Nephrotoxicity in Patients with Vancomycin Trough Concentrations of 15-20 μg/ml in a Pediatric Intensive Care Unit

Vancomycin efficiency and safety of a dosage of 40–60 mg/kg/d and corresponding trough concentrations in children with Gram-positive bacterial sepsis

Background

Optimal vancomycin trough concentrations and dosages remain controversial in sepsis children. We aim to investigate vancomycin treatment outcomes with a dosage of 40-60 mg/kg/d and corresponding trough concentrations in children with Gram-positive bacterial sepsis from a clinical perspective.

Methods

Children diagnosed with Gram-positive bacterial sepsis and received intravenous vancomycin therapy between January 2017 and June 2020 were enrolled retrospectively. Patients were categorized as success and failure groups according to treatment outcomes. Laboratory, microbiological, and clinical data were collected. The risk factors for treatment failure were analyzed by logistic regression.

Results

In total, 186 children were included, of whom 167 (89.8%) were enrolled in the success group and 19 (10.2%) in the failure group. The initial and mean vancomycin daily doses in failure group were significantly higher than those in success group [56.9 (IQR =42.1-60.0) vs. 40.5 (IQR =40.0-57.1), P=0.016; 57.0 (IQR =45.8-60.0) vs. 50.0 (IQR =40.0-57.6) mg/kg/d, P=0.012, respectively] and median vancomycin trough concentrations were similar between two groups [6.9 (4.0-12.1) vs.7.3 (4.5-10.6) mg/L, P=0.568)]. Moreover, there was no significant differences in treatment success rate between vancomycin trough concentrations ≤15 mg/L and >15 mg/L (91.2% vs. 75.0%, P=0.064). No vancomycin-related nephrotoxicity adverse effects occurred among all enrolled patients. Multivariate analysis revealed that a PRISM III score ≥10 (OR =15.011; 95% CI: 3.937-57.230; P<0.001) was the only independent clinical factor associated with increased incidence of treatment failure.

Conclusions

Vancomycin dosages of 40-60 mg/kg/d are effective and have no vancomycin-related nephrotoxicity adverse effects in children with Gram-positive bacterial sepsis. Vancomycin trough concentrations >15 mg/L are not an essential target for these Gram-positive bacterial sepsis patients. PRISM III scores ≥10 may serve as an independent risk factor for vancomycin treatment failure in these patients.

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.

Pharmacokinetics of Antibiotics in Pediatric Intensive Care: Fostering Variability to Attain Precision Medicine

Children show important developmental and maturational changes, which may contribute greatly to pharmacokinetic (PK) variability observed in pediatric patients. These PK alterations are further enhanced by disease-related, non-maturational factors. Specific to the intensive care setting, such factors include critical illness, inflammatory status, augmented renal clearance (ARC), as well as therapeutic interventions (e.g., extracorporeal organ support systems or whole-body hypothermia [WBH]). This narrative review illustrates the relevance of both maturational and non-maturational changes in absorption, distribution, metabolism, and excretion (ADME) applied to antibiotics. It hereby provides a focused assessment of the available literature on the impact of critical illness—in general, and in specific subpopulations (ARC, extracorporeal organ support systems, WBH)—on PK and potential underexposure in children and neonates. Overall, literature discussing antibiotic PK alterations in pediatric intensive care is scarce. Most studies describe antibiotics commonly monitored in clinical practice such as vancomycin and aminoglycosides. Because of the large PK variability, therapeutic drug monitoring, further extended to other antibiotics, and integration of model-informed precision dosing in clinical practice are suggested to optimise antibiotic dose and exposure in each newborn, infant, or child during intensive care.

Pharmacokinetics and Target Attainment of Antibiotics in Critically Ill Children: A Systematic Review of Current Literature

BACKGROUND

Pharmacokinetics (PK) are severely altered in critically ill patients due to changes in volume of distribution (Vd) and/or drug clearance (Cl). This affects the target attainment of antibiotics in critically ill children. We aimed to identify gaps in current knowledge and to compare published PK parameters and target attainment of antibiotics in critically ill children to healthy children and critically ill adults.

METHODS

Systematic literature search in PubMed, EMBASE and Web of Science. Articles were labelled as relevant when they included information on PK of antibiotics in critically ill, non-neonatal, pediatric patients. Extracted PK-parameters included Vd, Cl, (trough) concentrations, AUC, probability of target attainment, and elimination half-life.

RESULTS

50 relevant articles were identified. Studies focusing on vancomycin were most prevalent (17/50). Other studies included data on penicillins, cephalosporins, carbapenems and aminoglycosides, but data on ceftriaxone, ceftazidime, penicillin and metronidazole could not be found. Critically ill children generally show a higher Cl and larger Vd than healthy children and critically ill adults. Reduced target-attainment was described in critically ill children for multiple antibiotics, including amoxicillin, piperacillin, cefotaxime, vancomycin, gentamicin, teicoplanin, amikacin and daptomycin. 38/50 articles included information on both Vd and Cl, but a dosing advice was given in only 22 articles.

