Determining the optimal vancomycin daily dose for pediatrics: a meta-analysis

Optimizing vancomycin therapeutic drug monitoring compliance in pediatric oncology: towards personalized medication management

Aim: Vancomycin, a crucial treatment for Gram-positive bacteria, necessitates therapeutic drug monitoring (TDM) to prevent treatment failures. We investigated the healthcare professional's compliance toward TDM of vancomycin recommendations and follow-up levels. Materials & methods: We collected data from 485 patients who received vancomycin in the Children's Cancer Hospital Egypt 57357 medical records system (Cerner) over 4 months, from January to April 2020. Results: Our data shows that only 54% of patients had TDM requests from healthcare professionals for the total patients who received vancomycin treatment. The healthcare professionals' compliance with the recommendations was 91.7%, while the follow-up levels were 66.7%. Conclusion: While overall adherence to recommendations is strong, enhancing compliance with follow-up levels remains a priority for improvement.

Individualized antibiotic dosage regimens for patients with augmented renal clearance

Objectives: Augmented renal clearance (ARC) is a state of enhanced renal function commonly observed in 30%-65% of critically ill patients despite normal serum creatinine levels. Using unadjusted standard dosing regimens of renally eliminated drugs in ARC patients often leads to subtherapeutic concentrations, poor clinical outcomes, and the emergence of multidrug-resistant bacteria. We summarized pharmaceutical, pharmacokinetic, and pharmacodynamic research on the definition, underlying mechanisms, and risk factors of ARC to guide individualized dosing of antibiotics and various strategies for optimizing outcomes. Methods: We searched for articles between 2010 and 2022 in the MEDLINE database about ARC patients and antibiotics and further provided individualized antibiotic dosage regimens for patients with ARC. Results: 25 antibiotic dosage regimens for patients with ARC and various strategies for optimization of outcomes, such as extended infusion time, continuous infusion, increased dosage, and combination regimens, were summarized according to previous research. Conclusion: ARC patients, especially critically ill patients, need to make individualized adjustments to antibiotics, including dose, frequency, and method of administration. Further comprehensive research is required to determine ARC staging, expand the range of recommended antibiotics, and establish individualized dosing guidelines for ARC patients.

Population Pharmacokinetics and Pharmacodynamics of Vancomycin in Pediatric Patients With Various Degrees of Renal Function

OBJECTIVE

Although vancomycin dosage recommendations in the pediatric setting for methicillin-resistant Staphylococcus aureus (MRSA) infection indicate that ≥60 mg/kg/day is correlated to a desired area under the vancomycin concentration time curve from 0 to 24 hours to minimum inhibitory concentration ratio (AUC0–24 hr/MIC) ≥400, for some patients this dosage is inadequate or relates to toxicity. This study purposed to explore vancomycin dosing for pediatrics with various degrees of renal function.

METHODS

Routine monitoring data were retrospectively collected from patients, aged 1 month to 18 years. Population pharmacokinetic analysis was performed by using non-linear mixed-effect model with NONMEM software, and Monte Carlo simulation was conducted by using Crystal Ball software.

RESULTS

Two hundred twelve patients with 348 vancomycin serum concentrations were included. Median age was 3.5 years (IQR, 0.9–10.9), median weight was 14.0 kg (IQR, 7.2–30.4), with baseline estimated glomerular filtration rate (eGFR) ranging from 15.5 to 359.3 mL/min/1.73 m2. A 1-compartment model with first-order elimination sufficiently described vancomycin PK. The dosing targeting AUC0–24hr/MIC ≥400 and AUC0–24hr <800 mg•h/L for pediatric patients with eGFRs of 15 to 29, 30 to 59, 60 to 89, 90 to 129, and 130 to 160 mL/min/1.73 m2 was 12.5, 25, 40, 60, and 70 mg/kg/day, respectively. All vancomycin dosing obtained >85% of the cumulative fraction of response across the MIC distribution of MRSA.

CONCLUSIONS

Vancomycin dosing of 12.5, 25, 40, 60, and 70 mg/kg/day is suggested for pediatric patients with eGFRs of 15 to 29, 30 to 59, 60 to 89, 90 to 129, and 130 to 160 mL/min/1.73 m2, respectively.

