Clinical Pharmacokinetics of Atypical Antipsychotics: An Update

Highly sensitive electrochemical determination of cariprazine using a novel Ti3C2@CoAl2O4 nanocomposite: application to pharmaceutical and biological sample analysis

Cariprazine (CAR) is an atypical antipsychotic drug used for the treatment of schizophrenia and bipolar disorder. This study presents the development of a novel, highly sensitive electrochemical sensor based on a Ti3C2@CoAl2O2 nanocomposite-modified glassy carbon electrode (GCE) for the detection of CAR in pharmaceutical and biological samples. The innovative Ti3C2@CoAl2O2 composite, synthesized and characterized through Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and thermogravimetric analysis, revealed exceptional structural integrity, morphology, composition, and thermal stability. The electrochemical properties of the modified electrode were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy, demonstrating enhanced conductivity, an increased electroactive surface area, and reduced charge transfer resistance compared to the bare GCE. Differential pulse voltammetry was employed for CAR detection under optimized conditions, yielding a linear range of 0.2-5.6 μM with a regression equation Ipa (μA) = 0.133 CCAR (μM) + 0.09 (R2 = 0.993). The limit of detection and limit of quantification were determined as 0.02 µM and 0.07 µM, respectively, highlighting the sensor's high sensitivity. The modified electrode exhibited excellent repeatability with a relative standard deviation (RSD) of = 2.9% and reproducibility (RSD = 2.8%), along with strong selectivity against common interfering substances. The sensor was successfully applied to human blood serum, urine, and CAR tablets, achieving high recovery values (98.52-103.94%), confirming its reliability for real-sample analysis. These findings underline the novelty and potential of the Ti3C2@CoAl2O2-modified GCE as a powerful tool for the accurate, selective, and sensitive determination of CAR in clinical and pharmaceutical applications.

The relationship between cortical synaptic terminal density marker SV2A and glutamate early in the course of schizophrenia: a multimodal PET and MRS imaging study

Loss of glutamatergic terminals is hypothesised to contribute to excitation-inhibition imbalance in schizophrenia, supported by evidence that the normal positive association between glutamate concentrations and synaptic terminal density is not found in patients with chronic schizophrenia. However, it is unknown whether the relationship between synaptic terminal density and glutamate levels is altered early in the course of illness. To address this, we investigated [11C]UCB-J distribution volume ratio (DVR) and glutamatergic markers in healthy volunteers (HV) and in antipsychotic-naïve/free patients with schizophrenia (SCZ) recruited from first-episode psychosis services. Forty volunteers (HV n = 19, SCZ n = 21) underwent [11C]UCB-J positron emission tomography and proton magnetic resonance spectroscopy (1H-MRS) imaging in the anterior cingulate cortex (ACC) and left hippocampus to index [11C]UCB-J DVR and creatine-scaled glutamate (Glu/Cr) and glutamate in combination with glutamine (Glx/Cr). In the HV but not SCZ group, [11C]UCB-J DVR was significantly positively associated with Glu/Cr (Spearman's rho = 0.55, p = 0.02) and Glx/Cr (Spearman's rho = 0.73, p = 0.0004) in the ACC, and with Glu/Cr in the left hippocampus (Spearman's rho = 0.77, p = 0.0001). DVR was significantly lower in the ACC in the SCZ group compared to the HV group (Kolmogorov-Smirnov Z = 1.44, p = 0.03). Together, these findings indicate that the normal relationship between levels of a synaptic terminal density marker and levels of glutamate is disrupted early in the course of schizophrenia. This is consistent with the hypothesis that there is loss of glutamatergic terminals at illness onset.

Effect of CYP3A5*3 genotype on exposure and efficacy of quetiapine: A retrospective, cohort study

BACKGROUND

The involvement of cytochrome P450 3A5 (CYP3A5) in the metabolism of quetiapine has been proposed, though conclusive evidence is lacking. This study aimed to quantitatively assess the impact of CYP3A5 genetic variability on quetiapine exposure in a Chinese patient population.

METHODS

Patient data were retrospectively collected from the database of the Mental Health Centre at the First Hospital of Hebei Medical University, covering the period from September 1, 2019, to July 1, 2023. The study included patients genotyped for CYP3A5 who were treated with quetiapine. Inclusion criteria for the analysis of pharmacokinetic parameters, such as serum concentrations of the drug and its metabolites, included oral administration of quetiapine, availability of information on the prescribed daily dose and concomitant medications, and the determination of steady-state blood levels at the time of sampling (after at least 3 days of continuous administration at the same dose). Exclusion criteria comprised polypharmacy with known CYP3A4 inducers or inhibitors, as well as patients with hepatic or renal insufficiency. The primary endpoint was the exposure to quetiapine and N-dealkylquetiapine, measured using dose-corrected concentrations (C/D). The secondary endpoint was the metabolism of quetiapine to N-dealkylquetiapine, assessed by the ratio of metabolite to parent drug concentrations. The third endpoint is the differences in adverse reactions, QTc intervals, and biochemical parameters among patients with different CYP3A5 genotypes.

RESULT

Based on the inclusion and exclusion criteria, clinical data from 207 patients were ultimately included in the study. Of these, 20 patients had the CYP3A5*1/*1 genotype, 78 had the CYP3A5*1/*3 genotype, and 109 had the CYP3A5*3/*3 genotype. The CYP3A5*3 variant was found to significantly impact the metabolism of quetiapine. The C/D values for both quetiapine and N-dealkyl quetiapine were notably higher in individuals with the *3/*3 genotype compared to those with the *1/*1 and *1/*3 genotypes (P1 < 0.001 and P2 = 0.002, respectively). A comparison of the variability in metabolic ratios among different genotype groups revealed no significant difference (P = 0.067). However, a post hoc analysis indicated that the metabolic ratio in poor metabolizers was significantly lower than that in intermediate metabolizers (P = 0.021). The analysis of adverse reaction incidence and QTc intervals among different genotypes showed no statistically significant differences (P = 0.652, P = 0.486). However, comparison of biochemical parameters across different genotype groups revealed that alanine aminotransferase, uric acid, hemoglobin, and gamma-glutamyl transferase levels were significantly higher in patients with the CYP3A5*3/*3 genotype compared to those with the CYP3A5*1/*1 and CYP3A5*1/*3 genotypes.

CONCLUSION

The results indicated that the genetic polymorphism of CYP3A5*3 significantly influences the metabolism of quetiapine. Specifically, carriers of the CYP3A5*3/*3 genotype exhibited higher blood levels of quetiapine, with a greater likelihood of these levels exceeding the therapeutic range. This finding underscores the need for clinicians to pay special attention to the efficacy and occurrence of adverse reactions when prescribing quetiapine to patients carrying the CYP3A5*3/*3 genotype.

Preliminary Determination of the Therapeutic Reference Range of Lurasidone in Chinese Patients and Analysis of the Factors Influencing Lurasidone Dose-Corrected Concentrations

BACKGROUND

The aim of this study was to determine the therapeutic reference range of lurasidone, and to analyze the factors influencing the dose-corrected concentration of lurasidone in Chinese psychiatric patients, thereby providing a basis for the development of individualized dosing of lurasidone.

METHODS

A retrospective analysis was conducted for hospitalized patients who had received lurasidone and undergone blood concentration monitoring from May 2022 to September 2023 at the Affiliated Brain Hospital of Guangzhou Medical University. Analyses were based on patient demographic data, treatment regimens, and administered drug concentrations.

RESULTS

Data for a total of 123 lurasidone steady-state trough concentrations were collected from 120 hospitalized patients. It was found that 85.56% of lurasidone steady-state trough concentrations were below the lower limit of the lurasidone therapeutic reference range (15 ng·mL-1), and that the median steady-state trough concentration was 7.09 ng·mL-1 (IQ1-IQ3 = 4.12-11.82 ng·mL-1). Gender, age, and co-medication with valproic acid were found to be significant factors influencing lurasidone steady-state trough concentration/daily dose (C/D) values. C/D values for females were 14% higher than those obtained for males. Among patients who did not receive concomitant administration of valproic acid, the C/D values were 55% higher than those who had received co-administered valproic acid. Furthermore, C/D values obtained for elderly patients (≥60 years) were 140% higher than those recorded for adolescents (<18 years) and 157% higher than those in younger adults (18-60 years).

CONCLUSIONS

The findings of this study indicated that the guideline-recommended therapeutic reference range (15-40 ng·mL-1) for lurasidone may not be appropriate, at least for the Chinese population. More extensive therapeutic drug monitoring is recommended for elderly female patients and those receiving co-medication with lurasidone and valproic acid.

Alert prescribing of clozapine: a comparison of five drug-drug interaction sources

Introduction

Clozapine, an antipsychotic used in the treatment of schizophrenia, is known for its serious side effects. In order to promote patient safety, drug-drug interaction (DDI) databases can be consulted by clinicians. In this study, the degree of consensus between five sources on DDIs with clozapine is determined.