CONCLUSION

The majority of studies focus on agents where TDM is applied, while other antibiotics lack data altogether. The larger Vd and higher Cl in critically ill children might warrant a higher dose or extended infusions of antibiotics in this patient population to increase target-attainment. Studies frequently fail to provide a dosing advice for this patient population, even if the necessary information is available. Our study shows gaps in current knowledge and encourages future researchers to provide dosing advice for special populations whenever possible.

Impact of the Implementation of a Vancomycin Protocol on Trough Serum Vancomycin Concentrations in a Pediatric Intensive Care Unit

BACKGROUND

Vancomycin is an antibiotic that is widely used in pediatric intensive care, but the safe and effective use of this drug is challenging.

OBJECTIVE

This study aimed to assess the impact of a vancomycin protocol on trough serum concentrations.

METHODS

We conducted a retrospective quasiexperimental study in patients aged ≤ 18 years in intensive care who received vancomycin for at least 5 days. Patients were divided into two groups: before and after a protocol implemented in 2017 that suggested an initial vancomycin dose of 60 mg/kg/day, target serum levels of 15-20 μg/mL, and dose adjustments. We compared patient characteristics, target serum level achievement, and vancomycin levels over time.

RESULTS

Each group contained 65 patients; most were male infants with heart disease as the main reason for hospitalization. Only 29.2% of the patients had pretreatment cultures for bacteria identification recorded, with 1.5% identified as methicillin-resistant Staphylococcus aureus. For the first serum levels, 10.8% of patients in the pre-protocol group and 21.5% in the post-protocol group achieved the 15-20 μg/mL target (p = 0.153); during the first 5 days of treatment, this proportion significantly increased from 52.3 to 73.8% (p = 0.018). We observed a difference between the first and fifth levels: 8.9 μg/mL (95% confidence interval [CI] - 3.1 to 21) pre-protocol and 0.4 μg/mL (95% CI - 6.1 to 6.9) post-protocol (p = 0.175).

CONCLUSIONS

Reaching adequate trough vancomycin concentrations in critically ill pediatric patients remains a challenge, and clinical practice protocols allow better dose adjustment and control even when monitoring technologies are unavailable.

Vancomycin-associated Nephrotoxicity and Risk Factors in Critically Ill Children Without Preexisting Renal Injury

BACKGROUND

A recent systematic review concluded that critically ill pediatric patients have higher odds of vancomycin-related nephrotoxicity [odds ratio (OR): 3.61, 95% CI: 1.21-10.74]. We aimed to assess the incidence and risk factors for vancomycin-associated nephrotoxicity in critically ill children without preexisting renal injury.

METHODS

A cohort of children admitted to a pediatric intensive care unit, from 2011 to 2016 treated with vancomycin without preexisting renal injury. The main diagnosis, therapeutic interventions and medications administered in this period were evaluated. Generalized estimating equation models were used to assess the association between clinical covariates and the dependent variable pediatric risk, injury, failure, loss, end-stage renal disease (pRIFLE).

RESULTS

Hundred ten patients, representing 1177 vancomycin days, were analyzed. Vancomycin-associated nephrotoxicity was seen in 11.8%. In a multivariate model, higher vancomycin doses were not associated with poorer renal function (P = 0.08). Higher serum vancomycin levels were weakly associated with pRIFLE classification (OR: 1.05, 95% CI: 1.02-1.07). Furosemide or amphotericin B in addition to the vancomycin treatment was associated with impaired renal function (OR: 2.56, 95% CI: 1.38-4.8 and OR: 7.7 95% CI: 2.55-23, respectively).

CONCLUSIONS

Vancomycin-associated nephrotoxicity in acute ill children without preexisting renal injury, measured with pRIFLE, is close to 11.8%. Furosemide and amphotericin B in addition to the vancomycin treatment are strong predictors of worse pRIFLE scores. The influence of acute kidney injury status at pediatric intensive care unit admission and the method used for renal function assessment might influence the incidence of vancomycin-associated nephrotoxicity and its associated risk factors.

Management of Pediatric Acute Hematogenous Osteomyelitis, Part II: A Focus on Methicillin-Resistant Staphylococcus aureus, Current and Emerging Therapies

Methicillin-resistant Staphylococcus aureus (MRSA) has become the most prevalent cause of acute hematogenous osteomyelitis (AHO) in pediatric patients. This increase in MRSA is due to the rise in community-acquired MRSA. Therefore, it is important that clinicians are aware of the various and upcoming therapies that cover this bacterium. A literature search of the Medline database was performed from creation through January 2018. Articles chosen for the review emphasize well-established MRSA treatment options for pediatric AHO, newer therapies on the horizon, and important pharmacokinetics and pharmacodynamic concepts for treatment. Traditional therapies, including vancomycin and clindamycin, remain effective for the treatment of pediatric AHO. When these agents cannot be used, evidence in AHO has been growing for daptomycin, linezolid, and ceftaroline. Further initial pediatric data with the long-acting lipoglycopeptides show promise and in the future may provide a role in AHO treatment in children.

