Evidence-based Guideline for Therapeutic Drug Monitoring of Vancomycin: 2020 Update by the Division of Therapeutic Drug Monitoring, Chinese Pharmacological Society

Validation and development of population pharmacokinetic model of vancomycin using a real-world database from a nationwide free web application

INTRODUCTION

Vancomycin requires a population pharmacokinetic (popPK) model to estimate the area under the concentration-time curve (AUC), and an AUC-guided dosing strategy is necessary. This study aimed to develop a popPK model for vancomycin using a real-world database pooled from a nationwide web application (PAT).

METHODS

In this retrospective study, the PAT database between December 14, 2022 and April 6, 2023 was used to develop a popPK model. The model was validated and compared with six existing models based on the predictive performance of datasets from another PAT database and the Kumamoto University Hospital. The developed model determined the dosing strategy for achieving the target AUC.

RESULTS

The modeling populations consisted of 7146 (13,372 concentrations from the PAT database), 3805 (7540 concentrations from the PAT database), and 783 (1775 concentrations from Kumamoto University Hospital) individuals. A two-compartment popPK model was developed that incorporated creatinine clearance as a covariate for clearance and body weight for central and peripheral volumes of distribution. The validation demonstrated that the popPK model exhibited the smallest mean absolute prediction error of 5.07, outperforming others (ranging from 5.10 to 5.83). The dosing strategies suggested a first dose of 30 mg/kg and maintenance doses adjusted for kidney function and age.

CONCLUSIONS

This study demonstrated the updating of PAT through the validation and development of a popPK model using a vast amount of data collected from anonymous PAT users.

Identification of vancomycin exposure target in neonates: how much is enough?

OBJECTIVES

Vancomycin is commonly used in neonates with the same pharmacokinetics/pharmacodynamics (PK/PD) target as adults. However, no evidence supports this practice, and the association between trough concentrations and treatment outcomes has been widely questioned. This study aimed to identify the optimal PK/PD predictor and assess the correlation between AUC/MIC, trough concentration and the vancomycin efficacy in neonates.

METHODS

This study retrospectively collected neonates who used vancomycin and constructed a population pharmacokinetic (PPK) model to estimate the AUC. Logistic analyses were used to identify the variables related to efficacy. Classification and regression tree analysis was used to explore thresholds. The correlation between trough concentration and AUC/MIC on the first day was analysed using a linear regression model.

RESULTS

PPK modelling involved 131 neonates. Postmenstrual age and current weight were included in the covariate analysis. Forty-eight patients were included in the efficacy analysis, 13 of whom were infected with MRSA. The best-performance PK/PD target for efficacy was AUC0-24  h/MIC ≥ 331. The trough concentration was correlated with AUC0-24  h/MIC (r2 = 0.32), but individual differences existed. AUC0-24  h/MIC ranged up to 2.5-fold for a given trough concentration.

CONCLUSIONS

AUC0-24  h/MIC ≥ 331 was the optimal target of vancomycin efficacy in neonates. The trough concentration was not a reliable predictor of efficacy and AUC0-24  h/MIC. AUC-guided dosage adjustments are more valuable in clinical applications.

Evaluation of target area under the concentration-time curve of vancomycin in an initial dosing design: a retrospective cohort study

OBJECTIVES

Area under the concentration-time curve (AUC)-guided dosing of vancomycin was introduced in a clinical setting; however, the target range of non-steady-state AUCs, such as Day 1 AUC and Day 2 AUC, remains controversial. Therefore, we sought to determine pharmacokinetic parameter thresholds and identify independent risk factors associated with acute kidney injury (AKI) to establish a safe initial dosing design for vancomycin administration.

METHODS

A single-centre, retrospective, cohort study of hospitalized patients treated with vancomycin was conducted to determine the threshold of both non-steady-state AUCs (Day 1 and 2 AUCs) and trough levels at the first blood sampling point (therapeutic drug monitoring, TDM). In addition, independent risk factors associated with AKI were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

The thresholds for predicting AKI were estimated as 456.6 mg·h/L for AUC0-24h, 554.8 mg·h/L for AUC24-48h, 1080.8 mg·h/L for AUC0-48h and 14.0 μg/mL for measured trough levels, respectively. In a multivariate analysis, Day 2 AUC ≥ 554.8 mg·h/L [adjusted odds ratio (OR), 57.16; 95% confidence interval (CI), 11.95-504.05], piperacillin/tazobactam (adjusted OR, 15.84; 95% CI, 2.73-127.70) and diuretics (adjusted OR, 4.72; 95% CI, 1.13-21.01) were identified as risk factors for AKI.

CONCLUSIONS

We identified thresholds for both AUCs in the non-steady-state and trough levels at the first TDM. Our results highlight the importance of monitoring not only the AUC but also trough levels during vancomycin treatment to reduce the likelihood of AKI.

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.

Risk factors analysis and construction of predictive models for acute kidney injury in overweight patients receiving vancomycin treatment

BACKGROUND

Vancomycin-induced acute kidney injury (VI-AKI) is one of its serious adverse reactions. The purpose of this study is to discuss the risk factors for VI-AKI in overweight patients and construct a clinical prediction model based on the results of the analysis.

METHODS

Multivariable logistic regression analysis was used to identify risk factors for VI-AKI and constructed nomogram models. The performance of the nomogram was evaluated based on the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA).

RESULT

Cancer (OR 4.186, 95% CI 1.473-11.896), vancomycin trough concentration >20.0 μg/mL (OR 6.251, 95% CI 2.275-17.180), concomitant furosemide (OR 2.722, 95% CI 1.071-6.919) and vasoactive agent (OR 2.824, 95% CI 1.086-7.340) were independent risk factors for VI-AKI. The AUC of the nomogram validation cohorts were 0.807 (95% CI 0.785-0.846). The calibration curve revealed that the predicted outcome was in agreement with the actual observations. Finally, the DCA curves showed that the nomogram had a good clinical applicability value.

CONCLUSION

There are four independent risk factors for the occurrence of VI-AKI in overweight patients, and the nomogram prediction model has good predictive ability, which can provide reference for clinical decision-making.

Evaluation of Pharmacy Intern Interventions on Antimicrobial Use in University-Affiliated Hospitals: A Retrospective Analysis

Background: Appropriate use of antimicrobials is essential to enhance therapeutic safety and efficacy. Clinical pharmacists play a crucial role in optimizing antimicrobial use; however, the contribution of pharmacy interns in antimicrobial use has not been studied. The objective of this study was to ascertain the quantity and nature of interventions related to antimicrobials documented by pharmacy interns, along with the rates at which physicians accepted these interventions. Methods: From August 2017 to March 2022, this study retrospectively evaluated antimicrobial-related interventions recorded by pharmacy interns during their rotations at King Khalid University. The categories of interventions included medication selection, addition of antimicrobials, dose or frequency adjustments, medication discontinuation, de-escalation, therapeutic drug monitoring, and others. Statistical analysis was conducted to identify patterns and correlations. Results: This study evaluated 1295 antimicrobial-related interventions, with high physician acceptance rates of 91.6% and 4.0% accepted with modifications. The most frequent interventions were dose/frequency adjustments (36.3%) and medication discontinuation (23%). Vancomycin, colistin, and meropenem were the most frequently intervened antimicrobials. Documented clinical outcomes included enhancing treatment efficacy (37.3%), reducing treatment toxicity (26.81%), and avoiding unnecessary antimicrobial exposure (21.8%). Significant correlations were observed between hospital units and intervention types, indicating unit-specific intervention patterns. Conclusions: Theses findings highlight the vital role of pharmacy interns in optimizing antimicrobial therapy. Future research should focus on evaluating the long-term clinical and economic benefits of their involvement.

Simultaneous Quantification of Vancomycin, Linezolid and Voriconazole in Human Plasma by UHPLC-MS/MS: Application in Therapeutic Drug Monitoring

OBJECTIVE

Individual differences challenge the treatment of vancomycin, linezolid and voriconazole in severe infections. This study aimed to build a simple and economical method for simultaneous determination of the three antibiotics in human plasma by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and provided a reference for therapeutic drug monitoring (TDM) of infected patients.

METHODS

The plasma samples were precipitated by acetonitrile and detected and separated on a shim-pack GIST C18 column following the gradient elution within 5 min. Mass quantification was performed on multiple reaction monitoring mode under positive electrospray ionization.

RESULTS

The linear ranges of vancomycin, linezolid and voriconazole were 1.00-100.00, 0.10-15.00 and 0.10-20.00 μg·mL-1, respectively, with good linearity (R2 > 0.99). The accuracy and precision, matrix effect, extraction recovery and stability were validated, and the results all meet the acceptance criteria of China Food and Drug Administration (CFDA) guidelines.

CONCLUSION

The UHPLC-MS/MS method was established and validated for the simultaneous determination of vancomycin, linezolid and voriconazole in human plasma and successfully applied to routine TDM for individualized treatment.

Successful treatment of Enterococcus gallinarum infection in a neonate with vancomycin: a case report

BACKGROUND

Enterococcus gallinarum (EG) is typically found in the gastrointestinal tracts of birds and mammals. Although its strains are rarely isolated from clinical specimens, EG can lead to septicemia in immunocompromised individuals. EG infections are uncommon in household settings, but their incidence has been rising due to increased antibiotic usage and invasive treatments, particularly in Neonatal Intensive Care Units (NICUs). EG inherently exhibits resistance to vancomycin but is highly sensitive to linezolid. Despite showing in vitro resistance, vancomycin has shown clinical efficacy in treating EG meningitis.