Methods

The summary of product characteristics of clozapine, Delphicare interaction database, Stockley's interaction checker, the Lexicomp interaction database, and the interaction database of Clinical Pharmacology are included. By comparing the original categories assigned to interactions with clozapine by the included DDI sources, a degree of consensus between sources is determined. Furthermore, based on the combined information, an evaluation on the severity of each potential interaction is made.

Results

One hundred eighty-three potential DDIs with clozapine are retrieved from the five included sources. A consensus between sources is found in 47.5% (n = 87) of DDIs.

Conclusion

This study shows major discrepancies between five different sources on DDIs with clozapine. The potential impact of the use of one specific database on patient safety and prescribing behavior could prove to be problematic.

Nomogram model for predicting medication adherence in patients with various mental disorders based on the Dryad database

OBJECTIVE

Treatment compliance among psychiatric patients is related to disease outcomes. How to assess patient compliance remains a concern. Here, we established a predictive model for medication compliance in patients with psychotic disorders to provide a reference for early intervention in treatment non-compliance behaviour.

DESIGN

Clinical information for 451 patients with psychotic disorders was downloaded from the Dryad database. The Least Absolute Shrinkage and Selection Operator regression and logistic regression were used to establish the model. Bootstrap resampling (1000 iterations) was used for internal validation and a nomogram was drawn to predict medication compliance. The consistency index, Brier score, receiver operating characteristic curve and decision curve were used for model evaluation.

SETTING

35 Italian Community Psychiatric Services.

PARTICIPANTS

451 patients prescribed with any long-acting intramuscular (LAI) antipsychotic were consecutively recruited, and assessed after 6 months and 12 months, from December 2015 to May 2017.

RESULTS

432 patients with psychotic disorders were included for model construction; among these, the compliance rate was 61.3%. The Drug Attitude Inventory-10 (DAI-10) and Brief Psychiatric Rating Scale (BPRS) scores, multiple hospitalisations in 1 year and a history of long-acting injectables were found to be independent risk factors for treatment noncompliance (all p<0.01). The concordance statistic of the nomogram was 0.709 (95% CI 0.652 to 0.766), the Brier index was 0.215 and the area under the ROC curve was 0.716 (95% CI 0.669 to 0.763); decision curve analysis showed that applying this model between the threshold probabilities of 44% and 63% improved the net clinical benefit.

CONCLUSION

A low DAI-10 score, a high BPRS score, multiple hospitalisations in 1 year and the previous use of long-acting injectable drugs were independent risk factors for medication noncompliance in patients with psychotic disorders. Our nomogram for predicting treatment adherence behaviour in psychiatric patients exhibited good sensitivity and specificity.

Mapping of c-Fos Expression in Rat Brain Sub/Regions Following Chronic Social Isolation: Effective Treatments of Olanzapine, Clozapine or Fluoxetine

The c-Fos as a marker of cell activation is used to identify brain regions involved in stimuli processing. This review summarizes a pattern of c-Fos immunoreactivity and the overlapping brain sub/regions which may provide hints for the identification of neural circuits that underlie depressive- and anxiety-like behaviors of adult male rats following three and six weeks of chronic social isolation (CSIS), relative to controls, as well as the antipsychotic-like effects of olanzapine (Olz), and clozapine (Clz), and the antidepressant-like effect of fluoxetine (Flx) in CSIS relative to CSIS alone. Additionally, drug-treated controls relative to control rats were also characterized. The overlapping rat brain sub/regions with increased expression of c-Fos immunoreactivity following three or six weeks of CSIS were the retrosplenial granular cortex, c subregion, retrosplenial dysgranular cortex, dorsal dentate gyrus, paraventricular nucleus of the thalamus (posterior part, PVP), lateral/basolateral (LA/BL) complex of the amygdala, caudate putamen, and nucleus accumbens shell. Increased activity of the nucleus accumbens core following exposure of CSIS rats either to Olz, Clz, and Flx treatments was found, whereas these treatments in controls activated the LA/BL complex of the amygdala and PVP. We also outline sub/regions that might represent potential neuroanatomical targets for the aforementioned antipsychotics or antidepressant treatments.

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: Focus on antipsychotics

BACKGROUND

For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms. To find the optimal individual dose and dosage strategy, specialised tools are used. Three tools have been proven useful to personalise drug treatments: therapeutic drug monitoring (TDM) of drug levels, pharmacogenetic testing (PG), and molecular neuroimaging.

METHODS

In these Guidelines, we provide an in-depth review of pharmacokinetics, pharmacodynamics, and pharmacogenetics for 45 antipsychotics. Over 30 international experts in psychiatry selected studies that have measured drug concentrations in the blood (TDM), gene polymorphisms of enzymes involved in drug metabolism, or receptor/transporter occupancies in the brain (positron emission tomography (PET)).

RESULTS

Study results strongly support the use of TDM and the cytochrome P450 (CYP) genotyping and/or phenotyping to guide drug therapies. Evidence-based target ranges are available for titrating drug doses that are often supported by PET findings.

CONCLUSION

All three tools discussed in these Guidelines are essential for drug treatment. TDM goes well beyond typical indications such as unclear compliance and polypharmacy. Despite its enormous potential to optimise treatment effects, minimise side effects and ultimately reduce the global burden of diseases, personalised drug treatment has not yet become the standard of care in psychiatry.

Bupropion Increased More than Five Times the Systemic Exposure to Aripiprazole: An In Vivo Study in Wistar albino Rats

Background/Objectives: In psychiatric disorders, antipsychotics and antidepressant medication are often administered together. Aripiprazole, a third-generation antipsychotic drug, is extensively metabolized by CYP2D6 and CYP3A4 isoenzymes, while bupropion, used in depressive disorders, is known as a moderate or strong CYP2D6 enzyme inhibitor. This in vivo experiment aimed to assess the presence of a pharmacokinetic drug interaction between aripiprazole and bupropion and its magnitude on the systemic exposure of aripiprazole. Methods: 24 healthy Wistar albino male rats were included in two study groups. A single dose of 8 mg/kg aripiprazole was given to rats in the reference group, while the test group received repeated doses of bupropion for 6 days, followed by a single dose of aripiprazole. An LC-MS/MS method was developed for the concomitant quantification of aripiprazole and its active metabolite, dehydroaripiprazole, and non-compartmental analysis was employed to assess their pharmacokinetic parameters. Results: The mean AUC0-∞ of aripiprazole increased 5.65-fold (1117.34 ± 931.41 vs. 6311.66 ± 2978.71 hr·ng/mL), the mean Cmax increased by 96.76% and the apparent systemic clearance decreased over 9-fold after bupropion repeated doses. The exposure to aripiprazole's active metabolite increased as well, having a 4-fold increase in the mean AUC0-∞ (from 461.13 ± 339.82 to 1878.66 ± 1446.91 hr·ng/mL) and a 2-fold increase in the mean Cmax. Conclusions: The total exposure to the aripiprazole parent compound and active moiety significantly increased after bupropion pretreatment in this preclinical in vivo experiment. Clinical studies should further establish the significance of this interaction in humans.

Acute Quetiapine Intoxication: Relationship Between Ingested Dose, Serum Concentration and Clinical Presentation-Structured Literature Review and Analysis

Over the past decade, quetiapine has become one of the most commonly used psychotropic drugs in acute intoxication events worldwide. A structured literature review and analysis were conducted to assess the relationship between the kinetic and dynamic profiles in acute quetiapine intoxication. The correlation between dose and peak serum concentration (cmax) was determined using Pearson's correlation coefficient. Binary logistic regression was used to evaluate dose and cmax as predictors of the most common clinical events, signs and symptoms. One hundred and thirty-four cases of acute quetiapine ingestion were included in the analysis, with a median ingested dose of 10 g and a median cmax of 4 mg/L. The typical half-life was estimated to be 16.5 h, significantly longer than at therapeutic doses. For the immediate-release formulation, a biphasic disposition could not be excluded. Dose and cmax demonstrated a weak but significant correlation (r = 0.256; N = 63; p = 0.043). Central nervous system depression and tachycardia were the most common clinical signs. Higher doses and concentrations increased the risk of severe intoxication and were good predictors of intubation, tachycardia, hypotension, QTc prolongation and seizures, but not QRS prolongation, arrhythmia, heart block, hypokalaemia or acidosis. The thresholds for dose and cmax that increased the risk for individual signs and symptoms varied widely. However, doses > 3 g or cmax > 2 mg/L can be considered as alert levels that represent a high risk for severe clinical course of acute quetiapine intoxication.

