Abstract
Clozapine is the preferred treatment for refractory schizophrenia. However, clozapine use is constrained by the risk of clozapine‑induced seizures (CISs). The molecular mechanisms behind CISs are complex and poorly understood. The objective of this study was to identify the core targets and signaling pathways contributing to CISs using network pharmacology and molecular docking. Potential targets for clozapine and seizures were screened using multiple databases, and overlapping targets were identified. Protein-protein interaction (PPI) networks were constructed using the STRING database and visualized in Cytoscape to identify core targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of the core targets were performed, and a disease-target-pathway-drug network was constructed. The docking of clozapine with the core targets was evaluated to determine the stability of their interactions. Of the 656 potential targets for clozapine and 1260 targets for seizure, 104 targets overlapped. PPI analysis of the overlapping targets yielded 12 core targets. KEGG pathway enrichment analysis demonstrated that glutamatergic, dopaminergic, and GABAergic synapses may be key pathways mediating CIS. The molecular docking results showed that clozapine had strong binding affinities for the core targets, BDNF, GRIN2B, GRIN2A, and GAD1. Thus, clozapine may interfere with the glutamatergic, dopaminergic, and GABAergic synaptic pathways by modulating BDNF, GRIN2B, GRIN2A, and GAD1. Modulation of these core targets may contribute to excitatory–inhibitory imbalance in the central nervous system, thereby potentially increasing seizure susceptibility. This study provides an integrative perspective on the potential pathophysiology of CIS and suggests directions for future experimental validation and risk intervention strategies.
Subject terms: Schizophrenia, Target identification
Introduction
Schizophrenia is a chronic psychiatric disorder, affecting tens of millions of people worldwide and imposing a substantial public-health burden. Over the past 30 years, its global incidence has increased by approximately 37%1. Clozapine is the highly effective first-line treatment for refractory schizophrenia2. However, the clinical utility of clozapine is limited by adverse effects, including seizures3–5. The incidence of clozapine-induced seizures (CIS) is up to 3.5%6. The risk of CIS positively correlates with clozapine dose, plasma concentration, and rate of dose escalation, which can severely impact patient quality of life and compromise treatment adherence; these effects can ultimately lead to poor clinical outcomes7. Electroencephalographic (EEG) studies revealed that clozapine slows background rhythms and induces epileptiform discharges, even in patients without clinically apparent seizures8. Unfortunately, the molecular mechanisms underlying CISs are poorly understood.
Most current studies concerning the mechanism of CIS have focused on the broad and complex pharmacology of clozapine. Clozapine interacts with numerous neurotransmitter receptors, including dopamine, serotonin, and histamine receptors, which are critical for maintaining excitability in neural networks9–12. For example, serotonin receptors are widely distributed in brain circuits implicated in seizure generation, and clozapine acts as a potent serotonin receptor antagonist. Reduced central serotonin can increase neuronal excitability, lower the seizure threshold, and elevate seizure susceptibility13–15. Clozapine acts on numerous targets via diverse mechanisms, and single‑target approaches are insufficient to comprehensively explain the epileptogenic effects of clozapine. Therefore, seizure is treated as an integrated gene network in this study, and the key nodes and pathways through which clozapine perturbs that network are identified.
Network pharmacology provides a systems-level approach to characterize complex drug–disease interactions. Biomolecular networks are constructed using network pharmacology to identify synergistic, multi‑target, and multi‑pathway mechanisms of drug action rather than following a single‑target paradigm16. Molecular docking simulates drug–target binding at the molecular level, providing a molecular basis for drug design and precision therapeutic strategies17. Therefore, this study combines network pharmacology and molecular docking to systematically identify the potential targets and molecular mechanisms of clozapine-induced seizures. The goal of this study is to provide an integrative, systems-level perspective on the potential neurotoxic mechanisms of clozapine that may inform future experimental validation and the development of safer clinical dosing strategies. The overall study workflow is shown in Fig. 1.
Fig. 1.

Technological roadmap of the study.
Methods
Identification of potential target genes of clozapine
The chemical structure and canonical Simplified Molecular Input Line Entry System for clozapine were obtained from PubChem18 (https://pubchem.ncbi.nlm.nih.gov/). To identify putative targets of clozapine, the following four databases were searched using the keyword “clozapine”: SwissTargetPrediction19 (http://swisstargetprediction.ch/), PharmMapper database20, GeneCards21 (https://www.genecards.org/), and DrugBank22 (https://go.drugbank.com/). The retrieved targets were mapped to gene symbols using the UniProt database23 (https://www.uniprot.org/). The target genes from the four databases were combined, and overlapping genes were eliminated.
Identification of seizure-related target genes
The GeneCards21 (https://www.genecards.org/) and Online Mendelian Inheritance in Man24 (OMIM, https://www.omim.org/) databases were searched for Homo sapiens genes related to seizures. The retrieved genes from the two databases were combined, and overlapping genes were eliminated.
Common targets of clozapine and seizures
The potential targets of clozapine and seizures were uploaded to the online bioinformatics platform25 (http://www.bioinformatics.com.cn/), and a Venn diagram was constructed to identify common targets.
Protein–protein interaction network construction and selection of core targets
A protein–protein interaction (PPI) network of the common targets was generated using the STRING database with the organism restricted to Homo sapiens. The minimum required interaction score was set to 0.4, corresponding to the default “medium confidence” threshold recommended by STRING, which has been widely adopted in network pharmacology studies to balance the retention of biologically meaningful interactions with the exclusion of low-confidence associations26. Disconnected nodes were excluded from subsequent topological analysis. The PPI network was visualized and analyzed in Cytoscape27 (v3.10.1). Core targets were identified based on the degree centrality, betweenness centrality, and closeness centrality using the CytoNCA plugin. Targets that exceeded the median value for all three centrality measures were retained as core targets.
Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses
To identify the biological functions of the core targets, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted using the DAVID online tool28 (https://david.ncifcrf.gov/). The GO analysis covered three domains: biological processes (BPs), cellular components (CCs), and molecular functions (MFs). Enriched terms were defined as terms with a significance threshold of p < 0.05. The top 10 significantly enriched terms from each GO category and the top 10 KEGG pathways were visualized as bubble diagrams using the Bioinformatics platform (http://www.bioinformatics.com.cn). Cytoscape27 (v3.10.3) was used to construct a disease-pathway-target-drug network to intuitively illustrate the relationship between clozapine and seizure.
Molecular docking
Molecular docking was performed using AutoDock Vina (https://autodocksuite.scripps.edu/adt/) to determine the binding affinities between clozapine and the core targets. To generate the 3D ligand structure of clozapine, the 2D structure was retrieved from PubChem18, the energy was minimized using ChemBio3D (https://library.bath.ac.uk/chemistry-software/chem3d), and the optimized structure was converted to the PDBQT format using AutoDockTools (v1.5.6). Receptor structures were obtained from the Protein Data Bank (PDB)29, and water molecules and co-crystallized ligands were removed in PyMOL 2.4.1 (https://pymol.org/2/). The crystal structures used for docking were selected according to the following criteria: Homo sapiens origin, appropriate structural resolution, inclusion of a complete or functionally relevant domain suitable for ligand docking, and absence of extensive missing residues in the predicted binding region. AutoDockTools was used to add polar hydrogens and assign Gasteiger charges before saving the receptors as PDBQT files. A docking grid box was defined for each target, encompassing the active site. Docking calculations were performed using AutoDock Vina. The lowest-energy binding models were selected for visualization and interaction analysis using PyMOL 2.4.1 and Discovery Studio 2025.
Results
Screening of potential targets of clozapine and seizure
Screening for core targets revealed 656 potential targets of clozapine, after removing duplicates, and 1260 potential targets of seizure. A comparison of the two screening results revealed 104 overlapping targets (Fig. 2A).
Fig. 2. Target prediction of clozapine and seizure.

A Venn diagram of potential overlapping targets. B Construction of a PPI network of intersection targets. C Core targets for seizure treatment were identified using Cytoscape. The color intensity, node size, and number of connecting lines in the diagram indicate the strength of the connections among targets. Twelve core targets were identified according to topological parameters, including degree centrality (DC), betweenness centrality (BC), and closeness centrality (CC).
PPI network construction and identification of key targets
The 104 overlapping targets were submitted to the STRING database to construct the PPI network (Fig. 2B). After removing all disconnected nodes and edges, the network consisted of 104 nodes and 774 edges. The PPI network was reconstructed and visualized using Cytoscape (v3.10.3), as shown in Figure 2C1. Targets with degree centrality, betweenness centrality, and closeness centrality above the median for each metric were selected, yielding the key targets (Figure 2C2 and 2C3). The twelve key targets included brain-derived neurotrophic factor (BDNF), amyloid precursor protein (APP), insulin (INS), glutamate ionotropic receptor NMDA type subunit 2B (GRIN2B), and catenin beta 1 (CTNNB1), glial fibrillary acidic protein (GFAP), tyrosine hydroxylase (TH), glutamate decarboxylase 1 (GAD1), glutamate ionotropic receptor NMDA type subunit 2 A (GRIN2A), pro-opiomelanocortin (POMC), synaptosomal-associated protein 25 (SNAP25), and metabotropic glutamate receptor 1 (GRM1).
GO enrichment and KEGG pathway analysis
The GO and KEGG enrichment analyses revealed 342 BPs, 83 CCs, 98 MFs, and 104 KEGG pathways. The top 10 enriched BPs included chemical synaptic transmission, negative regulation of gene expression, neurotransmitter transport, gamma-aminobutyric acid signaling pathway, regulation of presynaptic membrane potential, positive regulation of gene expression, response to xenobiotic stimulus, locomotor behavior, neuron apoptotic process, and regulation of synaptic plasticity. The most enriched MF terms included transmitter-gated monoatomic ion channel activity involved in regulation of postsynaptic membrane potential, ligand-gated monoatomic ion channel activity involved in regulation of presynaptic membrane potential, glutamate-gated calcium ion channel activity, ligand-gated monoatomic ion channel activity, glutamate binding, GABA-gated chloride ion channel activity, GABA-A receptor activity, identical protein binding, protein binding, and signaling receptor binding. The most enriched CC terms included dendrite, plasma membrane, postsynaptic membrane, presynaptic membrane, axon, neuron projection, synapse, cell surface, neuronal cell body, and GABAergic synapse. The top 10 enriched terms from each GO category are presented in a bubble chart (Fig. 3A).
Fig. 3. Enrichment analysis of clozapine‑induced seizure.

A The top 10 functions from the GO enrichment analysis of clozapine‑induced seizure. B The top 10 KEGG signaling pathways associated with clozapine‑induced seizure. C Sankey diagram based on KEGG enrichment analysis. The left rectangular nodes of the Sankey diagram represent the therapeutic targets, the right nodes represent the KEGG pathways, and the lines represent the associations between the targets and pathways.
The top 10 KEGG enrichment pathways are detailed in Table 1. Their connections to target genes are illustrated in the bubble plots in Fig. 3B. As shown in the Sankey diagram in Fig. 3C, the glutamatergic synapse, dopaminergic synapse, and GABAergic synapse pathways are likely contributors to clozapine-associated seizure induction.
Table 1.
