Search Results (177)

Objectives: This study aimed to elucidate the determinants of interindividual variability in the pharmacokinetics of ibrutinib among healthy Chinese subjects, focusing on the influence of demographic characteristics, dietary conditions, and genetic polymorphisms on CYP enzymes and ABC transporters. Methods: Thirty-two participants were randomly assigned to either a fasting (n = 16) or fed (n = 16) group, each receiving a single 140 mg oral dose of ibrutinib. Plasma concentrations were quantified using a validated UPLC–MS/MS method. Genetic polymorphisms in CYP3A4, CYP3A5, CYP2D6, and ABCG2 were identified by Sanger sequencing. Pharmacokinetic parameters, including apparent clearance (CL/F), maximum plasma concentration (Cmax), area under the plasma concentration–time curve (AUC0-t), and time to maximum concentration (Tmax), were estimated by non-compartmental analysis and statistically evaluated for associations with demographic, dietary, and genetic variables. Results: Food intake significantly affected ibrutinib pharmacokinetics, with postprandial administration resulting in reduced CL/F and increased Cmax and AUC0-t (p < 0.01). Gender differences were also observed, as females exhibited higher CL/F, lower Cmax, and AUC0-t than males (p < 0.05). The CYP2D6 c.100C>T polymorphism significantly decreased CL/F and increased exposure in fasting and male subjects (p < 0.05), but this effect was absent under fed conditions. Conversely, the ABCG2 c.421C>A variant was associated with increased CL/F and decreased AUC0-t (p < 0.05), while other genotypes exerted negligible effects. Conclusions: Ibrutinib pharmacokinetics are significantly modulated by dietary status, gender, and genetic polymorphisms, particularly CYP2D6 c.100C>T and ABCG2 c.421C>A. These findings underscore the importance of integrating pharmacogenetic and physiological factors into individualized dosing strategies to optimize therapeutic efficacy and minimize adverse effects. Full article

Background/Objectives: Pharmacogenetic variability plays a crucial role in determining both the efficacy and toxicity of chemotherapy for gastrointestinal cancers. However, data on allele frequencies and their clinical relevance in Russian populations remain scarce. Methods: We conducted a prospective observational study of 412 patients with gastrointestinal malignancies between 2020 and 2023. Pharmacogenetic testing was performed prior to the initiation of chemotherapy using real-time allele-specific PCR and microarray hybridization technology. Polymorphisms in the DPYD, UGT1A1, CYP2C8, CYP3A5, GSTP1, ERCC1, XPC, CDA, MTHFR, TYMS, and SLC31A1 genes were analyzed. Results: The frequency of most variants was consistent with those reported in European populations, reflecting the ethnic proximity of the studied cohort. Several clinically relevant variants were identified: DPYD rs2297595 occurred more frequently than in European cohorts, and UGT1A1 rs8175347 was observed at a higher prevalence, underscoring the potential risk of irinotecan-related neutropenia and diarrhea. CYP2C8 rs10509681 was present at frequencies comparable to European populations and is associated with an increased risk of taxane-induced peripheral neuropathy. Other markers (GSTP1, ERCC1, CDA, SLC31A1, MTHFR, TYMS) demonstrated variable associations with chemotherapy efficacy and toxicity, consistent with findings from previous international studies. Conclusions: This study provides the first comprehensive description of pharmacogenetic polymorphisms in a Russian cohort of patients with gastrointestinal cancers. Our findings confirm the clinical importance of DPYD and UGT1A1 testing and highlight additional variants of potential interest. Full article

Background and objectives: Warfarin is a commonly used anticoagulant with a narrow therapeutic index that requires a precise dose to achieve efficacy and safety. Genetic variations in the CYP2C9 and VKORC1 genes significantly contribute to individual responses to warfarin, influencing both drug metabolism and pharmacodynamics. The current study aims to investigate the frequency of CYP2C9 and VKORC1 variant genotypes and determine the appropriate warfarin dosage for patients in Saudi Arabia. Materials and Methods: Blood samples were collected from 100 Saudi patients undergoing treatment with warfarin. DNA was extracted and purified from the whole blood, and variants in the CYP2C9 and VKORC1 genes were analyzed using multiplex PCR techniques. Results: The analysis revealed that the VKORC1 GG genotype was the most common, at 54%, followed by GA at 30%, and the AA at 16%. For CYP2C9, the *1/*1 genotype predominated at 71%, whereas the *1/*2 genotype was found in 14%, the *1/*3 genotype was found in 11%, and the *2/*3 genotype was found in in 2%, being less frequently observed. Patients with VKORC1 GG required significantly higher warfarin doses than those with GA and AA genotypes. Similarly, CYP2C9 *1/*1 patients required higher doses than those with *1/*3 and *2/*3 variants. No significant differences in INR levels across genotypes were found, indicating that while genetic variations influence dosing, they do not significantly alter the therapeutic INR range. Conclusions: The findings indicate that genetic variations influence drug metabolism and response in the Saudi population, aligned with global studies. Such tailored approaches could enhance treatment efficacy and reduce adverse effects, underscoring the role of pharmacogenomics in patient care and optimizing warfarin therapy in unique genetic populations. Full article

