Vancomycin Therapeutic Drug Monitoring (TDM) and Its Association with Clinical Outcomes: A Retrospective Cohort

Rapid and sensitive determination of vancomycin using an AIE-active fluorescent probe for clinical monitoring

Vancomycin (Van) is the preferred drug for clinically treating severe infections caused by Gram-positive bacteria, especially in the intensive care unit (ICU). However, due to safety concerns, strict management and administration of Van are required in clinical practice. Hence, there is a need to develop a rapid and accurate method for determining the concentration of Van. In this study, a cyanostilbene-based fluorescent probe, Cy-KAA, is designed for the rapid, highly sensitive and selective detection of Van. In the probe, the L-Lys-D-Ala-D-Ala polypeptide moiety can interact with Van, resulting in a rapid fluorescence response that reaches a plateau within 2 minutes. Cy-KAA can be employed for the detection of Van in clinical ICU samples, demonstrating a strong correlation with the traditional HPLC method (consistency up to 0.99). These findings highlight the high accuracy and potential utility of Cy-KAA as a powerful tool for real-time monitoring of Van levels in clinical practice, thereby providing valuable guidance for precise drug administration.

Risk Factors for Nephrotoxicity Among Neonates Receiving Vancomycin: A Systematic Review and Meta-analysis

BACKGROUND

Nephrotoxicity may increase the risk of neonatal mortality. Early identification of risk factors for nephrotoxicity is essential to improve clinical outcomes. This study aimed to determine the risk factors for nephrotoxicity in neonates receiving vancomycin to promote the safe use of vancomycin.

METHODS

We searched international and Chinese databases from 1990 to 24 March 2024 for studies involving neonates receiving vancomycin and reporting their nephrotoxic outcomes. Effects were estimated with 95% confidence intervals (CIs), odds ratios (ORs), and standardized mean differences. We evaluated the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool.

RESULTS

In total, the study included 12 retrospective cohort studies involving 2079 neonates. In neonates receiving vancomycin, the incidence of nephrotoxicity varied from 2.7 to 20.0%. Moderate-quality evidence indicated that furosemide (OR 5.80; 95% CI 2.98-11.28), amphotericin B (OR 2.75; 95% CI 1.23-6.12), patent ductus arteriosus (OR 5.93; 95% CI 2.80-12.55), and necrotizing enterocolitis (OR 4.49; 95% CI 2.12-9.49) were risk factors for nephrotoxicity in neonates receiving vancomycin. Low-quality evidence suggested that vasoactive agents (OR 9.23; 95% CI 1.06-80.62) were risk factors. Subgroup analysis with moderate-quality evidence identified a steady-state vancomycin trough concentration > 20 mg·L-1 (OR 6.87; 95% CI 3.81-12.39) as a risk factor. Very low-quality evidence indicated that aminoglycosides (OR 0.29; 95% CI 0.13-0.62) were not risk factors.

CONCLUSIONS

This study reveals the nephrotoxic risk factors for neonates receiving vancomycin, which could help in the implementation of measures to prevent further renal impairment.

PROSPERO REGISTRATION NUMBER

CRD42024564584.

Recommended approaches for integration of population pharmacokinetic modelling with precision dosing in clinical practice

Current methods of dose determination have contributed to suboptimal and inequitable health outcomes in underrepresented patient populations. The persistent demand to individualise patient treatment, alongside increasing technological feasibility, is leading to a growing adoption of model-informed precision dosing (MIPD) at point of care. Population pharmacokinetic (popPK) modelling is a technique that supports treatment personalisation by characterising drug exposure in diverse patient groups. This publication addresses this important shift in clinical approach, by collating and summarising recommendations from literature. It seeks to provide standardised guidelines on best practices for the development of popPK models and their use in MIPD software tools, ensuring the safeguarding and optimisation of patient outcomes. Moreover, it consolidates guidance from key regulatory and advisory bodies on MIPD software deployment, as well as technical requirements for electronic health record integration. It also considers the future application and clinical impact of machine learning algorithms in popPK and MIPD. Ultimately, this publication aims to facilitate the incorporation of high-quality precision-dosing solutions into standard clinical workflows, thereby enhancing the effectiveness of individualised dose selection at point of care.

