Optimised versus standard dosing of vancomycin in infants with Gram-positive sepsis (NeoVanc): a multicentre, randomised, open-label, phase 2b, non-inferiority trial

Vancomycin Dosing and Its Association With Acute Kidney Injury in Pediatric Cardiac Intensive Care Patients Under 3 Months of Age

BACKGROUND

The standard vancomycin regimen for term neonates is 45 mg/kg/day. However, the optimal starting vancomycin dosing for achieving therapeutic levels in young infants in cardiac intensive care units remains unknown. Moreover, data on the association of supratherapeutic vancomycin levels with acute kidney injury (AKI) are limited.

METHODS

Retrospective study of infants ≤3 months old, receiving vancomycin following congenital heart surgery at postoperative intensive care unit admission. Assessed were vancomycin dosing, achievement of therapeutic trough concentration of 10-20 mg/L and development of AKI, based on the modified Kidney Disease Improving Global Outcomes criteria.

RESULTS

Inclusion criteria were met by 109 patients with a median age of 8 days (IQR: 6-16). The mean (SD) vancomycin dose required for achieving therapeutic concentration was 28.9 (9.1) mg/kg at the first postoperative day. Multivariate logistic regression identified higher preoperative creatinine levels and shorter cardiopulmonary bypass time as predictors of supratherapeutic vancomycin concentrations (c-index 0.788). During the treatment course, 62 (56.9%) developed AKI. Length of stay and mortality were higher in those who developed AKI as compared with those who did not. Multivariate logistic regression identified higher vancomycin concentration as a predictor for postoperative AKI, OR, 3.391 (95% CI: 1.257-9.151), P = 0.016 (c-index 0.896).

CONCLUSION

Our results support a lower starting vancomycin dose of ~30 mg/kg/day followed by an early personalized therapeutic approach, to achieve therapeutic trough concentrations of 10-20 mg/L in cardiac postoperative term infants. Supratherapeutic concentrations are associated with an increased risk for AKI, which is prevalent in this population and associated with adverse outcomes.

Age-Related Changes in Vancomycin Protein Binding: Is It Time to Take It Seriously?

BACKGROUND

Vancomycin (VAN) protein binding in plasma is influenced by illness and age; hence, doses titrated according to total concentrations are fraught. In this study, model-estimated free VAN concentrations (EFVC) were compared with assumed free VAN concentrations (AFVC) in neonates, children, and adults in the intensive care unit and those on dialysis.

METHODS

Patient cohorts were identified from the hospital database. Demographics, clinical characteristics, total VAN concentrations, and laboratory variables were obtained from electronic health records. EFVC was derived from 6 models identified in the literature. For all models, total VAN concentration was the most important predictor; other predictors included albumin, total protein, and dialysis status. The AFVC was calculated as 50% of the total concentration (ie, assumption of 50% bound).

RESULTS

Differences between EFVC and AFVC in adults were insignificant; however, differences in pediatric intensive care unit patients, according to 2 different models, were significant: mean ± SD = 4.1 ± 1.58 mg/L and 4.7 ± 2.46 mg/L ( P < 0.001); the percentages within the free VAN trough range = 30.4% versus 55.1% and 30% versus 55.1%; and the supratherapeutic percentages = 65.2% versus 31.9% and 66.7% versus 31.9%, respectively. In neonates, the difference between EFVC and AFVC was mean ± SD = 6.9 ± 1.95 mg/L ( P < 0.001); the percentages within the free VAN trough range for continuous and intermediate dosing were 0% versus 81.3% and 14.3% versus 71.4%, and the supratherapeutic percentages were 100% versus 6.25% and 71.4% versus 0%, respectively.

CONCLUSIONS

The fraction of free unbound VAN is higher in sick children and neonates than in adults. Therefore, total VAN concentrations do not correlate with the pharmacologically active free VAN concentrations in the same manner as in adults. Adjusting VAN doses in neonates and children to target the same total VAN concentration as the recommended therapeutic range for adults may result in toxicfree concentrations.