Basic information about the KEGG enrichment results.
| ID | Term | Count | Gene | P-value |
|---|---|---|---|---|
| hsa05030 | Cocaine addiction | 12 | GRIN2A/DDC/CDK5/TH/MAOA/BDNF/PDYN/GRIN2B/GNAI1/SLC6A3/SLC18A2/GRIN1 | 2.91E-12 |
| hsa04727 | GABAergic synapse | 14 | GABRA2/GABBR2/GABRA1/GABRB1/KCNJ6/GABBR1/SLC32A1/GABRA5/GAD1/CACNA1C/SLC6A1/GNAI1/GLS/GNAO1 | 9.24E-12 |
| hsa04724 | Glutamatergic synapse | 14 | SLC1A2/SLC1A3/CACNA1C/GRIK2/GRIN2B/GNAI1/GRM1/GRIN1/GLS/GNAO1/PPP3CA/GRIN2A/GRM7/GNAQ | 2.85E-10 |
| hsa04728 | Dopaminergic synapse | 14 | DDC/KCNJ6/MAOA/CACNA1C/GRIN2B/SLC6A3/GNAI1/MAPK10/GNAO1/PPP3CA/GRIN2A/TH/GNAQ/SLC18A2 | 1.45E-09 |
| hsa05031 | Amphetamine addiction | 11 | PPP3CA/GRIN2A/DDC/TH/MAOA/CACNA1C/PDYN/GRIN2B/SLC6A3/SLC18A2/GRIN1 | 2.89E-09 |
| hsa04024 | cAMP signaling pathway | 16 | GABBR2/CREBBP/GABBR1/BDNF/HTR1A/CACNA1C/GRIN2B/GNAI1/GRIN1/MAPK10/POMC/PAK1/GRIN2A/PDE10A/PIK3CA/CRH | 1.74E-08 |
| hsa04726 | Serotonergic synapse | 12 | GNAO1/CYP2C9/APP/GABRB1/KCNJ6/DDC/MAOA/GNAQ/HTR1A/CACNA1C/GNAI1/SLC18A2 | 3.96E-08 |
| hsa05032 | Morphine addiction | 11 | GNAO1/GABRA2/GABBR2/GABRA1/GABRB1/KCNJ6/GABBR1/PDE10A/SLC32A1/GABRA5/GNAI1 | 4.50E-08 |
| hsa04723 | Retrograde endocannabinoid signaling | 13 | GABRA2/GABRA1/GABRB1/KCNJ6/SLC32A1/GABRA5/CACNA1C/GNAI1/GRM1/MAPK10/GNAO1/GNAQ/NDUFS1 | 6.36E-08 |
| hsa05034 | Alcoholism | 14 | NTRK2/DDC/MAOA/BDNF/PDYN/GRIN2B/SLC6A3/GNAI1/GRIN1/GNAO1/GRIN2A/TH/CRH/SLC18A2 | 1.06E-07 |
Disease-pathway-target-drug network construction
A disease–pathway–target–drug network was constructed to understand the potential mechanisms by which clozapine influences seizures. The network comprised 116 nodes (1drug node, 10 pathway nodes, 104 target nodes, and 1 disease node) and 245 edges (Fig. 4). Node types are distinguished by visual attributes (color and shape). The edges represent predicted associations between components.
Fig. 4.

Disease–pathway–target–drug network diagram illustrating the effects of clozapine on seizure.
Molecular docking
Based on the PPI topology and KEGG enrichment analysis, four potential core targets, BDNF, GRIN2B, GRIN2A, and GAD1, were selected for molecular docking with clozapine. The following crystal structures were used for docking: BDNF (PDB ID: 5FTO), GAD1 (PDB ID: 2OKJ), GRIN2A (PDB ID: 9MUL), and GRIN2B (PDB ID: 5EWJ). The highest docking affinity scores (AutoDock Vina) for each target were as follows: BDNF, −9.0 kcal/mol; GAD1, −8.5 kcal/mol; GRIN2A, −8.2 kcal/mol; and GRIN2B, −9.8 kcal/mol (Table 2). Lower binding energies indicate stronger predicted ligand–target affinity; the observed binding affinities ranged from −8.2 to −9.8 kcal/mol, indicating favorable clozapine binding to these targets. Clozapine established hydrogen‑bonding interactions with LEU1122(A) of BDNF (PDB: 5FTO); ASN256(A), ASP373(A), and ASN402(A) of GAD1 (PDB: 2OKJ); LYS534(A) of GRIN2A (PDB: 9MUL); and THR110(C) of GRIN2B (PDB: 5EWJ). The simulated binding interactions with these core targets are shown in Fig. 5A-D.
Table 2.
Binding energy of Clozapine with core targets.
| Targets | PDB identifier | Docking score ((kcal/Mol)) |
|---|---|---|
| BDNF | 5FTO | −9.0 |
| GRIN2A | 9MUL | −8.2 |
| GRIN2B | 5EWJ | −9.8 |
| GAD1 | 2OKJ | −8.5 |
Fig. 5. Molecular docking results of clozapine with core targets.

A Clozapine and BDNF. B Clozapine and GAD1. C Clozapine and GRIN2A. D Clozapine and GRIN2B.
Discussion
We integrated network pharmacology and molecular docking to identify the potential molecular mechanisms mediating clozapine-induced seizures. Our results suggest that clozapine induces seizures by disrupting the neuronal excitatory-inhibitory balance via modulation of multiple molecular targets and signaling pathways. These findings provide a new theoretical basis for clinical risk mitigation and provide the basis for the development of individualized treatment strategies. Although several of the identified targets have been previously associated with both clozapine action and seizure susceptibility, the present study integrates these dispersed findings into a coherent multi-target, multi-pathway model that may help explain the polypharmacological basis of CIS.