CASE PRESENTATION

A neonate born at 30 + 2 weeks gestation was admitted to the Neonatal Intensive Care Unit (NICU) after EG was detected in blood and cerebrospinal fluid cultures. Susceptibility testing indicated that the bacterial strain was resistant to vancomycin and sensitive to linezolid. Initially, vancomycin was selected for treatment. However, due to persistent EG cultures in the blood and cerebrospinal fluid, the treatment was adjusted to linezolid. This led to a rapid decrease in platelet (PLT) count, suspected to be an adverse reaction. Concurrently, the patient experienced recurrent fever and elevated inflammatory marker levels, prompting the discontinuation of linezolid and a return to vancomycin. Subsequent administration of vancomycin stabilized the patient's condition, as evidenced by improved C-reactive protein (CRP), procalcitonin (PCT), and cerebrospinal fluid parameters, ultimately leading to discharge after an eight-week treatment period.

CONCLUSION

This retrospective analysis highlights the efficacy of vancomycin in treating EG infections, suggesting that specific genetic phenotypes may influence treatment sensitivity. Monitoring vancomycin blood levels is crucial for determining treatment effectiveness.

Retrospective Study of Factors Affecting the Accuracy of Predicting Vancomycin Concentrations in Patients Aged 75 Years and Above

Background and Objectives: The predicted serum concentrations of vancomycin are determined using population pharmacokinetic parameters. However, the accuracy of predicting vancomycin serum concentrations in the older population remains unclear. Therefore, this study aimed to investigate the accuracy of predicting vancomycin serum concentrations and identifying elements that diminish the prediction accuracy in older people. Materials and Methods: A total of 144 patients aged 75 years or older were included. The serum vancomycin concentrations in the patients were predicted based on population pharmacokinetic parameters common in Japan. We examined the accuracy of serum vancomycin concentration prediction in elderly individuals by comparing the predicted and measured serum vancomycin concentrations in each patient. The prediction accuracy was evaluated using the mean prediction error (ME) and mean absolute error of prediction (MAE) calculated from the measured and predicted serum vancomycin concentrations in each patient. Results: The ME for all patients was 0.27, and the 95% CI included 0, indicating that the predicted values were not significantly biased compared to the measured values. However, the predicted serum concentrations in the <50 kg body weight and serum creatinine (Scr) < 0.6 mg/dL groups were significantly biased compared to the measured values. The group with a history of intensive care unit (ICU) admission showed the largest values for the ME and MAE. Conclusions: Our prediction accuracy was satisfactory but tended to be lower in underweight patients, those with low creatinine levels, and patients admitted to the ICU. Patients with multiple of these factors may experience a greater degree of decreased predictive accuracy.

A higher area under the concentration-time curve/minimum inhibitory concentration target as a potential prognostic factor for vancomycin treatment of methicillin-resistant Staphylococcus aureus meningitis: A case report

The area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) - guided approach is recommended for vancomycin therapeutic drug monitoring in severe methicillin-resistant Staphylococcus aureus (MRSA) infection. However, evidence regarding the efficacy of vancomycin AUC-guided strategies for the treatment of systemic infections is limited. This case report describes the successful treatment of MRSA meningitis, with vancomycin using a higher AUC/MIC target. A 61-year-old woman who underwent ventriculoperitoneal (VP) shunt placement for subarachnoid hemorrhage, developed MRSA meningitis due to shunt infection. Vancomycin was administered intravenously, with concurrent monitoring of serum and cerebrospinal fluid (CSF) vancomycin concentrations and AUC/MIC. On post-operative day (POD) 24 of VP shunt placement, the vancomycin trough concentration and AUC/MIC were 12.0 μg/mL and 515, respectively, with persistently positive CSF culture. On POD 28, the trough concentration and AUC/MIC were 18.6 μg/mL and 610, respectively. There were no major adverse events, and CSF culture turned negative on POD 30. The vancomycin CSF-to-serum ratio was approximately 41 %. For patients with MRSA meningitis, we suggest an optimal therapeutic range with a vancomycin AUC/MIC target near the upper limit of the therapeutic window.

Is it time to recommend AUC-based vancomycin therapeutic drug monitoring only? A cross-sectional survey in China

Background

The latest published therapeutic drug monitoring (TDM) guidelines for vancomycin recommend changing trough-based monitoring to area under the concentration-to-time curve (AUC)-based monitoring. This study aimed to evaluate the implementation status and perceptions of vancomycin AUC-based TDM in China and to determine the challenges in performing AUC-based TDM.

Methods

A nationwide cross-sectional survey was conducted in China using an online questionnaire. The questionnaire comprised a total of 25 questions with open- and closed-ended answers to collect information about the current implementation of vancomycin TDM and the participants' perceptions of these practices. The questionnaire responses were collected via the Questionnaire Star platform and analyzed.

Results

A total of 161 questionnaires were completed by 131 hospitals and were included. Approximately 59.5% (78/131) of the surveyed hospitals conducted vancomycin TDM; however, only 10.7% (14/131) of these hospitals performed AUC-based vancomycin TDM. Of the eligible participants, 58.4% (94/161) had experience with vancomycin TDM, and only 37 participants (37/161, 23.0%) had the ability to estimate the AUC, primarily through Bayesian simulation (33/161, 20.5%). The participants considered the following challenges to implementing AUC-based monitoring: (1) the high cost of AUC-based monitoring; (2) inadequate knowledge among pharmacists and/or physicians; (3) the complexity of AUC calculations; (4) difficulty obtaining AUC software; and (5) unclear benefit of AUC-based monitoring.

Conclusion

The majority of surveyed hospitals have not yet implemented AUC-based vancomycin TDM. Multiple challenges should be addressed before wide implementation of AUC-based monitoring, and guidance for trough-based monitoring is still needed.

Population pharmacokinetic analysis for dose regimen optimization of vancomycin in Southern Chinese children

Changes in physiological factors may result in large pharmacokinetic variability of vancomycin in pediatric patients, thereby leading to either supratherapeutic or subtherapeutic exposure and potentially affecting clinical outcomes. This study set out to characterize the disposition of vancomycin, quantify the exposure target and establish an optimal dosage regimen among the Southern Chinese pediatric population. Routine therapeutic drug monitoring data of 453 patients were available. We performed a retrospective population pharmacokinetic analysis of hospitalized children prescribed intravenous vancomycin using NONMEM® software. A one-compartment PPK model of vancomycin with body weight and renal functions as covariates based on a cutoff of 2 years old children was proposed in this study. Both internal and external validation showing acceptable and robust predictive performance of the model to estimate PK parameters. The value of area under the curve over 24 h to minimum inhibitory concentration ratio (AUC0-24/MIC) ≥ 260 was a significant predictor for therapeutic efficacy. Monte Carlo simulations served as a model-informed precision dosing approach and suggested that different optimal dose regimens in various scenarios should be considered rather than flat dosing. The evaluation of vancomycin exposure-efficacy relationship indicated that lower target level of AUC0-24/MIC may be needed to achieve clinical effectiveness in children, which was used to derive the recommended dosing regimen. Further prospective studies will be needed to corroborate and elucidate these results.

Case analysis of hepatotoxicity caused by vancomycin

BACKGROUND

Although the correlation between liver toxicity and vancomycin is generally considered low, it has been observed that the use of vancomycin can lead to abnormal liver function indicators, such as elevated aspartate aminotransferase, alanine aminotransferase, alpha fetoprotein, and jaundice. To further understand the clinical features associated with vancomycin-induced liver toxicity and to provide clinical guidance, we conducted an analysis of the characteristics and clinical manifestations of vancomycin-induced liver injury.

METHODS

Patients with liver function injury who received vancomycin treatment at the Third Xiangya Hospital of Central South University and Hunan Maternal and Child Health Hospital between 2016 and 2021 were selected for retrospective analysis of their general characteristics, vancomycin course, dose, liver function index, severity of liver injury, and concomitant medications.

RESULTS

Of the 4562 patients who received vancomycin, 17 patients were finally included, with an incidence rate of 0.37%. Of these patients, 12 were male (70.6%) and 5 were female (29.4%), ranging in age from 17 to 84 years with a mean average age of 45.41 ± 20.405 years. All patients were evaluated using Naranjo's score, with score ≥ 3. The dosage, time, and plasma concentration of vancomycin were analyzed and it was found that nine patients (52.94%) had abnormal liver function when initially given a dose of 1 g every 12 hours. In total, 14 patients (82.35%) with liver injury were taking vancomycin in combination with two to four drugs, and severe liver injury occurred in patients taking vancomycin in combination with two drugs. The occurrence time of liver injury was 2-12 days after starting vancomycin, with a mean of 4.53 ± 2.401 days. Of these patients, 16 patients (94.1%) showed liver function abnormalities within 7 days of taking the drug, and 2 patients with grade 3-4 liver injury both showed liver function abnormalities within 3 days of taking the drug. Only 4 of the 17 patients (23.53%) had vancomycin blood concentrations within the normal range, and there was no correlation found between blood concentration and severity of liver injury. Analysis of the correlation between the severity of liver injury and vancomycin showed that none of the patients had allergies such as rash, two patients (11.76%) had jaundice, and fatigue occurred in five patients (29.41%). The remaining ten patients (58.82%) had no symptoms related to liver injury. All 17 patients had abnormal aspartate aminotransferase/alanine aminotransferase levels and 9 patients also had abnormal bilirubin levels. In 15 patients (88.24%), the severity of liver injury was grade 1, indicating mild liver injury, and no correlation was observed between the severity of liver injury and creatinine. Of the 17 patients, 1 patient received no intervention, 4 patients stopped taking vancomycin after developing liver injury, 1 patient reduced the dose, and 11 patients (64.7%) were treated with hepatic protectant.