Recent Advances in Therapeutic Drug Monitoring of Voriconazole, Mycophenolic Acid, and Vancomycin: A Literature Review of Pediatric Studies

The review includes studies dated 2011-2021 presenting the newest information on voriconazole (VCZ), mycophenolic acid (MPA), and vancomycin (VAN) therapeutic drug monitoring (TDM) in children. The need of TDM in pediatric patients has been emphasized by providing the information on the differences in the drugs pharmacokinetics. TDM of VCZ should be mandatory for all pediatric patients with invasive fungal infections (IFIs). Wide inter- and intrapatient variability in VCZ pharmacokinetics cause achieving and maintaining therapeutic concentration during therapy challenging in this population. Demonstrated studies showed, in most cases, VCZ plasma concentrations to be subtherapeutic, despite the updated dosages recommendations. Only repeated TDM can predict drug exposure and individualizing dosing in antifungal therapy in children. In children treated with mycophenolate mofetil (MMF), similarly as in adult patients, the role of TDM for MMF active form, MPA, has not been well established and is undergoing continued debate. Studies on the MPA TDM have been carried out in children after renal transplantation, other organ transplantation such as heart, liver, or intestine, in children after hematopoietic stem cell transplantation or cord blood transplantation, and in children with lupus, nephrotic syndrome, Henoch-Schönlein purpura, and other autoimmune diseases. MPA TDM is based on the area under the concentration-time curve; however, the proposed values differ according to the treatment indication, and other approaches such as pharmacodynamic and pharmacogenetic biomarkers have been proposed. VAN is a bactericidal agent that requires TDM to prevent an acute kidney disease. The particular group of patients is the pediatric one. For this group, the general recommendations of the dosing may not be valid due to the change of the elimination rate and volume of distribution between the subjects. The other factor is the variability among patients that concerns the free fraction of the drug. It may be caused by both the patients' population and sample preconditioning. Although VCZ, MMF, and VAN have been applied in pediatric patients for many years, there are still few issues to be solve regarding TDM of these drugs to ensure safe and effective treatment. Except for pharmacokinetic approach, pharmacodynamics and pharmacogenetics have been more often proposed for TDM.

Population Pharmacokinetics of Vancomycin in the Pediatric Ventricular Assist Device Population

OBJECTIVES

Determine the pharmacokinetic disposition of vancomycin in the pediatric ventricular assist device population.

DESIGN

A retrospective, population pharmacokinetic study.

SETTING

Large, quaternary care children's hospital.

PATIENTS

Less than 19 years old initiated on vancomycin while undergoing ventricular assist device therapy from 2011 to 2018 in our institution.

INTERVENTIONS

Patient data were summarized by using descriptive statistical methods, and population pharmacokinetic analysis was performed by using NONMEM (Icon, PLC, Dublin, Ireland). Simulation was performed to identify a vancomycin dosing strategy that resulted in a trough concentration less than 15 mg/L and an area under the curve0-24:minimum inhibitory concentration ratio of greater than 400.

MEASUREMENTS AND MAIN RESULTS

A total of 69 patients (male 50.7%, median age 7.1 years [interquartile range, 2.4-11.9]) met study criteria (HeartWare [Framingham, MA] = 37, Berlin Heart [Berlin, Germany] = 22, Impella [Abiomed, Danvers, MA] = 4, RotaFlow [Maquet, Hirrlingen, Germany] right ventricular assist device = 3, HeartMate II [Abbott Laboratories, Abbott Park, IL] = 2, Berlin Heart biventricular assist device = 1). Patients received a median of 21 doses (interquartile range, 13-44 doses) of IV vancomycin (14.8 ± 1.8 mg/kg/dose) along with vancomycin as an intrathoracic irrigation (n = 48; 69.6%). The mean serum concentration was 12.2 ± 5.2 mg/L at 11.2 ± 6.9 hours after a dose. A one-compartment pharmacokinetic model best fit the data with allometric scaling on clearance and volume of distribution. Clearance was characterized by total body weight and serum creatinine, and volume of distribution was characterized by total body weight. Simulation identified doses greater than 15 mg/kg/dose with extended intervals were necessary to achieve endpoints.

CONCLUSIONS

Vancomycin dosing in pediatric ventricular assist device patients should be altered in comparison to nonventricular assist device patients and should be accompanied with frequent serum concentration monitoring.

Common bacterial infections and their treatment in hospitalized pediatric patients

PURPOSE

Common bacterial infections in pediatric patients that the hospital pharmacist may encounter are reviewed, and guidance on the safe and effective use of antibiotics to treat those infections is provided.

SUMMARY

Pharmacists play a key role in evaluating and creating antibiotic treatment plans for patients with infections. Bacterial infections are a common reason for hospital admission in pediatric patients, and pharmacists working in hospitals may be consulted to provide treatment and monitoring recommendations. It is important for pharmacists to be aware of similarities and differences in adult and pediatric populations with regard to presenting signs and symptoms of bacterial infections, common causative pathogens, and antibiotic selection, dosing, and monitoring. This article reviews current approaches to treatment of common bacterial infections in pediatric patients and also provides general suggestions for antibiotic use.

CONCLUSION

Pharmacists have an opportunity to positively impact the care of pediatric patients with bacterial infections. Especially at facilities where pediatric patients are not regularly treated, pharmacists can potentially improve care through provision of recommendations for optimal antibiotic selection, dosing, and monitoring.

