The Whole Price of Vancomycin: Toxicities, Troughs, and Time

Ultrasensitive and selective vancomycin detection using aptamer-modified multi-doped laser-induced graphene extended-gate field-effect transistor

Vancomycin (Van), a widely utilized glycopeptide antibiotic in clinical settings, necessitates precise bloodstream concentration monitoring due to its narrow therapeutic window, ensuring drug efficacy while preventing adverse effects. In this work, we have engineered an extended-gate field-effect transistor (EG-FET) sensor tailored for vancomycin detection. This novel sensor configuration comprises a detachable multi-doped graphene EG electrode sensing element paired with a commercial field-effect transistor (FET). The EG electrode design integrates a sophisticated multistage doping process, incorporating MnO2 and Au nanoparticles into laser-induced graphene (LIG), thereby augmenting both functional and electrical characteristics of LIG. To achieve specific recognition, a vancomycin aptamer is immobilized onto the electrode surface, enabling selective binding with vancomycin and translating this interaction into a measurable electrical signal. This collaborative mechanism empowers the EG-FET sensor to exhibit exceptional sensitivity and selectivity towards vancomycin. Notably, the sensor demonstrates a wide linear response ranging from 1 nM to 100 μM, spanning the entire therapeutic window of vancomycin (6-35 μM), boasting an impressive detection limit of 0.187 nM. We have innovated a portable wireless sensing system, coupled with a Janus membrane for expedited plasma separation, consolidating a portable platform dedicated to vancomycin sensing. Furthermore, we have realized the detection of vancomycin concentration in patient's blood using this sensor, and the results are reliable. This comprehensive study underscores the immense potential of multi-doped graphene EG-FET sensors in the realm of antibiotic detection, thereby contributing a pivotal tool towards the realization of precision medicine strategies.

Implementation of AUC-Guided Vancomycin Dosing: What Role Remains for Trough-Only Monitoring? A Retrospective, Cohort Study

BACKGROUND

The 2020 consensus guidelines for drug monitoring of vancomycin recommended AUC-guided dosing to reduce acute kidney injury (AKI) and improve clinical outcomes in patients with serious methicillin-resistant Staphylococcus aureus (MRSA) infections previously managed with trough concentrations of 15-20 mg/L.

OBJECTIVES

To determine if AUC-guided dosing of vancomycin reduces AKI and improves clinical outcomes including non-invasive infections with S. aureus compared with trough-only dosing broadened to concentrations of 10-20 mg/L.

METHODS

A retrospective, single-center, cohort study was conducted over 12 months comparing Bayesian software-guided AUC-dosing with trough-only dosing. Information collected included patient demographics, co-morbidities, concurrent nephrotoxins, assessment measures of drug exposure, and patient outcomes. Nominal data were analyzed using the chi-square test, and continuous data using the independent t test.

RESULTS

Based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria, the incidence of AKI was 7.65% and 6.06% (P = 0.56), among 183 patients in the AUC-guided and 165 subjects in the trough-only groups, respectively. Individuals in the trough-only group were younger, had fewer co-morbidities and admissions to the ICU. A lower incidence of AKI findings among trough-only subjects was likely a result of the duration of therapy (mean of 4.2 days), mean trough concentrations <15 mg/L, and fewer concurrent nephrotoxins. AUC-guided dosing significantly reduced the total daily dose, 2.29 vs 2.54 g/day (P = 0.01), but provided no significant reductions in cumulative dose, duration of therapy, length of hospital stays, or overall patient outcomes.

CONCLUSION

AUC-guided vancomycin dosing did not reduce the incidence of AKI nor impact patient outcomes vs trough-only dosing. Successful clinical outcomes with lower average trough concentrations may have resulted from the treatment of nonbacteremic skin soft tissue infections (SSTI), suggesting an indication for further exploration of vancomycin dosing strategies.

N-chlorotaurine does not alter structural tendon properties: a comparative biomechanical study

INTRODUCTION

N-chlorotaurine (NCT) is a well-tolerated antiseptic with broad-spectrum microbicidal activity and could therefore be a promising alternative to vancomycin, the current standard of care for the prevention of postoperative septic arthritis (PSA) after anterior cruciate ligament reconstruction (ACLR).

MATERIALS AND METHODS

The aim of this study was to evaluate whether soaking bovine extensor tendons in N-chlorotaurine (NCT), vancomycin, or 0.9% saline influences structural tendon properties. In this controlled biomechanical study, fifty bovine extensor tendons were randomized into groups and soaked for 10 min in distilled water solutions containing either 1% vancomycin, 1% NCT, 5% NCT, 5% NCT with 0.1% ammonium chloride, or 0.9% saline. Tendons were then mounted in cryo-clamps and subjected to uniaxial tensile testing until failure. Failure mode, ultimate load, ultimate elongation, and stiffness of the linear region from the load-elongation curve were extracted and compared for each graft.

RESULTS

No statistically significant differences were detected across all measured parameters (p > 0.05) and solutions. The mean ultimate load, ultimate elongation, stiffness and elastic modulus were not statistically significantly different between all five tested solutions.

CONCLUSIONS

Both NCT and vancomycin even at high concentrations do not impair structural tendon properties compared to 0.9% saline. NCT appears to be safe for clinical use from a biomechanical perspective.

101 Machine Learning Algorithms for Mining Esophageal Squamous Cell Carcinoma Neoantigen Prognostic Models in Single-Cell Data

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumors in the digestive tract, characterized by a high recurrence rate and inadequate immunotherapy options. We analyzed mutation data of ESCC from public databases and employed 10 machine learning algorithms to generate 101 algorithm combinations. Based on the optimal range determined by the concordance index, we randomly selected one combination from the best-performing algorithms to construct a prognostic model consisting of five genes (DLX5, MAGEA4, PMEPA1, RCN1, and TIMP1). By validating the correlation between the prognostic model and antigen-presenting cells (APCs), we revealed the antigen-presentation efficacy of the model. Through the analysis of immune infiltration in ESCC, we uncovered the mechanisms of immune evasion associated with the disease. In addition, we examined the potential impact of the five prognostic genes on ESCC progression. Based on these insights, we identified anti-tumor small-molecule compounds targeting these prognostic genes. This study primarily simulates the tumor microenvironment (TME) and antigen presentation processes in ESCC patients, predicting the role of the neoantigen-based prognostic model in ESCC patients and their potential responses to immunotherapy. These results suggest a potential approach for identifying therapeutic targets in ESCC, which may contribute to the development of more effective treatment strategies.

Future applications of cyclic antimicrobial peptides in drug delivery

INTRODUCTION

Cyclic antimicrobial peptides (CAMPs) are gaining attention as promising candidates in advanced drug delivery systems due to their structural stability, resistance to proteolytic degradation, and versatile therapeutic potential. Their unique properties enable applications that extend beyond combating multidrug-resistant (MDR) pathogens. Their amphipathic and cell-penetrating properties allow them to efficiently transport drugs across cellular membranes.

AREAS COVERED

This review explores the structural advantages and mechanisms of action of CAMPs, emphasizing their role in drug delivery. The literature analysis (2010-2024) from PubMed, Scopus, and Web of Science highlights developments in CAMP-conjugated therapies, liposomal formulations, and encapsulation systems. The review also examines their antimicrobial potency, amphipathic and cell-penetrating properties, and integration into nanocarrier technologies to enhance drug stability, bioavailability, and precision targeting. Challenges such as toxicity, scalability, and cost are also discussed. CAMPs have the potential to revolutionize drug delivery through their robustness and multifunctionality, particularly in precision medicine.

EXPERT OPINION

Future advancements in peptide engineering, nanotechnology, and AI-driven design are expected to enhance CAMPs' therapeutic specificity, reduce toxicity, and broaden their applications, including oncology and gene therapy, paving the way for their integration into next-generation therapeutics.

An alternative approach to combat multidrug-resistant bacteria: new insights into traditional Chinese medicine monomers combined with antibiotics

Antibiotic treatment is crucial for controlling bacterial infections, but it is greatly hindered by the global prevalence of multidrug-resistant (MDR) bacteria. Although traditional Chinese medicine (TCM) monomers have shown high efficacy against MDR infections, the inactivation of bacteria induced by TCM is often incomplete and leads to infection relapse. The synergistic combination of TCM and antibiotics emerges as a promising strategy to mitigate the limitations inherent in both treatment modalities when independently administered. This review begins with a succinct exploration of the molecular mechanisms such as the antibiotic resistance, which informs the antibiotic discovery efforts. We subsequently provide an overview of the therapeutic effects of TCM/antibiotic combinations that have been developed. Finally, the factors that affect the therapeutic outcomes of these combinations and their underlying molecular mechanisms are systematically summarized. This overview offers insights into alternative strategies to treat clinical infections associated with MDR bacteria and the development of novel TCM/antibiotic combination therapies, with the goal of guiding their appropriate usage and further development.