Twelve core targets were identified by screening the databases. Based on favorable molecular-docking affinities, which had the most direct and well-characterized mechanistic links to seizure, GRIN2A, GRIN2B, GAD1, and BDNF, were selected for detailed discussion. Molecular docking simulations showed that clozapine bound to GRIN2A, GRIN2B, GAD1, and BDNF with predicted binding energies ranging from −8.2 to −9.8 kcal/mol, suggesting favorable predicted interactions. The remaining core targets imply that additional, potentially synergistic mechanisms of clozapine action may also be involved in clozapine-induced seizures.
Insulin (INS) modulates neuronal excitability through ATP-sensitive potassium channels and GABAergic transmission30, and both hyperinsulinemic hypoglycemia and insulin-resistance states are recognized as seizure-related conditions31,32. Clozapine is also associated with metabolic abnormalities, including impaired glucose regulation and insulin resistance33, and INS-related signaling may represent an indirect contributor to CIS. Amyloid precursor protein (APP), beyond its canonical role in synaptic structure34, has been implicated in the regulation of neuronal excitability and linked to epileptiform activity in neurodegenerative conditions35,36. GFAP reflects astrocytic activation and points toward a possible role of glial dysfunction and neuroinflammation37. TH and POMC, which regulate the synthesis of dopamine and endogenous opioid peptides, respectively, contribute to upstream neuromodulation38,39. SNAP25 is essential for synaptic vesicle release40 CTNNB1 may be involved in synaptic function and structural stabilization41,42. Therefore, our model does not exclude these targets but proposes that they may act as modulatory factors that interact with the more direct excitatory–inhibitory mechanisms mediated by glutamatergic and GABAergic pathways.
The NMDA receptor is a tetrameric complex composed of two GluN1 and two GluN2 subunits43. GRIN2A and GRIN2B encode the GluN2A and GluN2B subunits, respectively. GluN2A and GluN2B regulate glutamatergic synaptic transmission and maintain the excitatory–inhibitory balance in neural networks44–46. These two subunits differ in their spatial and temporal expression and functional roles. GluN2B is widely expressed during early embryonic development and is essential for neuronal development. GluN2A is primarily expressed postnatally and contributes to the functional maintenance of mature neurons47,48. Pathogenic variants of GRIN2A and GRIN2B, causing gain or loss of function, can precipitate seizures by disrupting the function of NMDA receptors49–54.
Based on this background, clozapine-induced seizures may be related to the dysregulation of GRIN2A and GRIN2B. Clozapine has been reported to alter the expression of these NMDA receptor subunits. For example, chronic clozapine treatment upregulates GRIN2B55 and downregulates GRIN2A expression in the hippocampus56. Given that NMDA receptors containing GluN2A and GluN2B critically regulate glutamatergic synaptic transmission, Ca2+ influx, and neuronal excitability, clozapine-induced alterations in GRIN2A/GRIN2B expression may indirectly disrupt NMDA receptor-mediated excitatory signaling. Such perturbation may increase network excitability and potentially increase seizure susceptibility43,44,57,58.
Clozapine may also impair inhibitory systems by disrupting excitatory signaling. GAD1 encodes glutamic acid decarboxylase 67 (GAD67), the major rate-limiting enzyme for 90% of basal GABA synthesis in the central nervous system59. GABA is the principal inhibitory neurotransmitter. Thus, reduced GABAergic function contributes to the generation of seizures60. Functional defects in GAD1 trigger seizures. For example, GAD1 knockout rats exhibit abundant spike-wave discharges in the EEG at an early age61, and biallelic pathogenic variants of GAD1 cause infantile-onset epilepsy in humans62. We identified a potential high-affinity interaction between clozapine and GAD1, suggesting that clozapine may inhibit GAD1 activity, reduce GABA synthesis, and weaken global inhibitory control.
In clinical studies, the clozapine dose positively correlated with serum BDNF levels63, and serum BDNF levels were higher in clozapine-treated patients compared with patients treated with typical antipsychotics64. Animal studies also demonstrated that chronic clozapine treatment increases BDNF expression in the rat hippocampus65. BDNF plays an important role in the onset and development of epilepsy. Elevated serum BDNF levels correlate with seizure severity, enhanced excitatory synaptic transmission via TrkB receptor activation and downstream signaling, and a reduced seizure threshold66–68. Thus, clozapine-induced elevation of BDNF levels may synergize with the excitatory-inhibitory imbalance to augment neuronal excitability and facilitate circuit remodeling, increasing seizure risk. Taken together, these findings suggest that dysregulation of BDNF, GRIN2A, GRIN2B, and GAD1 may collectively disturb excitatory–inhibitory homeostasis and thereby increase seizure susceptibility.
BPs identified in the GO enrichment analysis included chemical synaptic transmission, neurotransmitter transport, and the GABAergic signaling pathway, response to xenobiotic stimulus, and the neuron apoptotic process. Based on these enriched BPs, clozapine may perturb neural signaling by affecting neurotransmitter release, recycling, and signal transduction. In addition, the enrichment of response to xenobiotic stimulus may reflect cellular adaptation to clozapine exposure, including drug metabolism, oxidative stress, and stress-response signaling69,70. These processes may alter neuronal vulnerability or modify the effects of clozapine on neurotransmission. Similarly, the enrichment of the neuron apoptotic process may contribute to long-term network instability, particularly under chronic drug exposure or in patients with pre-existing neurological vulnerability71,72. We therefore believe that these likely reflect general mechanisms related to drug metabolism and neurotoxicity, rather than mechanisms specific to CIS. Enriched CCs included the dendrite, the postsynaptic membrane, the presynaptic membrane, and axons, which are essential for neuronal signaling. The CC enrichment results, indicating that the main targets of clozapine are the regions involved in signal transmission and reception, support the BP results. The enriched MFs focused on functions of ligand-gated monoatomic ion channel activity and glutamate binding, in agreement with our GRIN analysis. These results suggest that the modulation of glutamate‑gated ion channels is a common feature of clozapine‑related targets.
