Prediction of an Optimal Dose of Aripiprazole in the Treatment of Schizophrenia From Plasma Concentrations of Aripiprazole Plus Its Active Metabolite Dehydroaripiprazole at Week 1

Towards Precision Medicine in Clinical Practice: Alinity C vs. UHPLC-MS/MS in Plasma Aripiprazole Determination

Therapeutic drug monitoring improves the benefit-risk balance of antipsychotic therapy. Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is considered the gold-standard method for measuring plasma drug concentrations; however, the Alinity C system has emerged as a promising alternative. This is the first study aimed at comparing UHPLC-MS/MS versus Alinity C in measuring plasma concentrations of aripiprazole and dehydroaripiprazole. A total of 86 plasma samples were analyzed. The active moiety of aripiprazole was measured in 60 samples using both systems and 26 samples were analyzed twice using Alinity C with an intermediate period of 6 months to assess its reproducibility. Spearman's correlation revealed a good association between the two assays (rs = 0.96) and no significance differences were found by McNemar's test when classifying samples between infra-, supra- and therapeutic ranges. Passing-Bablock regression showed a good correlation among methods (rs = 0.93) and a slope of 1.12 indicating a slight tendency of Alinity C to measure higher values than UHPLC-MS/MS. In addition, a good intra-method correlation across the two sequential analyses with Alinity C was obtained (rs = 0.99). Nonetheless, clinical decisions could be different in 15% of the cases depending on the chosen method. No differences were found in active moiety determination by Alinity C depending on the concentration of aripiprazole and dehydroaripiprazole of the samples.

CYP1A2*F Polymorphism Contributes at Least Partially to the Variability of Plasma Levels of Dehydroaripiprazole, an Active Metabolite of Aripiprazole, in Schizophrenic Patients

AIM

The relationship between CYP1A2 polymorphisms and the steady-state plasma levels of aripiprazole and its active metabolite, dehydroaripiprazole, were investigated in Japanese schizophrenic patients.

BACKGROUND

It has been implied that cytochrome P450 (CYP) 1A2 may play a role in the metabo-lism of aripiprazole. Genetic variations in the CYP1A2 gene have been reported.

OBJECTIVE

The authors investigated the relationship between 2 CYP1A2 polymorphisms, CYP1A2*C (-3860G>A) and CYP1A2*F (-163C>A), and the steady-state plasma levels/dose (C/D) ratios of aripiprazole and dehydroaripiprazole in Japanese schizophrenic patients.

METHODS

All 89 subjects (46 males and 43 females) had been receiving 2 fixed daily doses of aripiprazole (24 mg; n=56 and 12 mg: n=33) for more than 2 weeks. No other drugs were used except flunitrazepam and biperiden. The plasma drug levels were determined by LC/MS/MS. These CYP1A2 polymorphisms were detected using polymerase chain reaction analysis.

RESULTS

The mean C/D ratios of dehydroaripiprazole were significantly (P < 0.05) lower in patients with the A/A allele of CYP1A2*F than in those without the allele. No differences were found in the values of aripiprazole and the combination of aripiprazole and dehydroaripiprazole among the CYP1A2*F genotype. There were no differences in the values of aripiprazole, dehydroaripiprazole, or the combination of the 2 compounds among the CYP1A2*C genotype. The absence of the A allele of CYP1A2*F was correlated with the mean C/D ratios of dehydroaripiprazole (standardized partial correlation coefficient = 0.276, P < 0.01) by multiple regression analysis.

CONCLUSION

The findings of this study suggest that the CYP1A2*F polymorphism contributes at least partially to the variability in the steady-state plasma levels of dehydroaripiprazole.

Analysis of the correlation between clinical efficacy and blood concentration of olanzapine in schizophrenia patients

To analyze the relationship between olanzapine blood concentration and clinical efficacy in schizophrenia patients, which has been expected to provide a scientific reference basis for improving the treatment effect of olanzapine in schizophrenia patients. Four hundred eighty-six psychiatric inpatients were randomly selected from October 31, 2019, to October 31, 2020, and all enrolled patients were given olanzapine treatment, and the treatment effect of schizophrenia patients was assessed according to the Positive and Negative Symptom Scale subtraction rate, and divided into treatment effective and ineffective groups at 1, 2, and 3 weeks of treatment, respectively. The olanzapine blood concentration in the body was monitored at 1, 2, and 3 weeks of treatment, and the relationship between olanzapine blood concentration and treatment effect at different time points was analyzed. Patients in the ineffective group had lower olanzapine blood concentrations than the effective group in treatment 1, 2, and 3 weeks and lower Positive and Negative Symptom Scale score reduction rates than the effective group (P < .05); the differences in other baseline information between the groups were not statistically significant (P > .05). Logistic regression analysis showed that olanzapine blood concentration at different times of treatment was related to the treatment effect (odds ratio > 1, P < .05); the results of the bivariate Spearman linear correlation test showed that olanzapine blood concentration at different times of treatment was positively related to the treatment effect of schizophrenia patients (R > 0, P < .05). In schizophrenia patients treated with olanzapine, the higher the olanzapine blood concentration in patients, the better the clinical treatment effect. Accordingly, the clinical can develop individualized medication regimens based on the results of blood concentration testing in the body under the premise of ensuring safety, aiming to ensure maximum efficacy.