Mitigating Risk of Acute Kidney Injury Among Children With Methicillin-resistant Staphylococcus aureus Osteomyelitis

OBJECTIVE

Children with acute hematogenous osteomyelitis (AHO) from methicillin-resistant Staphylococcus aureus (MRSA) are treated with vancomycin despite the risk of acute kidney injury (AKI). This study evaluates the rate of AKI and resource utilization for children with or without AKI when vancomycin is used in this setting.

METHODS

Children with MRSA AHO treated with vancomycin were retrospectively studied. AKI was assessed by clinical diagnosis and Kidney Disease Improving Global Outcomes (KDIGO) criteria. Cohorts of children with or without AKI were compared for differences in treatment, resource utilization, and outcomes. Multivariate logistic regression analysis assessed factors associated with risk for AKI. Cost analysis was performed using the Pediatric Health Information System and Healthcare Cost and Utilization Project databases.

RESULTS

Among 85 children studied, 14 (16.5%) had chart-diagnosed AKI and 24 (28.2%) met KDIGO criteria. Children with AKI had more febrile days and higher thrombosis rates. They had longer vancomycin treatment (8 vs 5 d), higher troughs (27.8 vs 17.5 mg/L), and prolonged hospitalization (19.9 vs 11.1 d). Multivariate analysis found a maximum vancomycin trough level (odds ratio: 1.05, P = 0.003) with a cutoff of 21.7 mg/L predicted AKI.Only 2 of 20 (10%) children who had MRSA isolates with a minimum inhibitory concentration of 2 achieved therapeutic vancomycin levels. Pediatric Health Information System data of 3133 children with AHO treated with vancomycin identified 75 (2.4%) with AKI who had significantly longer lengths of stay (13 vs 7 d) and higher billed charges ($117K vs $51K) than children without AKI.

CONCLUSIONS

Chart documentation of AKI (16.5%) grossly underestimated KDIGO-defined occurrence (28.2%). This study showed that vancomycin-associated AKI required substantially greater resource utilization and higher health care costs. Lowering the targeted trough range, shortening the duration of vancomycin therapy, and considering alternative antibiotics when minimum inhibitory concentration ≥2 will reduce the risk and cost of AKI among children with MRSA AHO.

LEVEL OF EVIDENCE

Level III-retrospective comparative therapeutic study.

Impact of vancomycin area under the curve in early or later phase on efficacy and nephrotoxicity in patients with enterococcal bloodstream infections: a multicenter study

BACKGROUND

The optimal pharmacokinetic and pharmacodynamic (PK/PD) parameters of vancomycin that can improve outcomes in enterococcal infections remain controversial. To clarify the therapeutic target for this antibiotic, this study aimed to determine vancomycin PK/PD parameters associated with efficacy in the early (during 72 h) or later (after 72 h) phase of treatment and nephrotoxicity in enterococcal bloodstream infection patients.

METHODS

This multicenter retrospective study reviewed medical records of patients with enterococcal bloodstream infections treated with intravenous vancomycin infusion for at least 72 h between January 2016 and March 2024 at Phramongkutklao Hospital or Nopparatrajathanee Hospital in Bangkok, and Rachaburi Hospital in Rachaburi Province, Thailand. Patients with data available on serum vancomycin concentration were analyzed. The primary outcomes were 30-day mortality and acute kidney injury. The estimates of the mean 24-h area under the curve in the first 72 h (AUC24) and in steady state (AUCss) were determined by Bayesian theorem.

RESULTS

Overall, 201 vancomycin concentrations were measured within the first 72 h after vancomycin treatment, while 156 were in a steady state (> 72 h). According to Classification and Regression Tree analysis, vancomycin AUC at 420 mg·h/l was the PK/PD target for 30-day mortality. Results reveal that patients with AUC24 (early phase) and AUCss < 420 mg·h/l (later phase) had significantly higher 14-day, 30-day, and in-hospital mortality than AUC ≥ 420 mg·h/l groups. In addition, patients with AUC24 ≥ 420 mg·h/l in the early phase had significantly reduced microbiological failure (p = 0.004). Patients with AUC ≥ 700 mg·h/l in early and later phases had significantly increased acute kidney injury risk. In addition, patients receiving concomitant nephrotoxic drugs had an AUC cutoff value of 650 mg·h/l. Multivariate Cox regression analysis showed that vancomycin AUCss < 420 mg·h/l, unknown source of bacteremia, and acute kidney injury were significantly associated with 30-day mortality.

CONCLUSIONS

AUC 420-650 mg·h/l in early and later phases was the target of vancomycin's PK/PD in enterococcal bacteremia patients for efficacy and to prevent acute kidney injury. This study suggests close monitoring of vancomycin levels to ensure efficacy and safety.

Cyclic peptides: A powerful instrument for advancing biomedical nanotechnologies and drug development

Cyclic peptides have emerged as an essential tool in the advancement of biomedical nanotechnologies, offering unique structural and functional advantages over linear peptides. This review article aims to highlight the roles of cyclic peptides in the development of biomedical fields, with a particular focus on their application in drug discovery and delivery. Cyclic peptides exhibit exceptional stability, bioavailability, and binding specificity, making them ideal candidates for therapeutic and diagnostic applications. We explore the synthesis and design strategies that enable the precise control of cyclic peptide structures, leading to enhanced performance in targeting specific cellular pathways. The article also highlights recent breakthroughs in the use of cyclic peptides for creating innovative drug delivery systems, including nanoparticle conjugates and peptide-drug conjugates, which have shown promise in improving the efficacy and safety profiles of existing traditional treatments. The integration of cyclic peptides into nanotechnological frameworks holds significant promise for addressing unmet medical needs, providing a foundation for future advancements in personalized medicine and targeted drug delivery.

Intra-articular injection of vancomycin after arthrotomy closure following gentamicin-impregnated bone cementation in primary total knee arthroplasty provides a high intra-articular concentration while avoiding systemic toxicity: a prospective study

BACKGROUND

This study aimed to elucidate the safety and intra-articular elution profiles of vancomycin and gentamicin bone cement in patients undergoing primary total knee arthroplasty (TKA), with a focus on serum safety thresholds and therapeutic efficacy.

METHODS

Consecutive patients who underwent unilateral primary TKA were prospectively enrolled. The implants were fixed using gentamicin-impregnated bone cement, and after arthrotomy closure, 1000 mg of vancomycin suspended in 25 mL of normal saline was directly injected into the joint. Peripheral venous blood and drain fluid samples were collected 2, 8, and 24 h postoperatively. The serum and intra-articular concentrations of vancomycin and gentamicin were analyzed using liquid chromatography-tandem mass spectrometry within 24 h.

RESULTS

Clinical data reflecting renal and liver function were recorded preoperatively, and at 24 and 72 h postoperatively. A total of 100 patients were included. At 2, 8, and 24 h postoperatively, the serum vancomycin concentration was 7.0 ± 2.0, 5.7 ± 1.8, and 3.6 ± 1.4 µg/mL, respectively, while the intra-articular concentration was 468.5 (interquartile range [IQR] 286.0 to 774.8), 139.5 (IQR 52.0 to 295.3), and 34.4 (IQR 22.2 to 56.8) µg/mL, respectively; 33.2 (IQR 19.5 to 80.5) mg vancomycin was lost in drainage fluid at 24 h postoperatively. For gentamicin, the overall intra-articular concentration was 70.4 (IQR 35.4 to 109.2), 33.8 (IQR 17.8 to 73.9), and 21.1 (IQR 12.2 to 36.0) µg/mL at 2, 8, and 24 h postoperatively, respectively, with an undetectable serum concentration. No cases of acute renal injury, liver injury, ototoxicity, or anaphylaxis were observed.

CONCLUSIONS

Intra-articular injection of 1000 mg vancomycin after arthrotomy closure combined with gentamicin-impregnated bone cement provided a therapeutic intra-articular concentration while avoiding systemic toxicity over the initial 24 h after primary TKA. Therefore, intra-articular vancomycin administration may offer a safer alternative to intravenous antibiotics, reducing systemic toxicity; however, further large-scale studies are necessary.

TRIAL REGISTRATION

ClinicalTrials. Gov (registration number: NCT05338021).

Impact of vancomycin therapeutic drug monitoring on mortality in sepsis patients across different age groups: a propensity score-matched retrospective cohort study

Background

Due to its potent antibacterial activity, vancomycin is widely used in the treatment of sepsis. Therapeutic drug monitoring (TDM) can optimize personalized vancomycin dosing regimens, enhancing therapeutic efficacy and minimizing nephrotoxic risk, thereby potentially improving patient outcomes. However, it remains uncertain whether TDM affects the mortality rate among sepsis patients or whether age plays a role in this outcome.

Methods

We analyzed data from the Medical Information Mart of Intensive Care-IV database, focusing on sepsis patients who were admitted to the intensive care unit (ICU) and treated with vancomycin. The primary variable of interest was the use of vancomycin TDM during the ICU stay. The primary outcome was 30-day mortality. To control for potential confounding factors and evaluate associations, we used Cox proportional hazards regression and propensity score matching (PSM). Subgroup and sensitivity analyses were performed to assess the robustness of our findings. Furthermore, restricted cubic spline models were utilized to investigate the relationship between age and mortality among different groups of sepsis patients, to identify potential non-linear associations.

