Case report: dose-dependent interaction between dexamethasone and voriconazole in severely ill patients with non-Hodgkin's lymphoma being treated for invasive pulmonary aspergillosis.

Background: Voriconazole is primarily metabolized by CYP2C19 and CYP3A4. Drug interactions that affect this pathway can alter its plasma exposures, resulting in untargeted voriconazole concentrations. Case summary: In this case report, we describe the case of a 64-year-old man who was treated for non-Hodgkin's lymphoma with continuous glucocorticoids co-administrated with voriconazole against invasive pulmonary aspergillosis. A decrease in trough concentration (Cmin) of voriconazole was observed and related with co-administration of dexamethasone in the patient carrying the CYP2C19 *1*2 genotype: voriconazole Cmin/dose ratios of 0.018 (0.1 mg L-1/5.7 mg kg-1 day-1), 0.18 (1 mg L-1/5.7 mg kg-1 day-1), and 0.23 (2 mg L-1/8.6 mg kg-1 day-1) at dexamethasone doses of 20, 12.5, and 2.5 mg, respectively. Sub-therapeutic voriconazole Cmin was associated with high- and moderate-dose dexamethasone (20 and 12.5 mg), leading to failure of antifungal treatment. Conclusion: The extent of voriconazole-dexamethasone interaction was determined by the dose of dexamethasone and associated with the CYP2C19 *1*2 genotype. Therapeutic drug monitoring of voriconazole is necessary to avoid clinically relevant interactions for optimal antifungal therapy.

Is It Still Beneficial to Monitor the Trough Concentration of Vancomycin? A Quantitative Meta-Analysis of Nephrotoxicity and Efficacy.

This study conducted a quantitative meta-analysis to investigate the association of vancomycin indicators, particularly area under the curve over 24 h (AUC24) and trough concentrations (Ctrough), and their relationship with both nephrotoxicity and efficacy. Literature research was performed in PubMed and Web of Science on vancomycin nephrotoxicity and efficacy in adult inpatients. Vancomycin Ctrough, AUC24, AUC24/minimum inhibitory concentration (MIC), nephrotoxicity evaluation and treatment outcomes were extracted. Logistic regression and Emax models were conducted, stratified by evaluation criterion for nephrotoxicity and primary outcomes for efficacy. Among 100 publications on nephrotoxicity, 29 focused on AUC24 and 97 on Ctrough, while of 74 publications on efficacy, 27 reported AUC24/MIC and 68 reported Ctrough. The logistic regression analysis indicated a significant association between nephrotoxicity and vancomycin Ctrough (odds ratio = 2.193; 95% CI 1.582-3.442, p < 0.001). The receiver operating characteristic curve had an area of 0.90, with a cut-off point of 14.55 mg/L. Additionally, 92.3% of the groups with a mean AUC24 within 400-600 mg·h/L showed a mean Ctrough of 10-20 mg/L. However, a subtle, non-statistically significant association was observed between the AUC24 and nephrotoxicity, as well as between AUC24/MIC and Ctrough concerning treatment outcomes. Our findings suggest that monitoring vancomycin Ctrough remains a beneficial and valuable approach to proactively identifying patients at risk of nephrotoxicity, particularly when Ctrough exceeds 15 mg/L. Ctrough can serve as a surrogate for AUC24 to some extent. However, no definitive cut-off values were identified for AUC24 concerning nephrotoxicity or for Ctrough and AUC24/MIC regarding efficacy.

Optimizing vancomycin dosing in pediatrics: a machine learning approach to predict trough concentrations in children under four years of age.

