we found that Opcml is strongly expressed in the mouse hippocampus; ablation of Opcml leads to reduced phosphorylated cofilin and dysregulated F-actin dynamics, which disturbs the spine maturation. Furthermore, Opcml interacts with EphB2 to control the stability of spines by regulating the ephrin-EphB2-cofilin signaling pathway. Opcml-deficient mice display impaired cognitive behaviors and abnormal sensorimotor gating, which are similar to features in neuropsychiatric disorders such as schizophrenia. Notably, the administration of aripiprazole partially restores the abnormal behaviors in Opcml^-/- mice by increasing the phosphorylated cofilin level and facilitating spine maturation. We demonstrated a critical role of the schizophrenia-susceptible gene OPCML in spine maturation and cognitive behaviors via regulating the ephrin-EphB2-cofilin signaling pathway, providing further insights into the characteristics of schizophrenia.

In Vivo and Cellular Trafficking of Acetalated Dextran Microparticles for Delivery of a Host-Directed Therapy for Salmonella enterica Serovar Typhi Infection

Previously we have encapsulated host-directed therapy AR-12 into acetalated dextran (Ace-DEX) microparticles (MPs) to mitigate drug toxicity and passively target phagocytic host cells. Herein, we have improved upon our initial emulsion-based formulation of Ace-DEX MPs encapsulating AR-12 (AR-12/MPs) by improving the drug encapsulation efficiency, evaluating sterilization processes for manufacturing, and understanding cellular and in vivo trafficking of the MPs. By using an alternative solvent system, ethyl acetate, we report an increased encapsulation efficiency of AR-12 while maintaining the pH-responsive degradation kinetics of Ace-DEX MPs. To better manufacture this novel antimicrobial formulation, we sterilized AR-12/MPs by gamma irradiation or ethylene oxide and evaluated their efficacy against intracellular Salmonella enterica serovar Typhi. Sterilized AR-12/MPs resulted in a significant reduction in intracellular bacterial burden compared to Blank/MPs. We also characterized intracellular trafficking of Ace-DEX MPs encapsulating fluorophores, which demonstrated internalization of MPs in endo/lysosomal compartments and time and degradation-rate dependent lysosomal escape into cytosolic compartments. Additionally, in vivo toxicity was mitigated following encapsulation of AR-12, where the maximum tolerated dose of AR-12 was increased compared to soluble treatment via intranasal, intravenous, and intraperitoneal administration routes. Following in vivo trafficking of Ace-DEX MPs via the same routes, intranasal administration demonstrated the highest accumulation in the lungs, liver, and kidneys, which persisted out to 240 h. Overall, we have advanced the formulation of this host-directed therapy and broadened the understanding of Ace-DEX MP delivery.