Results

A total of 14,053 sepsis patients met the study criteria, of whom 6,826 received at least one TDM during their ICU stay. After PSM, analysis of 4,329 matched pairs revealed a significantly lower 30-day mortality in the TDM group compared with the non-TDM group (23.3% vs.27.7%, p < 0.001). Multivariable Cox proportional hazards regression showed a significantly reduced 30-day mortality risk in the TDM group [adjusted hazard ratio (HR): 0.66; 95% confidence interval (CI): 0.61-0.71; p < 0.001]. This finding was supported by PSM-adjusted analysis (adjusted HR: 0.71; 95% CI: 0.66-0.77; p < 0.001) and inverse probability of treatment weighting analysis (adjusted HR: 0.72; 95% CI: 0.67-0.77; p < 0.001). Kaplan-Meier survival curves also indicated significantly higher 30-day survival in the TDM group (log-rank test, p < 0.0001). Subgroup analyses by gender, age, and race yielded consistent results. Patients with higher severity of illness-indicated by sequential organ failure assessment scores ≥6, acute physiology score III ≥40, or requiring renal replacement therapy, vasopressors, or mechanical ventilation-experienced more pronounced mortality improvement from vancomycin TDM compared with those with lower severity scores or not requiring these interventions. The results remained robust after excluding patients with ICU stays <48 h, those with methicillin-resistant Staphylococcus aureus infections, or when considering only patients with septic shock. In subgroup analyses, patients under 65 years (adjusted HR: 0.50; 95% CI: 0.43-0.58) benefited more from vancomycin TDM than those aged 65 years and older (adjusted HR: 0.75; 95% CI: 0.67-0.83). Notably, sepsis patients aged 18-50 years had the lowest mortality rate among all age groups, at 15.2% both before and after PSM. Furthermore, in this age group, vancomycin TDM was associated with a greater reduction in 30-day mortality risk, with adjusted HRs of 0.32 (95% CI: 0.24-0.41) before PSM and 0.30 (95% CI: 0.22-0.32) after PSM.

Conclusion

Vancomycin TDM is associated with reduced 30-day mortality in sepsis patients, with the most significant benefit observed in patients aged 18-50. This age group exhibited the lowest mortality rates and experienced the greatest reduction in mortality following TDM compared with older patients.

Clinical Efficacy and Safety of Vancomycin Based on Unbound Vancomycin Concentration Monitoring

OBJECTIVE

To monitor total trough concentration (Cmin_total) and unbound trough concentration (Cmin_free) of vancomycin in clinical samples and analyze the factors influencing them, and to assess their correlation with clinical efficacy and acute kidney injury (AKI).

METHODS

Plasma samples were processed by protein precipitation, followed by hollow-fiber centrifugal ultrafiltration to separate unbound vancomycin from plasma. Thereafter, Cmin_total and Cmin_free were determined using high-performance liquid chromatography. Clinical data of patients were collected. Factors affecting vancomycin Cmin_total, Cmin_free, and their correlation with clinical efficacy and nephrotoxicity were investigated.

RESULTS

A total of 146 samples from 105 included patients were collected. Cmin_total and Cmin_free of vancomycin ranged from 0.62 to 56.08 mcg·mL-1 and 0.61-38.51 mcg·mL-1, respectively. Cmin_total and Cmin_free were correlated (r = 0.8899), influenced by basal creatinine and cystatin C. Higher level of Cmin_free (˃8.6 mcg·mL-1) and nephrotoxic drugs concomitant were risk factors of vancomycin-associated AKI (P < 0.05); Cmin_total and Cmin_free thresholds of vancomycin-associated AKI were 15.35 and 6.83 mcg·mL-1, respectively.

CONCLUSIONS

vancomycin Cmin_total and Cmin_free, higher Cmin_total and Cmin_free were correlated and higher concentrations of both may increase the risk of AKI.

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 AUC0-24h/MIC ≥ 331. The trough concentration was correlated with AUC0-24h/MIC (r2 = 0.32), but individual differences existed. AUC0-24h/MIC ranged up to 2.5-fold for a given trough concentration.

CONCLUSIONS

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

Monitoring vancomycin blood concentrations reduces mortality risk in critically ill patients: a retrospective cohort study using the MIMIC-IV database

Background

The incidence and mortality of severe Gram-positive cocci infections are particularly high in intensive care units (ICUs). Vancomycin remains the treatment of choice for severe infections caused by Gram-positive cocci, particularly methicillin-resistant Staphylococcus aureus (MRSA). Some guidelines recommend therapeutic drug monitoring (TDM) for critically ill patients treated with vancomycin; however, there is currently a lack of evidence to support that TDM improves the mortality rates of these patients. Therefore, we designed this cohort study to compare the impact of monitoring vancomycin blood concentrations on mortality rates in critically ill patients and to provide evidence to support this routine clinical practice.

Methods

Data were extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV database for a retrospective cohort analysis of critically ill patients receiving intravenous vancomycin treatment. The primary outcome was the 28 day mortality rate. The propensity score matching (PSM) method was used to match the baseline characteristics between patients in the TDM group and the non-TDM group. The relationship between 28 day mortality and vancomycin TDM in the critically ill cohort was evaluated using Cox proportional hazards regression analysis and Kaplan-Meier survival curves. Validation of the primary outcomes was conducted by comparing the PSM model and the Cox proportional hazards regression model. The robustness of the conclusion was subsequently verified by subgroup and sensitivity analyses.

Results

Data for 18,056 critically ill patients who met the study criteria were collected from the MIMIC-IV database. Of these, 7,451 patients had at least one record of vancomycin blood concentration monitoring, which we defined as the TDM group. The TDM group exhibited a 28 day mortality rate of 25.7% (1,912/7,451) compared to 16.2% in the non-TDM group (1,723/10,605). After PSM, 4,264 patients were included in each of the TDM and non-TDM groups, with a 28 day mortality rate of 20.0% (1,022/4,264) in the TDM group and 26.4% (1,126/4,264) in the non-TDM group. Multivariate Cox proportional hazards analysis revealed a significantly lower 28 day mortality risk in the TDM group when compared to the non-TDM group (adjusted hazard ratio [HR]: 0.86; 95% confidence interval [CI]: 0.79, 0.93; p < 0.001). Further PSM analyses (adjusted HR: 0.91; 95% CI: 0.84, 0.99; p = 0.033) confirmed the lower risk of mortality in the TDM group. Kaplan-Meier survival analysis revealed a significantly higher survival rate at 28 days for the TDM group (log-rank test, p < 0.001). Subgroup analysis results indicated that patients with sepsis, septic shock, estimated glomerular filtration rate ≤ 60 mL/min/1.73 m2, undergoing renal replacement therapy, using vasoactive drugs, on mechanical ventilation, and those with higher severity scores (Acute Physiology Score III ≥40, Oxford Acute Severity of Illness Score ≥30, Simplified Acute Physiology Score II ≥ 30) significantly benefited from monitoring vancomycin blood concentrations. The results remained unchanged excluding patients staying in ICU for less than 48 h or those infected with MRSA.

Conclusion

This cohort study showed that monitoring vancomycin blood concentrations is associated with a significantly lower 28 day mortality rate in critically ill patients, highlighting the importance of routinely performing vancomycin TDM in these patients.

Vancomycin in Pediatric Patients with Cystic Fibrosis: Dose Optimization Using Population Pharmacokinetic Approach

BACKGROUND

An increase in Staphylococcus aureus infections has been reported in pediatric patients with cystic fibrosis (CF) over the last few years. This pathogen is commonly treated with vancomycin, an antibiotic for which therapeutic drug monitoring (TDM) is recommended. Updated guidelines were recently published regarding new targets of exposure for the TDM of vancomycin through a Bayesian approach, using population pharmacokinetic (popPK) models.

OBJECTIVES

This study aims to assess the predictive performance of vancomycin popPK models in pediatric patients with CF and to recommend optimal initial dosing regimens based on simulations.

METHODS

Patient data were collected from two centers in Canada, and a literature review was conducted to identify all published vancomycin popPK models for pediatric CF patients. External evaluation and simulations were performed according to patient and occasion of treatment.

RESULTS

A total of 53 vancomycin concentrations were collected from six pediatric CF patients. Only two popPK models of vancomycin for pediatric CF patients were identified through the literature review. The external evaluation results for both centers combined revealed a population bias of 28.1% and an imprecision of 33.7%. A re-estimation of parameters was performed to improve predictive performance. The optimal initial dosing regimen was 15 mg/kg/dose administered every 6 hours according to the per occasion remodel.

CONCLUSION

The predictive performance and identified optimal initial dosing regimens associated with the model were different depending on the data used, showing external evaluation's importance before implementing a model in clinical practice.

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.