Aripiprazole, but Not Olanzapine, Alters the Response to Oxidative Stress in Fao Cells by Reducing the Activation of Mitogen-Activated Protein Kinases (MAPKs) and Promoting Cell Survival

Prolonged use of atypical antipsychotics (AAPs) is commonly associated with increased cardiovascular disease risk. While weight gain and related health issues are generally considered the primary contributors to this risk, direct interference with mitochondrial bioenergetics, particularly in the liver where these drugs are metabolized, is emerging as an additional contributing factor. Here, we compared the effects of two AAPs with disparate metabolic profiles on the response of Fao hepatoma cells to oxidative stress: olanzapine (OLA), which is obesogenic, and aripiprazole (ARI), which is not. Results showed that cells treated with ARI exhibited resistance to H2O2-induced oxidative stress, while OLA treatment had the opposite effect. Despite enhanced survival, ARI-treated cells exhibited higher apoptotic rates than OLA-treated cells when exposed to H2O2. Gene expression analysis of pro- and anti-apoptotic factors revealed that ARI-treated cells had a generally blunted response to H2O2, contrasting with a heightened response in OLA-treated cells. This was further supported by the reduced activation of MAPKs and STAT3 in ARI-treated cells in response to H2O2, whereas OLA pre-treatment enhanced their activation. The loss of stress response in ARI-treated cells was consistent with the observed increase in the mitochondrial production of O2•-, a known desensitizing factor. The physiological relevance of O2•- in ARI-treated cells was demonstrated by the increase in mitophagy flux, likely related to mitochondrial damage. Notably, OLA treatment protected proteasome activity in Fao cells exposed to H2O2, possibly due to the better preservation of stress signaling and mitochondrial function. In conclusion, this study highlights the underlying changes in cell physiology and mitochondrial function by AAPs. ARI de-sensitizes Fao cells to stress signaling, while OLA has the opposite effect. These findings contribute to our understanding of the metabolic risks associated with prolonged AAP use and may inform future therapeutic strategies.

Unlocking the potential of lumateperone and novel anti-psychotics for schizophrenia

Schizophrenia is a devastating chronic mental health illness which includes a complex set of symptoms like hallucination, illusion and delusion, and to manage, lifelong antipsychotic medications are needed. Schizophrenia affects 1% of the population worldwide, and to date, two different classes of antipsychotics, i.e., typical and atypical antipsychotics, are available in the market, and there is an urgent need for promising antipsychotic drugs. In this review, we focus on recently approved antipsychotics and then focus on different antipsychotic drugs under clinical trials. In this review, we first focus on lumateperone in detail, which was approved in December 2019 by the Food and Drug Administration (FDA) and simultaneously modulates serotonin, glutamate and dopamine neurotransmitters and is used at doses of 10.5-, 21- and 42 mg, which show mild adverse effects like constipation, sedation, somnolence and fatigue. This review also focuses on a few more emerging antipsychotics like brexpiprazole, brilaroxazine, roluperidone, F17464, pimavanserin (ACP-103), xanomeline, BI 409306, BI 425809 and MK-8189 which are under different phase of clinical trials and might get approved soon. Brexpiprazole and brilaroxazine act on dopamine receptors, whereas xanomeline, pimavanserin and roluperidone do not act on D2 receptors and manage the symptoms. All the antipsychotic drugs covered did not show any other severe adverse effects except gastrointestinal issues and cardiometabolic risk factors. However, still rigorous clinical trials and modifications are needed to manage adverse effects, and we can expect a few antipsychotics to be on the market soon.

Pharmacokinetics and safety of a new generic lurasidone: a phase I bioequivalence study in healthy Chinese subjects

Latuda® is a novel antipsychotic drug for schizophrenia and bipolar depression. A bioequivalence trial was performed to investigate the bioequivalence of Latuda® and its generic drug lurasidone. Two independent trials were carried out, each involving 28 subjects. In the fasting trial, subjects were randomly assigned to two groups (1:1 ratio), receiving either 40 mg of generic lurasidone or Latuda®. After a 7-day washout period, subjects entered the second period with a crossover administration of 40 mg of generic lurasidone or Latuda®. The postprandial study design was similar to that of the fasting study. In the fasting study, the pharmacokinetic (PK) parameter values of generic lurasidone and Latuda® were as follows: the Cmax was 28.84 ± 19.34 ng/ml and 28.22 ± 21.19 ng/ml, respectively; the AUC0-t was 121.39 ± 58.47 h*ng/ml and 118.35 ± 52.24 h*ng/ml, respectively; and the AUC0-∞ was 129.63 ± 63.26 h*ng/ml and 126.59 ± 57.99 h*ng/ml, respectively. The primary pharmacokinetic parameter, Cmax, was assessed for equivalence using reference-scaled average bioequivalence (RSABE), while other parameters (AUC0-t, AUC0-∞) were evaluated using average bioequivalence (ABE). The results indicate that both Cmax and AUC meet the equivalence criteria. In the postprandial study, the PK values of generic lurasidone and Latuda® were as follows: the Cmax was 74.89 ± 32.06 ng/ml and 83.51 ± 33.52 ng/ml, respectively; the AUC0-t was 274.77 ± 103.05 h*ng/ml and 289.26 ± 95.25 h*ng/ml, respectively; and the AUC0-∞ was 302.44 ± 121.60 h*ng/ml and 316.32 ± 109.04 h*ng/ml, respectively. The primary pharmacokinetic parameters (Cmax, AUC0-t, AUC0-∞) were assessed for equivalence using ABE, and both met the equivalence criteria. In the study, lurasidone and Latuda® both exhibited acceptable safety and tolerability. The results displayed that lurasidone and Latuda® were bioequivalent and safe in healthy Chinese participants. Clinical Trial Registry: This trial is registered at chinadrugtrials.org.cn (no.: CTR20191717, date: 2019.08.29).

Second-generation antipsychotic quetiapine blocks voltage-dependent potassium channels in coronary arterial smooth muscle cells

Voltage-dependent K+ (Kv) channels play an important role in restoring the membrane potential to its resting state, thereby maintaining vascular tone. In this study, native smooth muscle cells from rabbit coronary arteries were used to investigate the inhibitory effect of quetiapine, an atypical antipsychotic agent, on Kv channels. Quetiapine showed a concentration-dependent inhibition of Kv channels, with an IC50 of 47.98 ± 9.46 μM. Although quetiapine (50 μM) did not alter the steady-state activation curve, it caused a negative shift in the steady-state inactivation curve. The application of 1 and 2 Hz train steps in the presence of quetiapine significantly increased the inhibition of Kv current. Moreover, the recovery time constants from inactivation were prolonged in the presence of quetiapine, suggesting that its inhibitory action on Kv channels is use (state)-dependent. The inhibitory effects of quetiapine were not significantly affected by pretreatment with Kv1.5, Kv2.1, and Kv7 subtype inhibitors. Based on these findings, we conclude that quetiapine inhibits Kv channels in both a concentration- and use (state)-dependent manner. Given the physiological significance of Kv channels, caution is advised in the use of quetiapine as an antipsychotic due to its potential side effects on cardiovascular Kv channels.

Drug-induced liver injury associated with atypical generation antipsychotics from the FDA Adverse Event Reporting System (FAERS)

BACKGROUND

Recent studies have shown that liver enzyme abnormalities were not only seen with typical antipsychotics (APs) but also with atypical antipsychotics (AAPs). During the last 20 years, the hepatotoxicity of various antipsychotics received much attention. However, systematic evaluations of hepatotoxicity associated with APs are limited.

METHODS

All drug related hepatic disorders cases were retrieved from the FDA Adverse Event Reporting System (FAERS) database using standardized MedDRA queries (SMQ) from the first quarter of 2017 to the first quarter of 2022. Patient characteristics and prognosis were assessed. In this study, a case/non-case approach was used to calculate reporting odds ratio (RORs) and 95% confidence intervals (CIs). We calculated the drug-induced liver injury (DILI) RORs for each AAPs.

RESULTS

A total of 408 DILI cases were attributed to AAPs during the study period. 18.6% of these were designated as serious adverse event (SAE), which include death (19.74%), hospitalization (68.42%), disability (2.63%), and life-threatening (9.21%) outcomes. The RORs values in descending order were: quetiapine (ROR = 0.782), clozapine (ROR = 0.665), aripiprazole (ROR = 0.507), amisulpride (ROR = 0.308), paliperidone (ROR = 0.212), risperidone (ROR = 0.198), ziprasidone (0.131).

CONCLUSION

The result found in our study was that all AAPs didn't have a significant correlation with increased hepatotoxicity. Future analysis of the FAERS database in conjunction with other data sources will be essential for continuous monitoring of DILI.

Initial dosage optimization of olanzapine in patients with bipolar disorder based on model-informed precision dosing: a study from the real world

Objectives

Olanzapine is used for treating bipolar disorder (BPD); however, the optimal initial dosing regimen is unclear. The present study aimed to investigate the optimal olanzapine initial dosage in patients with BPD via model-informed precision dosing (MIPD) based on a real-world study.

Methods

Thirty-nine patients with BPD from the real-world study were collected to construct the MIPD model.