KEGG pathway enrichment analysis supported the core-target results. Two functionally opposed pathways, the glutamatergic and GABAergic synapses, were enriched. GAD1 acts upstream in GABA synthesis59 and GRINs are downstream glutamate receptors43. The combined impact of clozapine on these pathways likely disrupts the excitatory–inhibitory balance, providing a theoretical model that may help inform future experimental investigation of the mechanisms underlying CIS73,74.
Pathway enrichment analyses also implicated the dopaminergic synapses, providing a higher-level perspective on the excitatory-inhibitory imbalance. Clozapine is a dopamine receptor antagonist modulating the dopamine system75. Thus, clozapine regulates the activity of glutamatergic neurons76. Based on these results, we propose the following integrated, epileptogenic hypothesis: clozapine alters dopaminergic signaling, perturbs glutamatergic and GABAergic synaptic functions, and disrupts the excitatory-inhibitory balance by affecting key molecules, including the GAD1 and GRIN subunits. These effects are amplified by clozapine‑induced upregulation of BDNF–TrkB signaling. Altogether, these effects increase neuronal excitability and seizure risk. This systems‑level model offers a coherent framework for the effects of clozapine, which can be experimentally validated.
Several additional mechanisms beyond those identified in the present analysis have been proposed to contribute to CIS and deserve consideration. First, clozapine has prominent antimuscarinic/anticholinergic activity, which may contribute to seizure susceptibility by disrupting cholinergic modulation of cortical and hippocampal circuits77,78. Cholinergic signaling regulates neuronal excitability, attention-related cortical activation, and interactions between excitatory–inhibitory interneuron networks79,80. Therefore, anticholinergic effects may indirectly amplify glutamatergic excitation or weaken GABAergic inhibitory control81, thereby converging with the excitatory–inhibitory imbalance proposed in our model. Second, clozapine substantially alters sleep architecture, and sleep disruption is a recognized facilitator of epileptiform activity, which can lower the seizure threshold and may further amplify underlying network instability82,83. Among the proposed mechanisms, clinical factors such as rapid dose titration, elevated plasma concentrations, and concomitant medications remain the most consistently reported determinants of CIS84,85. Thus, CIS may arise from the convergence of direct molecular effects, neurotransmitter receptor pharmacology, metabolic factors, anticholinergic activity, clinical factors, and sleep architecture changes, our molecular model, and is therefore best interpreted as a complement to these established pharmacological and clinical considerations, rather than as a substitute for them.
Our results provide evidence for a novel systems-level framework for clozapine‑associated seizures. However, this study has several limitations. First, our work employed network pharmacology and molecular docking, which are database and algorithm-driven predictive approaches. Although this approach is useful for prioritizing candidate targets and pathways, these findings require in vitro and in vivo validation. Second, we did not account for interindividual genetic variability. Susceptibility to epilepsy and the risk of clozapine‑induced seizures vary, and the interplay between drug effects and host genetic variations should be investigated using clinical genomics data. In summary, our computational results generated a valuable hypothesis to guide experimental validation and individualized risk assessment, but the exact mechanism should be elucidated in future studies.
Conclusions
This is the first study to systematically delineate the multi‑target, multi‑pathway mechanisms underlying clozapine‑induced seizures using network pharmacology and molecular docking. Our results suggest that clozapine may disrupt opposing glutamatergic and GABAergic synaptic systems via interactions with the core targets, GRIN2A, GRIN2B, GAD1, and BDNF. These effects may be mediated upstream by dopaminergic signaling, disrupting the excitatory-inhibitory balance of neurons to increase the risk of seizures. These results provide a new framework for developing potential interventions, predictive biomarkers, and individualized dosing strategies for preventing clozapine-induced seizures.
Author contributions
Jian Li, Bo Han, Xia Liu, Ranli Li, Xiaoyan Ma: Writing—original draft, Visualization, Software, Data curation, Methodology. Hongjun Tian, Fuqiang Mao, and Chuanjun Zhuo: Writing—review & editing, Visualization, Supervision.
Funding
This work was supported by grants from the National Natural Science Foundation of China (Nos. 82171503 and 81871052) to Chuanjun Zhuo; Tianjin Anding Hospital Talent Support Grant (30,0000RMB to Chuanjun Zhuo). The funders had no further role in the study design; collection, analysis, and interpretation of data; writing of the report; or decision to submit the paper for publication.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
These authors contributed equally: Daxiang Lian, Jian Li, Chuanjun Zhuo.
These authors jointly supervised this work: Jian Li, Fuqiang Mao, Chuanjun Zhuo.
