Interest of Fluvoxamine as an Add-On to Clozapine in Children With Severe Psychiatric Disorder According to CYP Polymorphisms: Experience From a Case Series

Exploring clozapine use in severe psychiatric symptoms associated with autism spectrum disorder: A scoping review

BACKGROUND

Patients with autism spectrum disorder (ASD) may experience severe psychiatric symptoms, often unresponsive to conventional pharmacological therapies, highlighting the need for more effective alternatives.

AIMS

This study aims to map and synthesize evidence on the use of clozapine as a therapeutic option for managing severe psychiatric symptomatology co-occurring with ASD.

METHODS

We conducted a scoping review on multiple sources following the JBI guidelines. The search strategy was inclusive, targeting both peer-reviewed publications and gray literature presenting empirical data on the use of clozapine therapy for patients with ASD accompanied by comorbid psychiatric symptoms. Two independent evaluators performed the selection of studies, data extraction, and critical appraisal.

RESULTS

The review included 46 studies, encompassing 122 ASD individuals who received clozapine therapy. The sources of evidence comprise 31 case reports, 8 case series, 6 retrospective observational studies, and 1 quasi-experimental prospective study. The tables present the findings along with a narrative summary. Clozapine treatment demonstrated benefits in four groups of severe and treatment-resistant psychiatric symptoms in ASD patients: disruptive behaviors, psychotic symptoms, catatonia, and mood symptoms. Although side effects were common, tolerability was generally satisfactory. However, severe adverse events, such as seizures, moderate neutropenia, and myocarditis, underscore the need for intensive clinical monitoring.

CONCLUSIONS

While clozapine shows promise as a pharmacological intervention for severe psychopathologies in ASD, more rigorous clinical studies are required to elucidate its efficacy and safety in this population. The limited robustness of the evidence calls for caution, signaling an early research stage into this topic.

[Experience of clinical use of fluvoxamine for the treatment of comorbid depression in childhood and adolescence]

OBJECTIVE

To identify the frequency of administration of fluvoxamine, to determine the main targets of the drug and the expediency of its use in depression of various genesis in children and adolescents.

MATERIAL AND METHODS

To assess the frequency of prescribing fluvoxamine, 195 medical histories of patients who were inpatients in the children's department of the Mental Health Research Center in 2023 were analyzed. To assess the dynamics of depression during treatment with fluvoxamine, a clinical group was formed of 12 patients aged 10 to 15 years (age 13.1±3.6 years) who received fluvoxamine for the treatment of depression with comorbid obsessive-compulsive and anxiety-phobic disorders. Clinical and psychopathological, psychometric (Hamilton Depression Rating Scale - HDRS) and statistical research methods were used.

RESULTS

In total, in 2023, fluvoxamine was received by 20% (n=37) of all inpatient patients of child age (from 7 to 16 years). All patients received combination therapy. The therapeutic targets were comorbid depressive, obsessive-compulsive and anxiety symptoms developing in the structure of nosologically heterogeneous states, with the dominance of schizophrenic spectrum disorders. Against the background of the use of the drug fluvoxamine for 4 weeks in the clinical group, there was a significant reduction in depressive symptoms on the HDRS. Adverse events during complex therapy were observed in 20% of patients, but were not severe, did not require discontinuation of therapy and were unreliably associated with the use of fluvoxamine.

CONCLUSION

The use of the fluvoxamine provides reduction of depressive symptoms within the framework of various nosologies, and is characterized by sufficient safety. The variety of therapeutic targets of the fluvoxamine, including antidepressant, anti-anxiety, cognitive effects, is certainly a significant advantage of the studied fluvoxamine for use in childhood.