Results

Weight, combined used quetiapine influenced olanzapine clearances in patients with BPD, where the clearance rates were 0.152:1 in patients with or without quetiapine under the same weight. We simulated olanzapine doses once a day or twice a day, of which twice a day was optimal. Without quetiapine, for twice-a-day olanzapine doses, 0.80, 0.70, and 0.60 mg/kg/day were suitable for 40- to 56-kg BPD patients, 56- to 74-kg BPD patients, and 74- to 100-kg BPD patients, respectively. With quetiapine, for twice-a-day olanzapine doses, 0.05 mg/kg/day was suitable for 40- to 100-kg BPD patients.

Conclusion

This study was the first to investigate the optimal olanzapine initial dosage in patients with BPD via MIPD based on a real-world study, providing clinical reference for the precision medication of olanzapine in BPD patients.

Increased antipsychotic drug concentration in hospitalized patients with mental disorders following COVID-19 infection: a call for attention

Purpose

Examine the alterations in antipsychotic concentrations following coronavirus disease-2019 (COVID-19) infection among hospitalized patients with mental disorders and conduct an analysis of the factors influencing these changes.

Methods

Data were collected from inpatients at Beijing Huilongguan Hospital between December 12, 2022, and January 11, 2023, pre- and post-COVID-19. Based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, 329 inpatients with mental disorders were included (3 with incomplete data excluded). Primary outcomes assessed changes in antipsychotic concentrations pre- and post-COVID-19, while secondary outcomes examined factors linked to concentration increases and antipsychotic dose adjustments.

Results

Clozapine (P < 0.001), aripiprazole (P < 0.001), quetiapine (P = 0.005), olanzapine (P < 0.001), risperidone (P < 0.001), and paliperidone (P < 0.001) concentrations increased post-COVID-19 in patients with mental disorders. Notably, clozapine concentration surpassing pre-infection levels was highest. Clozapine users were more likely to adjust their dose (50.4%) compared to olanzapine (17.5%) and other antipsychotics. Moreover, traditional Chinese patent medicines and antibiotics during COVID-19 infection were associated with antipsychotic reduction or withdrawal (OR = 2.06, P = 0.0247; OR = 7.53, P = 0.0024, respectively).

Conclusion

Antipsychotic concentrations in hospitalized patients with mental disorders increased after COVID-19 infection, that may be related not only to COVID-19, but also to the use of Chinese patent medicines during infection. The pre-infection concentration and types of antipsychotics, patient's gender, and combination of traditional Chinese medicine or antibiotics, were factors found to correlate with increased drug concentrations and necessitate dose adjustments.

Living systematic review and meta-analysis of plasma-concentrations of antipsychotic drugs in carriers and non-carriers of variant CYP450 genotypes: Living systematic review protocol

Introduction

Carriers of variant alleles of genes that encode liver CYP450 and UGT enzymes may experience abnormal plasma levels of antipsychotics and, consequently, worse efficacy or tolerability. Although pharmacogenomics is a rapidly developing field, current guidelines often rely on limited, underpowered evidence. We have previously demonstrated that meta-analysis is a viable strategy for overcoming this problem. Here, we propose a project that will expand our previous work and create a living systematic review and meta-analysis of drug plasma level differences between carriers and non-carriers of variant genotype-predicted phenotypes for every pharmacokinetic drug-gene interaction relevant to commonly used antipsychotic drugs.

Protocol

First, a baseline systematic review and meta-analysis will be conducted by searching for observational pharmacogenomics-pharmacokinetic studies. Data on dose-adjusted drug plasma levels will be extracted, and participants will be grouped based on their genotype for each drug-gene pair separately. Differences in plasma drug levels between different phenotypes will be compared using a random-effect ratio-of-means meta-analysis. The risk of bias will be assessed using ROBINS-I, and the certainty of evidence will be assessed using GRADE. Following the establishment of baseline results, the literature search will be re-run at least once every six months, and the baseline data will be updated and re-evaluated as new evidence is published. A freely available website will be designated to present up-to-date results and conclusions.

Discussion

This systematic review will provide evidence-based results that are continuously updated with evidence as it emerges in the rapidly developing field of pharmacogenomics. These results may help psychiatrists in their decision-making, as clinicians are becoming increasingly aware of the patients' genetic data as testing becomes more widespread and cheaper. In addition, the results may serve as a scientific basis for the development of evidence-based pharmacogenomics algorithms for personalized dosing of antipsychotics to mitigate potentially harmful drug-gene interactions.

Lactate: a prospective target for therapeutic intervention in psychiatric disease

ABSTRACT

Although antipsychotics that act via monoaminergic neurotransmitter modulation have considerable therapeutic effect, they cannot completely relieve clinical symptoms in patients suffering from psychiatric disorders. This may be attributed to the limited range of neurotransmitters that are regulated by psychotropic drugs. Recent findings indicate the need for investigation of psychotropic medications that target less-studied neurotransmitters. Among these candidate neurotransmitters, lactate is developing from being a waste metabolite to a glial-neuronal signaling molecule in recent years. Previous studies have suggested that cerebral lactate levels change considerably in numerous psychiatric illnesses; animal experiments have also shown that the supply of exogenous lactate exerts an antidepressant effect. In this review, we have described how medications targeting newer neurotransmitters offer promise in psychiatric diseases; we have also summarized the advances in the use of lactate (and its corresponding signaling pathways) as a signaling molecule. In addition, we have described the alterations in brain lactate levels in depression, anxiety, bipolar disorder, and schizophrenia and have indicated the challenges that need to be overcome before brain lactate can be used as a therapeutic target in psychopharmacology.

Synergistic action of vitamin D3 and A on motor activity regulation in mice model of extrapyramidal syndrome: Correlational insights into astrocyte regulation, cytokine modulation, and dopaminergic activity

BACKGROUND

Extrapyramidal syndromes (EPS) represent neurological side effects of antipsychotic medications, characterized by motor disturbances. While previous studies have indicated the neuroprotective effects of vitamin D and A against EPS, the underlying mechanisms of this protection remain unclear.

METHODS

Twenty-four adult mice were categorized into four groups: positive and negative control groups, one receiving a dopamine antagonist, and the other receiving both a dopamine antagonist and vitamins D and A. Sections of the corticobasal loop, specifically the motor cortex (M1) and basal nuclei (CPu), were prepared for Immunohistochemistry (IHC) and stained with Glial Fibrillary Acidic Protein (GFAP) to visualize reactive astrocytes. ELISA assays for TNF-α, IL-6, IL-4, IL-13, and dopamine levels were performed on homogenized brain sections.

RESULTS

The EPS group exhibited a significant increase in TNF-α and IL-6 levels in M1 and CPu. Treatment with dopamine agonists and vitamin D&A resulted in significant reductions in IL-6 levels. Only the Vitamin D&A group showed a significant decline in TNF-α. The EPS group recorded significant decreases in IL-4 and IL-13, with IL-13 significantly elevated in the dopamine agonist and Vitamin D&A groups. IL-4 was notably increased in the Vitamin D&A groups. Dopamine concentration significantly declined in the EPS group, with improvements observed in the groups treated with dopamine agonists, and vitamin D&A. Reactive astrocytes were significantly expressed in the M1 and CPu of the EPS group but poorly expressed in other groups.

CONCLUSIONS

EPS is linked to astrocyte activation, an upsurge in pro-inflammatory cytokines, a decline in anti-inflammatory cytokines, and dopamine in the corticobasal loop. Administration of vitamin D3 and A was found to suppres pro-inflammatory cytokines and repress anti-inflammatory cytokines associated with astrocyte activation.

Dose-dependent effect of lamotrigine on quetiapine serum concentration in patients using instant release tablets

PURPOSE

Lamotrigine was previously reported to reduce serum concentration of quetiapine. The aim of this study was to investigate whether lamotrigine dose or quetiapine formulation was of importance for the drug interaction.

METHODS

Patients combining lamotrigine with quetiapine (cases) were included retrospectively from a routine therapeutic drug monitoring (TDM) service, as were a control group of patients using quetiapine without any interacting drugs. The case and control groups were divided into groups using immediate release (IR) and extended release (XR) quetiapine. The case group was further split into high-dose (> 200 mg/day) and low-dose (≤ 200 mg/day) lamotrigine users. Quetiapine concentration-to-dose (C/D) ratio and metabolite-to-parent ratio (MPR) were compared between the control group and dose-separated case groups using ANOVA test and t-tests.

RESULTS

In total, 406 patients were included. The mean C/D ratio of IR quetiapine was 46% lower in the high-dose lamotrigine group compared with the control group (P < 0.001), while no interaction effect was present in the low dose lamotrigine group (P = 0.7). Regardless of lamotrigine dose, there was no difference in quetiapine C/D ratio for patients using the XR formulation (P = 0.4). The quetiapine MPR was unaffected regardless of formulation and lamotrigine dose (P ≥ 0.06).