[Potential Nephrotoxicity of Combination of Vancomycin and Piperacillin-Tazobactam: Recommendations from the AG ABS of the DGPI supported by experts of the GPN]

The combination of vancomycin and piperacillin/tazobactam (V+P/T) is used for empirical antibiotic treatment of severe infections, especially in immunocompromised patients and those colonized with multidrug-resistant bacteria. Nephrotoxicity is a frequently observed adverse effect of vancomycin. Its risk can be reduced by therapeutic drug monitoring and adjusted dosing. Piperacillin/tazobactam (P/T) rarely causes interstitial nephritis. The results of retrospective cohort studies in children predominantly show a low, clinically irrelevant, additive nephrotoxicity (defined as an increase in creatinine in the serum) of both substances. Due to the limitations of the existing publications, the ABS working group of the DGPI and experts of the GPN do not recommend against the use of P/T plus vancomycin. Preclinical studies and a prospective study with adult patients, which evaluated different renal function tests as well as clinical outcomes, do not support previous findings of additive nephrotoxicity. Time-restricted use of V+P/T can minimize exposure and the potential risk of nephrotoxicity. Local guidelines, developed in collaboration with the antibiotic stewardship team, should define the indications for empirical and targeted use of P/T and V+P/T. When using combination therapy with V+P/T, kidney function should be monitored through clinical parameters (volume status, balancing, blood pressure) as well as additional laboratory tests such as serum creatinine and cystatin C.

Development and validation of a nomogram to predict the risk of vancomycin-related acute kidney injury in critical care patients

Background

Vancomycin-associated acute kidney injury (AKI) leads to underestimated morbidity in the intensive care unit (ICU). It is significantly important to predict its occurrence in advance. However, risk factors and nomograms to predict this AKI are limited.

Methods

This was a retrospective analysis of two databases. A total of 1,959 patients diagnosed with AKI and treated with vancomycin were enrolled from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. According to the 7:3 ratio, the training set (n = 1,372) and the internal validation set (n = 587) were randomly allocated. The external validation set included 211 patients from the eICU Collaborative Research Database (eICU). Next, to screen potential variables, the least absolute shrinkage and selection operator (LASSO) regression was utilized. Subsequently, the nomogram was developed by the variables of the selected results in the multivariable logistic regression. Finally, discrimination, calibration, and clinical utility were evaluated to validate the nomogram.

Results

The constructed nomogram showed fine discrimination in the training set (area under the receiver operator characteristic curve [AUC] = 0.791; 95% confidence interval [CI]: 0.758-0.823), internal validation set (AUC = 0.793; 95% CI: 0.742-0.844), and external validation set (AUC = 0.755; 95% CI: 0.663-0.847). Moreover, it also well demonstrated calibration and clinical utility. The significant improvement (P < 0.001) in net reclassification improvement (NRI) and integrated differentiation improvement (IDI) confirmed that the predictive model outperformed others.

Conclusion

This established nomogram indicated promising performance in determining individual AKI risk of vancomycin-treated critical care patients, which will be beneficial in making clinical decisions.

Recommended doses of endovenous vancomycin are insufficient to achieve therapeutic concentrations in paediatric patients

OBJECTIVES

Vancomycin therapeutic drug monitoring is challenging, especially in the paediatric population where evidence is scarce. The main objective of this study was to analyse the achievement of therapeutic concentrations of vancomycin in paediatric patients and to evaluate the current monitoring method (trough levels), doses used, and the time required to achieve target concentrations.

METHODS

Paediatric patients on treatment and monitored with vancomycin from November 2019 to December 2021 were included. Those with only one determination of serum vancomycin concentration were excluded. Demographic variables, analytical and microbiological parameters and toxicity data were collected. Pharmacokinetic parameters were assessed at baseline and during treatment.

RESULTS

225 patients (40.9% female; 108 neonates, 49 infants and 68 children or adolescents) were included in the study. The main indications for vancomycin treatment were sepsis (33.9%) and fever of unknown origin (29.3%). Microbiological cultures were positive in 71.1%, mostly with Gram-positive bacteria (60.4%). Therapeutic levels of vancomycin were reached in only 20.1% of the participants in the first determination. After pharmacokinetic monitoring, 81.7% of patients reached therapeutic concentrations, requiring a 23% increase in the initial dose, a 2-day lag time and 1-2 dosage adjustments until the therapeutic concentration was reached. Of the total patients, 13 developed nephrotoxicity, nine neutropenia and one patient developed red man syndrome.

CONCLUSIONS

In our sample of paediatric patients, the recommended doses of vancomycin were insufficient to achieve therapeutic concentrations. Revision of the recommendations and/or a change in the method of pharmacokinetic monitoring is crucial to optimise treatment in this population.

Determining steady-state trough range in vancomycin drug dosing using machine learning

BACKGROUND

Vancomycin is a renally eliminated, nephrotoxic, glycopeptide antibiotic with a narrow therapeutic window, widely used in intensive care units (ICU). We aimed to predict the risk of inappropriate vancomycin trough levels and appropriate dosing for each ICU patient.

METHODS

Observed vancomycin trough levels were categorized into sub-therapeutic, therapeutic, and supra-therapeutic levels to train and compare different classification models. We included adult ICU patients (≥ 18 years) with at least one vancomycin concentration measurement during hospitalization at Mayo Clinic, Rochester, MN, from January 2007 to December 2017.

RESULT

The final cohort consisted of 5337 vancomycin courses. The XGBoost models outperformed other machine learning models with the AUC-ROC of 0.85 and 0.83, specificity of 53% and 47%, and sensitivity of 94% and 94% for sub- and supra-therapeutic categories, respectively. Kinetic estimated glomerular filtration rate and other creatinine-based measurements, vancomycin regimen (dose and interval), comorbidities, body mass index, age, sex, and blood pressure were among the most important variables in the models.

CONCLUSION

We developed models to assess the risk of sub- and supra-therapeutic vancomycin trough levels to improve the accuracy of drug dosing in critically ill patients.

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.

Whole blood multiplex measurements using electrochemical aptamer-based biosensors

Simultaneous measurements of various molecules ("multiplex") using electrochemical biosensors typically require multiple electrode implementations, which for neonates, hemophiliacs, etc. is problematic. Here, we introduce the oxazine ATTO 700 into electrochemical aptamer-based biosensors to achieve "true" multiplex, continuous and real-time measurements of two different molecules in undiluted whole blood using a single electrode.

In Vitro Performance of a Long-Range Surface Plasmon Hydrogel Aptasensor for Continuous and Real-Time Vancomycin Measurement in Human Serum

This study investigated the suitability of surface modification for a long-range surface plasmon (LRSP) aptasensor using two different hydrogels, aiming at real-time monitoring of vancomycin (VCM) in undiluted serum and blood. Three different layer structures were formed on a gold surface of LRSP sensor chip using poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-N-methacryloyl-(L)-tyrosinemethylester (MAT)] (PMM) and poly[MPC-co-2-ethylhexyl methacrylate (EHMA)-co-MAT] (PMEM). The peptide aptamer for VCM was immobilized in PMM and PMEM via MAT. Among four differently prepared sensor chips, the LRSP hydrogel aptasensor with PMM, referred to as the PMM hydrogel, exhibited the highest sensor output and superior antifouling properties. Following the optimization of the PMM hydrogel preparation conditions, the shelf life of the PMM hydrogel was determined to exceed 2 weeks, and the same sensor chip could be used for 102 days without significant performance deterioration. The PMM hydrogel was then applied for VCM measurement in undiluted serum in vitro, where it demonstrated a limit of detection of 0.098 μM and a dynamic range of 0.18-100 μM, covering the therapeutic range. Additionally, the PMM hydrogel enabled the continuous measurement of various VCM concentrations in serum without rinsing and showed a concentration-dependent output in undiluted blood. These findings underscore the potential of the PMM hydrogel for real-time and direct monitoring of VCM in body fluids.

Implementation of vancomycin AUC/MIC dosing vs traditional trough dosing and incidence of acute kidney injury at a rural community hospital

PURPOSE

Vancomycin treats methicillin-resistant Staphylococcus aureus infections in hospitalized patients, yet nephrotoxicity is a major risk. Dosing based on the ratio of vancomycin 24-hour area under the curve to minimum inhibitory concentration (AUC/MIC) is preferred over a trough-only vancomycin dosing approach to minimize the risk of acute kidney injury (AKI). This study compares the safety of AUC/MIC-guided and trough-only vancomycin dosing at a 255-bed hospital.

METHODS

A retrospective cohort study of adult patients with stable renal function who received at least 3 days of intravenous vancomycin via either AUC/MIC or trough-only dosing was conducted. The primary outcome was AKI occurrence during treatment. Secondary outcomes included the frequencies of therapeutic, subtherapeutic, and supratherapeutic vancomycin troughs. Relative risk calculations were performed for all outcomes.

RESULTS

600 patients from the trough-only group and 561 patients from the AUC/MIC group were included. 121 patients from the trough-only group and 87 patients from the AUC/MIC group experienced AKI during treatment (relative risk [RR], 0.769; 95% CI, 0.599-0.988; P = 0.0397). Compared with the trough-only group, the AUC/MIC group was significantly less likely to have supratherapeutic troughs (RR, 0.703; 95% CI, 0.611-0.809; P < 0.0001) and significantly more likely to have therapeutic troughs (RR, 1.14; 95% CI, 1.069-1.211; P < 0.0001), with no significant between-group difference in subtherapeutic troughs (RR, 1.03; 95% CI, 0.854-1.25; P = 0.74).