BACKGROUND: Vancomycin trough concentration is closely associated with clinical efficacy and toxicity. Predicting vancomycin trough concentrations in pediatric patients is challenging due to significant inter-individual variability and rapid physiological changes during maturation. AIM: This study aimed to develop a machine learning model to predict vancomycin trough concentrations and determine optimal dosing regimens for pediatric patients < 4 years of age using ML algorithms. METHOD: A single-center retrospective observational study was conducted from January 2017 to March 2020. Pediatric patients who received intravenous vancomycin and underwent therapeutic drug monitoring were enrolled. Seven ML models [linear regression, gradient boosted decision trees, support vector machine, decision tree, random forest, Bagging, and extreme gradient boosting (XGBoost)] were developed using 31 variables. Performance metrics including R-squared (R2), mean square error (MSE), root mean square error (RMSE), and mean absolute error (MAE) were compared, and important features were ranked. RESULTS: The study included 120 eligible trough concentration measurements from 112 patients. Of these, 84 measurements were used for training and 36 for testing. Among the seven algorithms tested, XGBoost showed the best performance, with a low prediction error and high goodness of fit (MAE = 2.55, RMSE = 4.13, MSE = 17.12, and R2 = 0.59). Blood urea nitrogen, serum creatinine, and creatinine clearance rate were identified as the most important predictors of vancomycin trough concentration. CONCLUSION: An XGBoost ML model was developed to predict vancomycin trough concentrations and aid in drug treatment predictions as a decision-support technology.

Vancomycin trough concentration in adult patients with periprosthetic joint infection: A machine learning-based covariate model.

AIMS: Although there are various model-based approaches to individualized vancomycin (VCM) administration, few have been reported for adult patients with periprosthetic joint infection (PJI). This work attempted to develop a machine learning (ML)-based model for predicting VCM trough concentration in adult PJI patients. METHODS: The dataset of 287 VCM trough concentrations from 130 adult PJI patients was split into a training set (229) and a testing set (58) at a ratio of 8:2, and an independent external 32 concentrations were collected as a validation set. A total of 13 covariates and the target variable (VCM trough concentration) were included in the dataset. A covariate model was respectively constructed by support vector regression, random forest regression and gradient boosted regression trees and interpreted by SHapley Additive exPlanation (SHAP). RESULTS: The SHAP plots visualized the weight of the covariates in the models, with estimated glomerular filtration rate and VCM daily dose as the 2 most important factors, which were adopted for the model construction. Random forest regression was the optimal ML algorithm with a relative accuracy of 82.8% and absolute accuracy of 67.2% (R2 =.61, mean absolute error = 2.4, mean square error = 10.1), and its prediction performance was verified in the validation set. CONCLUSION: The proposed ML-based model can satisfactorily predict the VCM trough concentration in adult PJI patients. Its construction can be facilitated with only 2 clinical parameters (estimated glomerular filtration rate and VCM daily dose), and prediction accuracy can be rationalized by SHAP values, which highlights a profound practical value for clinical dosing guidance and timely treatment.

Pharmacokinetics of tenofovir alafenamide, emtricitabine, and dolutegravir in a patient on peritoneal dialysis.

INTRODUCTION: Peritoneal dialysis (PD) is an effective renal replacement modality in people with HIV (PWH) with end-stage kidney disease (ESKD), particularly those with residual kidney function. Data on pharmacokinetics (PK) of antiretrovirals in patients on peritoneal dialysis are limited. METHODS: A single-participant study was performed on a 49-year-old gentleman with ESKD on PD and controlled HIV on once daily dolutegravir (DTG) 50 mg + tenofovir alafenamide (TAF) 25 mg / emtricitabine (FTC) 200 mg. He underwent serial blood plasma, peripheral blood mononuclear cell, and urine PK measurements over 24 h after an observed DTG + FTC/TAF dose. RESULTS: Plasma trough (Cmin) concentrations of TAF, tenofovir (TFV), FTC, and DTG were 0.05, 164, 1,006, and 718 ng/mL, respectively. Intracellular trough concentrations of TFV-DP and FTC-TP were 1142 and 11,201 fmol/million cells, respectively. Compared to published mean trough concentrations in PWH with normal kidney function, observed TFV and FTC trough concentrations were 15.5- and 20-fold higher, while intracellular trough concentrations of TFV-DP and FTC-TP were 2.2-fold and 5.4-fold higher, respectively. TFV and FTC urine levels were 20 times lower than in people with normal GFR. CONCLUSIONS: In a single ESKD PWH on PD, daily TAF was associated with plasma TFV and intracellular TFV-DP trough concentrations 15-fold and 2-fold higher than those of people with uncompromised kidney function, potentially contributing to nephrotoxicity. This suggests that TFV accumulates on PD; thus, daily TAF in PD patients may require dose adjustment or regimen change to optimize treatment, minimize toxicity, and preserve residual kidney function.