CONCLUSION

Although the study concluded that the incidence of liver injury was not high, the liver toxicity of vancomycin should still be considered and liver function indicators should be monitored during the clinical use of vancomycin.

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.

Vancomycin heteroresistance caused by unstable tandem amplifications of the vanM gene cluster on linear conjugative plasmids in a clinical Enterococcus faecium

Vancomycin heteroresistance is prone to missed detection and poses a risk of clinical treatment failure. We encountered one clinical Enterococcus faecium strain, SRR12, that carried a complete vanM gene cluster but was determined as susceptible to vancomycin using the broth microdilution method. However, distinct subcolonies appeared within the clear zone of inhibition in the E-test assay, one of which, named SRR12-v1, showed high-level resistance to vancomycin. SRR12 was confirmed as heteroresistant to vancomycin using population analysis profiling and displayed "revive" growth curves with a lengthy lag phase of over 13 hours when exposed to 2-32 mg/L vancomycin. The resistant subcolony SRR12-v1 was found to carry an identical vanM gene cluster to that of SRR12 but a significantly increased vanM copy number in the genome. Long-read whole genome sequencing revealed that a one-copy vanM gene cluster was located on a pELF1-like linear plasmid in SRR12. In comparison, tandem amplification of the vanM gene cluster jointed with IS1216E was seated on a linear plasmid in the genome of SRR12-v1. These amplifications of the vanM gene cluster were demonstrated as unstable and would decrease accompanied by fitness reversion after serial passaging for 50 generations under increasing vancomycin pressure or without antibiotic pressure but were relatively stable under constant vancomycin pressure. Further, vanM resistance in resistant variants was verified to be carried by conjugative plasmids with variable sizes using conjugation assays and S1-pulsed field gel electrophoresis blotting, suggesting the instability/flexibility of vanM cluster amplification in the genome and an increased risk of vanM resistance dissemination.

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.

Chinese guideline for the diagnosis and treatment of drug-induced liver injury: an update

Drug-induced liver injury (DILI) is an important adverse drug reaction that can lead to acute liver failure or even death in severe cases. Currently, the diagnosis of DILI still follows the strategy of exclusion. Therefore, a detailed history taking and a thorough and careful exclusion of other potential causes of liver injury is the key to correct diagnosis. This guideline was developed based on evidence-based medicine provided by the latest research advances and aims to provide professional guidance to clinicians on how to identify suspected DILI timely and standardize the diagnosis and management in clinical practice. Based on the clinical settings in China, the guideline also specifically focused on DILI in chronic liver disease, drug-induced viral hepatitis reactivation, common causing agents of DILI (herbal and dietary supplements, anti-tuberculosis drugs, and antineoplastic drugs), and signal of DILI in clinical trials and its assessment.

A Deep Learning-Based Approach for Prediction of Vancomycin Treatment Monitoring: Retrospective Study Among Patients With Critical Illness

BACKGROUND

Vancomycin pharmacokinetics are highly variable in patients with critical illnesses, and clinicians commonly use population pharmacokinetic (PPK) models based on a Bayesian approach to dose. However, these models are population-dependent, may only sometimes meet the needs of individual patients, and are only used by experienced clinicians as a reference for making treatment decisions. To assist real-world clinicians, we developed a deep learning-based decision-making system that predicts vancomycin therapeutic drug monitoring (TDM) levels in patients in intensive care unit.

OBJECTIVE

This study aimed to establish joint multilayer perceptron (JointMLP), a new deep-learning model for predicting vancomycin TDM levels, and compare its performance with the PPK models, extreme gradient boosting (XGBoost), and TabNet.

METHODS

We used a 977-case data set split into training and testing groups in a 9:1 ratio. We performed external validation of the model using 1429 cases from Kangwon National University Hospital and 2394 cases from the Medical Information Mart for Intensive Care-IV (MIMIC-IV). In addition, we performed 10-fold cross-validation on the internal training data set and calculated the 95% CIs using the metric. Finally, we evaluated the generalization ability of the JointMLP model using the MIMIC-IV data set.

RESULTS

Our JointMLP model outperformed other models in predicting vancomycin TDM levels in internal and external data sets. Compared to PPK, the JointMLP model improved predictive power by up to 31% (mean absolute error [MAE] 6.68 vs 5.11) on the internal data set and 81% (MAE 11.87 vs 6.56) on the external data set. In addition, the JointMLP model significantly outperforms XGBoost and TabNet, with a 13% (MAE 5.75 vs 5.11) and 14% (MAE 5.85 vs 5.11) improvement in predictive accuracy on the inner data set, respectively. On both the internal and external data sets, our JointMLP model performed well compared to XGBoost and TabNet, achieving prediction accuracy improvements of 34% and 14%, respectively. Additionally, our JointMLP model showed higher robustness to outlier data than the other models, as evidenced by its higher root mean squared error performance across all data sets. The mean errors and variances of the JointMLP model were close to zero and smaller than those of the PPK model in internal and external data sets.

CONCLUSIONS

Our JointMLP approach can help optimize treatment outcomes in patients with critical illnesses in an intensive care unit setting, reducing side effects associated with suboptimal vancomycin administration. These include increased risk of bacterial resistance, extended hospital stays, and increased health care costs. In addition, the superior performance of our model compared to existing models highlights its potential to help real-world clinicians.

Clinical application of vancomycin TDM in ventilated patients with gastrointestinal cancer: a propensity-matched analysis

BACKGROUND

Therapeutic drug monitoring (TDM) of vancomycin is widely recommended for clinical treatment. Due to the complexity of 24-h area under the curve (AUC) guided vancomycin monitoring in clinical practice, the vancomycin trough level remains the most common and practical method. The purpose of this study was designed to investigate the differences in the safety and efficacies of vancomycin TDM based on the two different monitoring methods, and further explore the clinical application of trough-guided vancomycin monitoring in patients with gastrointestinal cancer requiring mechanical ventilation.

METHODS

We included a total of 78 gastrointestinal cancer patients who required mechanical ventilation due to various diseases. All patients included in this study were aged 18 years or older and were treated with intravenous vancomycin therapy for more than 2 days due to documented or suspected Gram-positive bacterial infections, and have at least one available vancomycin plasma concentration. First, we compared the safety and efficacies of vancomycin TDM based on different monitoring methods as trough-guided monitoring or AUC-guided monitoring. Then, based on whether the initial vancomycin concentration achieving the target trough concentration (less than 48 h), patients were divided into early and delayed groups, and the clinical factors were compared between them. The primary endpoints include the incidence of new-onset acute kidney injury (AKI) or renal replacement therapy (RRT), clinical success rate and 28-day all-cause mortality. Finally, the overall relationship between trough concentration and potential covariates is screened by univariate and multivariate analysis to explore potential information covariates.

RESULTS

The research revealed that patients with gastrointestinal cancer exhibited significantly lower initial vancomycin trough concentrations (median [interquartile range (IQR)]: 6.90[5.28-11.20] mg/L). And there were no statistically significant differences in the safety and efficacies of vancomycin TDM based on the two different monitoring methods for the primary endpoint. Moreover, base on trough-guided vancomycin monitoring, the early group demonstrated a notably shorter duration of mechanical ventilation compared with the delayed group (χ2 = 4.532; p < 0.05; Fig. 2E). Propensity score weighting further confirmed that the duration of mechanical ventilation (χ2 = 6.607; p < 0.05; Fig. 2F) and duration of vasoactive agent (χ2 = 6.106; p < 0.05; Fig. 2D) were significantly shorter in the early group compared with delayed group. Multivariate regression analysis revealed that Cystatin C (Cys-C) was the most important variable for vancomycin target trough achievement (odds ratio, 5.274; 95% CI, 1.780 to 15.627; p = 0.003).

CONCLUSIONS

Trough-guided vancomycin monitoring is a simple and effective marker of TDM for ventilated patients with gastrointestinal cancer. Timely achievement of target trough concentrations for vancomycin can improve partial clinical outcomes in Gram-positive bacterial infections. Cys-C level is a potentially valuable parameter for predicting the vancomycin concentration.

How to Dose Vancomycin in Overweight and Obese Patients with Varying Renal (Dys)function in the Novel Era of AUC 400-600 mg·h/L-Targeted Dosing

BACKGROUND AND OBJECTIVE

The latest vancomycin guideline recommends area under the curve (AUC)-targeted dosing and monitoring for efficacy and safety. However, guidelines for AUC-targeted starting dosing in patients with obesity and/or renal insufficiency are currently lacking. This study quantifies the pharmacokinetics (PK) of vancomycin in this population and provides AUC-targeted dosing recommendations.

METHODS

Vancomycin concentrations (n = 1188) from therapeutic drug monitoring of 210 overweight and obese patients with varying degrees of renal (dys)function from the ward (74.8%) and intensive care unit (ICU, 25.2%) were pooled with published rich concentration-time data (n = 207) from 20 (morbidly) obese subjects undergoing bariatric surgery. A population model was developed using NONMEM 7.4. Stochastic simulations were performed to design dosing guidelines targeting an AUC24 between 400-600 mg·h/L.

RESULTS

Vancomycin clearance (CL) was found to increase linearly with total bodyweight and with renal function (CKD-EPI) in a power relation. Additionally, CL proved 15.5% lower in ICU patients. Our model shows that, to reach the target AUC between 400 and 600 mg·h/L in the first 48 h, two loading doses are required for both continuous infusion and intermittent dosing regimens. Maintenance doses were found to require adjustment for total bodyweight, renal function, and ICU admission status. With this guideline, the median AUC24 is well within the target from the start of the treatment onwards.