CONCLUSION

The effect of lamotrigine in reducing quetiapine concentration is only significant for patients using quetiapine IR tablets who are treated with lamotrigine doses > 200 mg/day. Because of high variability in the interaction effect, TDM of quetiapine should be recommended during co-prescription of high-dose lamotrigine.

Brexpiprazole toxicity in a paediatric patient

Brexpiprazole is a relatively new drug that has no published research or applications within the paediatric population. Brexpiprazole targets multiple receptors and can manifest as multisystem symptoms when ingested in supratherapeutic quantities. In this report, we discuss the case of a child in early childhood who presented with delayed neurological and cardiac symptoms 24 hours after accidental ingestion of brexpiprazole. Due to delayed onset, this case highlights that a high index of suspicion and prolonged observation are necessary to appropriately manage brexpiprazole overdose or accidental ingestion.

Relationship between plasma risperidone concentrations and clinical features in chronic schizophrenic patients in China

BACKGROUND

Prior studies have noted great variability in the plasma levels of risperidone (RIS). Plasma concentrations of RIS and its active moiety are highly variable and depend on absorption, metabolism, and other predictors of metabolic dysregulation; however, these factors are poorly understood and the association between metabolic change and change in psychopathology is uncertain.

AIM

To ascertain the characteristics of chronic schizophrenic patients treated with RIS, and to assess their relationship with plasma RIS levels.

METHODS

This was a descriptive cross-sectional study of 50 patients with a diagnosis of schizophrenic psychosis treated with RIS in a psychiatric service. The plasma concentrations of RIS and its metabolite 9-hydroxyrisperidone were determined by high performance liquid chromatography. The patients' demographic and clinical characteristics, and psychopathologies were assessed, and the associations between clinical variables and plasma levels of RIS were explored.

RESULTS

Male patients received higher doses of RIS than female ones, but plasma concentrations of RIS and risperidone + 9-hydroxyrisperidone (active moiety) were higher in female patients. Age and the mean scores of the general psychopathology subscale of the Positive and Negative Syndrome Scale (PANSS) were significantly positively correlated with plasma concentrations of risperidone + 9-hydroxyrisperidone adjusted for weight and dose in all 50 subjects. In male subjects, we found a statistically significant positive correlation between the concentrations of risperidone + 9-hydroxyrisperidone in plasma/(dose × kg) and age, mean PANSS negative subscale scores, mean PANSS general psychopathology subscale scores, and mean PANSS total scores.

CONCLUSION

Long-term use of RIS should be closely monitored in older patients and females to minimize the risk of high concentrations which could induce side effects.

The impact of CYP3A5*3 on oral quetiapine: A population pharmacokinetic model in Chinese bipolar disorder patients

BACKGROUND

There is great interindividual difference in the plasma concentration of quetiapine, and optimizing quetiapine therapy to achieve a balance between efficacy and safety is still a challenge. In our study, a population pharmacokinetic (PPK) model considering genetic information was developed with the expectation of comprehensively explaining this observation in Chinese patients with bipolar disorder.

METHODS

Patients who were dispensed quetiapine and underwent the therapeutic drug monitoring (TDM) were included. The genotypes of CYP3A5*3, CYP2D6*10, and ABCB1 C3435T/G2677T were analyzed. Finally, a multivariable linear regression model was applied to describe the PPK of quetiapine considering the covariates weight, height and genotype information.

RESULTS

A total of 175 TDM points from 107 patients were adopted for PPK model development. Resultantly, the CL/F of quetiapine in CYP3A5 expressers was 81.1 CL/h, whereas it was 43.6 CL/h in CYP3A5 nonexpressers. The interindividual variability in CL/F was 47.7 %. However, neither the ABCB1 nor CYP2D6 genotype was significantly associated with the predictor of quetiapine clearance in our study.

LIMITATIONS

Only trough concentrations were collected, and the span between different points was relatively wide, impeding the application of the typical nonlinear compartment model for PPK analysis. In addition, this was a single-center study which limited the sample of wild-type CYP3A5 carriers.

CONCLUSIONS

The currently established PPK model of quetiapine considering the contribution of the CYP3A5 genotype could efficiently predict the population and individual pharmacokinetic parameters of Chinese bipolar disorder patients, which could better guide the personalized therapy with quetiapine, thus to achieve the best clinical response.

Clinical and pharmacological factors influencing serum clozapine and norclozapine levels

Background

Clozapine (CLO) is a very effective antipsychotic, whose use is associated with dose-dependent risk of complications. Due to high interindividual variability in CLO metabolism, there is a need to identify factors affecting the blood concentrations of CLO and its active metabolite, norclozapine (NCLO).

Methods

A total of 446 blood samples (collected from 233 women and 213 men, aged from 18 to 77 years) were included in this study and analyzed for CLO and NCLO concentrations. The patients were treated at a psychiatric hospital in Warsaw in the years 2016-2021. Serum CLO and NCLO concentrations were determined with high-performance liquid chromatography coupled to UV.

Results

The following factors were shown to increase serum CLO and NCLO levels: higher CLO dose (p < 0.001), female sex (p < 0.001), nonsmoker status (p < 0.001), the use of more than two additional psychotropic drugs (only in the case of CLO; p = 0.046), concomitant use of beta-blockers (for CLO p = 0.049; for NCLO p < 0.001), and older age (for CLO p < 0.001; for NCLO p = 0.011). Despite the use of CLO at daily doses within the recommended range (200-450 mg), the evaluated serum CLO and NCLO levels were within the therapeutic ranges in only 37% and 75% of cases, respectively, with 5.6% of cases exceeding the CLO toxicity threshold.

Discussion

The use of CLO at recommended doses does not guarantee achieving therapeutic concentrations of CLO or NCLO. Women and nonsmokers were at the highest risk of having toxic CLO levels.

Inhibition of voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells by the atypical antipsychotic agent sertindole

The regulation of membrane potential and the contractility of vascular smooth muscle cells (VSMCs) by voltage-dependent K+ (Kv) potassium channels are well-established. In this study, native VSMCs from rabbit coronary arteries were used to investigate the inhibitory effect of sertindole, an atypical antipsychotic agent, on Kv channels. Sertindole induced dose-dependent inhibition of Kv channels, with an IC50 of 3.13 ± 0.72 μM. Although sertindole did not cause a change in the steady-state activation curve, it did lead to a negative shift in the steady-state inactivation curve. The application of 1- or 2-Hz train pulses failed to alter the sertindole-induced inhibition of Kv channels, suggesting use-independent effects of the drug. The inhibitory response to sertindole was significantly diminished by pretreatment with a Kv1.5 inhibitor but not by Kv2.1 and Kv7 subtype inhibitors. These findings demonstrate the sertindole dose-dependent and use-independent inhibition of vascular Kv channels (mainly the Kv1.5 subtype) through a mechanism that involves altering steady-state inactivation curves. Therefore, the use of sertindole as an antipsychotic drug may have adverse effects on the cardiovascular system.

Evaluating the efficacy and safety of the currently available once-every-two months long-acting injectable formulations of aripiprazole for the treatment of schizophrenia or as a maintenance monotherapy for bipolar I disorder in adults

INTRODUCTION

An aripiprazole long-acting injectable (LAI) antipsychotic is now available for gluteal administration every 2 months via two different formulations: aripiprazole lauroxil (AL) and aripiprazole monohydrate (Ari 2MRTU). These longer dosing regimens of aripiprazole LAI offer new potential benefits for patients.

AREAS COVERED

The authors review the evidence supporting the efficacy and safety of aripiprazole LAIs given every 2 months for the treatment of schizophrenia or bipolar disorder (BD) in adults. The article culminates with the authors' expert perspectives on the subject.

EXPERT OPINION

AL 1064 mg every 2 months has established efficacy for the treatment of schizophrenia based on pharmacokinetic bridging studies and prospective data for treatment of an acute exacerbation of schizophrenia. In an open-label trial, Ari 2MRTU showed efficacy for the treatment of schizophrenia and BD type I based on pharmacokinetic parameters (comparable to aripiprazole once-monthly 400 mg); it also showed efficacy regarding the secondary endpoints. Multiple doses of AL 1064 mg or Ari 2MRTU 960 mg are generally well tolerated, in line with the safety profile of oral aripiprazole, with the exception of the injection-site reactions. While AL may require a 1-day initiation regimen, Ari 2MRTU 960 covers all the recommended doses of oral aripiprazole (10-20 mg).

Abnormal blood concentration changes in a 71-year-old female who survived a 10,000mg overdose of clozapine: a case report

BACKGROUND

Clozapine is a highly effective second-generation antipsychotic with few extrapyramidal reactions, making it a preferred choice among clinicians. However, instances of acute clozapine poisoning resulting from suicide attempts and misuse have been reported. Through our review of existing literature, we identified that we believe to be the highest recorded overdose of clozapine in elderly patients, resulting in a nonfatal outcome.