Antibiotics, Analgesic Sedatives, and Antiseizure Medications Frequently Used in Critically Ill Neonates: A Narrative Review

Antibiotic, analgesic sedative, and antiseizure medications are among the most commonly used medications in preterm/sick neonates, who are at high risk of nosocomial infections, central nervous system complications, and are exposed to numerous painful/stressful procedures. These severe and potentially life-threatening complications may have serious short- and long-term consequences and should be prevented and/or promptly treated. The reported variability in the medications used in neonates indicates the lack of adequate neonatal studies regarding their effectiveness and safety. Important obstacles contributing to inadequate studies in preterm/sick infants include difficulties in obtaining parental consent, physicians' unwillingness to recruit preterm infants, the off-label use of many medications in neonates, and other scientific and ethical concerns. This review is an update on the use of antimicrobials (antifungals), analgesics (sedatives), and antiseizure medications in neonates, focusing on current evidence or knowledge gaps regarding their pharmacokinetics, indications, safety, dosage, and evidence-based guidelines for their optimal use in neonates. We also address the effects of early antibiotic use on the intestinal microbiome and its association with long-term immune-related diseases, obesity, and neurodevelopment (ND). Recommendations for empirical treatment and the emergence of pathogen resistance to antimicrobials and antifungals are also presented. Finally, future perspectives on the prevention, modification, or reversal of antibiotic resistance are discussed.

A Retrospective Study Evaluating Neonatal Vancomycin Loading Doses to Achieve a Therapeutic Target

BACKGROUND

Vancomycin is a glycopeptide antibiotic that has been used to treat hospital-acquired gram-positive infections for more than 5 decades. However, the literature is divided regarding the therapeutic advantages of vancomycin loading doses in neonates.

OBJECTIVES

This study aimed to investigate the effect of vancomycin loading doses on therapeutic target attainment in neonates with sepsis.

METHODS

A retrospective cohort study was conducted to compare the vancomycin target attainment (area under the curve 0-24 hours/minimum inhibitory concentration ≥400) in neonates before and after the 2019 change in vancomycin prescription guidelines at a neonatal unit in Cape Town, South Africa. As the standard of care, Bayesian modelling software was used to compute the area under the curve from the trough concentrations.

RESULTS

Two hundred ten neonates were included. Multivariate regression analysis showed a 2-fold increase in the odds of target attainment among neonates receiving a loading dose of vancomycin. Early target attainment (within 8-12 hours of treatment initiation) was significantly higher in the loading dose group compared with the no loading dose group [97/105 (92.4%) versus 64/105 (61.0%); P < 0.001]. However, the overall proportion of neonates achieving target attainment at 24 hours was similar between groups [73/105 (69.5%) in the loading dose group versus 62/105 (59.0%) in the no loading dose group; P = 0.110]. The nephrotoxicity rates were low [2/105 (1.9%) in the loading dose group and 2/105 (1.9%) in the no loading dose group].

CONCLUSIONS

The addition of a vancomycin loading dose to neonates may facilitate early therapeutic target attainment.

Understanding vancomycin nephrotoxicity augmented by β-lactams: a synthesis of endosymbiosis, proximal renal tubule mitochondrial metabolism, and β-lactam chemistry

The recent understanding that hydrophobic β-lactams have greater affinity for organic anion transporter-3 (OAT-3) of the proximal renal tubule could provide valuable insights for anticipating β-lactams that may exacerbate vancomycin-induced nephrotoxicity. Vancomycin alone provides oxidative stress on the highly metabolic proximal tubular cells. Hydrophobic β-lactams (eg, piperacillin and anti-staphylococcal β-lactams) could have greater OAT-3 mediated uptake into proximal tubular cells than hydrophilic β-lactams (eg, most cephalosporins and carbapenems), thereby causing greater mitochondrial stress on these susceptible cells. It remains to be seen whether concomitant drugs that inhibit OAT-3 mediated cellular uptake of β-lactams into proximal tubular cells or provide antioxidant effects might mitigate β-lactam augmented vancomycin nephrotoxicity. Furthermore, the serum creatinine rise seen with vancomycin and hydrophobic β-lactams might represent competition for creatinine-secreting transporters (of which OAT-3 is one), thus, indicating creatinine retention rather than renal injury. In the meantime, clinicians are advised to utilise less nephrotoxic combinations in both empirical and directed antibiotic selection settings until further research is conducted.

Association between vancomycin therapeutic drug monitoring and clinical outcomes in treating neonatal sepsis

BACKGROUND

Neonatal sepsis is commonly treated with vancomycin in the neonatal intensive care unit. Therapeutic drug monitoring of vancomycin is routinely used to personalise dosing to optimise effectiveness and avoid toxicity.

OBJECTIVES

This study aimed to define a target range by evaluating associations between vancomycin trough concentrations or area under the concentration time curve over 24 hours (AUC24h) and clinical outcomes in neonates.

METHODS

Neonates, who were admitted to the neonatal intensive care unit and received intravenous vancomycin, were included in this retrospective cohort study. For evaluating effectiveness, patients who received vancomycin for < 5 days were excluded. The AUC24h was estimated based on a study-derived population pharmacokinetic model. Primary outcomes were persistent/recurrent infections and mortality within 30 days. Secondary outcomes, including acute kidney injury (AKI), were also assessed. Logistic regression and classification and regression tree analyses were performed.