CONCLUSIONS

To achieve safe and effective vancomycin exposure for maintenance doses in overweight and obese patients, renal function, total bodyweight, and ICU admission status should be taken into account.

TRIAL REGISTRATION

The AMIGO trial was registered in the Dutch Trial Registry [NTR6058].

Population pharmacokinetics and individualized dosing of vancomycin for critically ill patients receiving continuous renal replacement therapy: the role of residual diuresis

Background: Vancomycin dosing is difficult in critically ill patients receiving continuous renal replacement therapy (CRRT). Previous population pharmacokinetic (PopPK) models seldom consider the effect of residual diuresis, a significant factor of elimination, and thus have poor external utility. This study aimed to build a PopPK model of vancomycin that incorporates daily urine volume to better describe the elimination of vancomycin in these patients. Methods: We performed a multicenter retrospective study that included critically ill patients who received intermittent intravenous vancomycin and CRRT. The PopPK model was developed using the NONMEM program. Goodness-of-fit plots and bootstrap analysis were employed to evaluate the final model. Monte Carlo simulation was performed to explore the optimal dosage regimen with a target area under the curve of ≥400 mg/L h and 400-600 mg/L h. Results: Overall, 113 observations available from 71 patients were included in the PopPK model. The pharmacokinetics could be well illustrated by a one-compartment model with first-order elimination, with the 24-h urine volume as a significant covariate of clearance. The final typical clearance was 1.05 L/h, and the mean volume of distribution was 69.0 L. For patients with anuria or oliguria, a maintenance dosage regimen of 750 mg q12h is recommended. Conclusion: Vancomycin pharmacokinetics in critically ill patients receiving CRRT were well described by the developed PopPK model, which incorporates 24-h urine volume as a covariate. This study will help to better understand vancomycin elimination and benefit precision dosing in these patients.

Comparative efficacy of vancomycin in treating ST5 and ST764 methicillin-resistant Staphylococcus aureus infections in adult patients

IMPORTANCE

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that is resistant to multiple drugs and can cause serious infections. In recent years, one of the most widespread strains of MRSA worldwide has been the clonal complex 5 (CC5) type. Sequence type 5 (ST5) and ST764 are two prevalent CC5 strains. Although ST5 and ST764 are genotypically identical, ST764 is classified as a hybrid variant of ST5 with characteristics of community-associated MRSA (CA-MRSA). In contrast to ST5, ST764 lacks the tst and sec genes but carries the staphylococcal enterotoxin B (seb) gene. Vancomycin is commonly used as the first-line treatment for MRSA infections. However, it is currently unclear whether the genetic differences between the ST5 and ST764 strains have any impact on the efficacy of vancomycin in treating MRSA infections. We conducted a prospective observational study comparing the efficacy of vancomycin against ST5-MRSA and ST764-MRSA in five hospitals in China. There were significant differences in bacteriological efficacy between the two groups, with virulence genes, such as the tst gene, being a risk factor for bacterial persistence (adjusted odds ratio, 4.509; 95% confidence interval, 1.216 to 16.724; P = 0.024). In the future, it may be necessary to consider personalized vancomycin treatment strategies based on the genetic characteristics of MRSA isolates.

Optimizing a high-sensitivity NanoLuc-based bioluminescence system for in vivo evaluation of antimicrobial treatment

Focal and systemic infections are serious threats to human health. Preclinical models enable the development of new drugs and therapeutic regimens. In vivo, animal bioluminescence (BL) imaging has been used with bacterial reporter strains to evaluate antimicrobial treatment effects. However, high-sensitivity bioluminescent systems are required because of the limited tissue penetration and low brightness of the BL signals of existing approaches. Here, we report that NanoLuc (Nluc) showed better performance than LuxCDABE in bacteria. However, the retention rate of plasmid constructs in bacteria was low. To construct stable Staphylococcus aureus reporter strains, a partner protein enolase (Eno) was identified by screening of S. aureus strain USA300 for fusion expression of Nluc-based luciferases, including Nluc, Teluc, and Antares2. Different substrates, such as hydrofurimazine (HFZ), furimazine (FUR), and diphenylterazine (DTZ), were used to optimize a stable reporter strain/substrate pair for BL imaging. S. aureus USA300/Eno-Antares2/HFZ produced the highest number of photons of orange-red light in vitro and enabled sensitive BL tracking of S. aureus in vivo, with sensitivities of approximately 10 CFU from mouse skin and 750 CFU from mouse kidneys. USA300/Eno-Antares2/HFZ was a powerful combination based on the longitudinal evaluation of the therapeutic efficacy of antibiotics. The optimized S. aureus Eno-Antares2/HFZ pair provides a technological advancement for the in vivo evaluation of antimicrobial treatment.

Vancomycin associated acute kidney injury in patients with infectious endocarditis: a large retrospective cohort study

Background: Vancomycin remains the cornerstone antibiotic for the treatment of infective endocarditis (IE). Vancomycin has been associated with significant nephrotoxicity. However, vancomycin associated acute kidney injury (AKI) has not been evaluated in patients with IE. We conducted this large retrospective cohort study to reveal the incidence, risk factors, and prognosis of vancomycin-associated acute kidney injury (VA-AKI) in patients with IE. Methods: Adult patients diagnosed with IE and receiving vancomycin were included. The primary outcome was VA-AKI. Results: In total, 435 of the 600 patients were enrolled. Of these, 73.6% were male, and the median age was 52 years. The incidence of VA-AKI was 17.01% (74). Only 37.2% (162) of the patients received therapeutic monitoring of vancomycin, and 30 (18.5%) patients had reached the target vancomycin trough concentration. Multiple logistic regression analysis revealed that body mass index [odds ratio (OR) 1.088, 95% CI 1.004, 1.179], duration of vancomycin therapy (OR 1.030, 95% CI 1.003, 1.058), preexisting chronic kidney disease (OR 2.291, 95% CI 1.018, 5.516), admission to the intensive care unit (OR 2.291, 95% CI 1.289, 3.963) and concomitant radiocontrast agents (OR 2.085, 95% CI 1.093, 3.978) were independent risk factors for VA-AKI. Vancomycin variety (Lai Kexin vs. Wen Kexin, OR 0.498, 95% CI 0.281, 0.885) were determined to be an independent protective factor for VI-AKI. Receiver operator characteristic curve analysis revealed that duration of therapy longer than 10.75 days was associated with a significantly increased risk of VA-AKI (HR 1.927). Kidney function was fully or partially recovered in 73.0% (54) of patients with VA-AKI. Conclusion: The incidence of VA-AKI in patients with IE was slightly higher than in general adult patients. Concomitant contrast agents were the most alarmingly nephrotoxic in patients with IE, adding a 2-fold risk of VA-AKI. In patients with IE, a course of vancomycin therapy longer than 10.75 days was associated with a significantly increased risk of AKI. Thus, closer monitoring of kidney function and vancomycin trough concentrations was recommended in patients with concurrent contrast or courses of vancomycin longer than 10.75 days.

Model-informed precision dosing of vancomycin for rapid achievement of target area under the concentration-time curve: A simulation study

In this study, we aimed to evaluate limited sampling strategies for achieving the therapeutic ranges of the area under the concentration-time curve (AUC) of vancomycin on the first and second day (AUC0-24 , AUC24-48 , respectively) of therapy. A virtual population of 1000 individuals was created using a population pharmacokinetic (PopPK) model, which was validated and incorporated into our model-informed precision dosing tool. The results were evaluated using six additional PopPK models selected based on a study design of prospective or retrospective data collection with sufficient concentrations. Bayesian forecasting was performed to evaluate the probability of achieving the therapeutic range of AUC, defined as a ratio of estimated/reference AUC within 0.8-1.2. The Bayesian posterior probability of achieving the AUC24-48 range increased from 51.3% (a priori probability) to 77.5% after using two-point sampling at the trough and peak on the first day. Sampling on the first day also yielded a higher Bayesian posterior probability (86.1%) of achieving the AUC0-24 range compared to the a priori probability of 60.1%. The Bayesian posterior probability of achieving the AUC at steady-state (AUCSS ) range by sampling on the first or second day decreased with decreased kidney function. We demonstrated that second-day trough and peak sampling provided accurate AUC24-48 , and first-day sampling may assist in rapidly achieving therapeutic AUC24-48 , although the AUCSS should be re-estimated in patients with reduced kidney function owing to its unreliable predictive performance.

Age-associated augmented renal clearance and low BMI trigger suboptimal vancomycin trough concentrations in children with haematologic diseases: data of 1453 paediatric patients from 2017 to 2022

BACKGROUND

It is usually difficult for the trough concentration of vancomycin to reach the recommended lower limit of 10 mg/L per the label dose in the paediatric population. Moreover, children with haematologic diseases who suffer from neutropenia are more likely to have lower exposure of vancomycin, and the risk factors have been poorly explored.

METHOD

We reviewed and analysed the initial trough concentration of vancomycin and synchronous cytometry and biochemical parameters in the blood of 1453 paediatric patients with haematologic diseases over a 6 year period, from 2017 to 2022.

RESULTS

Forty-five percent of the enrolled children had vancomycin trough concentrations below 5 mg/L after receiving a dose of 40 mg/kg/day, and the multiple regression showed that age (OR = 0.881, 95% CI 0.855 to 0.909, P < 0.001), BMI (OR = 0.941, 95% CI 0.904 to 0.980, P = 0.003) and the glomerular filtration rate (OR = 1.006, 95% CI 1.004 to 1.008, P < 0.001) were independent risk factors. A total of 79.7% of the children experienced augmented renal clearance, which was closely correlated to age-associated levels of serum creatinine. The vancomycin trough concentration was higher in children with aplastic anaemia than in those with other haematologic diseases due to a higher BMI and a lower glomerular filtration rate.