Nephrotoxicity With Vancomycin in the Pediatric Population: A Systematic Review and Meta-Analysis

BACKGROUND

Vancomycin is frequently used to treat methicillin-resistant Staphylococcus aureus infections in pediatric patients. Vancomycin exposure may lead to an increase in frequency of nephrotoxicity. Our aim was to conduct a systematic review to describe predictors of nephrotoxicity associated with vancomycin, including documented trough concentrations ≥15 mg/L. We also aimed to use a meta-analysis to assess the impact of a vancomycin trough ≥15 mg/L on nephrotoxicity.

METHODS

A literature search was performed using PubMed, Cochrane Library, Embase and Web of Sciences database. We included randomized clinical trials and observational studies evaluating the relationship between vancomycin troughs and nephrotoxicity in pediatric-age patients. Studies not measuring troughs or defining a different cut-off point than 15 mg/L were excluded. Data on age, exclusion criteria, nephrotoxicity definition, risk factors for nephrotoxicity and vancomycin trough levels were extracted from selected papers.

RESULTS

Ten studies were identified for meta-analysis. All subjects had comparatively normal baseline serum creatinine values. Common risk factors identified included elevated (≥15 mg/L) trough levels, renal impairment, hypovolemia and concurrent use of nephrotoxic medications. Troughs ≥15 mg/L increased nephrotoxicity by 2.7-fold (odds ratio (OR), 2.71; 95% confidence interval: 1.82-4.05; I(2) = 40%; Q = 0.09). These odds were further increased among patients in the pediatric intensive care unit (OR, 3.61; 95% confidence interval: 1.21-10.74; I(2) = 45%; Q = 0.18).

CONCLUSIONS

Though the rate of vancomycin-induced nephrotoxicity is increased in pediatric patients with higher vancomycin troughs, other factors such as intensive care unit admission, hypovolemia and concurrent nephrotoxic drug use appear to contribute to the development of nephrotoxicity.

Ceftaroline for Suspected or Confirmed Invasive Methicillin-Resistant Staphylococcus aureus: A Pharmacokinetic Case Series

OBJECTIVES

To describe the ceftaroline pharmacokinetics in critically ill children treated for suspected or confirmed methicillin-resistant Staphylococcus aureus infections, including blood stream infection and describe the microbiological and clinical outcomes.

DESIGN

Retrospective electronic medical record review.

SETTINGS

Free-standing tertiary/quaternary pediatric children's hospital.

PATIENTS

Critically ill children receiving ceftaroline monotherapy or combination therapy for suspected or confirmed methicillin-resistant S. aureus infections in the PICU.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Seven patients, three females (43%), and four males (57%), accounted for 33 ceftaroline samples for therapeutic drug management. A median of four samples for therapeutic drug management was collected per patient (range, 2-9 samples). The median age was 7 years (range, 1-13 yr) with a median weight of 25.5 kg (range, 12.6-40.1 kg). Six of seven patients (86%) demonstrated an increase in volume of distribution, five of seven patients (71%) demonstrated an increase in clearance, and 100% of patients demonstrated a shorter half-life estimate as compared with the package insert estimate. Six of seven patients (85.7%) had documented methicillin-resistant S. aureus growth from a normally sterile site with five of six (83.3%) having documented BSI, allowing six total patients to be evaluated for the secondary objective of microbiological and clinical response. All six patients achieved a positive microbiological and clinical response for a response rate of 100%.

CONCLUSIONS

These data suggest the pharmacokinetics of ceftaroline in PICU patients is different than healthy pediatric and adult patients, most notably a faster clearance and larger volume of distribution. A higher mg/kg dose and a more frequent dosing interval for ceftaroline may be needed in PICU patients to provide appropriate pharmacodynamic exposures. Larger pharmacokinetic, pharmacodynamic, and interventional treatment trials in the PICU population are warranted.

Incidence and Risk Factors for Vancomycin Nephrotoxicity in Acutely Ill Pediatric Patients

Background: Particularly with the current increased vancomycin dosing trends, the true risk of the agent's nephrotoxicity is not well characterized and remains of concern. Objective: To determine the incidence of vancomycin nephrotoxicity in acutely ill hospitalized children and to secondarily characterize the risk factors for this complication. Methods: A single-center retrospective cohort study conducted at UCSF Benioff Children's Hospital from June 2012 to June 2015. Inpatients 3 months to <19 years who received intravenous vancomycin for ≥48 hours were included. The primary outcome was incidence of nephrotoxicity, defined as an increase in serum creatinine by ≥50% from baseline. Univariate and multivariate analyses were conducted to identify risk factors for vancomycin nephrotoxicity. Results: A total of 291 patients (272 nonnephrotoxic and 19 nephrotoxic) were included in the analysis. Of the 19 patients, 12 (4.1%) were found to have moderate to severe toxicity. The median duration of therapy was 3 (3-5) and 4 (3-6) days for the group with "no nephrotoxicity" and "nephrotoxicity," respectively. The mean time for the serum creatinine to return to normal in patients with nephrotoxicity was 5.1 days. In the multivariate analysis, only final trough concentration ≥15mg/dL (odds ratio = 3.49, 95% confidence interval = 1.2-10.1; P = .021) and receipt of piperacillin/tazobactam (odds ratio = 3.14, 95% confidence interval = 1.02-9.6; P = .046) were significantly associated with nephrotoxicity. Conclusion: The rate of moderate to severe vancomycin-associated nephrotoxicity in acutely ill children is relatively uncommon and reversible. Kidney injury is associated with increased vancomycin trough concentrations and concomitant receipt of nephrotoxins, particularly piperacillin/tazobactam.