CONCLUSION

AUC/MIC dosing was associated with significantly lower risk of AKI, a lower risk of supratherapeutic trough levels, and a higher risk of therapeutic trough levels, with no significant difference in subtherapeutic troughs when compared to trough-only dosing. Limitations of this study included its retrospective nature and reliance on manual chart review.

Preparation Times and Estimated Costs for Vancomycin Formulations: Does the Difference Matter?

Objective Infections from methicillin-resistant Staphylococcus aureus are increasingly treated in longterm care facilities, but long-term care pharmacies face high costs in the provision of sterile vancomycin for intravenous administration. This study compares pharmaceutical costs of outsourced, compounded, and room temperature premixed vancomycin formulations in a long-term care pharmacy. Design This retrospective observational study reviewed 124 orders of vancomycin. Means for total pharmacy preparation time, pharmacist labor time, and extrapolated time over complete course of treatment were compared for three vancomycin preparations: outsourced, compounded by pharmacy, and room temperature premixed vancomycin formulations. Cost calculations were generated using ingredient costs as reported by the pharmacy and median pharmacist labor costs as published from national sources. Results Mean total preparation times and pharmacist preparation times were shortest for premixed vancomycin. Over full courses of treatment, mean pharmacy preparation time for compounded was 5 hours 3 minutes (mean of 28 treatments) and 2 hours 8 minutes for premixed (mean of 54 treatments). Data on pharmacist time in outsourced orders were not available. Total pharmacy costs were $993.94 for compounded vancomycin, $2220.34 for outsourced, and $809.36 for room temperature premixed vancomycin. Conclusion There were reduced preparation times for room temperature premixed vancomycin compared with compounded and outsourced formulations for skilled nursing facilities. As multiple drug-resistant organism infections are increasingly treated in long-term care, finding cost-effective approaches to medication provision from pharmacies is critical.

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.

Measuring and improving the timeliness of vancomycin therapeutic drug monitoring and potential patient safety impacts

Background

Timely vancomycin therapeutic drug monitoring (TDM) enables prompt dose adjustments and safe treatment. Local incidents prompted an investigation into the reasons for prolonged reporting times.

Objectives

To investigate the variation in reporting times of vancomycin concentrations between hospitals with and without on-site TDM processing, and patient safety implications.

Methods

Vancomycin concentration results for Hospital 1 (off-site monitoring), Hospitals 2 and 3 (both on-site monitoring) from June to December 2021 were retrospectively analysed. Retrospective data collection was repeated for Hospital 1 three months post on-site TDM commencement for comparison. Vancomycin clinical incidents at Hospital 1 were reviewed to identify examples of when delays in reporting of results potentially contributed towards adverse patient outcomes.

Results

Hospital 1 had a median reporting time of 11.13 h compared with Hospital 2 and Hospital T3 (1.73 h and 1.70 h respectively). Following the commencement of on-site TDM at Hospital 1, the reporting time reduced to 1.33 h (p < 0.001). Several incidents at Hospital 1 during the period of off-site monitoring involved delays to TDM results.

Conclusions

Off-site processing of TDM introduced significant delays in reporting of vancomycin concentrations, which was significantly improved by transitioning to onsite availability of testing. This study also highlights the impact of accurate problem identification in improving patient safety.

Association of piperacillin and vancomycin exposure on acute kidney injury during combination therapy

Objectives

Acute kidney injury (AKI) is a well-documented adverse effect observed with piperacillin/tazobactam in combination with vancomycin. The pharmacokinetics of these antibiotics when given in combination have not been previously evaluated. The purpose of this study was to compare the exposure of vancomycin + piperacillin/tazobactam in patients with and without AKI.

Methods

Ninety adult patients, who received at least 72 h of vancomycin + piperacillin/tazobactam combination therapy and had available serum concentrations of vancomycin and piperacillin were included in the study. Nephrotoxicity was defined as a 1.5-fold increase in serum creatinine within 7 days from baseline. Median daily AUCs were calculated in those with nephrotoxicity (vancomycin + piperacillin/tazobactam 'N') versus those without nephrotoxicity (vancomycin + piperacillin/tazobactam 'WN') during the first 7 days of combination therapy.

Results

The overall incidence of AKI in those receiving vancomycin + piperacillin/tazobactam was 20% (18/90). The median daily vancomycin AUCs did not differ between the vancomycin + piperacillin/tazobactam 'WN' and vancomycin + piperacillin/tazobactam 'N' groups. Although not statistically significant, the median daily vancomycin AUCs in the vancomycin + piperacillin/tazobactam 'N' group were numerically greater on Day 5 and trended downwards thereafter. For the piperacillin group, the median daily AUCs did not vary between groups, except on Day 7 where the vancomycin + piperacillin/tazobactam 'WN' group had statistically greater median piperacillin AUC than the vancomycin + piperacillin/tazobactam 'N' group (P = 0.046).

Conclusions

Utilizing serum creatinine-defined AKI, our study did not find any significant differences in vancomycin and piperacillin/tazobactam exposure between the groups with and without nephrotoxicity. These data indicate that vancomycin + piperacillin/tazobactam should not be avoided due to the risk of overexposure; instead, clinicians should continue to use these therapies cautiously.

Enterococci, Van Gene-Carrying Enterococci, and Vancomycin Concentrations in the Influent of a Wastewater Treatment Plant in Southeast Germany

Vancomycin-resistant (VR) Enterococcus spp. can be detected in high concentrations in wastewaters and pose a risk to public health. During a one-year study (September 2022-August 2023), 24 h composite raw wastewater samples (n = 192) of a municipal wastewater treatment plant were investigated for cultivable enterococci. After growth on Slanetz-Bartley agar (SBA), a mean concentration of 29,736 ± 9919 cfu/mL was calculated. Using MALDI-TOF MS to characterize randomly picked colonies (n = 576), the most common species were found to be Enterococcus faecium (72.6%), E. hirae (13.7%), and E. faecalis (8.0%). Parallel incubation of wastewater samples on SBA and VRESelect agar resulted in a mean rate of VR enterococci of 2.0 ± 1.5%. All the tested strains grown on the VRESelect agar (n = 172) were E. faecium and carried the vanA (54.6%) or vanB gene (45.4%) with limited sequence differences. In susceptibility experiments, these isolates showed a high-level resistance to vancomycin (>256 µg/mL). Concentration of vancomycin was determined in 93.7% of 112 wastewater samples (mean: 123.1 ± 64.0 ng/L) and varied between below 100 ng/L (the detection limit) and 246.6 ng/L. A correlation between the concentration of vancomycin and the rate of VR strains among the total enterococci could not be found. The combination of incubation of samples on SBA and a commercial vancomycin-containing agar applied in clinical microbiology with a multiplex PCR for detection of van genes is an easy-to-use tool to quantify and characterize VR Enterococcus spp. in water samples.

Serum concentration of continuously administered vancomycin influences efficacy and safety in critically ill adults: a systematic review

OBJECTIVES

Vancomycin is used to treat Gram-positive infections in critically ill adults. For vancomycin administered by continuous infusion (CI), various target ranges have been used, ranging from 15-20 mg/L to 30-40 mg/L. This systematic literature review was conducted to investigate the impact of steady-state serum concentration (Css) of CI on safety and efficacy of therapy in critically ill adults.

METHODS

Relevant literature was identified by searching two electronic databases (PubMed, Cochrane Library) and Google Scholar from inception until July 2023, focusing on studies reporting measured Css and treatment outcomes (e.g. mortality, nephrotoxicity) with CI. Due to study heterogeneity, a narrative synthesis of the evidence was performed.

RESULTS

Twenty-one publications were included with a total of 2949 patients. Mortality was higher (two studies, n = 388 patients) and clinical cure was lower (one study, n = 40 patients) with Css < 15 mg/L measured 24 h after initiation of CI (C24). An adequate loading dose appeared most important for maintaining higher C24. Generally, higher Css was associated with higher rates of acute kidney injury (AKI) (15 studies, n = 2331 patients). It was calculated that Css < 25 mg/L (versus ≥25 mg/L) was preferable for reducing nephrotoxicity (three studies, n = 515 patients).

CONCLUSIONS

Despite sparse data availability, the target range of 15-25 mg/L in CI may increase clinical cure and reduce mortality and AKI. In future research, vancomycin Css cohorts should be formed to allow evaluation of the impact of Css of CI on treatment outcomes.

Machine learning in medication prescription: A systematic review

BACKGROUND

Medication prescription is a complex process that could benefit from current research and development in machine learning through decision support systems. Particularly pediatricians are forced to prescribe medications "off-label" as children are still underrepresented in clinical studies, which leads to a high risk of an incorrect dose and adverse drug effects.