References
- 1.Solmi, M. et al. Incidence, prevalence, and global burden of schizophrenia-data, with critical appraisal, from the Global Burden of Disease (GBD) 2019. Mol. Psychiatry28, 5319–5327 (2023). [DOI] [PubMed] [Google Scholar]
- 2.Keepers, G. A. et al. The American Psychiatric Association practice guideline for the treatment of patients with schizophrenia. Am. J. Psychiatry177, 868–872 (2020). [DOI] [PubMed] [Google Scholar]
- 3.Tanzer, T. et al. Overcoming clozapine’s adverse events: a narrative review of systematic reviews and meta-analyses. Expert Opin. Drug Saf.23, 811–831 (2024). [DOI] [PubMed] [Google Scholar]
- 4.Balbuena, L. et al. Clozapine, relapse, and adverse events: a 10-year electronic cohort study in Canada. Br. J. Psychiatry225, 572–578 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Partanen, J. J. et al. High burden of ileus and pneumonia in clozapine-treated individuals with schizophrenia: a Finnish 25-year follow-up register study. Am. J. Psychiatry181, 879–892 (2024). [DOI] [PubMed] [Google Scholar]
- 6.Kumlien, E. & Lundberg, P. O. Seizure risk associated with neuroactive drugs: data from the WHO adverse drug reactions database. Seizure19, 69–73 (2010). [DOI] [PubMed] [Google Scholar]
- 7.Górska, N., Słupski, J. & Cubała, W. J. Antipsychotic drugs in epilepsy. Neurologia i Neurochirurgia Pol.53, 408–412 (2019). [DOI] [PubMed] [Google Scholar]
- 8.Jackson, A. & Seneviratne, U. EEG changes in patients on antipsychotic therapy: a systematic review. Epilepsy Behav.95, 1–9 (2019). [DOI] [PubMed] [Google Scholar]
- 9.Albitar, O., Harun, S. N., Zainal, H., Ibrahim, B. & Sheikh Ghadzi, S. M. Population pharmacokinetics of clozapine: a systematic review. BioMed. Res. Int.2020, 9872936 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Correll, C. U. Strategies for switching between oral postsynaptic antidopaminergic antipsychotics in patients with schizophrenia: a systematic review. CNS Drugs 1-23 (2025). [DOI] [PMC free article] [PubMed]
- 11.Rammes, G. et al. Identification of a domain which affects kinetics and antagonistic potency of clozapine at 5-HT3 receptors. PLoS ONE4, e6715 (2009). [DOI] [PMC free article] [PubMed]
- 12.Humbert-Claude, M., Davenas, E., Gbahou, F., Vincent, L. & Arrang, J.-M. Involvement of histamine receptors in the atypical antipsychotic profile of clozapine: a reassessment in vitro and in vivo. Psychopharmacology220, 225–241 (2012). [DOI] [PubMed] [Google Scholar]
- 13.Pottoo, F. H. et al. Estrogen and serotonin: complexity of interactions and implications for epileptic seizures and epileptogenesis. Curr. Neuropharmacol.17, 214–231 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Detyniecki, K. Do psychotropic drugs cause epileptic seizures? A review of the available evidence. Curr. Top Behav. Neurosci. 55, 267-279 (2021). [DOI] [PubMed]
- 15.Le, D.-S., Su, H., Liao, Z.-L. & Yu, E.-Y. Low-dose clozapine-related seizure: a case report and literature review. World J. Clin. Cases9, 5611 (2021). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Hopkins, A. L. Network pharmacology: the next paradigm in drug discovery. Nat. Chem. Biol.4, 682–690 (2008). [DOI] [PubMed] [Google Scholar]
- 17.Pinzi, L. & Rastelli, G. Molecular docking: shifting paradigms in drug discovery. Int. J. Mol. Sci.20, 4331 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Kim, S. et al. PubChem 2025 update. Nucleic Acids Res.53, D1516–D1525 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Gfeller, D. et al. SwissTargetPrediction: a web server for target prediction of bioactive small molecules. Nucleic Acids Res.42, W32–W38 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Wang, X. et al. PharmMapper 2017 update: a web server for potential drug target identification with a comprehensive target pharmacophore database. Nucleic Acids Res.45, W356–W360 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Stelzer, G. et al. The GeneCards suite: from gene data mining to disease genome sequence analyses. Curr. Protoc. Bioinforma.54, 1.30. 31–31.30. 33 (2016). [DOI] [PubMed] [Google Scholar]
- 22.Knox, C. et al. DrugBank 6.0: the DrugBank knowledgebase for 2024. Nucleic Acids Res.52, D1265–D1275 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Consortium U UniProt: a worldwide hub of protein knowledge. Nucleic Acids Res.47, D506–D515 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Amberger, J. S. & Hamosh, A. Searching online mendelian inheritance in man (OMIM): a knowledgebase of human genes and genetic phenotypes. Curr. Protoc. Bioinforma.58, 1.2. 1–1.2. 12 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Bardou, P., Mariette, J., Escudié, F., Djemiel, C. & Klopp, C. jvenn: an interactive Venn diagram viewer. BMC Bioinforma.15, 293 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Szklarczyk, D. et al. The STRING database in 2023: protein-protein association networks and functional enrichment analyses for any sequenced genome of interest. Nucleic Acids Res51, D638–d646 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Shannon, P. et al. Cytoscape: a software environment for integrated models of biomolecular interaction networks. Genome Res.13, 2498–2504 (2003). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Dennis, J.rG. et al. DAVID: database for annotation, visualization, and integrated discovery. Genome Biol.4, R60 (2003). [PMC free article] [PubMed] [Google Scholar]
- 29.Berman, H. M. et al. The protein data bank. Nucleic Acids Res.28, 235–242 (2000). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Sherin, A. et al. Cholinergic and GABAergic receptor functional deficit in the hippocampus of insulin-induced hypoglycemic and streptozotocin-induced diabetic rats. Neuroscience202, 69–76 (2012). [DOI] [PubMed] [Google Scholar]