Machine learning and population pharmacokinetics: a hybrid approach for optimizing vancomycin therapy in sepsis patients

Predicting vancomycin exposure is essential for optimizing dosing regimens in sepsis patients. While population pharmacokinetic (PPK) models are commonly used, their performance is limited. Machine learning (ML) models offer advantages over PPK models, but it remains unclear which model-PPK, Bayesian, ML, or hybrid PPK-ML-is best for predicting vancomycin exposure across different clinical scenarios in sepsis patients. This study compares the performance of these models in predicting the 24 hour area under the blood concentration curve (AUC24) to support precision dosing in sepsis care. Data from sepsis patients treated with intravenous vancomycin were sourced from the MIMIC-IV database. The data set was split into training and testing sets, and four models-PPK, Bayesian, ML, and hybrid-were developed. In the testing set, AUC24 was predicted using all models, and performance was evaluated using mean absolute error, mean squared error, root mean squared error, mean absolute percentage error (MAPE), and R². A total of 4,059 patients were included. In the absence of vancomycin concentration data, the hybrid model outperformed both PPK and Bayesian models, with MAPE improvements of 58% and 17%, respectively. When vancomycin concentration data were available, the Bayesian model demonstrated the best performance (MAPE: 13.37% vs 68.17%, 34.17%, and 28.52% for PPK, Random Forest, and hybrid models). The hybrid model is recommended to predict AUC24 when concentration data were unavailable, while the Bayesian model should be used when concentrations were available, offering robust strategies for precise vancomycin dosing in sepsis patients.

IMPORTANCE

This study evaluates and compares the performance of four models-PPK, Bayesian, ML, and hybrid PPK-ML-in predicting vancomycin exposure (AUC24) in sepsis patients using real-world data from the MIMIC-IV database. These results underscore the importance of selecting appropriate models based on the availability of concentration data, providing valuable guidance for precision dosing strategies in sepsis care. This work contributes to advancing personalized vancomycin therapy, optimizing dosing regimens, and improving clinical outcomes in sepsis patients.

Prediction of Area Under the Curve from Urinary Vancomycin Concentrations Measured Using a Simple Method

Therapeutic drug monitoring (TDM) is recommended during vancomycin (VCM) administration to adjust the dosage such that the area under the curve (AUC) remains between 400 and 600 µg·h/mL (minimum inhibitory concentration = 1 µg/mL). However, measuring the AUC requires frequent blood sampling, which increases the burden of added time and cost for testing on both patients and healthcare personnel. Therefore, we aimed to address these issues by developing a simple and rapid method for measuring urinary VCM levels using solid-phase extraction and fluorescence spectrometry. The developed method had a quantification range of 100-2,000 µg/mL, with an accuracy of 100.0%-108.5% for concentrations of 200, 1,000, and 2,000 µg/mL. The intra- and inter-day relative standard deviations were below 3.39% and 4.48%, respectively. Furthermore, to predict the AUC from urinary VCM concentrations, we calculated the slope of the urinary concentrations at 7-12 h post-VCM administration in six patients. The slope for one patient differed significantly from that for the others, and the AUC was obtained using practical AUC-guided TDM for vancomycin (PAT) ver. 3.0c for the patient whose value deviated from the recommended range. A negative correlation was observed between the slope and AUC, with a correlation coefficient of 0.65, suggesting the potential for predicting AUC from urinary concentration trends. The use of urine samples, which can be easily obtained, for VCM dose adjustment is expected to contribute to providing more appropriate drug therapy to patients and reduce the burden on healthcare professionals.