RESULTS

A total of 448 patients (123 patients for effectiveness analysis) were included. A vancomycin trough > 10 mg/L was associated with 70% lower odds of persistent/recurrent infections (adjusted OR 0.30, 95% CI 0.09-0.86; P = 0.023). Patients who took more than a day to reach target range had 1.4 times higher odds of persistent/recurrent infections or death (P = 0.04). A vancomycin trough > 15 mg/L was associated with a three times higher risk of AKI (P = 0.003). An AUC24h of 420-650 mg*h/L was also associated with the lowest risk of composite outcomes (adjusted OR 0.29, 95% CI 0.08-0.86; P = 0.025).

CONCLUSION

A vancomycin trough target range of 10-15 mg/L and achievement of this target within a day of treatment initiation were associated with the most optimal clinical outcomes in treating neonatal sepsis.

Physicochemical Characteristics of Antimicrobials and Practical Recommendations for Intravenous Administration: A Systematic Review

Most antimicrobial drugs need an intravenous (IV) administration to achieve maximum efficacy against target pathogens. IV administration is related to complications, such as tissue infiltration and thrombo-phlebitis. This systematic review aims to provide practical recommendations about diluent, pH, osmolarity, dosage, infusion rate, vesicant properties, and phlebitis rate of the most commonly used antimicrobial drugs evaluated in randomized controlled studies (RCT) till 31 March 2023. The authors searched for available IV antimicrobial drugs in RCT in PUBMED EMBASE®, EBSCO® CINAHL®, and the Cochrane Controlled Clinical trials. Drugs' chemical features were searched online, in drug data sheets, and in scientific papers, establishing that the drugs with a pH of <5 or >9, osmolarity >600 mOsm/L, high incidence of phlebitis reported in the literature, and vesicant drugs need the adoption of utmost caution during administration. We evaluated 931 papers; 232 studies were included. A total of 82 antimicrobials were identified. Regarding antibiotics, 37 reach the "caution" criterion, as well as seven antivirals, 10 antifungals, and three antiprotozoals. In this subgroup of antimicrobials, the correct vascular access device (VAD) selection is essential to avoid complications due to the administration through a peripheral vein. Knowing the physicochemical characteristics of antimicrobials is crucial to improve the patient's safety significantly, thus avoiding administration errors and local side effects.

Role of fluid status markers as risk factors for suboptimal vancomycin concentration during continuous infusion in neonates: an observational study

Vancomycin is widely used in neonatal sepsis but proportion of newborn reaching recommended concentration is variable. Fluid status impact on vancomycin level remains understudied. We aimed to study fluid factors impacting vancomycin concentration at 24 h of treatment. We performed a prospective and retrospective observational monocentric study of NICU patients requiring a vancomycin treatment. We used a continuous infusion protocol, with age-appropriate loading and maintenance doses. Vancomycin target serum concentration after 24 h (C_24h) was above 20 mg/L. Demographic, infections, and organ failure variables were analyzed as potential predictors of C_24h. Over the study period, 70 infective episodes in 52 patients were included. At treatment initiation, the median post-natal age was 12.5 days (IQR 7-23), post menstrual age 30 weeks (IQR 28-35), and median weight 1140 g (IQR 835-1722). Germs isolated were mainly gram-positive with 73.5% being coagulase-negative Staphylococci. Median C_24h was 18.7 mg/L (IQR 15.4-22.4). Overall, 41 (58.6%) treatments had a C_24h < 20 mg/L. After multivariate analysis, higher creatinine level (OR 1.03 (95% CI 1.002-1.06)) was associated with C_24h ≥ 20 mg/L; weight gain the day before infection (OR 0.21 (95% CI 0.05-0.79)) and positive biomarkers of inflammation (OR 0.22 (0.05-0.94)) were associated with C_24h < 20 mg/L.

CONCLUSION

Vancomycin C_24h was underdosed in 60% of patients and factors linked to changes in vancomycin pharmacokinetic such as volume of distribution and clearance, linked to creatinine level, inflammation, or weight gain, were identified.

WHAT IS KNOWN

• Adjustment of vancomycin regimen remains difficult due to inter- and intra-individual variability of vancomycin pharmacokinetics. • Impact of fluid status on vancomycin concentration in critically ill neonates is incompletely studied.

WHAT IS NEW

• Proportion of patients with adequate vancomycin concentration using a target adapted to nosocomial gram-positive bacteria MIC is low. • We confirmed the role of creatinine level and report two new factors associated with low vancomycin concentration: presence of systemic inflammation and weight gain.