- 31.Palladino, A. A. & Stanley, C. A. The hyperinsulinism/hyperammonemia syndrome. Rev. Endocr. Metab. Disord.11, 171–178 (2010). [DOI] [PubMed] [Google Scholar]
- 32.Schauwecker, P. E. The effects of glycemic control on seizures and seizure-induced excitotoxic cell death. BMC Neurosci.13, 94 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Larsen, J. R. et al. High prevalence of prediabetes and metabolic abnormalities in overweight or obese schizophrenia patients treated with clozapine or olanzapine. CNS Spectr.24, 441–452 (2019). [DOI] [PubMed] [Google Scholar]
- 34.Chau, D. D., Ng, L. L., Zhai, Y. & Lau, K. F. Amyloid precursor protein and its interacting proteins in neurodevelopment. Biochem Soc. Trans.51, 1647–1659 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Turner, P. R., O’Connor, K., Tate, W. P. & Abraham, W. C. Roles of amyloid precursor protein and its fragments in regulating neural activity, plasticity and memory. Prog. Neurobiol.70, 1–32 (2003). [DOI] [PubMed] [Google Scholar]
- 36.Kamondi, A., Grigg-Damberger, M., Löscher, W., Tanila, H. & Horvath, A. A. Epilepsy and epileptiform activity in late-onset Alzheimer disease: clinical and pathophysiological advances, gaps and conundrums. Nat. Rev. Neurol.20, 162–182 (2024). [DOI] [PubMed] [Google Scholar]
- 37.Azzolini, F. et al. Neuroinflammation is associated with GFAP and sTREM2 levels in multiple sclerosis. Biomolecules12, 222 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Altbürger, C., Holzhauser, J. & Driever, W. CRISPR/Cas9-based QF2 knock-in at the tyrosine hydroxylase (th) locus reveals novel th-expressing neuron populations in the zebrafish mid-and hindbrain. Front. Neuroanat.17, 1196868 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39.Rocha, A., Godino-Gimeno, A., Cerdá-Reverter, J. M. Evolution of proopiomelanocortin. Vitamins and Hormones: (Elsevier, 2019) 1-16. [DOI] [PubMed]
- 40.Shu, J. et al. The relationship between SNAP25 and some common human neurological syndromes. Curr. Pharm. Des.30, 2378–2386 (2024). [DOI] [PubMed] [Google Scholar]
- 41.Chau, D. D.-L., Ng, L. L.-H., Zhai, Y. & Lau, K.-F. Amyloid precursor protein and its interacting proteins in neurodevelopment. Biochem. Soc. Trans.51, 1647–1659 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Zhuang, W., Ye, T., Wang, W., Song, W. & Tan, T. CTNNB1 in neurodevelopmental disorders. Front. Psychiatry14, 1143328 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 43.Hansen, K. B. et al. Structure, function, and pharmacology of glutamate receptor ion channels. Pharmacol. Rev.73, 1469–1658 (2021). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Chou, T.-H. et al. Molecular mechanism of ligand gating and opening of NMDA receptor. Nature632, 209–217 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Tumdam, R., Hussein, Y., Garin-Shkolnik, T. & Stern, S. NMDA receptors in neurodevelopmental disorders: pathophysiology and disease models. Int. J. Mol. Sci.25, 12366 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Gjerulfsen, C. E. et al. Spectrum of NMDA receptor variants in neurodevelopmental disorders and epilepsy. Methods Mol. Biol. 2799, 1-11 (2024). [DOI] [PubMed]
- 47.Bagasrawala, I., Memi, F., Radonjic, N. V. & Zecevic, N. N-methyl d-aspartate receptor expression patterns in the human fetal cerebral cortex. Cereb. Cortex27, 5041–5053 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 48.Karizbodagh, M. P. et al. Developmental regulation and lateralization of N-methyl-d-aspartate (NMDA) receptors in the rat hippocampus. Neuropeptides89, 102183 (2021). [DOI] [PubMed] [Google Scholar]
- 49.Amador, A. et al. Modelling and treating GRIN2A developmental and epileptic encephalopathy in mice. Brain143, 2039–2057 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 50.Swanger, S. A. et al. Mechanistic insight into NMDA receptor dysregulation by rare variants in the GluN2A and GluN2B agonist binding domains. Am. J. Hum. Genet.99, 1261–1280 (2016). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 51.Mangano, G. D. et al. De novo GRIN2A variants associated with epilepsy and autism and literature review. Epilepsy Behav.129, 108604 (2022). [DOI] [PubMed] [Google Scholar]
- 52.Korinek, M. et al. Disease-associated variants in GRIN1, GRIN2A and GRIN2B genes: insights into NMDA receptor structure, function, and pathophysiology. Physiol. Res.73, S413 (2024). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 53.Myers, S. J. et al. Distinct roles of GRIN2A and GRIN2B variants in neurological conditions. F1000Research8, F1000 Faculty Rev–F1000 Faculty1940 (2019). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 54.Gao, K. et al. A de novo loss-of-function GRIN2A mutation associated with childhood focal epilepsy and acquired epileptic aphasia. PLoS One12, e0170818 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 55.Schmitt, A. et al. Die Wirkung von Antipsychotika auf glutamaterge Neurotransmission im Tiermodell. Der Nervenarzt75, 16–22 (2004). [DOI] [PubMed] [Google Scholar]
- 56.Krzystanek, M. et al. Effects of long-term treatment with the neuroleptics haloperidol, clozapine and olanzapine on immunoexpression of NMDA receptor subunits NR1, NR2A and NR2B in the rat hippocampus. Pharmacol. Rep.67, 965–969 (2015). [DOI] [PubMed] [Google Scholar]