Vitamin D deficiency is highly prevalent in Pakistan, but there is limited data on its genetic aspects. This case–control pilot study aimed to determine the association of rs782153744, rs200183599, rs118204011, and rs28934604 with vitamin D deficiency along rs7041 which has been studied in our population. The DNA of a total of 600 subjects (300 cases and 300 controls) was extracted and genotyped by tetra ARMS PCR, followed by Sanger DNA sequencing of exon 4 of the CYP2R1 and CYP27B1 genes and exon 8 of the GC gene. SNP Stat was employed to analyze the data, while logistic regression was used to calculate the p-values and odds ratios (ORs). The R package version R studio (2025.05.1) Build 513 was used to statistically analyze rs782153744. In silico modeling of wild and mutant CYP2R1 and GC proteins was performed in Swiss-Model, Swiss-Dock, Discovery Studio, and PyMol using 3c6g and IJ78 as templates to perform binding pocket analysis of vitamin D3. The rs782153744 showed a protective association in the additive (OR: 0.15, 95% CI: 0.08–0.27, p-value < 0.001), recessive (OR: 0.19, 95% CI: 0.10–0.33, p-value < 0.001), and dominant (OR: 0.19, CI = 0.10–0.33, p-value < 0.001) models, while GC rs7041 (T > A, T > G) displayed a p-value < 0.0001 across all genetic models. Sanger sequencing yielded insignificant results, and the SNPs rs200183599, rs118204011, and rs28934604 had no significant association with vitamin D deficiency. The molecular pocket analysis of wild and mutant CYP2R1 proteins carrying rs782153744 polymorphisms revealed no changes. GC proteins carrying the rs7041 polymorphism revealed a shift in their 3D and 2D configuration, as well as a change in the amino acid residue of the binding pocket of VD3. The risk-associated rs7041 and protective rs782153744 variants back genetic screening for vitamin D deficiency risk stratification, allowing targeted supplementation in predisposed subjects and assisting in formulating a genotype-specific therapeutic approach. Full article

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with a fivefold increase in stroke risk. Direct oral anticoagulants (DOACs), including apixaban, are now the preferred therapy for stroke prevention in patients with non-valvular AF (NVAF). However, interindividual variability in drug response and safety remains a major challenge, particularly in elderly patients with comorbidities and polypharmacy. Genetic polymorphisms in drug-metabolizing enzymes and transporters may contribute to variability in apixaban exposure and bleeding risk. This study aimed to evaluate the association of polymorphisms in ABCB1, CYP3A4, and CYP3A5 with steady-state plasma concentrations of apixaban (Cssmin) and hemorrhagic complications in elderly patients with NVAF. Methods: This cross-sectional study included 197 patients (mean age 83 ± 8 years; 67% women) with NVAF treated with apixaban (5 mg twice daily). Genotyping of ABCB1 (rs1045642, rs2032582, rs1128503), CYP3A4*22 (rs35599367), and CYP3A5*3 (rs776746) was performed using allele-specific real-time PCR. Cssmin of apixaban was determined by high-performance liquid chromatography coupled with tandem mass spectrometry. Associations with bleeding events were evaluated. Results: Bleeding events were recorded in 40 patients (20.3%). An association signal was observed for ABCB1 rs1045642, where carriers of the CC genotype had a higher risk of bleeding compared with alternative alleles (OR = 2.805; 95% CI: 1.326–5.935; p = 0.006). After correction for multiple testing, the association remained significant only under the log-additive model (OR = 1.93 per C allele; 95% CI: 1.17–3.20; q = 0.0275; p_adj = 0.044), while recessive and codominant effects did not withstand Bonferroni adjustment. No significant associations were observed for rs2032582, rs1128503, CYP3A4*22, or CYP3A5*3. None of the studied polymorphisms, including rs1045642, significantly affected Cssmin. Concomitant therapy, particularly with antiarrhythmic drugs and statins (rosuvastatin), also increased bleeding risk. Conclusions: The findings highlight the potential contribution of ABCB1 rs1045642 and specific drug–drug interactions to the risk of hemorrhagic complications in elderly NVAF patients receiving apixaban. Full article