Advancements in Managing Choledocholithiasis and Acute Cholangitis in the Elderly: A Comprehensive Review

The increasing elderly population has led to a rising prevalence of choledocholithiasis and acute cholangitis, presenting unique diagnostic and therapeutic challenges owing to age-related physiological changes and multiple comorbidities. This comprehensive review synthesizes current evidence and recent advances in managing these conditions in elderly patients, with a particular focus on diagnostic innovations, therapeutic strategies, and perioperative optimization. Recent advances in diagnostic modalities, including enhanced imaging techniques and AI-assisted systems, have improved early detection accuracy, whereas minimally invasive interventions, particularly endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic common bile duct exploration (LCBDE), have demonstrated superior outcomes when combined with comprehensive perioperative care. The implementation of multidisciplinary approaches and personalized treatment strategies has significantly improved patient outcomes, with evidence supporting the critical role of early antibiotic intervention, careful surgical selection, and enhanced recovery protocols in reducing morbidity and mortality. The optimal management of elderly patients with choledocholithiasis and acute cholangitis requires a systematic, individualized approach incorporating advanced diagnostic techniques, minimally invasive interventions, and comprehensive perioperative care, while future research should focus on developing age-specific treatment algorithms and validating novel therapeutic approaches.

Therapeutic Drug Monitoring of Vancomycin in Hemodialysis Patients in a Hospital in North-East Romania

Background/Objectives: Vancomycin is a reserve antibiotic that is frequently prescribed for central venous catheter (CVC)-associated infections in hemodialysis patients. Hemodialysis patients are very fragile patients and the presence of CVCs increases the risk of sepsis. We conducted a prospective study, evaluating the needs of changes in vancomycin dosing for treatment based on the use of the new 2020 vancomycin dosing guidelines, to increase drug safety (preventing subtherapeutic or supratherapeutic doses and offering therapeutic concentrations of the drug) in a particular group of patients with sepsis caused by catheter infections and being on intermittent hemodialysis. Methods: This prospective study included patients with sepsis caused by catheter infections and being on intermittent hemodialysis, treated with vancomycin, admitted in the nephrology department and intensive care unit (ICU). Vancomycin levels were adjusted according to the 2020 vancomycin guidelines. Results: In our study, nine (45%) patients had a vancomycin AUC between 400 and 600 mcg × h/mL, five (25%) patients had a subtherapeutic AUC, and six (30%) patients had a supratherapeutic AUC. It is important to mention that in 10 (50%) of the patients included in the study, the loading and maintenance doses mentioned in the protocol were respected, but 50% of them had a supratherapeutic AUC. We observed that a supratherapeutic AUC occurred when the loading dose was 1500 mg or 2000 mg, and in one case at 1000 mg with a low BMI. Conclusions: a therapeutic level of vancomycin can often be difficult to achieve because of different reasons, mainly in hemodialysis patients.

Evaluation of the appropriateness of vancomycin therapeutic drug monitoring in the intensive care unit with a clinical pharmacy approach, a cross-sectional study

OBJECTIVES

Vancomycin, a glycopeptide antibiotic has antibacterial activity against Gram-positive bacteria and is frequently used in the intensive care unit (ICU). Inappropriate therapeutic drug monitoring (TDM) of vancomycin is a common problem encountered in hospital daily practice. The aim of this study was to evaluate the appropriateness of vancomycin trough-guided TDM in patients treated in the ICU using a clinical pharmacy approach.

METHODS

The study was conducted retrospectively in patients over 18 years old who had at least one vancomycin trough level and who had received intravenous (IV) vancomycin for ≥3 days between 1 November 2020 and 1 April 2022. The study included 137 patients. Patient demographics and relevant vancomycin TDM data were collected from medical records. The appropriateness of TDM was evaluated according to the criteria established based on the monitoring recommendations specified in consensus guidelines for therapeutic drug monitoring of vancomycin published by the American Society of Health-System Pharmacists (ASHP) in 2009 and 2020.