CONCLUSION

Age-associated augmented renal clearance and low BMI values contributed to suboptimal trough concentrations of vancomycin in children with haematologic diseases, and the effects of long-term use of cyclosporine and glucocorticoids need to be taken into account.

Optimization of Voriconazole Dosing Regimens Against Aspergillus Species and Candida Species in Pediatric Patients After Hematopoietic Cell Transplantation: A Theoretical Study Based on Pharmacokinetic/Pharmacodynamic Analysis

This study aimed to optimize the dosing regimens of voriconazole (VRC) for pediatric patients after hematopoietic cell transplantation with different cytochrome P450 (CYP) 2C19 phenotypes and body weights, based on pharmacokinetic (PK)/pharmacodynamic (PD) analysis. The PK parameters of VRC were derived from previous literature. Combined with key factors affecting VRC, patients were categorized into 9 subgroups based on different CYP2C19 phenotypes (poor metabolizer/intermediate metabolizer, normal metabolizer, and rapid metabolizer/ultrarapid metabolizer) and typical body weights (15, 40, and 65 kg). Monte Carlo simulation was used to investigate dosing regimens for different groups. The area under the 24-hour free drug concentration-time curve to the minimum inhibitory concentration (MIC) > 25 was used as the target value for effective treatment. The probability of target achievement and the cumulative fraction of response were determined on the basis of the assumed MICs and MICs distribution frequency of Aspergillus species and Candida species. When the MIC was ≤1 mg/L, 4 mg/kg every 12 hours was sufficient for optimal effects in groups 1-3 and groups 5 and 6; however, 6 mg/kg every 12 hours was required for group 4, and 8 mg/kg every 12 hours was required for groups 7-9. In empirical treatment, lower (2-6 mg/kg every 12 hours) and higher (6-12 mg/kg every 12 hours) dosing regimens were recommended for Candida spp. and Aspergillus spp., respectively. Our findings will assist in selecting appropriate dosing regimens of VRC for pediatric patients after hematopoietic cell transplantation with different CYP2C19 phenotypes and body weights. Clinically, it is better to continuously adjust the dosing on the basis of the therapeutic drug monitoring.

Pharmaceutical care model in precision medicine in China

Pharmacy service is to provide individualized pharmaceutical care for patients, which should follow the current evidence-based pharmacy, and constantly verify the evidence and then produce new evidence. In pharmaceutical care, differences are often found in the efficacy and adverse reactions of drugs among individuals, even within individuals, which are closely related to patients' genetics, liver and kidney functions, disease states, and drug interactions. Back in the 1980s, therapeutic drug monitoring (TDM) has been applied to routinely monitor the blood drug concentration of patients taking antiepileptic drugs or immunosuppressants after transplantation to provide individualized dosage recommendations and accumulate a large amount of pharmacokinetic (PK)/pharmacodynamic (PD) data. As individualized pharmaceutical care proceeds, the concept of precision medicine was introduced into pharmacy services in combination with evidence-based pharmacy, PK/PD theories, and big data to further promote the TDM technology and drugs, and carry out pharmacogenomics analysis. The TDM and pharmacogenomics have been applied gradually to the fields of antimicrobial, antitumor, and antipsychotic drugs and immunosuppressants. Based on the concept of precision pharmacy, we adopted approaches including PK/PD, quantitative pharmacology, population pharmacokinetics, and big data machine learning to provide more personalized pharmacy services, which is mainly for special patients, such as critical patients, patients with interaction risk of multiple drugs, patients with liver and renal insufficiency, pregnant women, children, and elderly patients. As the service pattern of precision pharmacy has been constructed and constantly improved, better evidence in clinical practice will be produced to provide patients with better precision pharmacy service.

Status and Quality of Guidelines for Therapeutic Drug Monitoring Based on AGREE II Instrument

BACKGROUND

With the progress of therapeutic drug monitoring (TDM) technology and the development of evidence-based medicine, many guidelines were developed and implemented in recent decades.

OBJECTIVE

The aim was to evaluate the current status of TDM guidelines and provide suggestions for their development and updates based on Appraisal of Guidelines for Research and Evaluation (AGREE) II.

METHODS

The TDM guidelines were systematically searched for among databases including PubMed, Embase, China National Knowledge Infrastructure, Wanfang Data, and the Chinese biomedical literature service system and the official websites of TDM-related associations. The search period was from inception to 6 April 2023. Four researchers independently screened the literature and extracted data. Any disagreement was discussed and reconciled by another researcher. The quality of guidelines was assessed using the AGREE II instrument.

RESULTS

A total of 92 guidelines were included, including 57 technical guidelines, three management guidelines, and 32 comprehensive guidelines. The number of TDM guidelines has gradually increased since 1979. The United States published the most guidelines (20 guidelines), followed by China (15 guidelines) and the United Kingdom (ten guidelines), and 23 guidelines were developed by international organizations. Most guidelines are aimed at adult patients only, while 28 guidelines include special populations. With respect to formulation methods, there are 23 evidence-based guidelines. As for quality evaluation results based on AGREE II, comprehensive guidelines scored higher (58.16%) than technical guidelines (51.36%) and administrative guidelines (50.00%).

CONCLUSION

The number of TDM guidelines, especially technical and comprehensive ones, has significantly increased in recent years. Most guidelines are confronted with the problems of unclear methodology and low quality of evidence according to AGREE II. More evidence-based research on TDM and high-quality guideline development is recommended to promote individualized therapy.

Pharmaceutical care model in precision medicine in China

Pharmacy service is to provide individualized pharmaceutical care for patients, which should follow the current evidence-based pharmacy, and constantly verify the evidence and then produce new evidence. In pharmaceutical care, differences are often found in the efficacy and adverse reactions of drugs among individuals, even within individuals, which are closely related to patient's genetics, liver and kidney functions, disease states, and drug interactions. Back in the 1980s, therapeutic drug monitoring (TDM) has been applied to routinely monitor the blood drug concentration of patients taking antiepileptic drugs or immunosuppressants after transplantation to provide individualized dosage recommendations and accumulate a large amount of pharmacokinetic (PK)/pharmacodynamic (PD) data. As individualized pharmaceutical care proceeds, the concept of precision medicine was introduced into pharmacy services in combination with evidence-based pharmacy, PK/PD theories and big data to further promote the TDM technology and drugs, and carry out pharmacogenomics analysis. The TDM and pharmacogenomics have been applied gradually to the fields of antimicrobial, antitumor and antipsychotic drugs and immunosuppressants. Based on the concept of precision pharmacy, we adpoted approaches including PK/PD, quantitative pharmacology, population pharmacokinetics, and big data machine learning to provide more personalized pharmacy services, which is mainly for special patients, such as critical patients, patients with interaction risk of multiple drugs, patients with liver and renal insufficiency, pregnant women, children and elderly patients. As the service pattern of precision pharmacy has been constructed and constantly improved, better evidence in clinical practice will be produced to provide patients with better precision pharmacy service.

Individualized Delivery of Vancomycin by Model-Informed Bayesian Dosing Approach to Maintain an AUC24 Target in Critically Ill Patients

INTRODUCTION

Monitoring of AUC24 was updated recommendation in the guideline for the therapeutic drug monitoring (TDM) of vancomycin in Chinese pharmacological society published in 2020. Vancomycin pharmacokinetic profiles are diverse and unique in critically ill patients because of the drastic variability of the patients' physiological parameters, while the study for population pharmacokinetic (PPK) models in Chinese critically ill patients has been rarely reported. The objectives of this study were to construct a PPK model to describe the pharmacokinetic characteristics of vancomycin in critically ill patients and to individualize vancomycin dosing by model-informed Bayesian estimation for maintenance of AUC24 target at 400-650 mg h/L recommended by the 2020 guideline.

METHODS

Vancomycin with different dosing was administered intravenously over 1 h for critically ill patients, TDM was started at 48 h or 72 h since initiation of vancomycin therapy for patients. Blood samples were collected from patients for trough concentrations or Cmax. Vancomycin concentrations were determined by high-performance liquid chromatography method with ultraviolet detection. PPK model was performed using the nonlinear mixed-effect model (NONMEM®). Individual PK parameters for critically ill patients treated with vancomycin were estimated using a post hoc empirical Bayesian method based on the final PPK model. AUC24 was calculated as the total daily dose divided by the clearance (L/h).

RESULTS

The PPK of vancomycin was determined by a one-compartment model with creatinine clearance as fixed effects. The PK estimates in the final model generally agreed with the median estimates and were contained within the 95% CI generated from the bootstrap results, indicating good precision and stability in the final model. The visual predictive check plots showed the adequate predictive performance of the final PK model and supported a good model fit. The model-informed Bayesian estimation was used to predict the AUC24 of critically ill patient by the acquired TDM results, and the dosing adjustment by maintenance of AUC24 at 400-650 mg h/L had made a great therapeutic effect for the case.

CONCLUSION

This study established a PPK model of vancomycin in Chinese critically ill patients, and individualized dosing of vancomycin by model-informed Bayesian estimation to maintain an AUC24 target at 400-650 mg h/L has been successfully applied in clinic. This result supports the continued use of model-informed Bayesian estimation to vancomycin treatment in critically ill patients.