Clopidogrel is widely used as an antiplatelet therapy for acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Genetic factors influence variability in clopidogrel response, with non-functional CYP2C19 alleles increasing the risk of major adverse cardiovascular events (MACEs). While CYP2C19 genotype-guided therapy after PCI improves outcomes, MACEs persist at variable rates. Pharmacogenomics (PGx) has primarily focused on genes related to drug metabolism, but therapeutic failure may stem from individual disease predisposition. This study aims to identify novel genetic variants underlying adverse events after PCI despite PGx-guided therapy. A custom sequencing panel was analyzed in 244 ACS-PCI-stent patients and 99 controls without cardiovascular (CV) disease. Association analysis was performed independent of treatment and by prescribed treatment (clopidogrel or prasugrel), complemented by random forest models to predict risk during antiplatelet therapy. No polymorphism reached genomic significance, but in clopidogrel-treated patients, rs2472434 in ABCA1, related to altered lipid metabolism, was strongly associated with secondary CV events (p = 1.7 × 10⁻³). Variants in the clopidogrel pathway, including CYP2C19, ABCB1, and UGT2B7, were also identified and may influence clopidogrel response. Predictive models incorporating these variants effectively discriminated patients with and without events (p = 0.02445). Our findings support combined genotyping of CYP2C19 loss-of-function and ABCB1 C3435T variants to guide antiplatelet therapy and suggest additional targets, such as rs2472434 (ABCA1) and rs7439366 (UGT2B7), to improve risk prediction of adverse CV events. Therefore, the unexplained variability in clopidogrel response may be due to disease pathogenesis itself, highlighting the need for a paradigm shift in PGx studies. Full article

Background and Objectives: The aim of this study was to evaluate the potential predictive value of VKORC1, CYP4F2, and GGCX polymorphisms, as well as other clinical and demographic factors, for 5-year mortality in patients with acute ischemic stroke (AIS). Materials and Methods: The study enrolled 252 patients who were consecutively hospitalized for AIS. Demographic data, comorbidities, and laboratory tests were collected. Genotyping of the VKORC1 rs9923231 (-1639G > A; VKORC1*2), CYP4F2 rs2108622 (1347C > T), and GGCX rs11676382 (12970C > G) polymorphisms was performed. Mortality was noted if it occurred within five years following the 30 days after discharge, using the National Health Insurance House registry. Results: Death was recorded in 71 (28.1%) patients. In multivariate analysis the following variables were independent variables associated with 5-year mortality: age > 72 years (OR 2.83 (95%CI 1.32; 6.08), p = 0.007), a lesion volume > 12.6 mL (OR 4.05 (95%CI 2.05; 7.99), p < 0.001), and an NIHSS score > 7 (OR—2.64 (95%CI 1.31; 5.31), p = 0.006). VKORC1 (-1639G > A) SNP m/m variant was only marginally associated with mortality. Conclusions: In this study which included AIS patients, VKORC1, CYP4F2, and GGCX polymorphisms did not independently predict mortality. The VKORC1 variant was only marginally associated with mortality, but this was attenuated after correction for multiple testing. Advanced age, NIHSS score, and the lesion volume were independent predictors of long-term mortality in AIS patients. Full article