CASE PRESENTATION

The case report involves a 71-year-old female with a history of depression who ingested a dose of 10,000 mg of clozapine. Approximately 6 h after the overdose, the clozapine level was 5,200 μg/L, significantly surpassing the recommended therapeutic concentration range of 350-600 μg/L. After gastric lavage and hemoperfusion, the blood level dropped to 1847.11 μg/L. Notably, during therapeutic drugs monitoring (TDM), we found a perplexing spike in the patient's blood level to 5554.15 μg/L after the second hemoperfusion.

CONCLUSION

In this case we mainly focused on the abnormal fluctuations in the concentration of clozapine. We conducted a comprehensive analysis of potential factors contributing to this abnormal phenomenon in terms of the patient's age, clinical symptoms, various laboratory test indexes, and the pharmacokinetics of clozapine. Our findings underscore the importance of timely TDM and the precision of results in managing elderly patients experiencing high-dose clozapine poisoning.

Quantifying the effects of practicing a semantic task according to subclinical schizotypy

The learning ability of individuals within the schizophrenia spectrum is crucial for their psychosocial rehabilitation. When selecting a treatment, it is thus essential to consider the impact of medications on practice effects, an important type of learning ability. To achieve this end goal, a pre-treatment test has to be developed and tested in healthy participants first. This is the aim of the current work, which takes advantage of the schizotypal traits present in these participants to preliminary assess the test's validity for use among patients. In this study, 47 healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a semantic categorization task twice, with a 1.5-hour gap between sessions. Practice was found to reduce reaction times (RTs) in both low- and high-SPQ scorers. Additionally, practice decreased the amplitudes of the N400 event-related brain potentials elicited by semantically matching words in low SPQ scorers only, which shows the sensitivity of the task to schizotypy. Across the two sessions, both RTs and N400 amplitudes had good test-retest reliability. This task could thus be a valuable tool. Ongoing studies are currently evaluating the impact of fully deceptive placebos and of real antipsychotic medications on these practice effects. This round of research should subsequently assist psychiatrists in making informed decisions about selecting the most suitable medication for the psychosocial rehabilitation of a patient.

Third-Generation Antipsychotics and Lurasidone in the Treatment of Substance-Induced Psychoses: A Narrative Review

This narrative review explores the efficacy and tolerability of third-generation antipsychotics (TGAs)-aripiprazole, cariprazine, brexpiprazole, and lurasidone-for the management of substance-induced psychosis (SIP). SIP is a psychiatric condition triggered by substance misuse or withdrawal, characterized by unique features distinct from those of primary psychotic disorders. These distinctive features include a heightened prevalence of positive symptoms, such as hallucinations and delusions, in addition to a spectrum of mood and cognitive disturbances. This review comprehensively investigates various substances, such as cannabinoids, cocaine, amphetamines, and LSD, which exhibit a greater propensity for inducing psychosis. TGAs exhibit substantial promise in addressing both psychotic symptoms and issues related to substance misuse. This review elucidates the distinctive pharmacological properties of each TGA, their intricate interactions with neurotransmitters, and their potential utility in the treatment of SIP. We advocate for further research to delineate the long-term effects of TGAs in this context and underscore the necessity for adopting an integrated approach that combines pharmacological and psychological interventions. Our findings underscore the intricate and multifaceted nature of treating SIP, highlighting the potential role of TGAs within therapeutic strategies.

Risperidone plasma level, and its correlation with CYP2D6 gene polymorphism, clinical response and side effects in chronic schizophrenia patients

BACKGROUND

To explore the influence of CYP2D6 genetic polymorphism on risperidone metabolism, thereby affecting risperidone's effects and safeties in patients with chronic schizophrenia.

METHODS

Sixty-nine subjects with chronic schizophrenia treated with risperidone were recruited. CYP2D6 genotypes was determined using targeted sequencing and translated into phenotype using activity system. Risperidone plasma concentrations were measured using HPLC. Positive and Negative Symptom Scale (PANSS) and Brief Psychiatric Rating Scale (BPRS) were used to evaluate the existence and severity of psychiatric symptoms, Barnes Akathisia Scale (BAS) and Extrapyramidal Symptom Rating Scale (ESRS) for neurological side effects. Metabolic and endocrine status assess were also included.

RESULTS

The plasma drug concentrations varied hugely among individuals. Intermediate metabolizer (IM) group had higher plasma levels of RIP and dose corrected RIP concentration, RIP/9-OH-RIP ratio and C/D ratio than normal metabolizer (NM) group (p < 0.01). There was no statistic difference between responders and non-responders in dose-adjusted plasma concentrations and ratios of RIP/9-OH-RIP and C/D. The occurrence of EPS was related to active moiety levels in 4th week (p < 0.05). The prolactin (PRL) levels in two follow-ups were both significantly higher than baseline (p < 0.01). PRL change from baseline to week 4 and week 8 were both positively associated with active moiety concentration detected in week 4 (p < 0.05).

CONCLUSIONS

The risperidone plasma levels have great inter- and intraindividual variations, and are associated with the CYP2D6 phenotypes, as well as the changes in serum prolactin in patients diagnosed with chronic schizophrenia.

Cariprazine augmentation of clozapine in schizophrenia-a retrospective chart review

The aim of our study was to evaluate the efficacy of cariprazine augmentation of clozapine in treatment-resistant schizophrenia in a retrospective chart review. Among 916 medical records of schizophrenia patients, we identified 12 individuals treated with a combination of those drugs for a duration of 3-60 weeks [median 32 (10-40)]. Clinical Global Impression-Improvement (CGI-I) scores were used to measure the treatment response between the introduction of cariprazine augmentation of clozapine and the last point of observation. The majority of the patients presented treatment response (9/12 patients, 75%) after 4-16 weeks of therapy [median 6 (4-12)]. Treatment was associated with the decrease in positive, negative, affective, and anxiety symptom severity, as well as improvement of patient global functioning. One patient discontinued the treatment due to side effects (akathisia), and two patients halted the therapy due to the exacerbation of psychotic symptoms. Our study presents a thorough clinical description of the largest number of treatment-resistant schizophrenia patients medicated using cariprazine augmentation of clozapine in a "real-world" setting. Our results suggest that the use of this combination may lead to the improvement in a broad range of symptoms of patients with this condition.

Insights into the population pharmacokinetics and pharmacodynamics of quetiapine: a systematic review

INTRODUCTION

Quetiapine exhibits notable pharmacokinetic and pharmacodynamic (PK/PD) variability, the origins of which are poorly understood. This systematic review summarizes published population PK/PD studies and identifies significant covariates accounting for this variability to inform precision dosing.

METHODS

We systematically searched the PubMed, Web of Science, and Embase databases and compared study characteristics, model parameters, and covariate effects. Visual predictive distributions were used to compare different models. Forest plots and Monte Carlo simulations were used to assess the influence of covariates.

RESULTS

Six population PK and three population PK/PD studies were included. The median apparent clearance in adults was 87.7 L/h. Strong and moderate cytochrome P450 3A4 inducers increased the apparent clearance approximately fourfold, while strong cytochrome P450 3A4 inhibitors reduced it by 93%. The half-maximum effect concentrations were 82.8 ng/mL for the Brief Psychiatric Rating Scale and 583 ng/mL for dopamine D2 receptor occupancy. Both treatment duration and quetiapine exposure were associated with weight gain.

CONCLUSIONS

Concurrent administration of potent or moderate CYP3A4 inducers and inhibitors need to be avoided in quetiapine-treated patients. When co-medication is required, it is recommended to adjust the dosage based on therapeutic drug monitoring. Additional research is warranted to delineate the dose-exposure-response relationships of quetiapine and active metabolite norquetiapine in pediatrics, geriatrics, hepatically-impaired patients, and women using contraceptives or are pregnant or menopausal.

PROSPERO REGISTRATION

CRD42023446654.

Evidence for Therapeutic Drug Monitoring of Atypical Antipsychotics

Second-generation antipsychotics (SGAs), also known as atypical antipsychotics, are a newer class of antipsychotic drugs used to treat schizophrenia, bipolar disorder, and related psychiatric conditions. The plasma concentration of antipsychotic drugs is a valid measure of the drug at its primary target structure in the brain, and therefore determines the efficacy and safety of these drugs. However, despite the well-known high variability in pharmacokinetics of these substances, psychiatric medication is usually administered in uniform dosage schedules. Therapeutic drug monitoring (TDM), as the specific method that can help personalised medicine in dose adjustment according to the characteristics of the individual patient, minimizing the risk of toxicity, monitoring adherence, and increasing cost-effectiveness in the treatment, thus seems to be an elegant tool to solve this problem. Non-response to therapeutic doses, uncertain adherence to medication, suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM of SGAs. This review aims to summarize an overview of the current knowledge and evidence of the possibilities to tailor the dosage of selected SGAs using TDM, including the necessary pharmacokinetic parameters for personalised pharmacotherapy.