METHODS

PubMed, IEEE Xplore and PROSPERO were searched for relevant studies that developed and evaluated well-performing machine learning algorithms following the PRISMA statement. Quality assessment was conducted in accordance with the IJMEDI checklist. Identified studies were reviewed in detail, including the required variables for predicting the correct dose, especially of pediatric medication prescription.

RESULTS

The search identified 656 studies, of which 64 were reviewed in detail and 36 met the inclusion criteria. According to the IJMEDI checklist, five studies were considered to be of high quality. 19 of the 36 studies dealt with the active substance warfarin. Overall, machine learning algorithms based on decision trees or regression methods performed superior regarding their predictive power than algorithms based on neural networks, support vector machines or other methods. The use of ensemble methods like bagging or boosting generally enhanced the accuracy of the dose predictions. The required input and output variables of the algorithms were considerably heterogeneous and differ strongly among the respective substance.

CONCLUSIONS

By using machine learning algorithms, the prescription process could be simplified and dosing correctness could be enhanced. Despite the heterogenous results among the different substances and cases and the lack of pediatric use cases, the identified approaches and required variables can serve as an excellent starting point for further development of algorithms predicting drug doses, particularly for children. Especially the combination of physiologically-based pharmacokinetic models with machine learning algorithms represents a great opportunity to enhance the predictive power and accuracy of the developed algorithms.

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.

Renogrit attenuates Vancomycin-induced nephrotoxicity in human renal spheroids and in Sprague-Dawley rats by regulating kidney injury biomarkers and creatinine/urea clearance

Vancomycin, is widely used against methicillin-resistant bacterial infections. However, Vancomycin accumulation causes nephrotoxicity which leads to an impairment in the filtration mechanisms of kidney. Traditional herbal medicines hold potential for treatment of drug-induced nephrotoxicity. Herein, we investigated protective properties of plant-based medicine Renogrit against Vancomycin-induced kidney injury. Phytometabolite analysis of Renogrit was performed by UHPLC. Spheroids formed from human proximal tubular cell (HK-2) were used for in vitro evaluation of Vancomycin-induced alterations in cell viability, P-gp functionality, NAG, KIM-1 levels, and mRNA expression of NGAL and MMP-7. The in vivo efficacy of Renogrit against Vancomycin-induced nephrotoxicity was further evaluated in Sprague-Dawley (SD) rats by measurement of BUN, serum creatinine, and their respective clearances. Moreover, eGFR, kidney-to-body weight ratio, GSH/GSSG ratio, KIM-1, NAG levels and mRNA expression of KIM-1 and osteopontin were also analyzed. Changes in histopathology of kidney and hematological parameters were also observed. Renogrit treatment led to an increase in cell viability, normalization of P-gp functionality, decrease in levels of NAG, KIM-1, and reduction in mRNA expression of NGAL and MMP-7. In Vancomycin-challenged SD rats, Renogrit treatment normalized altered kidney functions, histological, and hematological parameters. Our findings revealed that Renogrit holds a clinico-therapeutic potential for alleviating Vancomycin-associated nephrotoxicity.

Rapid Colloidal Gold Immunoassay for Pharmacokinetic Evaluation of Vancomycin in the Cerebrospinal Fluid and Plasma of Beagle Dogs

Vancomycin (VAN), a glycopeptide antibiotic, is the preferred therapeutic agent for treating Gram-positive bacteria. Rapid and precise quantification of VAN levels in cerebrospinal fluid (CSF) and plasma is crucial for optimized drug administration, particularly among elderly patients. Herein, we introduce a novel clinical test strip utilizing colloidal gold competitive immunoassay technology for the expedient detection of VAN. This test strip enables the detection of VAN concentrations in clinical samples such as plasma within 10 min and has a limit of detection of 10.3 ng/mL, with an inhibitory concentration 50% (IC50) value of 44.5 ng/mL. Furthermore, we used the test strip for pharmacokinetic analysis of VAN in the CSF and plasma of beagle dogs. Our results provide valuable insights into the fluctuations of the drug concentration in the CSF and plasma over a 24 h period after a single intravenous dose of 12 mg/kg. The test strip results were compared with the results obtained via liquid chromatography-mass spectrometry methods, and the measured VAN concentrations in the CSF and plasma via both of the methods showed excellent agreement.

Intraarticular vancomycin decreased the risk of acute postoperative periprosthetic joint infection without increasing complication in primary total joint arthroplasty-a prospective study

OBJECTIVES

To investigate the preventive effect of intraarticularly administered vancomycin on acute postoperative periprosthetic joint infection (PJI) in total joint arthroplasty (TJA).

METHODS

Consecutive patients who underwent unilateral primary TJA were prospectively enrolled. The patients were divided into vancomycin group and control group according to whether 1 g of vancomycin powder suspended in 30 ml normal saline was intraarticularly administered after arthrotomy closure. Acute postoperative PJI and aseptic wound complication were evaluated within 3 months postoperatively. Vancomycin-associated toxicity including acute renal failure, ototoxicity and anaphylaxis was also evaluated.

RESULTS

In terms of demographic parameters and comorbidities, no significant difference was found between the two groups. Intra-articular vancomycin significantly lowered the risk of acute postoperative PJI after primary TJA (P = 0.015) and primary total knee arthroplasty (P = 0.031). However, for patients who underwent total hip arthroplasty, the PJI rate was comparable between the two groups. Overall, the risk of aseptic wound complication between the two groups was also similar. Vancomycin-associated acute renal injury, ototoxicity, or anaphylaxis was not observed.

CONCLUSIONS

Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TJA lowered the risk of acute postoperative PJI without increasing the risk of aseptic wound complication and vancomycin-associated systemic toxicity.

Parenteral Vancomycin in the Treatment of MRSA-Associated Diabetic Foot Infections: An Unnecessary Risk

Diabetic foot infections (DFIs) are a common and costly complication of diabetes. Soft tissue and bone infections in DFIs frequently lead to amputation and/or sepsis which can be costly for both the patient and the healthcare system. Staphylococcus aureus is the most commonly identified causative agent in DFIs, and people with diabetes may have an increased risk of infection with methicillin-resistant Staphylococcus aureus (MRSA). In addition to increased susceptibility to severe infection, MRSA in DFIs is associated with high rates of treatment failure, morbidity, and hospitalization costs meaning appropriate treatment is a high priority. While hospitalized patients are usually treated with intravenous (IV) vancomycin, this can be costly in terms of inpatient stays, staffing costs, and adverse events. For example, vancomycin-associated acute kidney injury not only delays hospital discharge and increases costs but is also a particular concern for patients with diabetes who already have an increased risk of kidney problems. Vancomycin-resistant strains of S. aureus have also been identified, which means that alternative treatment options may need to be explored. Treatment alternatives to IV vancomycin, including oral antibiotics, have been shown to provide similar efficacy, with reduced costs, outpatient or home-based administration, and with fewer serious adverse effects. Although infectious disease specialists often use IV vancomycin alone, or in combination, as a first-line therapeutic option, they are increasingly seeing the value of outpatient or at-home oral antibiotics as an alternative. This manuscript reviews the evidence for true costs of vancomycin therapy for MRSA-associated DFIs and examines the alternatives.

Comparison of Vancomycin Trough-Based and 24-Hour Area Under the Curve Over Minimum Inhibitory Concentration (AUC/MIC)-Based Therapeutic Drug Monitoring in Pediatric Patients

OBJECTIVES

Vancomycin 24-hour area under the curve over minimum inhibitory concentration (AUC/MIC) monitoring has been recommended over trough-based monitoring in pediatric patients. This study compared the proportion of target attainment between vancomycin AUC/MIC and trough-based methods, and identified risk factors for subtherapeutic initial extrapolated targets.

METHODS

This was a retrospective, observational study conducted at KK Women's and Children's Hospital (KKH), Singapore. Patients aged 1 month to 18 years with stable renal function who received intravenous vancomycin between January 2014 and October 2017, with at least 2 vancomycin serum concentrations obtained after the first dose of vancomycin, were included. Using a pharmacokinetic software, namely Adult and Pediatric Kinetics (APK), initial extrapolated steady-state troughs and 24-hour AUC were determined by using a one-compartmental model. Statistical tests included Wilcoxon rank sum test, McNemar test, logistic regression, and classification and regression tree (CART) analysis.

RESULTS

Of the 82 pediatric patients included, a significantly larger proportion of patients achieved therapeutic targets when the AUC/MIC-based method (24, 29.3%) was used than with the trough-based method (9, 11.0%; p < 0.01). Patients with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 or with age <13 years had an increased risk of obtaining subtherapeutic targets. However, empiric vancomycin doses of 60 mg/kg/day would be sufficient to achieve serum therapeutic targets, using the AUC/MIC-based method.

CONCLUSION

The AUC/MIC-based vancomycin monitoring may be preferred because a larger proportion of patients could achieve initial therapeutic targets. Future prospective studies with larger sample size will be required to determine the optimal vancomycin strategy for pediatric patients.