Association between tenofovir plasma trough concentrations in the early stage of administration and discontinuation of up to five years tenofovir disoproxil fumarate due to renal function-related adverse events in Japanese HIV-1 infected patients.

BACKGROUND: The relationship between plasma tenofovir (TFV) concentration at the beginning of tenofovir disoproxil fumarate (TDF) administration and the development of renal dysfunction during long-term administration of TDF has not been demonstrated yet. The objective of the present study was to determine whether plasma TFV trough concentrations during early TDF administration could serve as an indicator of renal dysfunction when TDF is administered for long periods. METHODS: We included 149 HIV-1 infected Japanese patients who were prescribed TDF. We investigated the relationship between plasma TFV trough concentrations and the rate of discontinuation due to the development of renal dysfunction for up to five years after the start of TDF administration. We also examined how the decrease in renal function over time due to TDF administration was related to factors associated with high TFV levels and plasma TFV trough concentrations. RESULTS: The median TFV trough concentration in the TDF discontinuation group was 88 ng/mL, which was significantly higher (p = 0.0041), than that in the continuation group (72 ng/mL). Further, using an ROC curve, the cut-off value for TFV trough concentration at which TDF discontinuation was significantly high was found to be 98 ng/mL. Logistic multivariate analysis of factors associated with discontinuation of TDF due to renal function-related adverse events showed that being ≥ 50 years old (OR = 2.96; 95% CI, 1.01-8.64), having eGFR < 80 mL/min/1.73m2 at the start of TDF administration (OR = 5.51; 95% CI, 1.83-17.5), and TFV trough concentration ≥ 98 ng/mL (OR = 2.96; 95% CI, 1.16-7.60) were independent factors. CONCLUSIONS: The results suggested that the importance of measuring TFV concentrations to evaluate the risk of developing renal function-related adverse events during long-term TDF administration.

Age-Related Differences in Vancomycin-Associated Nephrotoxicity and Efficacy in Methicillin-Resistant Staphylococcus aureus Infection: A Comparative Study between Elderly and Adult Patients.

Elderly patients (age ≥ 65 years) are susceptible to methicillin-resistant Staphylococcus aureus (MRSA) infections, with potential for more adverse treatment outcomes or complications compared to younger adults (18-64 years). This study compared vancomycin-associated nephrotoxicity and efficacy in elderly and adult patients and investigated the correlation between vancomycin pharmacokinetic/pharmacodynamic (PK/PD) indices and clinical outcomes. A prospective study was conducted in 10 hospitals in Shanghai from October 2012 to November 2019. A total of 164 patients with MRSA infections were enrolled, including 83 elderly and 81 adult patients. Vancomycin therapeutic drug monitoring (TDM) was performed in all patients, indicating significantly higher vancomycin trough concentrations (Ctrough), 24-h area under the curve (AUC24) values, and AUC24/minimum inhibitory concentration (AUC24/MIC) values in elderly patients compared to adult patients. The incidence of vancomycin-associated nephrotoxicity was nearly three times higher in elderly patients (18.1% vs. 6.2%, p = 0.020), despite similar clinical and microbiological efficacy. Of particular importance, a Ctrough > 20 mg/L was found as an independent factor of nephrotoxicity in elderly patients. Further analysis of patients with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2 also revealed that elderly patients had significantly higher vancomycin-related PK/PD indices and more nephrotoxicity than adult patients. In conclusion, elderly patients receiving vancomycin therapy face a higher risk of nephrotoxicity, which requires close vancomycin TDM, especially when the Ctrough exceeds 20 mg/L.

Exploring clozapine pharmacokinetics in Tunisian schizophrenic patients: A population-based modelling approach investigating the impact of genetic and non-genetic variables.