Association of Acute Kidney Injury With Concomitant Vancomycin and Piperacillin/Tazobactam Treatment Among Hospitalized Children

IMPORTANCE

β-Lactam antibiotics are often coadministered with intravenous (IV) vancomycin hydrochloride for children with suspected serious infections. For adults, the combination of IV vancomycin plus piperacillin sodium/tazobactam sodium is associated with a higher risk of acute kidney injury (AKI) compared with vancomycin plus 1 other β-lactam antibiotic. However, few studies have evaluated the safety of this combination for children.

OBJECTIVE

To assess the risk of AKI in children during concomitant therapy with vancomycin and 1 antipseudomonal β-lactam antibiotic throughout the first week of hospitalization.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study focused on children hospitalized for 3 or more days who received IV vancomycin plus 1 other antipseudomonal β-lactam combination therapy at 1 of 6 large children's hospitals from January 1, 2007, through December 31, 2012. The study used the Pediatric Health Information System Plus database, which contains administrative and laboratory data from 6 pediatric hospitals in the United States. Patients with underlying kidney disease or abnormal serum creatinine levels on hospital days 0 to 2 were among those excluded. Patients 6 months to 18 years of age who were admitted through the emergency department of the hospital were included. Data were collected from July 2015 to March 2016. Data analysis took place from April 2016 through July 2017. (Exact dates are not available because the data collection and analysis processes were iterative.).

MAIN OUTCOMES AND MEASURES

The primary outcome was AKI on hospital days 3 to 7 and within 2 days of receiving combination therapy. Acute kidney injury was defined using KDIGO criteria and was based on changes in serum creatinine level from hospital days 0 to 2 through hospital days 3 to 7. Multiple logistic regression was performed using a discrete-time failure model to test the association between AKI and receipt of IV vancomycin plus piperacillin/tazobactam or vancomycin plus 1 other antipseudomonal β-lactam antibiotic.

RESULTS

A total of 1915 hospitalized children who received combination therapy were identified. Of the 1915 patients, a total of 866 (45.2%) were female and 1049 (54.8%) were male, 1049 (54.8%) were identified as white in race/ethnicity, and the median (interquartile range) age was 5.6 (2.1-12.7) years. Among the cohort who received IV vancomycin plus 1 other antipseudomonal β-lactam antibiotic, 157 patients (8.2%) had antibiotic-associated AKI. This number included 117 of 1009 patients (11.7%) who received IV vancomycin plus piperacillin/tazobactam combination therapy. After adjustment for age, intensive care unit level of care, receipt of nephrotoxins, and hospital, IV vancomycin plus piperacillin/tazobactam combination therapy was associated with higher odds of AKI each hospital day compared with vancomycin plus 1 other antipseudomonal β-lactam antibiotic combination (adjusted odds ratio, 3.40; 95% CI, 2.26-5.14).

CONCLUSIONS AND RELEVANCE

Coadministration of IV vancomycin and piperacillin/tazobactam may increase the risk of AKI in hospitalized children. Pediatricians must be cognizant of the potential added risk of this combination therapy when making empirical antibiotic choices.

Piperacillin-tazobactam versus cefepime incidence of acute kidney injury in combination with vancomycin and tobramycin in pediatric cystic fibrosis patients

BACKGROUND

Cystic fibrosis (CF) patients often receive prolonged courses of broad spectrum antibiotics, such as piperacillin-tazobactam or cefepime in combination with vancomycin and tobramycin. The objective of this study was to determine the difference in AKI for pediatric CF patients receiving piperacillin-tazobactam or cefepime in combination with vancomycin and tobramycin.

METHODS

IRB approval from a single CF center was obtained for this retrospective cohort study. Charts were evaluated from December 1, 2008 to June 30,2015. Patients were included if they had a diagnosis of CF, age 30 days to 18 years, and received intravenous vancomycin, tobramycin, and piperacillin-tazobactam or cefepime. The primary outcome was difference of AKI incidence in patients receiving piperacillin-tazobactam or cefepime, as defined by modified pediatric risk, injury, failure, loss, end stage renal disease (pRIFLE) criteria.