RESULTS

Of a total of 238 vancomycin trough levels measured in patients, 32.4% were collected at an inappropriate time. When patients were evaluated in terms of TDM appropriateness according to vancomycin level ranges (<10 µg/mL, 10-20 µg/mL and >20 µg/mL), we found the appropriate TDM was significantly higher in the therapeutic range (10-20 µg/mL) (p <0.001). Of the total 238 vancomycin trough concentrations taken from patients, 77 (32.4%) were measured at an inappropriate time. This caused dose withholding, wrong adjustments and therapy failure. The total TDM appropriateness of vancomycin was significantly higher in the therapeutic range defined as 10-20 µg/mL when evaluated based on 'TDM appropriateness criteria' (p <0.001).

CONCLUSION

Our study shows that appropriate vancomycin TDM increases the likelihood of achieving target trough concentrations. Involvement of clinical pharmacists in TDM management may prevent the development of adverse reactions by ensuring appropriate sampling time and appropriate interpretation of vancomycin levels.

Optimizing the dosing regimens of linezolid against gram-positive cocci in critically ill patients with different renal functions: a Monte Carlo simulation

To promote the accurate administration of linezolid, this study aimed to evaluate its dosage regimens in critically ill patients with varying renal functions. This evaluation was based on a combined analysis of pharmacokinetic (PK), pharmacodynamic (PD), and toxicodynamic (TD) indices. The percentage of therapeutic target attainment (PTTA) was used as the index for PK/PD/TD, defined as simultaneously meeting two PK/PD criteria (AUC0-24h/MIC ≥ 100 and Css between 2.6-7.8 mg/L) and adjusted for toxicity probability, with MICs ranging from 0.5 to 8 mg/L. The recommended doses of linezolid for patients: 600 mg every 12 h for normal renal function or mild renal impairment, 300 mg every 12 h for severe renal impairment, 450 mg every 12 h for moderate renal impairment, and 600 mg every 8 h for supra-normal renal function. In conclusion, specific dosing regimens should be adopted for patients with varying renal functions, combined with therapeutic drug monitoring, to ensure the safety and efficacy of linezolid.

Global research trends in therapeutic drug monitoring of antimicrobials from 2000 to 2023: a bibliometric analysis

Objective

The practice of therapeutic drug monitoring (TDM) is widely used for maximizing the clinical efficacy of antimicrobials. However, a systematic bibliometric analysis providing an overview of this field is lacking at present. The aim of the current study was to identify hotspots and trends in antimicrobial TDM, highlight collaborations and influences among countries, institutions, and journals, and assess the knowledge base for further development of clinical research.

Research Design and Methods

Articles and reviews related to TDM of antimicrobials from the Web of Science Core Collection were collected. CiteSpace and VOSviewer, two visualization tools, were utilized to graphically assess the key elements within this domain, including mapping of countries and regions, institutions, keywords, and references associated with the field of antimicrobial TDM. Through this approach, we were able to successfully provide a comprehensive visual overview of the research landscape, highlighting the significant players and thematic trends in the literature.

Results

From 2000 to 2023, a total of 17,236 authors from 4,112 institutions in 112 countries/regions published 3,710 papers in 819 academic journals. The United States had the highest number of publications, with University of Queensland identified as the most active institution. The journal with the greatest number of publications was Therapeutic Drug Monitoring, whereas Antimicrobial Agents and Chemotherapy was the most co-cited journal. Current research focuses on pharmacokinetics, pharmacodynamics, vancomycin, posaconazole, invasive fungal infection and critically ill patients. Promising hotspots for future research include vancomycin, voriconazole, meropenem, isavuconazole, posaconazole, and teicoplanin. Moreover, vancomycin and critically ill patients remain a hot topic of future research.

Conclusion

Using bibliometric and visualization methods, the research hotspots of antimicrobial drugs in TDM were analyzed. The continued increase in the number of annual publications demonstrates the vital significance of TDM for antimicrobials. Data from this study provide a valuable reference for future research trends in TDM of antimicrobial agents.

Antibiotic dose optimisation in the critically ill: targets, evidence and future strategies

PURPOSE OF REVIEW

To highlight the recent evidence for antibiotic pharmacokinetics and pharmacodynamics (PK/PD) in enhancing patient outcomes in sepsis and septic shock. We also summarise the limitations of available data and describe future directions for research to support translation of antibiotic dose optimisation to the clinical setting.