Evidence of pharmacogenetics-based fluvoxamine use as an add-on to clozapine treatment in psychiatry

Pharmacological treatments used for psychiatric disorders, such as clozapine, demonstrate large interindividual variability in terms of possible adverse effects and therapeutic benefit. This variability can be explained by multiple factors, including pharmacogenetic factors. Clozapine efficacy can be impacted by CYP polymorphisms. A growing body of literature on pharmacogenetics suggests the clinical benefit of concomitant use of clozapine and fluvoxamine to improve global pharmacotherapeutic management. This article reviews and discusses available clinical and pharmacological data and limitations of clozapine augmentation with fluvoxamine based on pharmacogenetic rationale and clinical experience. The aim is to provide an updated approach on how to use the pharmacological and pharmacogenetic profile to improve clozapine efficacy and tolerance in severely ill patients.

Adverse Drug Reactions of Olanzapine, Clozapine and Loxapine in Children and Youth: A Systematic Pharmacogenetic Review

Children and youth treated with antipsychotic drugs (APs) are particularly vulnerable to adverse drug reactions (ADRs) and prone to poor treatment response. In particular, interindividual variations in drug exposure can result from differential metabolism of APs by cytochromes, subject to genetic polymorphism. CYP1A2 is pivotal in the metabolism of the APs olanzapine, clozapine, and loxapine, whose safety profile warrants caution. We aimed to shed some light on the pharmacogenetic profiles possibly associated with these drugs’ ADRs and loss of efficacy in children and youth. We conducted a systematic review relying on four databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations and checklist, with a quality assessment. Our research yielded 32 publications. The most frequent ADRs were weight gain and metabolic syndrome (18; 56.3%), followed by lack of therapeutic effect (8; 25%) and neurological ADRs (7; 21.8%). The overall mean quality score was 11.3/24 (±2.7). In 11 studies (34.3%), genotyping focused on the study of cytochromes. Findings regarding possible associations were sometimes conflicting. Nonetheless, cases of major clinical improvement were fostered by genotyping. Yet, CYP1A2 remains poorly investigated. Further studies are required to improve the assessment of the risk–benefit balance of prescription for children and youth treated with olanzapine, clozapine, and/or loxapine.

The role of alcohol intake in the pharmacogenetics of treatment with clozapine

Clozapine (CLZ) is an atypical antipsychotic reserved for patients with refractory psychosis, but it is associated with a significant risk of severe adverse reactions (ADRs) that are potentiated with the concomitant use of alcohol. Additionally, pharmacogenetic studies have explored the influence of several genetic variants in CYP450, receptors and transporters involved in the interindividual response to CLZ. Herein, we systematically review the current multiomics knowledge behind the interaction between CLZ and alcohol intake, and how its concomitant use might modulate the pharmacogenetics. CYP1A2*1F, *1C and other alleles not yet discovered could support a precision medicine approach for better therapeutic effects and fewer CLZ ADRs. CLZ monitoring systems should be amended and include alcohol intake to protect patients from severe CLZ ADRs.

Development of an optimized and generic cost-utility model for analyzing genome-guided treatment data

Economic evaluation is an integral component of informed public health decision-making in personalized medicine. However, performing economic evaluation assessments often requires specialized knowledge, expertise, and significant resources. To this end, developing generic models can significantly assist towards providing the necessary evidence for the cost-effectiveness of genome-guided therapeutic interventions, compared to the traditional drug treatment modalities. Here, we report a generic cost-utility analysis model, developed in R, which encompasses essential economic evaluation steps. Specifically, critical steps towards a comprehensive deterministic and probabilistic sensitivity analysis were incorporated in our model, while also providing an easy-to-use graphical user interface, which allows even non-experts in the field to produce a fully comprehensive cost-utility analysis report. To further demonstrate the model's reproducibility, two sets of data were assessed, one stemming from in-house clinical data and one based on previously published data. By implementing the generic model presented herein, we show that the model produces results in complete concordance with the traditionally performed cost-utility analysis for both datasets. Overall, this work demonstrates the potential of generic models to provide useful economic evidence for personalized medicine interventions.