- 57.Traynelis, S. F. et al. Glutamate receptor ion channels: structure, regulation, and function. Pharm. Rev.62, 405–496 (2010). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 58.Staley, K. Molecular mechanisms of epilepsy. Nat. Neurosci.18, 367–372 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 59.Miwa, H. et al. GAD67-mediated GABA synthesis and signaling impinges on directing basket cell axonal projections toward Purkinje cells in the cerebellum. Cerebellum21, 905–919 (2022). [DOI] [PubMed] [Google Scholar]
- 60.Ahring, P. K. et al. Gain-of-function variants in GABRD reveal a novel pathway for neurodevelopmental disorders and epilepsy. Brain145, 1299–1309 (2022). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 61.Liu, D., Fujihara, K., Yanagawa, Y., Mushiake, H. & Ohshiro, T. Gad1 knock-out rats exhibit abundant spike-wave discharges in EEG, exacerbated with valproate treatment. Front. Neurol.14, 1243301 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 62.Neuray, C. et al. Early-infantile onset epilepsy and developmental delay caused by bi-allelic GAD1 variants. Brain143, 2388–2397 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 63.Mosiołek, A. & Mosiołek, J. The effects of treatment in psychotic disorders—changes in BDNF levels and clinical outcomes: Systematic review. Int. J. Environ. Res. Public Health20, 2111 (2023). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 64.L & Huang, T. Effects of antipsychotics on the BDNF in schizophrenia. Curr. Med. Chem.20, 345–350 (2013). [DOI] [PubMed] [Google Scholar]
- 65.Bai, O., Chlan-Fourney, J., Bowen, R., Keegan, D. & Li, X. M. Expression of brain-derived neurotrophic factor mRNA in rat hippocampus after treatment with antipsychotic drugs. J. Neurosci. Res.71, 127–131 (2003). [DOI] [PubMed] [Google Scholar]
- 66.Meshkinkhood, N. et al. Unveiling molecular dynamics of MeCp2, CDKL5 and BDNF in the hippocampus of individuals with intractable mesial temporal lobe epilepsy. J. Cell. Mol. Med.29, e70373 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 67.Wang, X., Hu, Z. & Zhong, K. The role of brain-derived neurotrophic factor in epileptogenesis: an update. Front. Pharmacol.12, 758232 (2021). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 68.Nowroozi, A., Salehi, M. A. & Mohammadi, S. Brain-derived neurotrophic factor in patients with epilepsy: a systematic review and meta-analysis. Epilepsy Res.178, 106794 (2021). [DOI] [PubMed] [Google Scholar]
- 69.Schaber, G., Stevens, I., Gaertner, H. J., Dietz, K. & Breyer-Pfaff, U. Pharmacokinetics of clozapine and its metabolites in psychiatric patients: plasma protein binding and renal clearance. Br. J. Clin. Pharm.46, 453–459 (1998). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 70.Hendouei, N. et al. Alterations in oxidative stress markers and its correlation with clinical findings in schizophrenic patients consuming perphenazine, clozapine and risperidone. Biomed. Pharmacother.103, 965–972 (2018). [DOI] [PubMed] [Google Scholar]
- 71.Pitkänen, A. & Lukasiuk, K. Mechanisms of epileptogenesis and potential treatment targets. Lancet Neurol.10, 173–186 (2011). [DOI] [PubMed] [Google Scholar]
- 72.Merenlender-Wagner, A. et al. Autophagy has a key role in the pathophysiology of schizophrenia. Mol. Psychiatry20, 126–132 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 73.Sills, G. J. & Rogawski, M. A. Mechanisms of action of currently used antiseizure drugs. Neuropharmacology168, 107966 (2020). [DOI] [PubMed] [Google Scholar]
- 74.Rodrigues, T. C. M. L. et al. Epileptic targets and drugs: a mini-review. Curr. Drug Targets24, 212–224 (2023). [DOI] [PubMed] [Google Scholar]
- 75.Thomas, T., Fang, Y., Yuriev, E. & Chalmers, D. K. Ligand binding pathways of clozapine and haloperidol in the dopamine D2 and D3 receptors. J. Chem. Inf. Modeling56, 308–321 (2016). [DOI] [PubMed] [Google Scholar]
- 76.Schwieler, L., Engberg, G. & Erhardt, S. Clozapine modulates midbrain dopamine neuron firing via interaction with the NMDA receptor complex. Synapse52, 114–122 (2004). [DOI] [PubMed] [Google Scholar]
- 77.de Leon, J. et al. Serum antimuscarinic activity during clozapine treatment. J. Clin. Psychopharmacol.23, 336–341 (2003). [DOI] [PubMed] [Google Scholar]
- 78.Phillips, H. N. & Tormoehlen, L. Toxin-Induced Seizures. Neurol. Clin.38, 867–879 (2020). [DOI] [PubMed] [Google Scholar]
- 79.Sarter, M., Hasselmo, M. E., Bruno, J. P. & Givens, B. Unraveling the attentional functions of cortical cholinergic inputs: interactions between signal-driven and cognitive modulation of signal detection. Brain Res. Brain Res. Rev.48, 98–111 (2005). [DOI] [PubMed] [Google Scholar]
- 80.Picciotto, M. R., Higley, M. J. & Mineur, Y. S. Acetylcholine as a neuromodulator: cholinergic signaling shapes nervous system function and behavior. Neuron76, 116–129 (2012). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 81.Kruglikov, I. & Rudy, B. Perisomatic GABA release and thalamocortical integration onto neocortical excitatory cells are regulated by neuromodulators. Neuron58, 911–924 (2008). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 82.Cohrs, S. Sleep disturbances in patients with schizophrenia: impact and effect of antipsychotics. CNS Drugs22, 939–962 (2008). [DOI] [PubMed] [Google Scholar]
- 83.Eriksson, S. H. Epilepsy and sleep. Curr. Opin. Neurol.24, 171–176 (2011). [DOI] [PubMed] [Google Scholar]
- 84.Caetano, D. Use of anticonvulsants as prophylaxis for seizures in patients on clozapine. Australas. Psychiatry22, 78–83 (2014). [DOI] [PubMed] [Google Scholar]
- 85.Williams, A. M. & Park, S. H. Seizure associated with clozapine: incidence, etiology, and management. CNS Drugs29, 101–111 (2015). [DOI] [PubMed] [Google Scholar]