Relationship between clinical efficacy and plasma concentration-dose ratio of risperidone in patients with schizophrenia

This study aimed to retrospectively explore the relationship between clinical efficacy and plasma concentration-dose ratio of risperidone (RIS) in 252 patients with schizophrenia taking RIS orally. After the same dose of RIS treatment, the plasma concentration of RIS/9-hydroxyrisperidone (9-OH-RIS), the total plasma concentration of RIS, and the ratio of the steady-state plasma concentration to the daily dose of the total active product (C/D) showed individual difference. The RIS plasma concentration was significantly higher in patients taking high doses than those taking lower doses ( P  = 0.003). There was a statistically significant difference in C/D ratio between males and females ( P  = 0.003). There were significant differences in ratio of C/D and the total plasma concentration of RIS between patients under 60 years and over 60 years ( P  = 0.016; P  = 0.005). Logistic regression analysis showed that the therapeutic effect and adverse reactions of RIS were correlated with the ratio of C/D in patients with schizophrenia ( P  = 0.038; P  < 0.001). It has been suggested that the importance of monitoring of the plasma concentration of RIS in patients with schizophrenia and the ratio of C/D may be used as the reference for RIS personalized treatment.

Monoamines' role in islet cell function and type 2 diabetes risk

The two monoamines serotonin and melatonin have recently been highlighted as potent regulators of islet hormone secretion and overall glucose homeostasis in the body. In fact, dysregulated signaling of both amines are implicated in β-cell dysfunction and development of type 2 diabetes mellitus (T2DM). Serotonin is a key player in β-cell physiology and plays a role in expansion of β-cell mass. Melatonin regulates circadian rhythm and nutrient metabolism and reduces insulin release in human and rodent islets in vitro. Herein, we focus on the role of serotonin and melatonin in islet physiology and the pathophysiology of T2DM. This includes effects on hormone secretion, receptor expression, genetic variants influencing β-cell function, melatonin treatment, and compounds that alter serotonin availability and signaling.

Clinical Consequences of Altered Drug Disposition in Obesity: Call for Change

Obesity is a serious condition with many known comorbid conditions and other health risks. Despite the rising global rates of obesity, drug disposition in this population is typically understudied, which results in limited information guiding the use of drugs in patients with obesity. Presently, dosing adjustments for patients with obesity typically focus on addressing altered drug clearance with body size and are therefore limited to chronic dosing recommendations. These instructions are variable and rarely based on dedicated studies in people with obesity. This review briefly discusses the current clinical use of body measurements to guide chronic dosing instructions and highlights the need for obesity-specific dosing instructions when the half-life of a drug is prolonged (typically through increased volume of distribution) in people with obesity. Examples of drugs with apparent opportunities for either ramp-up, loading, or washout instructions for patients based on body mass index are identified, specifically for vortioxetine, posaconazole, and brexpiprazole. We call for inclusion of people with obesity in clinical studies as a special subpopulation during drug development and propose the use of body mass index to guide dosing decisions among these patients.

Association of clozapine and norclozapine levels with patient and therapy characteristics-focus on interaction with valproic acid

PURPOSE

The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use.

METHODS

This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients' data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ.

RESULTS

A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability.

CONCLUSION

The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.

Study on the daily dose and serum concentration of clozapine in psychiatric patients and possible influencing factors of serum concentration

BACKGROUND

Clozapine is the most effective drug for treatment-resistant schizophrenia, and the dosage and concentration of clozapine in the treatment of mental illness vary greatly in different populations and are affected by many factors.

METHODS

The serum clozapine concentration of 3734 psychiatric patients was detected, and data on daily dose, sex, age and other medical records were collected for statistical analysis.

RESULTS

The mean daily dose, mean serum concentration and mean C/D (concentration/dose) ratio of clozapine were 191.02 ± 113.47 mg/day, 326.15 ± 235.66 ng/mL and 1.94 ± 1.25 ng/mL per mg/day, respectively. There was difference in daily dose between sexes, and females had higher daily dose (p <0.01), higher serum clozapine concentrations (p < 0.01) and higher C/D ratios (p < 0.01). There were significant differences in daily dose (p < 0.001), serum drug concentration (p < 0.001) and C/D ratio (p < 0.001) among different age groups. The daily dose decreased with age (p for trend < 0.001), and the C/D ratio increased with age (p for trend < 0.001). Inpatients and outpatients had no difference in daily dose, but inpatients had higher serum concentration (p < 0.001) and C/D ratio (p < 0.001). There was no difference in daily dose among different occupations, but there were significant differences in serum concentration (p < 0.001) and C/D ratio (p < 0.001), and unemployed patients may have higher serum concentration and C/D ratio. Duration of disease, comorbidity, marital status, and psychotic type may influence the daily dose and serum concentration.

CONCLUSIONS

The effective daily dose and serum concentration of clozapine in the study area may be lower than recommended levels, and women have higher serum concentrations and slower metabolic rates. With increasing age, the daily dose decreases, and the metabolic rate slows. Inpatient status and occupation of patients may influence the serum concentration and metabolic rate of clozapine.

Body mass index as a predictor of the outcomes of acute clozapine toxicity: a cross-sectional study

Acute antipsychotic overdose is frequently reported nowadays. Clozapine is one of the atypical agents that are highly lipophilic, highly protein-bound, has a large volume of distribution, and accumulates in the brain and other tissues. Obesity is an essential factor controlling patients' treatment and clinical course. The current study aimed to study the prognostic value of body mass index (BMI) in patients with acute clozapine poisoning. All patients were evaluated on admission using the Poison Severity Score (PSS) and Glasgow Coma Score (GCS). The BMI was calculated. Mortality and the need for ICU admission were defined as primary outcomes, whereas secondary outcomes included cardiovascular complications and the need for mechanical ventilation. Thirty-eight patients presented with acute clozapine poisoning. The mean age of included patients was 25.2 ± 6. Patients were categorized regarding BMI into average weight (26.3%), overweight (31.6%), and obese (42.1%). Pearson's correlation indicated a significant positive correlation between BMI and respiratory rate (r = .364, p = .025). A significant negative correlation existed between BMI and GCS (r = .674, p ≤ .001). ROC curve reveals that BMI is an excellent predictor for the requirement of mechanical ventilation area under the curve (AUC > .9), a fair predictor of ICU admission AUC (.747). BMI had a sensitivity of 100% and specificity of 51.7 for the prediction of ICU admission. In conclusion, obesity increased the severity of toxicity and the incidence of poor clinical outcomes in patients with acute clozapine poisoning.

Case report: Hyperactive delirium after a single dose of zolpidem administered additionally to psychopharmacotherapy including clozapine

The non-benzodiazepine hypnotic zolpidem is frequently administered as a short term psychopharmacotherapy for insomnia. Although it is well-established in a broad clinical routine and often well-tolerated, severe delirium and complex sleep behavior were reported in rare cases. Hereby, it remains unclear whether zolpidem's potential for delirium might be enhanced when combined with further psychopharmacotherapeutics. The present case report portrays a young male Caucasian inpatient with schizoaffective disorder, who was admitted due to severe hyperactive delirium after a single dose of zolpidem 10 mg that was administered in addition to already established psychopharmacotherapy including clozapine 200 mg/day, aripiprazole 15 mg/day and cariprazine 4.5 mg/day. In detail, disorientation, agitation, confabulations, bizarre behavior, and anterograde amnesia occurred shortly after ingestion of zolpidem and gained in intensity within a couple of hours. Once zolpidem was discontinued, the abovementioned symptoms subsided completely and did not reoccur. Since a clear temporal association could be drawn between the intake of zolpidem and the onset of hyperactive delirium, the present clinical experience should serve as a cautionary note for combining potent sedative-hypnotics and substances with anticholinergic properties, even in young adults in a good general condition. Moreover, our case argues for the necessity of further research into the pathomechanism of the interaction potential of non-benzodiazepines as zolpidem, especially with substances exerting anticholinergic properties, which are known for their potential to precipitate delirium. Therefore, the metabolic pathways of the concurrently administered substances should be further taken into account.

The potential effect of metformin on cognitive and other symptom dimensions in patients with schizophrenia and antipsychotic-induced weight gain: a systematic review, meta-analysis, and meta-regression

Introduction

Metformin has shown good efficacy in the management of antipsychotic-induced metabolic syndrome (MetS) in patients with schizophrenia or schizoaffective disorders. Its ability to induce antidepressant behavioural effects and improve cognitive functions has also been investigated: yet information has not been systematized. The aim of this study was therefore to investigate the effects of metformin on cognitive and other symptom dimension in schizophrenic patients treated with antipsychotics through a systematic review and meta-analysis.

Methods

We searched PubMed, ClinicalTrials.Gov, Embase, PsycINFO, and WHO ICTRP database up to February 2022, Randomised Controlled Trials (RCT) evaluating patients diagnosed with schizophrenia and related disorders, who were treated with metformin as add-on therapy to antipsychotics for the treatment of weight gain and in which changes in psychiatric symptoms and cognitive functions were evaluated.