Clozapine is characterized by a large within- and between-patient variability in its pharmacokinetics, attributed to non-genetic and genetic factors. A cross-sectional analysis of clozapine trough concentration (Clz C0) issued from Tunisian schizophrenic patients was collected and analysed using a nonparametric modelling approach. We assessed the impact of demographic covariates (age, weight and sex), patient's habits (smoking status, alcohol and caffeine intake) and the genetic factors (CYP1A2*1C, CYP1A2*1F and CYP2C19*2 polymorphisms) on each pharmacokinetic parameter. An external validation of this pharmacokinetic model using an independent data set was performed. Fit goodness between observed- and individual-predicted data was evaluated using the mean prediction error (% MPE), the mean absolute prediction error (% MAPE) as a measure of bias, and the root mean squared error (% RMSE) as a measure of precision. Sixty-three CLz C0 values issued from 51 schizophrenic patients were assessed in this study and divided into building and validation groups. CYP1A2*1F polymorphism and smoking status were the only covariates significantly associated with clozapine clearance. Precision parameters were as follows: 1.02%, 0.95% and 22.4%, respectively, for % MPE, % MAPE and % RMSE. We developed and validated an accurate pharmacokinetic model able to predict Clz C0 in Tunisian schizophrenic patients using the two parameters CYP1A2*1F polymorphism and smoking.

Association between trough serum vancomycin concentration and vancomycin-associated acute kidney injury and 30-day mortality in critically ill elderly adults.

BACKGROUND: Vancomycin-associated acute kidney injury (VA-AKI) is the most clinically relevant side effect of vancomycin. The objective of this study was to investigate the association between VTC and VA-AKI as well as 30-day mortality in critically ill elderly adults. METHOD: Elderly patients with trough serum vancomycin concentration records(VTC) in the Medical Information Mart-IV (MIMIC-IV) and eICU databases were retrospectively studied. RESULTS: A total of 3,146 critically ill elderly adults were finally enrolled. The incidence of VA-AKI in the elderly population was 76.5%. Logistic regression analysis revealed significant relationships between VA-AKI and various factors, including VTC, comorbidities, and laboratory indicators, and SOFA, and GCS score. For each mg/L increase, the OR for VA-AKI increased by 2.5%. The association between VTC and 30-day mortality was found to be statistically significant (odds ratio (OR): 1.021, 95% CI: 1.010-1.031), P < 0.001). The Restricted cubic splines (RCS) curves revealed that VTC ranged of 19.67 to 35.72 mg/l for AKI and 19.17 to 42.86 mg/l for 30-day mortality exhibit OR with 95% CI above 1, indicating statistically significant associations with an increased risk of AKI and 30-day mortality, respectively. In the subgroup analysis, VTC was identified as a risk factor for VA-AKI in specific patient groups, including white individuals, female patients, those with shock, patients with SOFA > 6, patients with baseline creatinine > 1.2 mg/dl and patients with or without exposed to other nephrotoxic medications. CONCLUSION: This study found the significant association between VTC and the incidence of VA-AKI and 30-day mortality in critically ill elderly adults. The RCS curves indicated concentration ranges for AKI (19.67-35.72 mg/L) and 30-day mortality (19.17-42.86 mg/L), signifying increased risk.

Falsely Elevated Tacrolimus (FK506) Trough Levels in a Liver Transplant Recipient.

Antibody-conjugated magnetic immunoassay (ACMIA) for tacrolimus (FK506) may detect falsely elevated tacrolimus trough levels, a commonly underreported event. We report a case of falsely elevated whole-blood tacrolimus levels in a patient post-orthotopic liver transplantation. A 71-year-old male patient underwent liver transplantation in 2012. Post-transplantation, the patient was immediately started on tacrolimus for maintenance immunosuppression. His most recent dose was 0.5 mg four times weekly. During monitoring, trough levels were at 25.9 ng/mL using ACMIA. After this result, a decision was made to hold tacrolimus. After holding tacrolimus for seven days, detected trough levels were still continually greater than 20 ng/mL. Upon suspicion of falsely elevated results, liquid chromatography with mass spectroscopy (LC-MS) was used to check tacrolimus trough levels. Results showed normal trough levels of 7.6 ng/mL. Because of its narrow therapeutic window, tacrolimus levels need to be carefully monitored throughout treatment. When high tacrolimus levels are detected using ACMIA without a correlating clinical scenario, trough levels should be re-confirmed using LC-MS to prevent clinical decisions from being made based on falsely elevated results.