Fluorimetric monitoring of vancomycin using an allosteric probe-initiated sensing platform

Vancomycin is the first-line drug for infections of methicillin-resistant Staphylococcus aureus (MRSA) and multi-drug-resistant bacteria. The effective therapeutic concentration range of vancomycin is narrow, so it's essential to implement vancomycin therapeutic drug monitoring. However, conventional detection methods have disadvantages of expensive equipment, complicated operation, or poor reproducibility. Herein, a fluorescent sensing platform initiated by an allosteric probe was constructed for simple and sensitive monitoring of vancomycin at a low cost. The key point of this platform is the well-designed allosteric probe, which comprises an aptamer and a trigger sequence. When vancomycin exists, the combination of vancomycin and the aptamer will lead to a conformational change of the allosteric probe, thus exposing the trigger sequence. The trigger can react with the molecular beacon (MB) to generate fluorescent signals. In addition, the allosteric probe combined with hybridization chain reaction (HCR) was applied to develop an amplified platform, the linear range is from 0.5 μg mL^-1 to 50 μg mL^-1 with the limit of detection (LOD) of 0.26 μg mL^-1. Most importantly, this allosteric probe-initiated sensing platform shows good detection ability in human serum samples, and it also indicates great correlation and accuracy compared with HPLC. The present simple and sensitive allosteric probe-initiated platform has the potential to support the therapeutic drug monitoring of vancomycin, which is of great significance to promote the rational use of antibiotics in clinics.

Revolutionizing Precision Medicine: Exploring Wearable Sensors for Therapeutic Drug Monitoring and Personalized Therapy

Precision medicine, particularly therapeutic drug monitoring (TDM), is essential for optimizing drug dosage and minimizing toxicity. However, current TDM methods have limitations, including the need for skilled operators, patient discomfort, and the inability to monitor dynamic drug level changes. In recent years, wearable sensors have emerged as a promising solution for drug monitoring. These sensors offer real-time and continuous measurement of drug concentrations in biofluids, enabling personalized medicine and reducing the risk of toxicity. This review provides an overview of drugs detectable by wearable sensors and explores biosensing technologies that can enable drug monitoring in the future. It presents a comparative analysis of multiple biosensing technologies and evaluates their strengths and limitations for integration into wearable detection systems. The promising capabilities of wearable sensors for real-time and continuous drug monitoring offer revolutionary advancements in diagnostic tools, supporting personalized medicine and optimal therapeutic effects. Wearable sensors are poised to become essential components of healthcare systems, catering to the diverse needs of patients and reducing healthcare costs.

Vancomycin population pharmacokinetics analysis in Chinese paediatric patients with varying degrees of renal function and ages: development of new practical dosing recommendations

OBJECTIVES

To describe the pharmacokinetics of vancomycin in a large Chinese paediatric cohort with varying degrees of renal function and ages and to develop practical dosing guidelines.

PATIENTS AND METHODS

We conducted a retrospective population pharmacokinetic study using data from paediatric patients who received vancomycin between June 2013 and June 2022. A non-linear mixed-effect modelling approach with a one-compartment model structure was applied. Monte Carlo simulations were used to stimulate an optimal dosage regimen to achieve the target of AUC24/MIC between 400 and 650.

RESULTS

We analysed a total of 673 paediatric patients and 1547 vancomycin serum concentrations. Covariate analysis revealed that physiological maturation, renal function, albumin and cardiothoracic surgery (CTS) significantly affected vancomycin pharmacokinetics. The typical clearance and volume of distribution, standardized to 70 kg, were 7.75 L/h (2.3% relative standard error, RSE) and 36.2 L (1.7% RSE), respectively. Based on the model, we proposed an optimal dosing regimen that considers the patient's age and estimate glomerular filtration rate (eGFR) to achieve a target AUC24/MIC for CTS and non-CTS patients. We also found that a loading dose of 20 mg/kg can help patients with an eGFR of <60 mL/min/1.73 m2 achieve the target AUC on the first day of treatment.

CONCLUSIONS

We established vancomycin pharmacokinetic parameters in Chinese paediatric patients and proposed a dosing guideline integrating eGFR, age and CTS status, potentially improving clinical outcomes and reducing nephrotoxicity risk.

Model-Informed Precision Dosing of Vancomycin in Adult Patients Undergoing Hemodialysis

Model-informed precision dosing (MIPD) maximizes the probability of successful dosing in patients undergoing hemodialysis. In these patients, area under the concentration-time curve (AUC)-guided dosing is recommended for vancomycin. However, this model is yet to be developed. The purpose of this study was to address this issue. The overall mass transfer-area coefficient (KoA) was used for the estimation of vancomycin hemodialysis clearance. A population pharmacokinetic (popPK) model was developed, resulting in a fixed-effect parameter for nonhemodialysis clearance of 0.316 liters/h. This popPK model was externally evaluated, with a resulting mean absolute error of 13.4% and mean prediction error of -0.17%. KoA-predicted hemodialysis clearance was prospectively evaluated for vancomycin (n = 10) and meropenem (n = 10), with a correlation equation being obtained (slope of 1.099, intercept of 1.642; r = 0.927, P < 0.001). An experimental evaluation using an in vitro hemodialysis circuit validated the developed model of KoA-predicted hemodialysis clearance using vancomycin, meropenem, vitamin B6, and inulin in 12 hemodialysis settings. This popPK model indicated a maximum a priori dosing for vancomycin-a loading dose of 30 mg/kg, which achieves the target AUC for 24 h after first dose with a probability of 93.0%, ensured by a predialysis concentration of >15 μg/mL. Maintenance doses of 12 mg/kg after every hemodialysis session could achieve the required exposure, with a probability of 80.6%. In conclusion, this study demonstrated that KoA-predicted hemodialysis clearance may lead to an upgrade from conventional dosing to MIPD for vancomycin in patients undergoing hemodialysis.

Awareness, perception, and barriers of healthcare providers toward the revised consensus guideline for therapeutic monitoring of vancomycin

Background

A revised consensus guideline published in 2020 recommended transitioning vancomycin monitoring to the area under the concentration-time curve over 24 h to minimum inhibitory concentration (AUC₂₄/MIC). The decision to transition to AUC₂₄/MIC monitoring or to continue trough-based monitoring is made at the institutional level and is influenced by several factors, including healthcare providers and system-related factors. Changing current practices is expected to be difficult, and it is important to understand healthcare providers' perceptions and potential barriers before the transition. This study assessed the awareness and perception of physicians and pharmacists toward the revised guideline and identified barriers to their implementation in Kuwait.

Methods

A cross-sectional survey that employed a self-administered questionnaire was used. A random sample of physicians (n = 390), clinical microbiologists (n = 37), and clinical pharmacists (n = 48) across six Kuwaiti public hospitals were surveyed. Descriptive and comparative statistical analyses were performed. Factors associated with awareness and perceptions among the participants were identified.

Results

The response rate was 85.3% (n = 431). Participants had a high (median = 75%) awareness score for the updated vancomycin guideline, as well as a positive perception (median = 5). The main factor identified to affect the awareness and perception of participants following the group analysis was the years of experience. The main barriers identified were a lack of training to perform vancomycin AUC₂₄ calculations, a lack of accurate documentation sample time, and a long turnaround time for serum levels, which might hinder the implementation of the updated guideline.

Conclusion

Physicians, clinical microbiologists, and pharmacists working in Kuwait public hospitals were aware of the 2020 vancomycin monitoring guidelines with positive perceptions. Participants agreed on the several barriers to transitioning to the AUC₂₄/MIC approach, which should be considered by stakeholders before implementation.

Adapted Evidence-Based Clinical Practice Guidelines for Diagnosis and Treatment of Epilepsies in Children: A Tertiary Children's Hospital Update

HYPOTHESIS AND/OR BACKGROUND

We recently updated and merged the adapted clinical practice guidelines (CPGs) for the diagnosis and treatment of children with epilepsy of a tertiary-level hospital. Medical knowledge is always evolving. As a result, it is critical to revisit the clinical standards on a frequent basis to ensure that the best services are offered to the target receivers. The purpose of this article was to update and merge the CPGs at Alexandria University Children Hospital (AUCH) for the diagnosis (2014) and treatment (2016) of children with epilepsy to unify and standardize the practice for better care and outcome.

METHODS

This review and update CPG project was initiated by assembling a Guideline Review Group (GRG). The GRG conducted focus group discussions and decided to search any published updates of the recommendations of the previously identified high-quality and evidence-based CPG developed by the SIGN (Scottish Intercollegiate Guidelines Network) and to merge the two previous local CPGs under one comprehensive CPG for full management of epilepsy in children. The high quality of the selected source CPG from SIGN was based on quality assessment of CPGs undertaken previously using the Appraisal of Guidelines for Research and Evaluation II Instrument. The GRG followed the Checklist for the Reporting of Updated Guidelines (CheckUp), which is the CPG tool recommended by the Enhancing the Quality and Transparency of health Research Network for reporting of updated CPGs in addition to the RIGHT-Ad@pt Checklist for Adapted CPGs. The finalized updated CPG draft was sent to the external reviewer group topic experts.

RESULTS

The group updated 10 main categories of recommendations from one source CPG (SIGN). The recommendations included (1) epilepsy diagnosis; (2) recognition, identification, and referral; (3) pharmacological treatment of epilepsy and epilepsy syndromes; (4) nonpharmacological treatment of epilepsy and epilepsy syndromes; (5) managing pharmacoresistant epilepsy; (6) management of epilepsy in special groups; (7) medications; (8) children and caregiver education and support; (9) comorbidities and mortality; and (10) transitional care from pediatric to adult care services.

CONCLUSIONS

The finalized CPG provides evidence-based guidance to health care providers in AUCH for the diagnosis and management of epilepsy in children. The study also established the significance of a collaborative clinical and methodological expert group for the update of CPGs, as well as the usability of the "CheckUp" and "RIGHT-Ad@pt" CPG Tools.