Impact of implementing a vancomycin protocol to reduce kidney toxicity: A comparative study

Introduction: Vancomycin is a frequently used antibiotic for treating severe infections caused by multidrug-resistant, Gram-positive pathogens. To ensure its effectiveness and minimize the risk of nephrotoxicity, safe administration and dose monitoring are crucial. Understanding the impact of vancomycin serum levels on clinical outcomes is of paramount importance, necessitating improved knowledge on its use, dose monitoring, nephrotoxicity, and safe administration. Objective: This study aimed to evaluate the incidence of acute kidney injury (AKI) in patients receiving vancomycin before and after the implementation of an institutional protocol for vancomycin administration in a public tertiary hospital in southern Brazil. Materials and methods: A cross-sectional study design was employed, analyzing data from the electronic medical records of 422 patients who received vancomycin. The patient population was divided into two independent cohorts: those treated in 2016 (pre-protocol) and those treated in 2018 (post-protocol), following the implementation of the institutional vancomycin administration protocol. Results: The study included 211 patients in each year of assessment. Patients from both cohorts had a Charlson Comorbidity Index (CCI) score of 4. The post-protocol cohort consisted of older individuals, with a mean age of 62.8 years. In addition, patients in the post-protocol year had higher baseline creatinine levels, higher rates of intensive care unit (ICU) hospitalization, and increased use of vasopressors. In the pre-protocol year, patients received vancomycin therapy for a longer duration. When comparing the incidence of AKI between the two groups, an intervention study revealed rates of 38.4% in group 1 and 20.9% in group 2, indicating a significant reduction (p < 0.001) in the post-protocol group. A logistic regression model was developed to predict AKI, incorporating variables that demonstrated significance (p ≤ 0.250) in bivariate analysis and those recognized in the literature as important factors for AKI, such as the duration of therapy, vancomycin serum level, and ICU hospitalization. The logistic regression classification performance was assessed using a receiver operating characteristic (ROC) curve, yielding an area under the curve of 0.764, signifying acceptable discrimination of the regression model. Conclusion: Implementation of the institutional protocol for vancomycin administration resulted in a significant and cost-effective impact, ensuring appropriate therapeutic dosing, reducing adverse events (e.g., nephrotoxicity), and improving clinical outcomes for patients in the study population.

The inhibitory activity of a new scorpion venom-derived antimicrobial peptide Hp1470 against Gram-positive bacteria

Antimicrobial peptides (AMPs) are a new type of antibiotic and target a variety of microbes, including antibiotic-resistant strains; thus, AMPs have attracted widespread interest. Scorpion venoms contain many bioactive peptides, including AMPs, and have become an important natural resource of peptide-based drugs. Here, the antibacterial peptide gene Hp1470 from the venom of the scorpion Heterometrus petersii was characterized, and its antibacterial activity was determined. The cDNA sequence of Hp1470 is 300 nt in length and contains an open reading frame (ORF) of 207 nt. The ORF was shown to encode 68 amino acid residues, including a signal peptide (23 aa), a mature peptide (13 aa), a C-terminal posttranslational processing signal (3 aa), and a propeptide (29 aa). Multiple sequence alignment results indicated that Hp1470 is an antibacterial peptide. The mature peptide Hp1470, which has a molecular mass of 1564.09 Da, was further chemically synthesized with a purity of greater than 95%. Antimicrobial assays showed that the synthesized Hp1470 exerted an inhibitory effect on Gram-positive bacteria and clinical drug-resistant strains, including PRSA and MRSA, but not Gram-negative bacteria. Hp1470 was further found to protect mice from MRSA infection, suggesting its potential application as an in vivo antimicrobial agent. Interestingly, Hp1470 only inhibited bacterial growth but did not kill bacteria, which was consistent with scanning electron microscopy results showing that Hp1470 did not lyse the cell membrane of Staphylococcus aureus. Our work provides a new direction for developing antibacterial agents with different modes of action from natural scorpion venoms.

Optimizing Dynamic Antibiotic Treatment Strategies against Invasive Methicillin-Resistant Staphylococcus Aureus Infections using Causal Survival Forests and G-Formula on Statewide Electronic Health Record Data

Developing models for individualized, time-varying treatment optimization from observational data with large variable spaces, e.g., electronic health records (EHR), is problematic because of inherent, complex bias that can change over time. Traditional methods such as the g-formula are robust, but must identify critical subsets of variables due to combinatorial issues. Machine learning approaches such as causal survival forests have fewer constraints and can provide fine-tuned, individualized counterfactual predictions. In this study, we aimed to optimize time-varying antibiotic treatment -identifying treatment heterogeneity and conditional treatment effects- against invasive methicillin-resistant Staphylococcus Aureus (MRSA) infections, using statewide EHR data collected in Florida, USA. While many previous studies focused on measuring the effects of the first empiric treatment (i.e., usually vancomycin), our study focuses on dynamic sequential treatment changes, comparing possible vancomycin switches with other antibiotics at clinically relevant time points, e.g., after obtaining a bacterial culture and susceptibility testing. Our study population included adult individuals admitted to the hospital with invasive MRSA. We collected demographic, clinical, medication, and laboratory information from the EHR for these patients. Then, we followed three sequential antibiotic choices (i.e., their empiric treatment, subsequent directed treatment, and final sustaining treatment), evaluating 30-day mortality as the outcome. We applied both causal survival forests and g-formula using different clinical intervention policies. We found that switching from vancomycin to another antibiotic improved survival probability, yet there was a benefit from initiating vancomycin compared to not using it at any time point. These findings show consistency with the empiric choice of vancomycin before confirmation of MRSA and shed light on how to manage switches on course. In conclusion, this application of causal machine learning on EHR demonstrates utility in modeling dynamic, heterogeneous treatment effects that cannot be evaluated precisely using randomized clinical trials.

Vancomycin Therapeutic Drug Monitoring: A Cross-Sectional Survey of Canadian Hospitals

Background

Little is known about the current landscape of vancomycin therapeutic drug monitoring (TDM) in Canadian hospitals, which operate within publicly funded health care systems.

Objectives

To determine current TDM practices for vancomycin and associated challenges and to gather perceptions about TDM based on area under the concentration-time curve (AUC) in Canadian hospitals.

Methods

An electronic survey was distributed to hospital pharmacists in spring 2021 through multiple national and provincial antimicrobial stewardship, public health, and pharmacy organizations. The survey gathered data about hospital characteristics, TDM methods, inclusion criteria for patient selection, pharmacokinetic and pharmacodynamic targets, vancomycin susceptibility testing and reporting, and perceived barriers and challenges.

Results

In total, 120 pharmacists from 10 of the 13 provincial and territorial jurisdictions in Canada, representing 12.5% of Canadian acute care hospitals (n = 962), completed at least 90% of survey questions. The predominant TDM method was trough-based (107/119, 89.9%); another 10.1% of respondents (12/119) reported performing AUC-based TDM (with or without trough-based TDM), and 17.9% (19/106) of those not already using AUC-based TDM were considering implementing it within 1 to 2 years. Among hospitals performing trough-based TDM, 60.5% (66/109) targeted trough levels between 15 and 20 mg/L for serious infections with methicillin-resistant Staphylococcus aureus. One-quarter of the respondents using this method (27/109, 24.8%) agreed that trough-based TDM was of uncertain benefit, and about one-third (33/109, 30.3%) were neutral on this question. Multiple challenges were identified for trough-based TDM, including sub- or supra-therapeutic concentrations and collection of specimens at inappropriate times. Overall, 40.5% (47/116) of respondents agreed that AUC-based TDM was likely safer than trough-based TDM, whereas 23.3% (27/116) agreed that AUC-based TDM was likely more effective.

Conclusions

This survey represents a first step in developing evidence-based, standardized best practices for vancomycin TDM that are uniquely suited to the Canadian health care system.

Vancomycin-induced elevation of liver enzyme levels in a 3-year-old boy with bacterial meningitis: A pediatric case report

BACKGROUND

Vancomycin as a glycopeptide antibiotic agent plays a vital role in the treatment of gram-positive bacterial infections, especially methicillin-resistant Staphylococcus aureus. Vancomycin-induced liver disease is rarely reported previously; isolated cases have been reported only in adults and none in children except in a 3-month-old girl published in a Chinese journal.

CASE SUMMARY

A 3-year-old boy received vancomycin for the treatment of bacterial meningitis for more than 3 weeks. The baseline liver enzyme levels of alanine aminotransferase (ALT) (12 U/L), aspartate aminotransferase (AST) (18 U/L), and gamma-glutamyl transferase (GGT) (26 U/L) were obtained after administering vancomycin for 2 days. Liver enzyme levels of ALT (191 U/L), AST (175 U/L), and GGT (92 U/L) were obviously elevated after administering vancomycin for 22 days; this elevation was reversed after vancomycin discontinuation. This case suggested that regular examination of liver function is necessary for all individuals who initiated vancomycin.

PRACTICE IMPLICATIONS

This is a rarely known case of vancomycin-induced elevation of ALT and AST and the first reported case of vancomycin causing GGT elevation in children, which suggested that regular examination of liver function is required during the use of vancomycin in children and could help avoid progressive liver injury. This case adds to the limited number of reports on vancomycin-induced liver disease.