Purpose: Genetic polymorphisms within specific genes play a role in both the genetic predisposition to Major Depressive Disorder (MDD) and the variation observed in responses to antidepressant treatments. Pharmacogenetics examines how these polymorphisms affect medication response. This review highlights significant disparities in the pharmacogenetic influences on antidepressant response, with a focus on ethnic and sex-based differences. Methods: This review synthesizes findings from a comprehensive literature search conducted between 2000 and 2025. It utilized databases such as PubMed, Scopus, and Web of Science, using search terms including “pharmacogenetics”, “antidepressants”, “Major Depressive Disorder”, “CYP450”, “neuroplasticity”, and “genetic variations”. This review integrates pharmacogenetics with neurotransmitters and their transporters, neuroplasticity, growth factors, and the cytochrome P450 family, providing promising insights for personalized MDD treatment strategies. We analyzed and synthesized findings from over 50 relevant studies, focusing on those with a clear emphasis on genetic associations with antidepressant efficacy and adverse effects. Results: Pharmacogenetic analysis facilitates personalized antidepressant prescriptions by identifying key genetic variants that influence treatment outcomes. Specifically, variations in CYP2D6 and CYP2C19 can significantly impact drug metabolism and tolerability. A high percentage of patients with non-normal metabolizer phenotypes are predisposed to adverse drug reactions or ineffective responses. Furthermore, this review identifies significant ethnic and sex-based disparities in treatment response. For example, the L allele of the 5-HTTLPR polymorphism confers a higher likelihood of response and remission following SSRI treatment in white people compared to Asians. Additionally, in women, specific 5-HTTLPR polymorphisms have a more pronounced influence on mood and MDD pathophysiology, with a significant reduction in mood in response to tryptophan depletion. Conclusions: Integrating pharmacogenetic insights, encompassing genetic factors, neurotransmitter pathways, neuroplasticity, and the influence of ethnicity and sex, is crucial for developing personalized antidepressant treatment strategies. This will ultimately optimize patient recovery and minimize adverse effects. Full article

Psychotropic medication is commonly used for the treatment of mental health conditions. However, the genetic factors that influence psychotropic medication responses in children have not been thoroughly investigated. To address this gap, a systematic review and thematic analysis were conducted to examine the genetic impact of psychotropic medication response in children. The Down and Blacks and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklists assessed the quality of studies and health economics, respectively. Using PRISMA reporting guidelines, 50 articles were identified with a sample size ranging from 2 to 2.9 million individuals. Most of the studies reported on ethnicity, and approximately half of the studies (24/50) were performed in North America. Five themes emerged from the thematic analysis: (1) implications of non-CYP450 polymorphisms, (2) paediatric CYP450 pharmacogenetics, (3) genetic predictors of response, (4) insights for implementation and future research and (5) phenoconversion. The thematic analysis revealed that assessment of non-CYP450 polymorphisms and psychotropic medication response, especially in those with mental health conditions such as autism, would be helpful. Epilepsy onset, risk and treatment response were associated with non-CYP450 genetic variants. Phenoconversion of substrates associated with CYP2D6 and CYP2C19 metabolisers is common in individuals with mental health conditions, and ABCB1 variants can influence psychotropic medication responses. A multidisciplinary model could also help guide clinical decision-making in cases involving complex neurodevelopmental profiles. Using the Down and Blacks checklist, the average score from the 50 studies was 17.7 points (min. 14, max. 24). The health economic evaluation of studies using the CHEERS checklist gave an average score of 33.0% (range: 21.4% to 35.7%). The study provides an important resource of information for healthcare professionals, researchers and policymakers working at the intersection of child psychiatry, pharmacogenomics and precision medicine. Full article

Objectives: Silodosin, a selective α1A-adrenoceptor antagonist, is used to treat lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Genetic polymorphisms in drug-metabolizing enzymes and transporters may contribute to interindividual variability in its efficacy and safety. This study aimed to investigate the influence of CYP3A4, CYP3A5, UGT2B7, and ABCB1 polymorphisms on silodosin pharmacokinetics, efficacy, and safety in Russian patients with BPH. Methods: A prospective observational study included 103 Russian male patients with moderate-to-severe LUTS (IPSS > 8) due to BPH, treated with silodosin (8 mg daily) for 8 weeks. Genotyping for CYP3A4*1B, CYP3A4*22, CYP3A5*3, UGT2B7 (rs73823859, rs7439366, and rs7668282), and ABCB1 (rs4148738, rs1045642, rs2032582, and rs1128503) was performed using real-time PCR. The silodosin minimum steady-state plasma concentration (Css min) was measured via HPLC-MS. Efficacy was evaluated by the International Prostate Symptom Score (IPSS), quality of life scale, maximum urinary flow rate (Qmax), residual urine volume (RUV), and prostate volume at the baseline and week 8. Adverse drug reactions (ADRs) were recorded. Results: CYP3A4*22 CT carriers (n = 6) exhibited higher Css min (17.59 ± 2.98 vs. 9.0 ± 10.47 ng/mL, p = 0.049) but less absolute IPSS improvement (p < 0.05), likely due to higher baseline symptom severity. However, the change in IPSS (ΔIPSS_1–4) from the baseline to week 8 did not differ significantly (−5.78 ± 5.29 vs. −6.0 ± 4.54, p = 0.939). CYP3A5*3 GG homozygotes (n = 96) showed greater ΔIPSS_1–4 improvement (−6.25 ± 4.60 vs. 0.0 ± 9.53, p = 0.042) and a lower IPSS at day 28 (7.64 ± 4.50 vs. 20.0 ± 6.55, p < 0.001). UGT2B7 rs7439366 TT carriers (n = 34) had an improved Qmax (ΔQmax_1–4 5.4 vs. 3.3 and 2.0 mL/s for CC and CT, p = 0.041). ABCB1 1236C>T TT homozygotes (n = 25) showed a trend toward reduced RUV (p = 0.053). No polymorphisms were associated with adverse drug reactions (15 events in 42 patients, 35.7%). Conclusions: Genetic polymorphisms CYP3A4*22, CYP3A5*3, and UGT2B7 rs7439366 may modulate silodosin pharmacokinetics and efficacy parameters in BPH patients but not safety. Larger-scale studies are warranted to validate these initial findings. Full article