RECENT FINDINGS

Sepsis and septic shock are associated with poor outcomes and require antibiotic dose optimisation, mostly due to significantly altered pharmacokinetics. Many studies, including some randomised controlled trials have been conducted to measure the clinical outcome effects of antibiotic dose optimisation interventions including use of therapeutic drug monitoring. Current data support antibiotic dose optimisation for the critically ill. Further investigation is required to evolve more timely and robust precision antibiotic dose optimisation approaches, and to clearly quantify whether any clinical and health-economic benefits support expanded use of this treatment intervention.

SUMMARY

Antibiotic dose optimisation appears to improve outcomes in critically ill patients with sepsis and septic shock, however further research is required to quantify the level of benefit and develop a stronger knowledge of the role of new technologies to facilitate optimised dosing.

Antibiotic Resistance Profiles and MLST Typing of Staphylococcus Aureus Clone Associated with Skin and Soft Tissue Infections in a Hospital of China

Objective

To analyze the antibiotic resistance profile, virulence genes, and molecular typing of Staphylococcus aureus (S. aureus) strains isolated in skin and soft tissue infections at the First Affiliated Hospital, Gannan Medical University, to better understand the molecular epidemiological characteristics of S. aureus.

Methods

In 2023, 65 S. aureus strains were isolated from patients with skin and soft tissue infections. Strain identification and susceptibility tests were performed using VITEK 2 and gram-positive bacteria identification cards. DNA was extracted using a DNA extraction kit, and all genes were amplified using polymerase chain reaction. Multilocus sequence typing (MLST) was used for molecular typing.

Results

In this study, of the 65 S. aureus strains were tested for their susceptibility to 16 antibiotics, the highest resistance rate to penicillin G was 95.4%. None of the staphylococcal isolates showed resistance to ceftaroline, daptomycin, linezolid, tigecycline, teicoplanin, or vancomycin. fnbA was the most prevalent virulence gene (100%) in S. aureus strains isolated in skin and soft tissue infections, followed by arcA (98.5%). Statistical analyses showed that the resistance rates of methicillin-resistant S. aureus isolates to various antibiotics were significantly higher than those of methicillin-susceptible S. aureus isolates. Fifty sequence types (STs), including 44 new ones, were identified by MLST.

Conclusion

In this study, the high resistance rate to penicillin G and the high carrying rate of virulence gene fnbA and arcA of S.aureus were determine, and 44 new STs were identified, which may be associated with the geographical location of southern Jiangxi and local trends in antibiotic use. The study of the clonal lineage and evolutionary relationships of S. aureus in these regions may help in understanding the molecular epidemiology and provide the experimental basis for pathogenic bacteria prevention and treatment.

One-Step Detection of Vancomycin in Whole Blood Using the Lateral Flow Immunoassay

Vancomycin (VAN) is an effective antibiotic against Gram-positive bacteria and the first-line therapy to prevent and treat methicillin-resistant Staphylococcus aureus (MRSA) and severe infections. However, low concentrations of VAN can result in resistant strains. High doses of VAN can cause nephrotoxicity and ototoxicity; thus, VAN is a representative drug for which drug monitoring is recommended. Several methods have been proposed to detect VAN. Among them, lateral flow immunoassays (LFIAs) have advantages, such as simple and user-friendly operation, low sample volume requirement, and cost effectiveness. In this study, we developed an LFIA capable of rapid on-site detection such that the VAN concentration in plasma could be monitored within 20 min by a one-step detection process using whole blood without plasma separation. VAN can be detected in whole blood over a wide range of concentrations (20-10,000 ng/mL), and the LFIA reported here has a detection limit of 18 ng/mL. The applicability of the developed LFIA compared to the results of measuring VAN with a commercial enzyme-linked immunosorbent assay kit showed a satisfactory correlation (Spearman's rho, ρ = 0.891). Therefore, the developed LFIA enables rapid and wide-range VAN detection in whole blood and can aid in drug monitoring to evaluate patients' responses to treatment.