RESULTS

Seventy-one patients were included with a median (interquartile range) age 11 years (7-16) and weight 36.2 kg (22.7-50). AKI was identified in 54.5% (18/33) of patients receiving piperacillin-tazobactam and 13.2% (5/38) of patients receiving cefepime (P ≤ 0.0001). One patient receiving piperacillin-tazobactam experienced acute renal failure. There was a slight difference in length of admission (13 vs 10 days, P = 0.042), but no difference in days to maximum SCr (6 vs 3, P = 0.127) nor FEV1 percent predicted on admission (69% vs 65%, P = 1.00).

CONCLUSIONS

AKI occurred in nearly 55% of patients with piperacillin-tazobactam therapy versus 13% of patients with cefepime therapy, which suggests cefepime may be preferred in combination with vancomycin and tobramycin for pediatric CF patients.

The 6R's of drug induced nephrotoxicity

Drug induced kidney injury is a frequent adverse event which contributes to morbidity and increased healthcare utilization. Our current knowledge of drug induced kidney disease is limited due to varying definitions of kidney injury, incomplete assessment of concurrent risk factors and lack of long term outcome reporting. Electronic surveillance presents a powerful tool to identify susceptible populations, improve recognition of events and provide decision support on preventative strategies or early intervention in the case of injury. Research in the area of biomarkers for detecting kidney injury and genetic predisposition for this adverse event will enhance detection of injury, identify those susceptible to injury and likely mitigate risk. In this review we will present a 6R framework to identify and mange drug induced kidney injury – risk, recognition, response, renal support, rehabilitation and research.

Frequency of and Risk Factors for Acute Kidney Injury Associated With Vancomycin Use in the Pediatric Intensive Care Unit

BACKGROUND: Published information evaluating frequency of and risk factors for vancomycin-induced acute kidney injury (AKI) in the pediatric intensive care unit (PICU) population is conflicting. OBJECTIVES: The primary objective was to describe the proportion of our PICU patients who developed AKI with intravenous (IV) vancomycin. The secondary objective was to describe the associated potential risk factors. METHODS: Pediatric patients (0-18 years) who received their first IV vancomycin dose in the PICU were evaluated in this retrospective chart review. AKI was defined based on Pediatric-Modified RIFLE (pRIFLE) criteria. Patient demographics, vancomycin trough concentrations, concomitant nephrotoxins, and estimated creatinine clearance changes were analyzed. RESULTS: Of 265 patients included, the primary outcome of AKI (defined by meeting any pRIFLE criteria) occurred in 62 (23.4%) patients (48 category R, 11 category I, 3 category F). Patients who received vancomycin treatment for = 5 days were more likely to develop AKI (unadjusted odds ratio [uOR]: 2.52; 95% confidence interval [CI]: 1.11-5.73), as were patients with a maximum vancomycin trough level = 20 mg/L (OR: 2.99; 95% CI: 1.54-5.78) and patients on 1 (uOR: 2.29; 95% CI: 1.12-4.66) or more concurrent nephrotoxin (uOR: 3.11; 95% CI: 1.43-6.77). Among nephrotoxins, patients receiving furosemide concomitantly with vancomycin were more likely to develop AKI (uOR: 3.47; 95% CI: 1.92-6.27). After adjustment, only furosemide was a significant predictor of risk of AKI/AKI (adjusted OR: 3.52; 95% CI: 1.88-6.62). The study was limited by its retrospective and observational design, and confounding variables. CONCLUSIONS: Patients who were receiving vancomycin with concurrent furosemide were at highest risk of developing AKI.

Acute Kidney Injury in a Child Receiving Vancomycin and Piperacillin/Tazobactam

Recent reports have described increased risk of acute kidney injury (AKI) in adults receiving concomitant vancomycin and piperacillin/tazobactam, but few reports exist in children. We describe an 8-year-old girl who was admitted to the pediatric intensive care unit with respiratory distress secondary to pneumonia. She began treatment with vancomycin and piperacillin/tazobactam. She developed AKI, and piperacillin/tazobactam and vancomycin were discontinued. Following a furosemide infusion, her AKI resolved and serum creatinine returned to baseline. She later resumed piperacillin/tazobactam monotherapy for multidrug-resistant tracheitis with no evidence of AKI and was eventually discharged to a long-term care facility. The Naranjo probability scale supports a probable drug-related adverse event. Clinicians must be aware of the possibility of AKI with this combination and should monitor renal function and vancomycin concentrations vigilantly. Future prospective studies are needed to explore the incidence and clinical characteristics associated with AKI after this combination in children.

Continuous Infusion Vancomycin Through the Addition of Vancomycin to the Continuous Renal Replacement Therapy Solution in the PICU: A Case Series

OBJECTIVES

To describe our experience with achieving therapeutic serum vancomycin concentrations in pediatric continuous renal replacement therapy by using continuous infusion vancomycin by mixing vancomycin into the continuous renal replacement therapy solution.

DESIGN

Retrospective chart review.

SETTING

A 189-bed, freestanding children's tertiary care teaching hospital in Philadelphia, PA.