Cytochrome P450 (CYP450) enzymes play an essential role in the metabolism of drugs, particularly in phase I metabolic reactions. In this article, we present a comprehensive review of fifteen selected enzymes belonging to the CYP450 family. The enzymes included in this analysis are CYP7A1, CYP3A4, CYP3A5, CYP2D6, CYP2E1, CYP2C8, CYP2C18, CYP2C9, CYP2C19, CYP2B6, CYP2A6, CYP2A13, CYP1B1, CYP1A1, and CYP1A2. We examined the influence of natural, polymorphic variations within their primary amino acid sequences on their enzymatic function and mechanisms of action. To begin, we compiled a dataset of naturally occurring polymorphic variants for these enzymes. This was achieved through a detailed analysis of entries in the UniProt database, as well as an extensive review of the current scientific literature. For each variant, we included commentary regarding its potential impact on enzyme activity or drug response, based on evidence observed in in vitro experiments, in vivo studies, or clinical trials. Particular emphasis was placed on how such polymorphisms might alter the metabolism of xenobiotics, thereby potentially affecting pharmacological outcomes. In this respect, the work represents the first comprehensive source in the scientific literature that systematically gathers and organizes data on CYP450 polymorphisms, including an assessment of their potential significance in processes mediated by these enzymes. A more detailed comparison of the polymorphism-related in vitro studies is devoted to CYP3A4, an enzyme that displays the largest fraction of clinically significant polymorphs. Secondly, we aimed to establish possible molecular explanations for why specific polymorphisms exhibit clinically or experimentally observable effects. To explore this, we performed a qualitative structural analysis of the enzymes, focusing on shared structural characteristics among the examined members of the CYP450 family. The results of this analysis demonstrate that there is no single universal mechanism by which polymorphisms influence the function of CYP450 enzymes. Instead, the mechanisms vary and may include alterations in the orientation of the enzyme within the lipid membrane, changes affecting the association or dissociation of substrates and products at the active site, structural stabilization or destabilization of the enzyme’s reactive centers, modifications in the way the enzyme interacts with its ligand, or alterations in the character of the interface involved in contact with its redox partner (electron transfer protein). Furthermore, among the polymorphisms that significantly impact enzyme function, mutations involving the substitution of arginine residues for other amino acids appear to be overrepresented. Full article

Background/Objectives: Pain—whether acute, chronic, or neuropathic—remains a leading cause of disability and reduced quality of life worldwide. Despite advances in pharmacologic options, interindividual variability in response and susceptibility to adverse effects continues to challenge clinicians. In recent years, pharmacogenetics has emerged as a promising approach to optimize analgesic selection and dosing based on patient-specific genetic profiles. This perspective examines current pharmacogenetic evidence in pain management, focusing on validated biomarkers and their clinical implications. Methods: A narrative review was conducted of recent literature addressing the impact of genetic polymorphisms on the pharmacokinetics and pharmacodynamics of analgesic agents. Particular focus was given to genes involved in drug metabolism and transport as well as receptor signaling, along with the clinical applications of genotype-informed prescribing. Results: Substantial evidence indicates that genetic variants significantly influence patient responses to analgesics, contributing to both inadequate pain relief and heightened sensitivity to adverse effects. The main pharmacogenetic biomarkers appear to be CYP2C9 (for NSAIDs), CYP2D6 (for opioids and tricyclic antidepressants), CYP2C19 (for tricyclic antidepressants) and HLA-B*15:02 and HLA-A*31:01 for carbamazepine. PGx-informed strategies have shown promise in improving analgesic effectiveness, reducing opioid-related complications, and supporting opioid-sparing protocols. Conclusions: Pharmacogenetic screening represents a valuable tool for personalizing pain management. Incorporating validated pharmacogenetic biomarkers into clinical practice could improve treatment outcomes and patient safety. Further research, infrastructure development, and clinician education are essential for scaling PGx implementation in pain care. Full article