Therapeutic drug monitoring of free vancomycin concentration in practice: A new analytical technique based on the HFCF-UF sample separation method

The aim of this study was to establish a method for free vancomycin concentration determination in human plasma and apply it to clinical therapeutic drug monitoring (TDM). The unbound vancomycin in plasma was separated by the hollow fiber centrifugal ultrafiltration (HFCF-UF) technique and analyzed by HPLC. Chromatographic conditions were optimized, the specificity, linearity, precision, recovery and stability of the method were examined, and plasma samples of patients were measured. The standard curve for free vancomycin is y = 0.0277x - 0.0080 with good linearity within 0.25-50 μg·mL^-1 . The relative and absolute recovery rates for vancomycin were 98.63-101.0% and 88.41-101.2%, respectively. The intraday and interday precision RSDs were <10%. Plasma was stable under several conditions. The TDM value of the free vancomycin concentration of 20 patients was 0.99-38.51 μg·mL^-1 , and the correlation between the free and total concentrations was not significant. The unbound fraction of vancomycin ranged from 25.5 to 84.8%, with large variation. The operation of free vancomycin separation by HFCF-UF was simple and suitable for TDM in practice. The unbound fraction of vancomycin in clinical samples varied significantly between individuals. It is recommended to perform free concentration TDM in critically ill patients.

Determination of vancomycin exposure target and individualized dosing recommendations for critically ill patients undergoing continuous renal replacement therapy

STUDY OBJECTIVE

Few studies have been conducted to quantify the exposure target of vancomycin in intensive care unit (ICU) patients undergoing continuous renal replacement therapy (CRRT) and provide optimized dosage regimens. We aimed to determine vancomycin exposure target and dosing recommendations using data from an open database in critically ill patients undergoing CRRT.

DESIGN

A retrospective observational cohort study.

DATA SOURCE

A large public database.

PATIENTS

The adult patients who received intravenous vancomycin and CRRT treatment in the database between 2017 and 2019 were reviewed to determine eligibility. A total of 180 patients with 1186 observations were included in the population pharmacokinetic (PPK) model development. The clinical efficacy of vancomycin was analyzed in 159 eligible patients.

METHODS

A PPK model was developed to estimate individual pharmacokinetic (PK) parameters. The area under the concentration-time curve (AUC) was estimated by a Bayesian approach based on individual vancomycin concentrations. Multivariate logistic regression analyses were performed to identify the factors of clinical outcomes. Threshold of vancomycin exposure in predicting efficacy was identified via receiver operating characteristic (ROC) curve. Dosing recommendations were designed using Monte Carlo Simulations (MCS) based on the optimized exposure target.

MEASUREMENTS AND MAIN RESULTS

On covariate analysis, CRRT intensity significantly affected vancomycin PK. The AUC above 427 mg*h/L was the only significant predictor of clinical efficacy (adjusted odds ratio (aOR): 1.008, 95% confidence interval (CI): 1.004-1.011, p = 0.000). MCS indicated that vancomycin dosage regimens of 5 mg/kg q12h or 7.5 mg/kg q12h were recommended for patients with CRRT intensities of 20-25 mL/kg/h or 25.1-45 mL/kg/h, respectively.

CONCLUSIONS

An AUC threshold of 427 mg*h/L (assuming the minimal inhibitory concentration (MIC) = 1 mg/L) was a recommended efficacy exposure target of vancomycin for critically ill patients undergoing CRRT. Vancomycin 5-7.5 mg/kg q12h is recommended as the initial dosage regimens for ICU patients undergoing CRRT.

Optimal Use and Need for Therapeutic Drug Monitoring of Teicoplanin in Children: A Systematic Review

BACKGROUND

Teicoplanin is a glycopeptide antimicrobial that treats serious invasive infections caused by gram-positive bacteria, such as the methicillin-resistant Staphylococcus aureus. Despite some comparable advantages, there is no guideline or clinical recommendation for teicoplanin in the pediatric population, unlike vancomycin where abundant studies and the recently revised guideline on therapeutic drug level monitoring (TDM) exist.

METHODS

The systematic review was performed in accordance with the preferred reporting items for systematic reviews. Two authors (JSC and SHY) searched PubMed, Embase, and Cochrane Library databases using relevant terms independently.

RESULTS

Fourteen studies were finally included with a total of 1,380 patients. TDM was available in 2,739 samples collected in the nine studies. Dosing regimens varied widely, and eight studies used recommended dosing regimens. Timing for measuring TDM was mostly 72-96 hours or longer after the initiation of the first dose, which was expected to be a steady-state. The majority of studies had target trough levels of 10 µg/mL or above. Three studies reported that the clinical efficacy and treatment success rate of teicoplanin was 71.4%, 87.5%, and 88%. Adverse events associated with teicoplanin use were described in six studies with a focus on renal and/or hepatic impairment. Except for one study, no significant relation was noted between the incidence of adverse events and trough concentration.

CONCLUSION

Current evidence on teicoplanin trough levels in pediatric populations is insufficient due to heterogeneity. However, target trough levels with favorable clinical efficacy are achievable by recommended dosing regimen in the majority of patients.

Therapeutic Drug Monitoring of Vancomycin Concentrations for the Management of Bone and Joint Infections: An Urgent Need

Vancomycin is used for the treatment of bone and joint infections (BJI), but scarce information is available about its pharmacokinetic/pharmacodynamic (PK/PD) characteristics. We aimed to identify the risk factors associated with the non-achievement of an optimal PK/PD target in the first therapeutic drug monitoring (TDM). Methods: A retrospective study was conducted in a tertiary hospital from January 2020 to January 2022. Patients with BJI and TDM of vancomycin on day 2 of treatment were included. Initial vancomycin fixed doses (1 g every 8 h or 12 h) was decided by the responsible doctors. According to TDM results, dosage adjustments were performed. An AUC_24h/MIC < 400 mg × h/L, between 400 and 600 mg × h/L and >600 mg × h/L, were defined as suboptimal, optimal and supratherapeutic, respectively. Patients were grouped into these three categories. Demographic, clinical and PK characteristics were compared between groups. Nephrotoxicity at the end of treatment was assessed. Results: A total of 94 patients were included: 22 (23.4%), 42 (44.7%) and 30 (31.9%) presented an infratherapeutic, optimal and supratherapeutic PK/PD targets, respectively. A younger age and initial vancomycin dose <40 mg/kg/day were predictive factors for achieving a suboptimal PK/PD target, while older age, higher serum-creatinine and dose >40 mg/kg/day were associated with overexposure. The nephrotoxicity rate was 22.7%. More than 50% of patients did not achieve an optimal PK/PD. Considering age, baseline serum-creatinine and body weight, TDM is required to readily achieve an optimal and safe exposure.

Impact of pharmacist intervention in reducing vancomycin-associated acute kidney injury: A systematic review and meta-analysis

AIMS

The aim was to quantify the relationship between pharmacist intervention and vancomycin-associated acute kidney injury (AKI).

METHODS

Electronic databases were searched up to August 2020 for meta-analyses of cohort studies and/or randomized controlled trials. Studies that compared the incidence of AKI in patients between post- and prepharmacist intervention were investigated. The primary outcome was incidence of AKI. We also evaluated the influence of pharmacist intervention in risk factors of vancomycin-associated AKI.

RESULTS

The search strategy retrieved 1744 studies and 34 studies with 19 298 participants were included (22 published articles and 12 abstracts from conference proceedings). Compared with the preintervention group, the postintervention group patients had a significantly lower incidence of vancomycin-associated AKI: 7.3% for post- and 9.6% for preintervention (odds ratio [OR] 0.52, 95% confidence interval [CI]; 0.41, 0.67], P < .00001). The rate of attaining target concentration was significantly higher in the post- than preintervention group (OR 2.86, 95% CI [2.23, 3.67], P < .00001). The postintervention group significantly improved the percentage of serum creatinine laboratory tests than preintervention group (OR = 3.24, 95% CI 2.02, 5.19], P < .00001). Patients postintervention had markedly lower risk of mortality than preintervention patients (OR 0.47, 95% CI [0.31, 0.72], P = .0004).

CONCLUSION

Pharmacist intervention in vancomycin treatment significantly decreased the rate of vancomycin-associated AKI, while improving efficacy and reducing mortality. We speculate that this is because the pharmacist interventions optimized the rationality of vancomycin therapy, monitoring of vancomycin trough concentration and the monitoring of patients' renal function.

Population Pharmacokinetics and Dosage Optimization of Vancomycin in Pediatric Patients with Skin and Soft Tissue Infections, Bone, and Joint Infections

Vancomycin is recommended for the treatment of skin and soft tissue infections (SSTI) and bone and joint infections (BJI). However, a detailed investigation of the pharmacokinetic profile and optimal dosing regimens of vancomycin in pediatric patients with SSTI and BJI is lacking. We successfully developed a new PopPK model of vancomycin in this population by using scavenged blood samples with the typical values for clearance (CL) of 0.14 L/h/kg and volume of distribution (V) of 0.5 L/kg. Body weight was confirmed as the significant covariate on CL and V. The optimal dosing regimens of 75 mg/kg/day and 80 mg/kg/day were recommended for this specific population.