A Quasi-Experimental Evaluation of Single Trough-Based Area Under the Curve Guided Dosing on the Incidence of Vancomycin Associated Nephrotoxicity in Veteran Patients

Background: Two common dosing strategies for vancomycin are trough-based and area under the curve (AUC)-based dosing. Objective: To compare the incidence of nephrotoxicity in trough-based dosing group with the single trough-based AUC dosing at the Salem VA Medical Center. Methods: This retrospective study included patients who received trough-based dosing of vancomycin between January 1, 2017, and January 1, 2019 (preimplementation group) and AUC-based dosing (postimplementation) between October 1, 2019, and October 1, 2021, at the Salem VA Medical Center. The primary outcome was nephrotoxicity at 96 hours, 7 days, and entire hospital length of stay (LOS). Secondary outcomes included 30-day readmission and all-cause mortality rates, cumulative doses at 24, 48, and 72 hours, and percentage of patients considered at goal (AUC 400-600 or trough between 10 and 20 mg/L). Propensity score (PS) matching was utilized to adjust for confounding. Results: After PS matching 100 patients were included in preimplementation and 95 patients in the postimplementation group. The average study patient was a 68-year-old white male. There was significant reduction in the risk of nephrotoxicity in postimplementation cohort at 96 hours (adjusted (a)HR: 0.28, 95% CI (0.12-0.66); 7 days (aHR: 0.39, 95% CI (0.18-0.85); and entire hospital LOS (aHR: 0.46, 95% CI (0.22-0.95). Secondary outcomes showed no difference between the groups except significantly higher proportion of patients were considered at therapeutic goal in the postimplementation cohort compared with pre-implementation cohort. Conclusion: This hypothesis generating study shows that AUC-based dosing calculated using single trough concentration may result in reduced rate of nephrotoxicity than trough-based dosing.

Current Clinical Landscape and Global Potential of Bacteriophage Therapy

In response to the global spread of antimicrobial resistance, there is an increased demand for novel and innovative antimicrobials. Bacteriophages have been known for their potential clinical utility in lysing bacteria for almost a century. Social pressures and the concomitant introduction of antibiotics in the mid-1900s hindered the widespread adoption of these naturally occurring bactericides. Recently, however, phage therapy has re-emerged as a promising strategy for combatting antimicrobial resistance. A unique mechanism of action and cost-effective production promotes phages as an ideal solution for addressing antibiotic-resistant bacterial infections, particularly in lower- and middle-income countries. As the number of phage-related research labs worldwide continues to grow, it will be increasingly important to encourage the expansion of well-developed clinical trials, the standardization of the production and storage of phage cocktails, and the advancement of international collaboration. In this review, we discuss the history, benefits, and limitations of bacteriophage research and its current role in the setting of addressing antimicrobial resistance with a specific focus on active clinical trials and case reports of phage therapy administration.

Development and validation of a dried plasma spot LC-MS/MS method for therapeutic monitoring of vancomycin and comparison with enzyme-multiplied immunoassay

Vancomycin is used as an antimicrobial agent for the treatment of severe gram-positive infections. The importance of therapeutic monitoring of antimicrobials has led to the development of more specific sample preparation techniques capable of identifying with accuracy the concentration of this substance in the organism. An aliquot of 10 μl of plasma was transferred to Whatman 903 paper and dried at room temperature. The extraction method was performed by cutting and transferring the paper to a microtube and adding sodium phosphate buffer and internal standard. The mixture was shaken and centrifuged, and a 5-μl aliquot was injected into the analytical system. The optimization of the main parameters that can influence the extraction efficiency was performed using multivariate approaches to obtain the best conditions. The method developed was validated, providing coefficients of determination higher than 0.994 and a lower limit of quantification of 1 mg/L. Within- and between-run precision ranged from 11.4 to 17.30% and from 6.65 to 13.51%, respectively. This method was successfully applied to 75 samples of patients undergoing vancomycin therapy. The method was rapid, simple, and environmentally friendly with satisfactory analytical performance and was advantageous over the laborious and time-consuming methodologies used in therapeutic drug monitoring routine analyses.

Cost analysis of disease including treatment with dalbavancin in a Spanish hospital: ECODAL ANALYSIS

INTRODUCTION AND AIM

Dalbavancin is an antibiotic with activity against gram-positive bacteria that allows early discharge of patients requiring intravenous therapy. Outpatient treatment helps offset hospitalisation costs associated with standard intravenous treatment. Our objective was to assess the cost of disease management, including treatment with dalbavancin, in a Spanish hospital for 1 year, and the hypothetical costs associated with treatment with other therapeutic alternatives to dalbavancin.

METHODS

A single-centre, observational, retrospective post-hoc analysis was conducted based on electronic medical records analysing all patients who received dalbavancin treatment for 1 year; cost analysis was performed for the whole process. In addition, three scenarios designed on the basis of real clinical practice by clinical experts were hypothesised: (i) individual therapeutic alternative to dalbavancin, (ii) all patients treated with daptomycin, and (iii) all days of dalbavancin as outpatient treatment transformed into hospital stay. Costs were obtained from the hospital.

RESULTS

Thirty-four patients were treated with dalbavancin; their mean age was 57.9 years, and 70.6% were men. The main reasons for dalbavancin use were outpatient management (61.7%, n = 21) and ensuring treatment adherence (26.5%, n = 9). The main indications were: osteoarticular infection (32.4%) and infective endocarditis (29.4%). One-half (50%) of the infections were due to Staphylococcus aureus (23.5% were methicillin resistant). All patients achieved clinical resolution, and no costs associated with dalbavancin-associated adverse events or re-admissions were reported. The mean total cost of treatment was 22,738€per patient, with the greatest expenditures in interventions (8,413€) and hospital stay (6,885€). The mean cost of dalbavancin treatment was 3,936€; without dalbavancin, this cost could have been increased to 3,324-11,038€depending on the scenario, mainly due to hospital stays.

MAIN LIMITATION

Limited sample size obtained from a single centre.

CONCLUSION

The economic impact of the management of these infections is high. The cost of dalbavancin is offset by the decreased length of stay.

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.

Passively-targeted mitochondrial tungsten-based nanodots for efficient acute kidney injury treatment

Acute kidney injury (AKI) can lead to loss of kidney function and a substantial increase in mortality. The burst of reactive oxygen species (ROS) plays a key role in the pathological progression of AKI. Mitochondrial-targeted antioxidant therapy is very promising because mitochondria are the main source of ROS in AKI. Antioxidant nanodrugs with actively targeted mitochondria have achieved encouraging success in many oxidative stress-induced diseases. However, most strategies to actively target mitochondria make the size of nanodrugs too large to pass through the glomerular system to reach the renal tubules, the main damage site of AKI. Here, an ultra-small Tungsten-based nanodots (TWNDs) with strong ROS scavenging can be very effective for treatment of AKI. TWNDs can reach the tubular site after crossing the glomerular barrier, and enter the mitochondria of the renal tubule without resorting to complex active targeting strategies. To our knowledge, this is the first time that ultra-small negatively charged nanodots can be used to passively target mitochondrial therapy for AKI. Through in-depth study of the therapeutic mechanism, such passive mitochondria-targeted TWNDs are highly effective in protecting mitochondria by reducing mitochondrial ROS and increasing mitophagy. In addition, TWNDs can also reduce the infiltration of inflammatory cells. This work provides a new way to passively target mitochondria for AKI, and give inspiration for the treatment of many major diseases closely related to mitochondria, such as myocardial infarction and cerebral infarction.

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Mitochondrial-targeted antioxidant therapy is a very promising treatment for AKI.

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TWNDs have a strong ability to scavenge ROS, and their small size allows them to cross the glomerular filtration barrier.

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TWNDs passively target the mitochondria of renal tubular cells and are highly effective in restoring renal function.

Antimicrobial and the Resistances in the Environment: Ecological and Health Risks, Influencing Factors, and Mitigation Strategies

Antimicrobial contamination and antimicrobial resistance have become global environmental and health problems. A large number of antimicrobials are used in medical and animal husbandry, leading to the continuous release of residual antimicrobials into the environment. It not only causes ecological harm, but also promotes the occurrence and spread of antimicrobial resistance. The role of environmental factors in antimicrobial contamination and the spread of antimicrobial resistance is often overlooked. There are a large number of antimicrobial-resistant bacteria and antimicrobial resistance genes in human beings, which increases the likelihood that pathogenic bacteria acquire resistance, and also adds opportunities for human contact with antimicrobial-resistant pathogens. In this paper, we review the fate of antimicrobials and antimicrobial resistance in the environment, including the occurrence, spread, and impact on ecological and human health. More importantly, this review emphasizes a number of environmental factors that can exacerbate antimicrobial contamination and the spread of antimicrobial resistance. In the future, the timely removal of antimicrobials and antimicrobial resistance genes in the environment will be more effective in alleviating antimicrobial contamination and antimicrobial resistance.