Background/Objectives: Hypertension is a pathological condition characterized by elevated systolic and/or diastolic blood pressure. A range of pharmacotherapeutic agents are available to treat this condition and prevent complications, including the angiotensin II AT1-receptor blocker losartan. Following oral administration, losartan is exposed to a variety of enzymes that facilitate its metabolism or transportation. The structural characteristics of the genes that encode the enzymes may potentially impact the pharmacokinetics and pharmacodynamics of losartan, thereby modulating its effects on the treatment process. Methods: In this study, a computational model of losartan pharmacokinetics was developed, taking into account the influence of different alleles of the CYP2C9 gene, which plays a pivotal role in losartan metabolism, and the ABCB1 gene, which is responsible for losartan transport. Results: Alterations in the modeled activities of the enzymes encoded by CYP2C9 and ABCB1 result in changes in the losartan and its metabolite profiles that are consistent with known experimental data in real patients with different CYP2C9 and ABCB1 genotypes. Conclusions: The findings of the modeling can potentially be used to personalize drug therapy for arterial hypertension. Full article

CYP2C9 and CYP2C19 are major CYP450 enzymes that heavily influence the hepatic metabolism and bioactivation of many medications, including over-the-counter and narrow therapeutic index drugs. Compared to the wild-type alleles, genetic variants in either gene could potentially alter the pharmacokinetics of widely used medications, affect the desired therapeutic outcomes of a drug therapy, or increase the risk of undesired adverse events. The frequency of genetic polymorphisms associated with CYP450 enzymes can widely differ across and between racial and ethnic groups. This narrative review highlights the differences in CYP2C9 and CYP2C19 allele frequencies among European and Asian population subgroups, using published literature. Identifying the substantial differences across European and Asian populations, as well as within Asian subgroups, indicates the need to further scrutinize general population data. Clinical scientists and healthcare providers should advocate for more inclusive clinical pharmacogenomic data and racially and ethnically diverse pharmacogenomic databases. Clinical trials of limited racial and geographical diversity may not necessarily have strong external generalizability for all populations. Furthermore, clinical trials that designate an all-inclusive Asian population consisting of multiple ethnicities may not be adequate due to the perceived genetic differences among Asian subgroups. Gravitating towards a more comprehensive approach to utilizing pharmacogenomic data necessitates granular population-level genetic information which can be leveraged to improve how drug therapies are prescribed, achieve health equity, and advance the future of precision medicine. Full article

Background/Objectives: Avatrombopag (AVA), a thrombopoietin receptor agonist used to treat thrombocytopenia in patients with chronic liver disease, exhibits significant pharmacokinetic (PK) variability, particularly under fasting conditions. This study investigates the combined influence of food intake and genetic polymorphisms in CYP2C9 and ABCB1 on the PK and pharmacodynamics (PD) of AVA, with the goal of informing individualized dosing strategies. Methods: A pharmacogenetic analysis was conducted in 92 healthy participants, who received 20 mg of AVA under both fasting and fed conditions. A population PK/PD model was developed to evaluate the covariates effects on the PK variability. Monte Carlo simulations were used to predict AVA exposure and platelet count profiles under diverse dosing scenarios. Results: Food intake significantly reduced PK variability, with approximately 50% reductions in clearance (CL/F) and volume of distribution (Vd/F) compared to fasting conditions. Under fed conditions, CYP2C9 intermediate metabolizers showed a 1.70-fold increase in exposure compared to normal metabolizers, but this difference was not observed under fasting conditions. ABCB1 polymorphisms showed minimal impact, with the exception of ABCB1 (C1236T) heterozygotes, which exhibited 1.37-fold increased exposure. Despite the observed PK variability, simulations demonstrated a consistent platelet count response across dosing regimens. Conclusions: While food intake and genetic polymorphisms in CYP2C9 and ABCB1 influenced AVA PK, these factors may not require dose adjustments, as platelet count responses remained consistent across genotypes and dosing conditions in the Chinese participants. These findings support simplified dosing strategies without the need for pharmacogenetic testing in Chinese individuals and may contribute to more individualized thrombocytopenia management. Full article