The Benefit of Individualized Vancomycin Dosing Via Pharmacokinetic Tools: A Systematic Review and Meta-analysis

Background: Various pharmacokinetic (PK) equations and software have been developed to individualize vancomycin dosing. However, the benefit of using any PK information to guide vancomycin dosing has not been fully elucidated. Objective: To appraise available evidence on the effectiveness and safety of individualized vancomycin dosing via PK tools. Methods: PubMed, EMBASE, the Cochrane Library, and 2 Chinese literature databases were searched through August 1, 2019. Randomized controlled trials (RCTs) and cohort studies that reported the PK and clinical outcomes of individualized vancomycin dosing versus empirical dosing were included. Pooled risk ratios (RRs) and mean differences were calculated for dichotomous and continuous outcomes, respectively. Results: A total of 21 studies involving 4346 patients were finally included, of which 3 were RCTs and 18 were cohort studies. Meta-analysis revealed that PK-guided vancomycin dosing significantly increased the attainment of target trough concentration (RR = 1.59; 95% CI = 1.49-1.70) and decreased the incidence of nephrotoxicity (RR = 0.57; 95% CI = 0.46-0.71). Additionally, the available evidence showed that target area under the curve/minimum inhibitory concentration attainment rate and time to target concentration could improve. However, the evidence on clinical outcomes was scarce, and no significant differences were detected in clinical response rate, microbiological eradication rate, mortality, and length of hospital stay between PK-guided vancomycin dosing and empirical dosing strategies. Conclusion and Relevance: Individualized vancomycin dosing via PK tools significantly increases the attainment of target trough concentration and decreases the incidence of nephrotoxicity. Evidence on clinical effectiveness was limited and showed no significant benefit. Further well-designed studies are warranted to assess its clinical effectiveness and inform routine care.

Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in Children: a Reappraisal of Vancomycin

PURPOSE OF REVIEW

In the last 50 years, vancomycin has been the agent of choice to treat infections due to methicillin-resistant Staphylococcus aureus (MRSA). However, vancomycin treatment failure is not uncommon, even when MRSA strains are fully susceptible to vancomycin. Treatment with vancomycin requires careful monitoring of drug levels as there is a potential for nephrotoxicity. Resistance to clindamycin is not infrequent, which also limits therapeutic options for treating infections due to MRSA in children. This paper reviews the current data on pharmacokinetics and pharmacodynamics and clinical efficacy of vancomycin in children.

RECENT FINDINGS

Resistance to vancomycin in MRSA (MIC >2 mg/L) is infrequent; there is increasing evidence in the literature that vancomycin maybe ineffective against increasing proportion of isolates with MICs between 1 and 2 mg/L. Recent studies and meta-analyses have demonstrated that strains with high vancomycin MICs are associated with poor outcomes especially in patients with bacteremia and deep tissue infections due to MRSA. This gradual increase in vancomycin MIC has been reported as MIC creep or vancomycin heteroresistance. Patients infected with MRSA isolates that exhibit MIC creep experience poorer clinical outcomes, including delayed treatment response, increased mortality, increase rate of relapse, and extended hospitalization. There are limited data to guide vancomycin dosing in children with MRSA. Although the vancomycin area under the curve AUC₂₄/MIC ratio > 400 has been shown to predict clinical efficacy in adults, this relationship has not been documented very well for treatment outcomes in MRSA infections in children. Use of higher vancomycin dosages in attempts to achieve higher trough concentrations has been associated with increased nephrotoxicity. New recently approved antibiotics including ceftaroline, dalbavancin, and tedizolid offer a number of advantages over vancomycin to treat staphylococcal infections: improved antimicrobial activity, superior pharmacokinetics, pharmacodynamics, tolerability, and dosing, including once-daily and weekly regimens, and less need for monitoring drug levels.

Actual body weight-based vancomycin dosing in neonates

This study aimed to explore vancomycin pharmacokinetics and its covariates in critically ill neonates and to propose an easy applicable dosing nomogram for initial treatment. Individual vancomycin pharmacokinetic parameters were calculated based on therapeutic drug monitoring data using a one-compartmental model. A linear regression model was used for examination of covariates. The mean (SD) volume of distribution (Vd) and clearance (CL) for vancomycin were 0.73 (0.31) L/kg and 0.052 (0.020) L/h/kg, respectively. Vd was related to actual body weight (ABW), gestational and postmenstrual age. CL was also associated with ABW, gestational, postmenstrual age and also creatinine clearance. ABW was the strongest predictor for vancomycin pharmacokinetics and consequently dosing. Loading dose (mg) of 11.81 × ABW (kg) + 7.86 and maintenance dose (mg/day) of 40.92 × ABW (kg) -22.18 most closely approximated pharmacokinetic target. Vancomycin pharmacokinetics was mainly influenced by ABW in neonates and a practical ABW-based dosing algorithm was developed.