Unveiling drug induced nephrotoxicity using novel biomarkers and cutting-edge preventive strategies

Drug-induced nephrotoxicity is still a significant obstacle in pharmacotherapy of various diseases and it accounts for around 25 % of serious side-effects reported after drug administration. Furthermore, some groups of drugs such as nonsteroidal anti-inflammatory drugs, antibiotics, antiviral drugs, antifungal drugs, immunosuppressants, and chemotherapeutic drugs have the "preference" for damaging the kidney and are often referred to as the kidney's "silent killer". Clinically, the onset of acute kidney injury associated with drug administration is registered in approximately 20 % of patients and many of them develop chronic kidney disease vulnerability. However, current knowledge about the mechanisms underlying this dangerous phenomenon is still insufficient with many unknowns. Hence, the valuable use of these drugs in clinical practice is significantly limited. The main aim of this study is to draw attention to commonly prescribed nephrotoxic drugs by clinicians or drugs bought over the counter. In addition, the complex relationship between immunological, vascular and inflammatory events that promote kidney damage is discussed. The practical use of this knowledge could be implemented in the engineering of novel biomarkers for early detection of drug-associated kidney damage such as Kidney Injury Molecule (KIM-1), lipocalin associated with neutrophil gelatinase (NGAL) and various microRNAs. In addition, the utilization of artificial intelligence (AI) for the development of computer algorithms that could detect kidney damage at an early stage should be further explored. Therefore, this comprehensive review provides a new outlook on drug nephrotoxicity that opens the door for further clinical research of novel potential drugs or natural products for the prevention of drug-induced nephrotoxicity and accessible education.

Falsely decreased vancomycin caused by rheumatoid factor: A case report

BACKGROUND

Vancomycin is associated with potential nephrotoxicity and trough concentrations need to be monitored in certain patients. Falsely decreased vancomycin measurement may result in overtreatment and need to be identified promptly by clinicians and pharmacists to avoid toxicities.

METHODS AND RESULTS

We report a case of rheumatoid factor-mediated falsely low vancomycin measurement with Abbott particle-enhanced turbidimetric inhibition immunoassay (PETINIA) method. Reanalyzing the sample using an alternative method, removing the interferences using heterophile blocking reagent as well as rheumatoid factor clean-up solution all helped to solve the false results. Results from alternative method and interference studies showed vancomycin concentrations reached toxic concentrations in the patient and administration of the drug was immediately terminated. The patient experienced a transient increase in serum creatinine.

CONCLUSIONS

Even though most modern immunoassays use blocking agents to neutralize interfering antibodies such as rheumatoid factor, it is important for health care professionals to understand that occasional interference still occurs due to the heterogeneous nature of rheumatoid factor.

Vancomycin therapeutic drug monitoring in patients on continuous renal replacement therapy: a retrospective study

Objectives

This study aimed to investigate vancomycin therapeutic drug monitoring (TDM) in patients on continuous renal replacement therapy (CRRT) and explore the risk factors for exceeding the target concentration.

Methods

This retrospective study enrolled patients aged ≥18 years who were admitted to the intensive care unit and treated with ≥3 intravenous vancomycin doses during CRRT, and who underwent vancomycin TDM. Demographic and other information were collected. Multivariate logistic regression was used assess the risk factors for exceeding the target concentration.

Results

Sixty-nine patients were included, and 40.6% patients underwent TDM. Additionally, 14.5% of patients reached the optimal concentration, and 87.5% of patients who exceeded the target received a daily dose adjustment. The cumulative dose of vancomycin and serum albumin were risk factors for exceeding the target concentration in patients on CRRT.

Conclusions

Patients on CRRT did not meet the optimal vancomycin management; <50% of the patients routinely received vancomycin TDM, and <15% achieved the optimal concentration. Fewer patients in the subtherapeutic group received a daily dose adjustment than those who exceeded the target concentration. Cumulative vancomycin and serum albumin doses before TDM were the risk factors for exceeding the target concentration in CRRT patients.