Optimal exposure targets for vancomycin in the treatment of neonatal coagulase-negative Staphylococcus infection: A retrospective study based on electronic medical records

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PROSPERO REGISTRATION NUMBER

CRD42024564584.

Evaluation of an optimized intermittent vancomycin dosing regimen in infants

BACKGROUND

Many standard intermittent dosing regimens for vancomycin in infants fail to achieve the therapeutic target at steady state. This study used population pharmacokinetic (popPK) modelling and simulation to determine an optimized vancomycin dosing regimen, and clinically evaluated this regimen in infants aged 0-90 days.

METHODS

An optimized model-based dosing regimen to achieve an AUC24 of 400-650 mg/L·h was developed from a published vancomycin popPK model. The PTA of achieving the AUC24 target as well as a trough concentration of 10-20 mg/L (still commonly used in clinical practice as a surrogate for AUC24) was determined. This dosing regimen was implemented at The Royal Children's Hospital Melbourne, and evaluated over a 12 month period to determine the proportion of infants achieving the target AUC24 and trough concentration at steady state.

RESULTS

Using the validated model, the simulated PTA of achieving the target AUC24 and trough concentration with the optimized dosing regimen was 68% and 56%, respectively. This dosing regimen was clinically evaluated in 24 infants who received 26 vancomycin courses (median postmenstrual age 40 weeks, range 25-53; median weight 3250 g, range 650-5930). In 23/26 (88%) courses, the target AUC24 was achieved, with 2/26 (8%) and 1/26 (4%) having subtherapeutic and supratherapeutic AUC24, respectively. The first trough concentration taken at steady state was between 10 and 20 mg/L in 21/26 (81%) courses. No nephrotoxicity or ototoxicity was observed.

CONCLUSIONS

Our optimized vancomycin dosing regimen for infants aged 0-90 days achieved the target AUC24 in 88% and should be considered for routine use.

Continuous Versus Intermittent Vancomycin Infusions for Coagulase-negative Staphylococcus Bacteremia in Neonates: A Propensity-matched Cohort Study

BACKGROUND

Coagulase-negative staphylococci (CONS) are a major cause of late-onset neonatal sepsis, particularly in preterm infants, with high morbidity and mortality. While vancomycin is the first-line treatment for these infections, the optimal administration in neonates remains uncertain.

OBJECTIVE

We aim to compare the outcomes of neonates with CONS bacteremia treated with adjusted continuous infusion (CIV) versus standard intermittent infusion (IIV) of vancomycin.

METHODS

This retrospective study included 110 neonates, with 29 in the CIV group and 47 in the IIV group after propensity score matching. The primary outcome was treatment failure defined by the persistence of a positive blood culture for the same organism after at least 48 hours of vancomycin treatment.

RESULTS

After matching, the CIV group exhibited significantly lower treatment failure rates [5/29 (17%) vs. 26/47 (44%); P = 0.014] and a higher rate of achieving therapeutic vancomycin levels after 24 hours [20/29 (69%) vs. 26/47 (44%); P = 0.002] compared to the IIV group. No significant differences were observed in terms of acute kidney failure between the 2 groups.

CONCLUSION

Adjusted continuous vancomycin infusion in neonates with CONS bacteremia is associated with a lower treatment failure rate without an increase in renal toxicity compared to standard intermittent infusion. However, due to the observational design, larger prospective studies are needed to validate these results.

[Recommendations for antibiotic use in hospitalized preterm infants with late-onset sepsis in the neonatal intensive care unit]

Late-onset sepsis (LOS) is commonly seen in neonates who are hospitalized for extended periods, particularly in very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI). Currently, the management of LOS in preterm infants faces dual challenges of delayed diagnosis and treatment, as well as antibiotic overtreatment. To address these issues, the Hunan Neonatal Medical Quality Control Center and the Neonatology Group of Perinatal Medical Committee of Hunan Medical Association organized a group of neonatal experts from Hunan Province to formulate recommendations based on published literature and statistical data from the Hunan Neonatal Medical Quality Control Center, as well as real-world practices in most neonatal intensive care units in Hunan Province. The group of neonatal experts proposed 15 recommendations for the diagnosis and antibiotic treatment of LOS in hospitalized preterm infants in the neonatal intensive care unit.