Nomogram based on actual body weight for estimation of vancomycin maintenance dose in infants

BACKGROUND

Vancomycin is the first-choice antibiotic for infants with β-lactam-resistant gram-positive bacterial infection. Despite long experience of prescribing of this drug optimal dosing is still challenging. This study aimed at investigating variables predicting vancomycin clearance in order to propose optimal maintenance dosing in infants treated for suspected or culture-proven sepsis.

METHODS

Vancomycin pharmacokinetics was calculated in a one-compartmental model based on serum concentrations. A linear regression model was used to explore relationships between vancomycin clearance and expected covariates.

RESULTS

Twenty-two patients were enrolled into the study. Median (IQR) postnatal age was 157 (112-238) days. The median (IQR) volume of distribution and clearance for vancomycin were 0.50 (0.39-0.94) L/kg and 0.112 (0.095-0.133) L/h/kg, respectively. Vancomycin clearance was associated with actual body weight, height, body surface area, gestational age, postnatal age, postmenstrual age and estimate glomerular filtration rate. Actual body weight was the best predictive variable for vancomycin clearance. Daily maintenance dose (mg) calculated as 76.28 × actual body weight (kg) - 41.57 most closely approximated optimal dosing based on individual pharmacokinetics. This relationship was used to construct a dosing nomogram.

CONCLUSIONS

We developed an easy-to-use dosing nomogram for maintaining a vancomycin average steady-state concentration of 22.5 mg/L based on actual body weight.

Effective vancomycin concentrations in children: a cross-sectional study

OBJECTIVE

Analyze the microbiological effectiveness, based on the pharmacokinetics/pharmacodynamics correlation of vancomycin in pediatric patients, and to propose dose adjustment.

METHODS

This is an observational, cross-sectional study, conducted in a pediatric hospital, over a 1-year period (2016 to 2017). Children of both sexes, aged 2 to 12 years, were included in the study; burn children, and children in renal replacement therapy were excluded. For the pharmacokinetic analysis, two samples of 2mL of whole blood were collected, respecting the 2-hour interval between each withdrawal.

RESULTS

Ten pediatric patients with median age of 5.5 years and interquartile range (IQR) of 3.2-9.0 years, median weight of 21kg (IQR: 15.5-24.0kg) and median height of 112.5cm (IQR: 95-133cm), were included. Only one child achieved trough concentrations between 10µg/mL and 15µg/mL.

CONCLUSION

The empirical use of vancomycin in the children studied did not achieve the therapeutic pharmacokinetic/pharmacodynamic target for minimum inhibitory concentration of 1µg/mL.

The Relationship Between Vancomycin Trough Concentrations and AUC/MIC Ratios in Pediatric Patients: A Qualitative Systematic Review

BACKGROUND

In adults, the area under the concentration-time curve (AUC) divided by the minimum inhibitory concentration (MIC) is associated with better clinical and bacteriological response to vancomycin in patients with methicillin-resistant Staphylococcus aureus who achieve target AUC/MIC ≥ 400. This target is often extrapolated to pediatric patients despite the lack of similar evidence. The impracticalities of calculating the AUC in practice means vancomycin trough concentrations are used to predict the AUC/MIC.

OBJECTIVE

This review aimed to determine the relationship between vancomycin trough concentrations and AUC/MIC in pediatric patients.

METHODS

We searched the MEDLINE and Embase databases, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials using the medical subject heading (MeSH) terms vancomycin and AUC and pediatric* or paediatric*. Articles were included if they were published in English and reported a relationship between vancomycin trough concentrations and AUC/MIC.

RESULTS

Of 122 articles retrieved, 11 met the inclusion criteria. One trial reported a relationship between vancomycin trough concentrations, AUC/MIC, and clinical outcomes but was likely underpowered. Five studies found troughs 6-10 mg/l were sufficient to attain an AUC/MIC > 400 in most general hospitalized pediatric patients. One study in patients undergoing cardiothoracic surgery found a trough of 18.4 mg/l achieved an AUC/MIC > 400. Two oncology studies reported troughs ≥ 15 mg/l likely attained an AUC/MIC ≥ 400. In critical care patients: one study found a trough of 9 mg/l did not attain the AUC/MIC target; another found 7 mg/l corresponded to an AUC/MIC of 400.

CONCLUSIONS

Potential vancomycin targets varied based on the population studied but, for general hospitalized pediatric patients, troughs of 6-10 mg/l are likely sufficient to achieve AUC/MIC ≥ 400. For MIC ≥ 2 mg/l, higher troughs are likely necessary to achieve an AUC/MIC ≥ 400. More research is needed to determine the relationships between vancomycin trough concentrations, AUC/MIC, and clinical outcomes.