Results

A total of 19 RCTs met the inclusion criteria. Meta-analysis was performed on 12 eligible studies. We found a positive trend after 24 weeks of treatment in schizophrenic patients with stable conditions [SMD (95%CI) = -0.40 (-0.82;0.01), OR (95%CI) = 0.5 (-2.4;3.4)]. Better performance was detected in the Brief Assessment of Cognition in Schizophrenia and Positive and Negative Syndrome Scale (PANSS) with low heterogeneity among studies. One study reported changes in BACS-verbal memory subdomain in favour of placebo [MD (95%CI) = -16.03 (-23.65;8.42)]. Gastrointestinal disorders, xerostomia, and extrapyramidal syndrome were the most reported adverse effects. Psychiatric adverse events were also described: in particular, symptoms attributable to a relapse of schizophrenia.

Conclusion

Some degree of efficacy was found for Metformin in improving cognitive and other symptom dimensions in patients with Schizophrenia. Given the clinical relevance of this potential pharmacological effect, longer specific studies using adequate psychometric scales are strongly recommended. Likewise, how metformin acts in this context needs to be evaluated in order to enhance its efficacy or find more efficacious drugs.

Quetiapine Albumin Nanoparticles as an Efficacious Platform for Brain Deposition and Potentially Improved Antipsychotic Activity

Quetiapine (QP) is a second-generation short-acting antipsychotic drug extensively metabolized in the liver, producing pharmacologically inactive metabolites and leading to diminished bioavailability. Therefore, this study aimed to develop an intravenous QP albumin nanoparticles (NPs) system for improving QP antipsychotic activity and brain targeting. QP-loaded albumin NPs were prepared by the desolvation method. The fabricated NPs were characterized in terms of particle size, zeta potential, entrapment efficiency (EE%), and in vitro drug release. In vivo pharmacokinetics and biodistribution in rats were studied. In addition, the antipsychotic activity of the optimized platform was also investigated. Human serum albumin (HSA) concentration, pH, and stirring time were modulated to optimize QP albumin NPs with a particle size of 103.54 ± 2.36 nm and a QP EE% of 96.32 ± 3.98%. In addition, the intravenous administration of QP albumin NPs facilitated QP brain targeting with a 4.9-fold increase in targeting efficiency compared to the oral QP solution. The QP albumin NPs improved the QP antipsychotic activity, indicated by suppressing rats' hypermobility and reducing the QP's extrapyramidal side effects. The obtained results proposed that intravenous QP- NPs could improve QP brain targeting and its antipsychotic efficiency.

Augmentation of Brexpiprazole fluorescence through photoinduced electron transfer inhibition for the sensitive spectrofluorimetric assay of pharmaceutical dosage forms and spiked human plasma: Application to content uniformity testing

Brexpiprazole (BRX) is a new antipsychotic drug that recently was used in the treatment of schizophrenia and other psychosis. The presence of benzothiophene ring in its chemical structure makes BRX naturally fluoresces. However, the native fluorescence of the drug was low in neutral or alkaline medium owing to the occurrence of photoinduced electron transfer (PET) from the nitrogen of the piperazine ring to the benzothiophene ring. Protonation of this nitrogen atom using sulfuric acid could efficiently block PET process and thus retaining the strong fluorescence of the compound. Accordingly, a straightforward, highly sensitive, fast and green spectrofluorimetric approach was established for BRX determination. In 1.0 M sulfuric acid solution, BRX exhibited significant native fluorescence measured at emission wavelength of 390 nm after excitation at 333 nm. ICH requirements were used to evaluate the method. The fluorescence intensity and BRX concentration were found to be correlated linearly within the range of 5-220 ng mL^-1 with a coefficient of correlation 0.9999. The limit of quantitation was 2.38 ng mL^-1 while limit of detection was 0.78 ng mL^-1. The developed approach was successfully used to analyze BRX in biological fluids and pharmaceutical dosage form. The suggested approach worked well when applied for testing the uniformity of content.

Clinical outcomes of recommended active pharmacotherapy agents from NICE guideline for post-traumatic stress disorder: Network meta-analysis

BACKGROUND

Post-traumatic stress disorder (PTSD) is a mental disorder that can emerge after an individual experiences a traumatic event such as physical abuse, sexual/relationship violence, combat exposure, witnessing death, or serious injury. This study aimed to identify the most suitable drugs for the management of PTSD based on a network meta-analysis (NMA).

METHODS

Six databases (Ovid Medline, EMBase, CENTRAL, PsycINFO, Ovid Health and Psychosocial Instruments, and Web of Science) were searched from inception to September 6, 2022.

RESULTS

Thirty articles with a total of 5170 participants were included. Compared with placebo, active drugs including olanzapine (SMD = -0.66, 95% CI: -1.19 to -0.13), risperidone (SMD = -0.23, 95% CI: -0.42 to -0.03), quetiapine (SMD = -0.49, 95% CI: -0.93 to -0.04), venlafaxine (SMD = -0.29, 95% CI: -0.42 to -0.16), sertraline (SMD = -0.23, 95% CI: -0.34 to -0.11), paroxetine (SMD = -0.48, 95% CI: -0.60 to -0.36) and fluoxetine (SMD = -0.27, 95% CI: -0.42 to -0.12), significantly reduced the total clinician-administered PTSD scale score.

CONCLUSION

The results of this study support the use of paroxetine, venlafaxine, and quetiapine as first-line treatment for PTSD. In addition, quetiapine is recommended for patients with PTSD affected by symptoms of hyperarousal and re-experience disorder. Clinicians should prescribe medications based on the severity of PTSD symptoms and other conditions to develop the best treatment strategy for this patient population.

Longitudinal changes in clozapine dose in patients with treatment-resistant schizophrenia: a 5-year retrospective cohort study

This retrospective cohort study aimed to investigate the longitudinal changes in clozapine dose over a 5-year period in patients with treatment-resistant schizophrenia (TRS). Patients with TRS who were administered clozapine at a hospital between April 2012 and December 2016 and continued treatment with clozapine for at least 1 year were included. Clozapine doses were compared at the dose-fixation point, defined as when the same regimen of clozapine had been continued for 8 weeks or longer, and the post-dose-fixation phase, at 12, 36 and 60 months after clozapine initiation. We included 103 patients and found no significant differences in clozapine dose between the dose-fixation point and post-dose-fixation phase. Approximately half of the patients were categorized into an unchanged group at 12 months after clozapine initiation, whereas approximately 40% of patients were categorized into either the decreased or increased group at 60 months. Multivariable regression analysis revealed that the change in clozapine dose between the dose-fixation point and 60 months after clozapine initiation was negatively associated with clozapine dose at the dose-fixation point. On average, the clozapine dose was unchanged during long-term treatment in patients with TRS, although the dose was decreased or increased in approximately 40% of the patients.

Brexpiprazole—Pharmacologic Properties and Use in Schizophrenia and Mood Disorders

In 2002, the first III generation antipsychotic drug was registered—aripiprazole. Its partial dopaminergic agonism underlies its unique mechanism of action and the potentially beneficial influence on the positive, negative, or cognitive symptoms. Due to its relatively high intrinsic activity, the drug could often cause agitation, anxiety, or akathisia. For this reason, efforts were made to develop a drug which would retain the positive favorable actions of aripiprazole but present a more advantageous clinical profile. This turned out to be brexpiprazole, which was registered in 2015. Its pharmacodynamic and pharmacokinetic profile (similarly to the other most recent antipsychotics, i.e., lurasidone or cariprazine) shows promise of increasing the effectiveness of schizophrenia treatment in the dimensions in which the previous antipsychotics were not sufficiently effective, including negative, depressive, or cognitive symptoms. Like other new antipsychotics, it can also be useful in the treatment of mood disorders, for instance drug-resistant depression. Previous reviews focused on the use of brexpiprazole in specific diagnostic groups. The aim of this article is to provide the readers with an overview of data on the mechanism of action, clinical effectiveness in all studied diagnostic groups, as well as potential drug–food interactions, and the safety of brexpiprazole.

Combination of two long-acting injectable antipsychotics in treatment-resistant schizophrenia: A retrospective 12-month mirror-image study

To evaluate the efficacy and tolerability of the combination of two long-acting injections of antipsychotics (dual-LAIs) in non-adherent and resistant schizophrenia. Efficacy and tolerability were assessed in 13 patients admitted to a French hospital, using a retrospective 12-month mirror-image design. The number and total duration of hospitalizations significantly decreased after introducing dual-LAIs (2.6 vs. 1.3, P = 0.017; 142 days vs. 95 days, P = 0.046). The average duration of each hospitalization did not differ. No significant differences were observed in tolerance outcomes (body mass index, agranulocytosis, lipid profile, sugar levels). Patients with treatment-resistant schizophrenia and poor medication adherence can derive significant clinical benefits from dual-LAIs.