The crucial relationship between vancomycin minimum inhibitory concentration and therapeutic efficacy against methicillin-resistant coagulase-negative staphylococci

The area under the curve (AUC)/minimum inhibitory concentration (MIC) ratio was used as an indicator of the clinical efficacy of vancomycin. However, the target AUC/MIC has not been set for methicillin-resistant coagulase-negative staphylococci (MR-CNS), and the effectiveness of vancomycin in strains with high MIC is unknown. Therefore, we aimed to investigate the relationship between the vancomycin MIC and therapeutic efficacy in patients with MR-CNS bacteremia. The primary outcome was the difference in treatment failure rate when the MR-CNS vancomycin MIC was 1 or 2 µg/mL. The treatment failure rate did not significantly differ between the two groups (MIC 1 vs. MIC 2: 27.0% vs. 31.0%; p = 0.779). As a result of multivariate analysis, AUC/MIC0-24 h ≤230 was extracted as risk factor for treatment failure, suggesting the importance of a sufficient initial loading dose and early blood concentration monitoring to increase AUC/MIC0-24 h for successful treatment.

Association of Vancomycin AUC/MIC and Trough Concentration With Early Clinical Response in Enterococcus or Coagulase-Negative Staphylococcus Infection: A Prospective Study

This study was condcuted to examine the association of area under the curve (AUC)/minimum inhibitory concentration (MIC) and trough concentration (Ctrough) of vancomycin with treatment outcome and nephrotoxicity in infections caused by Enterococcus spp. and coagulase-negative Staphylococci (CoNS). Peak and trough concentrations were used to calculate AUC in 89 patients receiving vancomycin for infections with Enterococcus spp. (n = 65) or CoNS (n = 24). Correlations between Ctrough, AUC/MIC, early clinical response (ECR), and nephrotoxicity were assessed and cutoff values were determined. Sixty-three (70.8%) patients showed improvement in ECR and 10 (11.2%) experienced nephrotoxicity. Enterococcus spp. infections displayed correlations between AUC/MIC and ECR for AUC0-24 h/MIC (r2 = 0.27, P ≤ .05) and AUC24-48 h/MIC (r2 = 0.28, P ≤ .05), but not for Ctrough (r2 = 0.21, P > .05). There were no correlations between Ctrough (r2 = 0.26, P > .05), AUC0-24 h/MIC (r2 = -0.12, P > .05), AUC24-48 h/MIC (r2 = 0.01, P > .05) and ECR for CoNS. In the CoNS group, a moderate correlation was found between ECR and Ctrough at a cutoff value of 6.9 μg/mL. In addition, nephrotoxicity is also moderately associated with AUC0-24 h and AUC24-48 h at 505.7 and 667.1 μg•h/mL, respectively. A strong correlation between nephrotoxicity and Ctrough was observed when the cutoff value was 18.9 μg/mL. AUC/MIC during the first 48 h was a determinant of vancomycin efficacy in Enterococcus infections but not for CoNS. Ctrough was not correlated with clinical outcome. Nephrotoxicity could be predicted using Ctrough and AUC for infections with both pathogens.

Optimization of Vancomycin Initial Dosing Regimen in Neonates Using an Externally Evaluated Population Pharmacokinetic Model

BACKGROUND

Vancomycin therapeutic monitoring guidelines were revised in March 2020, and a population pharmacokinetics-guided Bayesian approach to estimate the 24-hour area under the concentration-time curve to the minimum inhibitory concentration ratio has since been recommended instead of trough concentrations. To comply with these latest guidelines, we evaluated published population pharmacokinetic models of vancomycin using an external dataset of neonatal patients and selected the most predictive model to develop a new initial dosing regimen.

METHODS

The models were identified from the literature and tested using a retrospective dataset of Canadian neonates. Their predictive performance was assessed using prediction- and simulation-based diagnostics. Monte Carlo simulations were performed to develop the initial dosing regimen with the highest probability of therapeutic target attainment.

RESULTS

A total of 144 vancomycin concentrations were derived from 63 neonates in the external population. Five of the 28 models retained for evaluation were found predictive with a bias of 15% and an imprecision of 30%. Overall, the Grimsley and Thomson model performed best, with a bias of -0.8% and an imprecision of 20.9%; therefore, it was applied in the simulations. A novel initial dosing regimen of 15 mg/kg, followed by 11 mg/kg every 8 hours should favor therapeutic target attainment.

CONCLUSIONS

A predictive population pharmacokinetic model of vancomycin was identified after an external evaluation and used to recommend a novel initial dosing regimen. The implementation of these model-based tools may guide physicians in selecting the most appropriate initial vancomycin dose, leading to improved clinical outcomes.