PATIENTS

Pediatric patients receiving continuous renal replacement therapy from April 1, 2009, through December 31, 2014.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were a total of 21 patients who received continuous renal replacement therapy during the study period. Of these, 11 (52.3%) received vancomycin in the continuous renal replacement therapy solution. The median (range) concentration of vancomycin added to the continuous renal replacement therapy solution was 25 mg/L (18-35 mg/L). The mean vancomycin plateau level was 22.8 ± 3.3 mg/L. All patients achieved a serum vancomycin plateau level that was greater than 15 mg/L. There were no adverse events related to the addition of vancomycin to the continuous renal replacement therapy solution.

CONCLUSIONS

The addition of vancomycin to the continuous renal replacement therapy solution(s) is an effective modality that is used for delivering vancomycin continuous infusion and for ensuring therapeutic vancomycin serum plateau levels in the setting of pediatric continuous renal replacement therapy. Further studies are required to evaluate whether this delivery method can lead to improved patient outcomes.

Vancomycin Dosing and Pharmacokinetics in Postoperative Pediatric Cardiothoracic Surgery Patients

OBJECTIVES

This study compared vancomycin trough concentrations and pharmacokinetic parameters in pediatric cardiothoracic surgery (CTS) patients versus those in controls receiving 20 mg/kg/dose, intravenously, every 8 hours.

METHODS

A retrospective study was conducted in children <18 years of age, following CTS, versus an age-and sex-matched control group. The primary objective was to determine differences in trough concentrations between groups. Secondary objectives included comparisons of pharmacokinetics between groups and development of vancomycin-associated acute kidney injury (AKI), defined as a doubling in serum creatinine from baseline. Also dosing projections were developed to target an area-under-the-curve-to-minimum inhibitory concentration (AUC:MIC) ratio of ≥400.

RESULTS

Twenty-seven patients in each group were evaluated. Mean trough concentrations were significantly different between groups (CTS: 18.4 mg/L; control: 8.8 mg/L; p < 0.01). Vancomycin-associated acute kidney injury AKI was significantly higher in the CTS group than in controls (25.9% versus 0%, respectively, p<0.01). There were significant differences in vancomycin elimination rates, with a high degree of variability, but no statistical differences in other parameters. Based on dosing projections, CTS patients would require 21 to 88 mg/kg/day, with a dosage interval determined by the child's glomerular filtration rate to achieve the target AUC:MIC ≥400.

CONCLUSIONS

Vancomycin dosage of 20 mg/kg/dose intravenously every 8 hours achieved significantly higher trough concentrations in CTS patients than in controls. Pharmacokinetic parameters were highly variable in CTS patients, indicating more individualization of dosage is needed. A future prospective study is needed to determine whether the revised dosage projections achieve the AUC:MIC target and to determine whether these regimens are associated with less vancomycin-associated AKI.

Pharmacodynamic Characteristics of Nephrotoxicity Associated With Vancomycin Use in Children

BACKGROUND

Limited studies incorporating population-based pharmacokinetic modeling have been conducted to determine pharmacodynamic indices associated with nephrotoxicity during vancomycin exposure in children.

METHODS

A retrospective cohort analysis was conducted from September 2003 to December 2011 at 2 hospitals. Nephrotoxicity was defined as an increase in serum creatinine concentration (SCr) by ≥0.5 mg/dL, or ≥50% increase in baseline SCr, either persisting for ≥2 consecutive days. A 1-compartment model with first-order kinetics was used in NONMEM 7.2 to estimate trough concentrations (Cmin) and area under the curve over 24 hours (AUC). Univariate, classification and regression tree (CART), and multivariate analyses were conducted to identify factors contributing to nephrotoxicity.

RESULTS

The analyses included 680 pediatric subjects with 1576 vancomycin serum concentrations. Based on univariate analysis, median Cmin (14.2 [interquartile range, IQR, 7.1-25.4] vs 8.4 [IQR, 5.5-12.4] mcg/mL; P = .001) and AUC (544 [IQR, 359-801] vs 378 [IQR, 304-494]; P < .001) were significantly higher in the nephrotoxic group compared with the non-nephrotoxic group. Using CART, we discovered that subjects with doses ≥60 mg/kg per day and AUC >1063 mg-h/L had a significantly higher occurrence of nephrotoxicity (P = .005). Adjusting for intensive care unit stay and concomitant nephrotoxic drugs, steady-state vancomycin Cmin ≥15 mcg/mL (adjusted odds ratio [aOR], 2.5; 95% confidence interval [CI], 1.1-5.8; P = .028) and AUC ≥800 mg-h/L (aOR, 3.7; 95% CI, 1.2-11.0; P = .018) were associated with increased risk of nephrotoxicity.

CONCLUSIONS

Our study describes the pediatric exposure-nephrotoxicity relationships for vancomycin. Vancomycin Cmin ≥15 mcg/mL and AUC ≥800 mg-h/L in children are independently associated with a > 2.5-fold increased risk of nephrotoxicity and may provide justification for use of alternative antibiotics in selected situations.