Correlation between trough concentration and AUC for elexacaftor, tezacaftor and ivacaftor.

Therapeutic drug monitoring (TDM) of elexacaftor, tezacaftor, ivacaftor (ETI) could be a useful tool to increase efficacy and decrease the risk of adverse effects in people with Cystic Fibrosis (pwCF). It is however unclear whether drug exposure should be monitored by assessment of trough (Cmin) levels or determination of the area under the curve (AUC). Hence, in this study the correlation between measured Cmin concentration and AUC was evaluated. Serial plasma samples, including Cmin, were drawn after administration of ETI in order to calculate the AUC and assess the correlation between the two parameters. A linear correlation between Cmin and AUC0-24h was found, with Pearson's r correlation coefficients of 0.963, 0.908 and 0.860 for elexacaftor, tezacaftor and ivacaftor, respectively. Exposure of ETI may be monitored by assessment of Cmin levels.

Osimertinib Plasma Trough Concentration in Relation to Brain Metastases Development in Patients With Advanced EGFR-Mutated NSCLC.

Introduction: Brain metastases (BM) are common in patients with advanced EGFR-mutated (EGFRm+) NSCLC. Despite good BM-related outcomes of osimertinib, several patients still experience intracranial progression. A possible explanation is pharmacologic failure due to low plasma trough levels (Cmin,SS) and consequently limited intracranial osimertinib exposure. We investigated the relation between osimertinib Cmin,SS and BM development or progression. Methods: A prospective multicenter cohort study, including patients receiving osimertinib for advanced EGFRm+ NSCLC. At osimertinib start, patients were allocated to the BM or no or unknown BM cohort and were further divided into subgroups based on osimertinib Cmin,SS (low, middle, and high exposure). Cumulative incidence of BM progression or development and overall survival were determined for each group. Results: A total of 173 patients were included, with 49 (28.3%) had baseline BM. Of these patients, 36.7% experienced BM progression, of which 16.7% in the low (<159.3 ng/mL), 40.0% in the middle, and 47.1% in the high (>270.7 ng/mL) Cmin,SS subgroups. After 12 months, the cumulative incidence of BM progression for the BM cohort was 20% (95% confidence interval [CI] 2.6-49.0), 31% (95% CI:10.6-53.9), and 31% (95% CI:10.8-54.5) per Cmin,SS subgroup, respectively. After 20 months, this was 20% (95% CI:2.6-49.0), 52% (95% CI:23.8-74.2), and 57% (95% CI:24.9-79.7), respectively. For the no or unknown BM cohort, 4.0% developed BM without differences within Cmin,SS subgroups. Conclusions: No relation was found between osimertinib Cmin,SS and BM development or progression in patients with advanced EGFRm+ NSCLC. This suggests that systemic osimertinib exposure is not a surrogate marker for BM development or progression.

Advanced gastrointestinal stromal tumor: reliable classification of imatinib plasma trough concentration via machine learning.

AIM: Patients with advanced gastrointestinal stromal tumors (GISTs) exhibiting an imatinib plasma trough concentration (IM Cmin) under 1100 ng/ml may show a reduced drug response rate, leading to the suggestion of monitoring for IM Cmin. Consequently, the objective of this research was to create a customized IM Cmin classification model for patients with advanced GISTs from China. METHODS: Initial data and laboratory indicators from patients with advanced GISTs were gathered, and the above information was segmented into a training set, validation set, and testing set in a 6:2:2 ratio. Key variables associated with IM Cmin were identified to construct the classification model using the least absolute shrinkage and selection operator (LASSO) regression and forward stepwise binary logistic regression. Within the training and validation sets, nine ML classification models were constructed via the resampling method and underwent comparison through the Brier scores, the areas under the receiver-operating characteristic curve (AUROC), the decision curve, and the precision-recall (AUPR) curve to determine the most suitable model for this dataset. Two methods of internal validation were used to assess the most suitable model's classification performance: tenfold cross-validation and random split-sample validation (test set), and the value of the test set AUROC was used to evaluate the model's classification performance. RESULTS: Six key variables (gender, daily IM dose, metastatic site, red blood cell count, platelet count, and percentage of neutrophils) were ultimately selected to construct the classification model. In the validation set, it is found by comparison that the Extreme Gradient Boosting (XGBoost) model has the largest AUROC, the lowest Brier score, the largest area under the decision curve, and the largest AUPR value. Furthermore, as evaluated via internal verification, it also performed well in the test set (AUROC = 0.725). CONCLUSION: For patients with advanced GISTs who receive IM, initial data and laboratory indicators could be used to accurately estimate whether the IM Cmin is below 1100 ng/ml. The XGBoost model may stand a chance to assist clinicians in directing the administration of IM.