Incidence of Antimicrobial-Associated Acute Kidney Injury in Children: A Structured Review

Acute kidney injury (AKI) is a commonly reported adverse effect of administration of antimicrobials. While AKI can be associated with poorer outcomes, there is little information available to understand rates of AKI in children exposed to various antimicrobials. We performed a structured review using the PubMed and Embase databases. Articles were included if they provided an AKI definition in patients who were < 19 years of age receiving an antimicrobial and reported the frequency of AKI. Author-defined AKI rates were calculated for each study and mean pooled estimates for each antimicrobial were derived from among all study participants. Pooled estimates were also derived for those studies that reported AKI according to pRIFLE (pediatric risk, injury, failure, loss, end stage criteria), AKIN (acute kidney injury network), or KDIGO (kidney disease improving global outcomes) creatinine criteria. A total of 122 studies evaluating 28 antimicrobials met the inclusion criteria. Vancomycin was the most commonly studied drug: 11,514 courses across 44 included studies. Among the 27,285 antimicrobial exposures, the overall AKI rate was 13.2% (range 0-42.1% by drug), but the rate of AKI varied widely across studies (range 0-68.8%). Cidofovir (42.1%) and conventional amphotericin B (37.0%) had the highest pooled rates of author-defined AKI. Eighty-one studies used pRIFLE, AKIN, or KDIGO AKI criteria and the pooled rates of AKI were similar to author-defined AKI rates. In conclusion, antimicrobial-associated AKI is reported to occur frequently in children, but the rates of AKI varies widely across studies and drugs. Most published studies examined hospitalized patients and heterogeneity in study populations and in author definitions of AKI are barriers to a comparison of nephrotoxicity risk among antimicrobials in children.

Effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit

OBJECTIVE

This study aimed to assess the effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit (PICU).

METHODS

A retrospective cohort study was performed of 126 infants and toddlers (aged between 29 days and 3 years) from the PICU of a tertiary care hospital who were administered intravenous vancomycin between January 2019 and December 2022. Information about their demographic factors, duration of PICU stay, time of administration and trough levels of vancomycin were retrieved. Descriptive statistics were used for demographic factors and multivariable logistic regression analyses were conducted to assess the determining factors.

RESULTS

Based on the trough concentration of vancomycin, the participants were divided into three groups as follows: 4-5 mg/L, 5-15 mg/L and >15 mg/L. The serum vancomycin concentration was significantly related to body weight, albumin, cystatin C, urea nitrogen in serum, serum creatinine and creatinine clearance (p<0.05) in these patients. Multivariate analysis showed that body weight, albumin, cystatin C, urea nitrogen in serum and creatinine clearance were independent contributors to the trough vancomycin concentration. There was no difference in the effectiveness of different trough concentrations on patients (p=0.241). The cumulative incidence of acute kidney injury was highest in the group with a trough concentration of vancomycin >15 mg/L (p<0.01).

CONCLUSIONS

Patients with a vancomycin trough concentration of 4-5 mg/L in the PICU had a high cure rate (79.4%) and a low incidence of acute kidney injury (HR 18.3, 95% CI 5.135 to 87.621; p<0.001). Therefore, the serum trough concentration should be considered but it should also be combined with the treatment effect to achieve individualised administration for the clinical application of vancomycin.

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

STUDY OBJECTIVE

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

DESIGN

A retrospective observational cohort study.

DATA SOURCE

A large public database.

PATIENTS

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

METHODS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Use of Antibiotics in Preterm Newborns

Due to complex maturational and physiological changes that characterize neonates and affect their response to pharmacological treatments, neonatal pharmacology is different from children and adults and deserves particular attention. Although preterms are usually considered part of the neonatal population, they have physiological and pharmacological hallmarks different from full-terms and, therefore, need specific considerations. Antibiotics are widely used among preterms. In fact, during their stay in neonatal intensive care units (NICUs), invasive procedures, including central catheters for parental nutrition and ventilators for respiratory support, are often sources of microbes and require antimicrobial treatments. Unfortunately, the majority of drugs administered to neonates are off-label due to the lack of clinical studies conducted on this special population. In fact, physiological and ethical concerns represent a huge limit in performing pharmacokinetic (PK) studies on these subjects, since they limit the number and volume of blood sampling. Therapeutic drug monitoring (TDM) is a useful tool that allows dose adjustments aiming to fit plasma concentrations within the therapeutic range and to reach specific drug target attainment. In this review of the last ten years’ literature, we performed Pubmed research aiming to summarize the PK aspects for the most used antibiotics in preterms.