Vancomycin dosing and target attainment in children

BACKGROUND/PURPOSE

The aim of this study is to determine the best dosing strategy for vancomycin by studying the associated factors and examining correlations between the area under the plasma concentration-time curve (AUC) values and trough concentrations in children.

METHODS

Children aged 3 months to 18 years were included if they received vancomycin for more than three doses between January 1, 2010 and December 31, 2012 and had one or more serum vancomycin trough concentrations. Vancomycin clearance (CL) was calculated using the following model: CL = 0.248*Wt^0.75*(0.48/serum creatinine)^0.361*[ln (age)/7.8]^0.995. The AUC (mg-h/L) was calculated by 24-hour dose (mg/kg/d)/CL(L/h). The value of AUC divided by the minimum inhibitory concentration (MIC) of vancomycin was AUC/MIC.

RESULTS

A total of 218 children were included. The mean age was 6.0 ± 5.1 years and the mean body weight was 20 ± 11.7 kg. Vancomycin trough concentrations were moderately correlated with AUC values (r² = 0.232, p < 0.01). Dosing of 15 mg/kg/dose q6h produced significantly higher AUC values (p < 0.001) and vancomycin trough concentrations (p < 0.001) compared to dosing of 10 mg/kg/dose q6h. In children receiving a 10-mg/kg/dose q6h, 5.6% (5/90) achieved the target trough concentrations of 15-20 μg/mL and 9.5% (5/90) achieved the goal AUC/MIC ≥ 400. In children receiving a 15-mg/kg/dose q6h, 13% (6/46) achieved the target trough concentrations of 15-20 μg/mL, whereas 54.3% (25/46) achieved the goal AUC/MIC ≥ 400.

CONCLUSION

A 15-mg/kg/dose q6h compared to a 10-mg/kg/dose q6h is more likely to achieve target trough concentrations of 15-20 μg/mL and the goal AUC/MIC ≥ 400.

Late-Occurring Vancomycin-Associated Acute Kidney Injury in Children Receiving Prolonged Therapy

Background: Acute kidney injury (AKI) in patients receiving vancomycin has been associated with trough concentrations ≥15 mg/L and longer therapy duration. The objective of this study was to determine the incidence and factors associated with late AKI in children receiving ≥8 days of vancomycin therapy. Methods: Children aged 30 days to 17 years who were admitted to our institution and received intravenous vancomycin for at least 8 days during January to December of 2007 and 2010 and had a suspected or proven gram-positive infection were included. Late AKI was categorized as AKI occurring after the first 7 days of therapy and within 48 hours following vancomycin discontinuation. The primary outcome was incidence of late AKI as determined by modified pRIFLE criteria. Results: One-hundred sixty-seven patients were included, with a median (interquartile range) age (years) and weight (kg) of 2 (1-7) and 12.5 (8.9-23.8). Late AKI was identified in 12.6% (21/167). A higher percentage of late AKI patients received concomitant treatment with intravenous acyclovir, amphotericin products, or piperacillin-tazobactam. Age <1 year was the only factor independently associated with late AKI development (odds ratio = 4.4; 95% confidence interval = 1.3-15.4). Conclusions: Late AKI occurred in nearly 13% of children receiving ≥8 days of vancomycin therapy. This study suggests that vancomycin trough concentrations are not associated with late AKI, but that age <1 year and concomitant administration of certain nephrotoxins may be factors associated with increased risk.

An evaluation of vancomycin dosing for complicated infections in pediatric patients

OBJECTIVE

To determine the incidence with which a vancomycin dosing regimen of 15 mg/kg per dose every 6 hours achieves steady-state trough concentrations of 15 to 20 mg/L in pediatric patients with complicated infections.

METHODS

We performed a retrospective chart review for patients admitted to our children's hospital between July 1, 2009, and June 30, 2011. Patients were included if they were between 1 month and 18 years of age, had at least 1 steady-state vancomycin trough obtained, received an initial vancomycin dose of 15 mg/kg per dose every 6 hours, and were being treated for a diagnosis of meningitis, pneumonia, osteomyelitis, bacteremia/sepsis, or endocarditis.

RESULTS

Seventy-four patients were enrolled, mean age of 4.2±3.9 years and weight of 17.0±11.2 kg. Five (6.8%) patients obtained an initial trough of 15 to 20 mg/L. Patients between 1.0 and 5.9 years of age were significantly less likely to achieve an initial trough of 15 to 20 mg/L compared with other age groups evaluated (P=.041). Thirty-four patients with initial subtherapeutic troughs received a dose adjustment and a follow-up vancomycin trough. Of these patients, 15 (44.1%) achieved a trough between 15 and 20 mg/L. The median dose for patients achieving a therapeutic trough at any point during the study was 80 mg/kg per day.

CONCLUSIONS

A vancomycin dosing regimen of 15 mg/kg per dose every 6 hours is not likely to achieve a trough concentration of 15 to 20 mg/L in pediatric patients with complicated infections. An initial regimen of 80 mg/kg per day for these patients may be more likely to result in therapeutic steady-state concentrations of vancomycin.