Influencing factors of clinical efficacy of roxadustat among hemodialysis patients.

OBJECTIVE: To explore independent influencing factors for clinical efficacy of roxadustat in hemodialysis patients. METHODS: Hemodialysis patients treated with roxadustat were enrolled. The plasma trough concentrations of roxadustat were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A multiple logistic regression model was established to determine the factors that affect clinical efficacy of roxadustat in patients undergoing hemodialysis. RESULTS: A total of 67 hemodialysis patients were enrolled in the study. The results showed that age, blood trough concentration of roxadustat, and baseline hemoglobin (Hb) level were independent factors of clinical efficacy of roxadustat (OR = 1.06, p = .025 for age; OR = 1.001, p = .037 for plasma concentration; and OR = 0.941, p = .003 for baseline Hb), with an AUC score of 0.859. CONCLUSIONS: Age, blood trough concentration of roxadustat, and baseline Hb level were independent influencing factors of the response to roxadustat in hemodialysis patients.

Serum trough concentration threshold and risk factors of cefoperazone-induced coagulopathy in critically ill patients: A retrospective case-control study.

PURPOSE: To analyze the risk factors influencing the development of cefoperazone-induced coagulopathy in critically ill patients and determine the threshold of serum trough concentration. METHODS: A retrospective case-control study was conducted in the intensive care unit patients treated with cefoperazone, and it was approved by the Ethical Committee of Drum Tower Hospital affiliated with the Medical School of Nanjing University (NO.2023-158-01). Patients were divided into the normal group and coagulopathy group based on prothrombin time. The clinical characteristics of the two groups were compared using univariate analysis. The serum concentration threshold and influencing factors of cefoperazone-induced coagulopathy in critically ill patients were analyzed using the receiver operating characteristic curve and multivariate logistic regression analysis. RESULTS: A total of 113 patients were included, and cefoperazone-induced coagulopathy occurred in 39 patients, with an incidence of 34.5%. These patients experienced significant prothrombin time prolongation around day 6 (median) after cefoperazone application. The serum trough concentration threshold of cefoperazone-induced coagulopathy in critically ill patients was 87.765 mg/l. Multivariate logistic regression analysis revealed that the APACHE II score (p = 0.034), prophylactic use of vitamin K1 (p < 0.001), hepatic impairment (p = 0.014), and Cmin ≥ 87.765 mg/l (p = 0.005) were associated with cefoperazone-induced coagulopathy. CONCLUSION: Cefoperazone-induced coagulopathy usually occurs on the 6th day of cefoperazone use in critically ill patients. The risk will increase in patients with an APACHE II score > 25, hepatic impairment, and cefoperazone Cmin ≥ 87.765 mg/l. Vitamin K1 is effective in preventing this adverse reaction.

Exploring the impact of patient-specific clinical features on osimertinib effectiveness in a real-world cohort of patients with EGFR mutated non-small cell lung cancer.