Current Status of Therapeutic Drug Monitoring in Mental Health Treatment: A Review

Therapeutic drug monitoring (TDM) receives growing interest in different psychiatric clinical settings (emergency, inpatient, and outpatient services). Despite its usefulness, TDM remains underemployed in mental health. This is partly due to the need for evidence about the relationship between drug serum concentration and efficacy and tolerability, both in the general population and even more in subpopulations with atypical pharmacokinetics. This work aims at reviewing the scientific literature published after 2017, when the most recent guidelines about the use of TDM in mental health were written. We found 164 pertinent records that we included in the review. Some promising studies highlighted the possibility of correlating early drug serum concentration and clinical efficacy and safety, especially for antipsychotics, potentially enabling clinicians to make decisions on early laboratory findings and not proceeding by trial and error. About populations with pharmacokinetic peculiarities, the latest studies confirmed very common alterations in drug blood levels in pregnant women, generally with a progressive decrease over pregnancy and a very relevant dose-adjusted concentration increase in the elderly. For adolescents also, several drugs result in having different dose-related concentration values compared to adults. These findings stress the recommendation to use TDM in these populations to ensure a safe and effective treatment. Moreover, the integration of TDM with pharmacogenetic analyses may allow clinicians to adopt precise treatments, addressing therapy on an individual pharmacometabolic basis. Mini-invasive TDM procedures that may be easily performed at home or in a point-of-care are very promising and may represent a turning point toward an extensive real-world TDM application. Although the highlighted recent evidence, research efforts have to be carried on: further studies, especially prospective and fixed-dose, are needed to replicate present findings and provide clearer knowledge on relationships between dose, serum concentration, and efficacy/safety.

Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry for Simultaneous Determination of Antipsychotic Drugs in Human Plasma and Its Application in Therapeutic Drug Monitoring

PURPOSE

We developed and validated an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous therapeutic drug monitoring (TDM) and clinical pharmacokinetic antipsychotic drugs: clozapine (CLP), chlorpromazine (CPZ), risperidone (RPD), paliperidone (PLD), quetiapine (QTP;), aripiprazole (APZ), dehydroaripiprazole (DAP), olanzapine (OZP), ziprasidone (ZRD), and amisulpride (ASP).

METHODS

Analytes and internal standards (ISs) were separated using a Phenomenex phenyl-hexyl column (50.0 × 2.1 mm, 1.7 μm) with water containing 0.1% formic acid and 2 mM ammonium acetate, and methanol containing 0.1% formic acid and 2 mM ammonium acetate as the mobile phase. The antipsychotic drugs and ISs were extracted from 50 μL of plasma using acetonitrile.

RESULTS

The calibration ranges were 25.0-1500.0 ng/mL for CLP, CPZ, DAP, and QTP, 10.0-600.0 ng/mL for CPZ and ZRD, 2.5-150.0 ng/mL for RPD, 5.0-300.0 ng/mL for PLD and OZP, and 20.0-1200.0 ng/mL for ASP. Validation was carried out according to the guidelines for bioanalytical validation, including assessment of calibration curves, specificity, accuracy, precision, recovery, stability, dilution integrity, and matrix effect. All the results satisfied the requirements.

CONCLUSION

The results provided significant information to support future clinical TDM and rational drug use research. The proposed method also provided a simple, reliable, specific, and suitable technique for TDM and pharmacokinetic studies.

Aripiprazole Cytotoxicity Coincides with Activation of the Unfolded Protein Response in Human Hepatic Cells

Schizophrenia is a mental disease that results in decreased life expectancy and well-being by promoting obesity and sedentary lifestyles. Schizophrenia is treated by antipsychotic drugs. Although the second-generation antipsychotics (SGA), Olanzapine and Aripiprazole, are more effective in treating schizophrenia, they display a higher risk of metabolic side effects, mostly by development of diabetes and insulin resistance, weight gain, and dyslipidemia. Endoplasmic reticulum (ER) stress is induced when ER homeostasis of lipid biosynthesis and protein folding is impaired. This leads to the activation of the unfolded protein response (UPR), a signaling cascade that aims to restore ER homeostasis or initiate cell death. Chronic conditions of ER stress in the liver are associated with diabetes and perturbed lipid metabolism. These metabolic dysfunctions resemble the pharmacological side effects of SGAs. We therefore investigated whether SGAs promote the UPR in human and mouse hepatocytes. We observed full-fledged activation of ER stress by Aripiprazole not by Olanzapine. This occurred at low micromolar concentrations and to variable intensities in different cell types, such as hepatocellular carcinoma, melanoma, and glioblastoma. Mechanistically, Aripiprazole caused depletion of ER calcium, leading to activation of inositol-requiring enzyme 1 (IRE1)and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), two major transducers of the UPR. Cells underwent apoptosis with Aripiprazole treatment, which coincided with UPR induction, and this effect was reduced by adding glutathione without affecting UPR itself. Deletion of IRE1 from HepG2, a human liver cancer cell line, protected cells from Aripiprazole toxicity. Our study reveals for the first time a cytotoxic effect of Aripiprazole that involves the induction of ER stress. SIGNIFICANCE STATEMENT: The antischizophrenic drug Aripiprazole exerts cytotoxic properties at high concentrations. This study shows that this cytotoxicity is associated with the induction of endoplasmic reticulum (ER) stress and IRE1 activation, mechanisms involved in diet-induced obesity. Aripiprazole induced ER stress and calcium mobilization from the ER in human and mouse hepatocytes. Our study highlights a new mechanism of Aripiprazole that is not related to its effect on dopamine signaling.