Balancing vancomycin efficacy and nephrotoxicity: should we be aiming for trough or AUC/MIC?

Sixty years later, the question that still remains is how to appropriately utilize vancomycin in the pediatric population. The Infectious Diseases Society of America published guidelines in 2011 that provide guidance for dosing and monitoring of vancomycin in adults and pediatrics. However, goal vancomycin trough concentrations of 15-20 μg/mL for invasive infections caused by methicillin-resistant Staphylococcus aureus were based primarily on adult pharmacokinetic and pharmacodynamic data that achieved an area under the curve to minimum inhibitory concentration ratio (AUC/MIC) of ≥400. Recent pediatric literature shows that vancomycin trough concentrations needed to achieve the target AUC/MIC are different than the adult goal troughs cited in the guidelines. This paper addresses several thoughts, including the role of vancomycin AUC/MIC in dosing strategies and safety monitoring, consistency in laboratory reporting, and future directions for calculating AUC/MIC in pediatrics.

Evaluation of vancomycin dosing and corresponding drug concentrations in pediatric patients

OBJECTIVE

To describe the relationships between dosing strategy, age, and vancomycin trough concentrations in pediatric patients.

METHODS

This is a retrospective review of hospitalized pediatric patients between 2 months and 17 years of age treated with intravenous vancomycin from 2008 to 2011. The primary outcome was the number of patients achieving a target trough concentration of 10 to 20 μg/mL in each age group and dosing group. The secondary outcomes were the number of patients in each group to achieve a trough concentration of 15 to 20 μg/mL and the incidence of vancomycin-induced nephrotoxicity.

RESULTS

A total of 102 patients were included in the analysis. Forty-six of 159 evaluated troughs (28.9%) were within the target range of 10 to 20 μg/mL. Dose was found to have a statistically significant effect on the ability to achieve a trough within the target range (P = .01). Of the 159 trough concentrations evaluated, only 11 (6.9%) were within the range of 15 to 20 μg/mL. Nephrotoxicity occurred in 7 patients and was not associated with supratherapeutic trough concentration or dose.

CONCLUSIONS

The number of trough concentrations within the target range of 10 to 20 μg/mL was low, and younger patients often needed doses >60 mg/kg per day to achieve a trough concentration in this range. The dose of vancomycin was found to have a statistically significant effect on the ability to achieve a trough concentration within the target range.

Vancomycin monitoring in children using bayesian estimation

BACKGROUND

Optimal monitoring of vancomycin in children needs evaluation using the exposure target with area under the curve (AUC) of the serum concentrations versus time over 24 hours. Our study objectives were to: (1) compare the accuracy and precision of vancomycin AUC estimations using 2 sampling strategies-1 serum concentration sample (1S, near trough) versus 2 samples (2S, near peak and trough) against the rich sample (RS) method; and (2) determine the performance of these strategies in predicting future AUC against an internal validation sample (VS).

METHODS

This was a retrospective cohort study using population-based pharmacokinetic modeling with Bayesian post hoc individual estimations in nonlinear mixed effects modeling (version 7.2). Pediatric subjects 3 months-21 years of age who received vancomycin ≥48 hours and had more than 3 drug samples within the first ≤96 hours of therapy were enrolled. Outcome measures were the accuracy, precision, and internal predictive performance of AUC estimations using 2 monitoring strategies (ie, 1S versus 2S) against the RS (which was derived from modeling all serum vancomycin concentrations obtained anytime during therapy) and VS (from serum concentrations obtained after 96 hours of therapy).

RESULTS

Analysis included 138 subjects with 712 vancomycin serum concentrations. Median age was 6.1 (interquartile range, 2.2-12.2) years, weight 22 (13-38) kg, and baseline serum creatinine 0.37 (0.30-0.50) mg/dL. Both accuracy and precision were improved with the 2S, compared with 1S, for AUC estimations (-2.0% versus -7.6% and 10.3% versus 12.8%, respectively) against the RS. Improved accuracy and precision were also observed for 2S when evaluated against VS in predicting future AUC.

CONCLUSIONS

Compared with 1S, the 2S sampling strategy for vancomycin monitoring improved accuracy and precision in estimating and predicting future AUC. Evaluating 2 drug concentrations in children may be prudent to ensure adequate drug exposure.

Treating paediatric community-acquired pneumonia in the era of antimicrobial resistance

Increasing levels of paediatric community-acquired pneumonia (CAP), caused by drug-resistant bacteria and antimicrobial resistance, vary with age and countries and, in some cases, serotypes. When empirical first-line treatment administration fails, paediatricians should consider second-line treatments based on the prevalence of local resistance. A more judicious use of antimicrobial agents is also required.

CONCLUSION

Knowledge of local epidemiology and an appropriate use of antimicrobial drugs are necessary to treat CAP in this era of antimicrobial resistance.