Osimertinib is prescribed to patients with metastatic non-small cell lung cancer (NSCLC) and a sensitizing EGFR mutation. Limited data exists on the impact of patient characteristics or osimertinib exposure on effectiveness outcomes. This was a Dutch, multicenter cohort study. Eligible patients were ≥18 years, with metastatic EGFRm+ NSCLC, receiving osimertinib. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and safety. Kaplan-Meier analyses and multivariate Cox proportional hazard models were performed. In total, 294 patients were included. Primary EGFR-mutations were mainly exon 19 deletions (54%) and p.L858R point mutations (30%). Osimertinib was given in first-line (40%), second-line (46%) or beyond (14%), with median PFS 14.4 (95% CI: 9.4-19.3), 13.9 (95% CI: 11.3-16.1) and 8.7 months (95% CI: 4.6-12.7), respectively. Patients with low BMI (<20.0 kg/m2 ) had significantly shorter PFS/OS compared to all other subgroups. Patients with a high plasma trough concentration in steady state (Cmin,SS ; >271 ng/mL) had shorter PFS compared to a low Cmin,SS (<163 ng/mL; aHR 2.29; 95% CI: 1.13-4.63). A significant longer PFS was seen in females (aHR = 0.61, 95% CI: 0.45-0.82) and patients with the exon 19 deletion (aHR = 0.58, 95% CI: 0.36-0.92). A trend towards longer PFS was seen for TP53 wild-type patients, while age did not impact PFS. Patients with a primary EGFR exon 19 deletion had longer PFS, while a low BMI, male sex and a high Cmin,SS were indicative for shorter PFS and/or OS. Age was not associated with effectiveness outcomes of osimertinib.

A systematic study to evaluate the safety of ticagrelor combined with aspirin in the treatment of PCI patients in Chinese population: A single nucleotide polymorphisms study.

The aim of this study was to identify genes and their associated loci related to ticagrelor pharmacokinetics and pharmacodynamics in Chinese patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). The study included 1115 patients with ACS who received a drug-eluting stent implantation between October 2019 and January 2021. Among them, 98 cases of adverse reactions were observed; thus, 97 cases without adverse reactions were selected as the comparison group. The steady-state serum drug concentration was determined via high-performance liquid chromatography-mass spectrometry, and 15 single nucleotide polymorphism (SNP) loci were genotyped using the SNaPshot SNP Multiplex System. Our results showed that age and sex may affect ticagrelor serum concentration in patients with ACS. In particular, the SNPs CYP3A4∗1 (rs2242480 C > T), IGT2B (rs5911 A > C), P2Y12 (rs6787801) and CYP3A5 (rs776746 C > T) may affect the steady-state blood concentration of ticagrelor after PCI in ACS patients, and CYP3A4∗1 may also be related to adverse events. In addition, we found that the SNPs PEAR1 (rs4661012 T > G) and P2Y12 (rs6787801 A > G) may be associated with dyspnea. These findings can provide a useful reference to establish guidelines for future clinical individualized dosage regimens of ticagrelor after PCI.

Linezolid dose adjustment according to therapeutic drug monitoring helps reach the goal concentration in severe patients, and the oldest seniors benefit more.

BACKGROUND: The elderly with severe infection increased dramatically in intensive care unit (ICU). Proper antimicrobial therapy help improve the prognosis. Linezolid, as an antimicrobial drug, is commonly utilized to treat patients infected with methicillin-resistant S. aureus and vancomycin-resistant enterococci. Clinical evidence suggests elderly patients prone to linezolid overexposure. Here, we describe the results of three years' linezolid adjustment experiences according to therapeutic drug monitoring (TDM), especially in the oldest old. METHODS: Linezolid therapeutic drug monitoring data were collected between January 2020 and November 2022 from patients who were admitted to ICU and treated with linezolid. All the patients started with a dosage of 600 mg, twice daily. The first TMD was carried out ten minutes before the seventh administration. The dosage adjustment was determined by the doctor according to the first TMD and patients' condition, and the repeated TDM was conducted as required. The dosage adjustment in different age group was recorded. Laboratory data were compared between the old and the oldest old. The high mortality risk of the oldest old was also explored. RESULTS: Data of 556 linezolid TDM from 330 patients were collected. Among which, 31.6%, 54.8%, and 75% of patients had supra-therapeutic linezolid trough concentrations at the first TDM assessment in different age group, leading to the dosage adjustment rate of 31.0%, 40.3%, 68.8% respectively. The linezolid dosage adjustments according to TDM help to reach therapeutic concentration. The oldest old was in high risk of linezolid overexposure with lowercreatinine clearance. The norepinephrine maximum dosage but not linezolid Cmin was associated with 28-day mortality in the oldest old. CONCLUSIONS: Elderly patients with linezolid conventional 600 mg twice-daily dose might be at a high risk of overexposure, especially in the oldest old. The linezolid dosage adjustments according to TDM help reach the therapeutic concentration. The high mortality of the oldest old was not related with initial linezolid overexposure.