A national survey of individualized pharmaceutical care practice in Chinese hospitals in 2019

Background: Individualized pharmaceutical care, which consists of therapeutic drug monitoring (TDM), pharmacogenetic (PGx) testing and pharmacist-managed clinic (PMC), is one of the most important trends in clinical pharmacy development in the future. While relevant studies in China were primarily single-center or regional. This study aims to explore the current status of individualized pharmaceutical care in China, find out the existing problems and provide references for its further development. Methods: An electronic questionnaire was used and national hospitals' pharmaceutical administration data from January to December 2019 were collected. The data were sorted into Excel for further statistical analysis. All analyses were descriptive. Results: The proportions of hospitals that performed TDM and PGx testing were 12.83% and 9.48%, respectively. The major responsible departments were the clinical laboratory and pharmacy department. External quality control was carried out in around 70% of hospitals for both TDM and PGx testing. More than half of hospitals provided TDM services for valproate sodium, digoxin, carbamazepine, vancomycin and cyclosporine. And an average of 6.84 drugs were performed TDM in 540 hospitals. Clopidogrel and warfarin were the top two drugs that performed PGx testing. As for the PMC, 10.03% of hospitals opened PMC, of which 60.00% had independent PMC. Approximately 80% of PMC services were free of charge. Conclusion: The development of individualized pharmaceutical care in China is still in the early stage. Different sectors have to coalesce to promote its implementation, including the appropriate education, coverage, reimbursement policies, high-quality evidence, data systems, health system processes and health policies, etc.

Analysis of a machine learning-based risk stratification scheme for acute kidney injury in vancomycin

Vancomycin-associated acute kidney injury (AKI) continues to pose a major challenge to both patients and healthcare providers. The purpose of this study is to construct a machine learning framework for stratified predicting and interpreting vancomycin-associated AKI. Our study is a retrospective analysis of medical records of 724 patients who have received vancomycin therapy from 1 January 2015 through 30 September 2020. The basic clinical information, vancomycin dosage and days, comorbidities and medication, laboratory indicators of the patients were recorded. Machine learning algorithm of XGBoost was used to construct a series risk prediction model for vancomycin-associated AKI in different underlying diseases. The vast majority of sub-model performed best on the corresponding sub-dataset. Additionally, the aim of this study was to explain each model and to explore the influence of clinical variables on prediction. As the results of the analysis showed that in addition to the common indicators (serum creatinine and creatinine clearance rate), some other underappreciated indicators such as serum cystatin and cumulative days of vancomycin administration, weight and age, neutrophils and hemoglobin were the risk factors for cancer, diabetes mellitus, heptic insufficiency respectively. Stratified analysis of the comorbidities in patients with vancomycin-associated AKI further confirmed the necessity for different patient populations to be studied.

Sequence Type 5 (ST5) as a Possible Predictor of Bacterial Persistence in Adult Patients with Methicillin-Resistant Staphylococcus aureus Pneumonia Treated with Vancomycin

Vancomycin remains the mainstay of treatment for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. This study assessed risk factors for vancomycin failure in 63 patients with MRSA pneumonia through detailed clinical, microbiological, pharmacokinetic/pharmacodynamic, and genetic analyses of prospective multicenter studies conducted from February 2012 to July 2018. Therapeutic drug monitoring was performed during vancomycin treatment, and the 24-h area under the curve (AUC_0-24) was calculated. All baseline strains were collected for MIC determination, heterogeneous vancomycin-intermediate S. aureus (hVISA) screening, and biofilm determination. Whole-genome sequencing was performed on the isolates to analyze their molecular typing and virulence and adhesion genes. Clinical signs and symptoms improved in 44 patients (44/63, 69.8%), with vancomycin daily dose (P = 0.045), peak concentration (P = 0.020), and sdrC (P = 0.047) being significant factors. Isolates were eradicated in 51 patients (51/63, 81.0%), with vancomycin daily dose (P = 0.009), cardiovascular disease (P = 0.043), sequence type 5 (ST5; P = 0.017), tst (P = 0.050), and sec gene (P = 0.044) associated with bacteriological failure. Although the AUC_0-24/MIC was higher in the groups with bacterial eradication, the difference was not statistically significant (P = 0.108). Multivariate analysis showed that no variables were associated with clinical efficacy; ST5 was a risk factor for bacterial persistence (adjusted odds ratio, 4.449; 95% confidence interval, 1.103 to 17.943; P = 0.036). ST5 strains had higher frequencies of the hVISA phenotype, biofilm expression, and presence of some adhesion and virulence genes such as fnbB, tst, and sec than non-ST5 strains. Our study suggests that ST5 is a possible predictor of bacterial persistence in MRSA pneumonia treated with vancomycin. IMPORTANCE Few studies have simultaneously examined the influence of clinical characteristics of patients with pneumonia, the vancomycin pharmacokinetic/pharmacodynamic (PK/PD) index, and the phenotypic and genetic characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains. We assessed risk factors for vancomycin failure in patients with MRSA pneumonia by analyzing these influences in a prospective multicenter study. Sequence type 5 (ST5) was a possible predictor of bacterial persistence in adult patients with MRSA pneumonia (adjusted odds ratio, 4.449). We found that this may be related to ST5 strains having higher levels of vancomycin heterogeneous resistance, biofilms, and the presence of adhesion and virulence genes such as fnbB, tst, and sec.

Therapeutic drug monitoring (TDM) as intervention: A cross-sectional analysis of characteristics of 173 registered clinical trials

Background

To examine fundamental characteristics of clinical trials with therapeutic drug monitoring (TDM) as intervention on world major clinical trials registry platform.

Methods

Cross-sectional analysis of clinical trials with TDM as intervention that were registered on WHO International Clinical Trials Registry Platform (ICTRP) or ClinicalTrials.gov. Relevant trial entries registered before and on March 2nd, 2022 were downloaded, deduplicated, and reviewed. Recruit country, monetary source, start years, study design, medical conditions, involved drugs, outcome measure, and subject information were extracted and analyzed.

Results

Overall, 173 clinical trials were included in this study. Majority of the trials were conducted in several economically prosperous countries. The earliest initiated trials dates back to 2002. Most of the trials were funded by hospitals (36.4%). A higher proportion of trials were conducted within one country (86.1%), as phase Ⅳ (34.1%) interventional study (82.7%), randomized (52.6%), parallel assignment (53.8%) and open label (67.0%). The most concerned medical condition were infectious or parasitic disease and neoplasms, with the most monitored drugs were immunosuppressants and β-lactam antibacterials. Most of the trials enroll no more than 50 subjects (30.6%), with both gender (95.4%), and adults (67.0%).

Conclusion

The trials were mainly conducted in several economically prosperous countries. The number of registered trials had gradually increased during the past years. Novel biological drugs have increasingly become the research hotspot. We expect that with abundant financial support, more high-quality large-scale, multicenter randomized clinical trials (RCTs) are designed and implemented to promote the development of TDM in the future.

Therapeutic drug monitoring practices of anti-infectives: An Asia-wide cross-sectional survey

Objectives: The current practice of therapeutic drug monitoring (TDM) in Asia is poorly documented. Our aim was to capture and describe TDM services delivered in hospitals across Asia, including aspects such as assay availability, interpretation of results and clinical decision-making. Methods: An online survey about anti-infective TDM practices, available in English and involving 50 questions, was promoted to people involved in TDM in Asia. The survey was open for responses from September to November 2021. Results: Of 207 responses from participants working in 14 Asian countries, 150 responses from 10 countries could be included. TDM services are available for many anti-infectives, providing assays based on chromatographic assays (100.0%) or immunoassays (39.3%). Clinicians (82.6%) and pharmacists (86.8%) were responsible for ordering and interpreting TDM. Most services provided reference targets and dose recommendations. Interpretative support was available to a varying degree. Assay results were available and clinical decision-making could be completed within 24 h in most hospitals (87.9% and 88.9% respectively). As the turnaround time of assay results decreased, the proportion of clinical decision-making completed within 8 h increased. Barriers to implementation of TDM included lack of funding or equipment (71.1%), lack of clinician interest or cooperation (47.0%), and lack of expertise (42.3%). Lack of expertise was the primary barrier for using precision dosing software (50.5%). Conclusion: There are significant differences and challenges in the development and practice of anti-infective TDM in Asian countries.

Pharmacokinetic assessment of vancomycin in critically ill patients and nephrotoxicity prediction using individualized pharmacokinetic parameters

Introduction: Therapeutic drug monitoring (TDM) and pharmacokinetic assessments of vancomycin would be essential to avoid vancomycin-associated nephrotoxicity and obtain optimal therapeutic and clinical responses. Different pharmacokinetic parameters, including trough concentration and area under the curve (AUC), have been proposed to assess the safety and efficacy of vancomycin administration. Methods: Critically ill patients receiving vancomycin at Nemazee Hospital were included in this prospective study. Four blood samples at various time intervals were taken from each participated patient. Vancomycin was extracted from plasma samples and analyzed using a validated HPLC method. Results: Fifty-three critically ill patients with a total of 212 blood samples from June 2019 to June 2021 were included in this study. There was a significant correlation between baseline GFR, baseline serum creatinine, trough and peak concentrations, AUCτ, AUC24h, Cl, and Vd values with vancomycin-induced AKI. Based on trough concentration values, 66% of patients were under-dosed (trough concentration <15 μg/ml) and 18.9% were over-dosed (trough concentration ≥20 μg/ml). Also, based on AUC24h values, about 52.2% were under-dosed (AUC24h < 400 μg h/ml), and 21.7% were over-dosed (AUC24h > 600 μg h/ml) that emphasizes on the superiority of AUC-based monitoring approach for TDM purposes to avoid nephrotoxicity occurrence. Conclusion: The AUC-based monitoring approach would be superior in terms of nephrotoxicity prediction. Also, to avoid vancomycin-induced AKI, trough concentration and AUCτ values should be maintained below the cut-off points.