Indocyanine green clearance test as a predictor of linezolid overexposure in septic patients.

OBJECTIVES: Hepatic impairment increases the risk of drug overexposure in septic patients. However, there is a lack of effective indicators to predict overexposure risk. The indocyanine green (ICG) clearance test is a helpful method for dynamically assessing hepatic function and perfusion. This study aimed to investigate whether the ICG test could serve as a potential predictor of linezolid trough concentration (Cmin) and to compare its efficacy with that of conventional liver function markers. METHODS: A total of 35 consecutive septic patients treated with linezolid were grouped into either linezolid Cmin of ≤7 µg/mL or >7 µg/mL. Correlations between linezolid Cmin and ICG-PDR (plasma disappearance rate), ICG-R15 (retention ratio after 15 min) and other traditional indicators were analysed by Spearman's rank test. A multivariable regression model was employed to discern factors contributing independently to overexposure. RESULTS: Statistical differences were observed between groups for APACHE II score (P = 0.031), SOFA score (P = 0.018), creatinine clearance (CLCr) (P = 0.003), thrombocytes (P = 0.039), lactate (P = 0.003), ICG-PDR (P < 0.001) and ICG-R15 (P < 0.001). Moreover, linezolid Cmin was correlated with ICG-PDR (ρ = -0.628, P < 0.001), ICG-R15 (ρ = 0.676, P < 0.001) and CLCr (ρ = -0.503, P = 0.002). ICG-PDR was identified as an independent predictor of linezolid overexposure, with an optimal cut-off value of 17.70%/min (93.3% sensitivity, 85.0% specificity; P < 0.001). CONCLUSIONS: This pilot clinical trial represents the first investigation of potential of the ICG test to predict linezolid overexposure in septic patients.

Effects of CYP3A4*22 polymorphism on trough concentration of tacrolimus in kidney transplantation: a systematic review and meta-analysis.

Purpose: Tacrolimus (Tac) is a widely used immunosuppressive agent in kidney transplantation. Cytochrome P450 (CYP), especially CYP3A4 enzymes are responsible for the metabolism of drugs. However, the correlation between plasma Tac concentration and CYP3A4*22 gene variants is controversial. This meta-analysis aims to evaluate the association between CYP3A4*22 polymorphism and the dose-adjusted trough concentration (C0/D) of Tac in adult kidney transplant patients. Methods: We conducted a literature review for qualifying studies using the PubMed, Web of Science, and Embase databases until July 2023. For the continuous variables (C0/D and daily dose), mean difference (MD) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the association between the CYP3A4 * 22 and Tac pharmacokinetics. We performed an additional analysis on the relationship of CYP3A5*3 with Tac PKs and analyzed the effects of CYP3A4*22 in CYP3A5 non-expressers. Results: Overall, eight eligible studies with 2,683 renal transplant recipients were included in this meta-analysis. The CYP3A4*22 allele was significantly associated with a higher C0/D (MD 0.57 ng/mL/mg (95% CI: 0.28 to 0.86; p = 0.0001) and lower mean daily dose requirement (MD -2.02 mg/day, 95% CI: -2.55 to -1.50; p < 0.00001). An additional meta-analysis demonstrated that carrying the CYP3A5*3 polymorphism greatly impacted Tac blood concentration. From the result with CYP3A5 non-expressers, CYP3A4*22 showed significant effects on the Tac C0/D and dose requirement even after adjusting the effect of CYP3A5*3. Conclusion: Patients with CYP3A4*22 allele showed significantly higher plasma C0/D of Tac and required lower daily dose to achieve the therapeutic trough level after kidney transplantation. These findings of our meta-analysis may provide further evidence for the effects of genetic polymorphism in CYP3A4 on the PKs of Tac, which will improve individualized treatment in a clinical setting.