The Nephrotoxicity of Vancomycin

Pathological Features of Recovery or Progression in Acute Tubular Necrosis: Single Centre Study

Acute tubular necrosis (ATN) is the most important and frequent cause of acute kidney injury (AKI). Controversy exists concerning the role of renal biopsy in the evaluation of ATN prognosis. We aim in our study to evaluate the role of renal biopsy for the detection of recovery and progression and rate of recovery of ATN. The study was designed to include all biopsies with the diagnosis in ATN in adults >21-year-old, from January 2016 to December 2018. Biopsies were recruited retrospectively and were reviewed by three pathologists and quantitated. Four histological ATN features were evaluated. Flattening cells, distension or dilatation, debris, and vacuolation and for each a score were attributed as follows: 0 = less than 5% of section, 1 = 6%-25%, 2 = 26%-50%, 3 = >50%. Thirty-five patients with 35 renal biopsies were analyzed. Flattening was seen <5% in nine patients, 6%-25% in 15 patients, 26%-50% in six patients. and >50% in five patients. Dilatation was seen <5% in 11 patient, 6%-25% in 10 patients, 26%-50% seen in six patients, and >50% in eight patients. The presence of debris was seen in <5% in 12 patients, 6%-25% in 12 patients, 26%-50% seen in six patients, and >50% seen in five patient. Vacuolation was seen in 5% in eight patients, 6%-25% in 14 patients, 26%-50% in seven patients, and >50% in six patients. It was found that flattening <5% and dilatation <5% and dilatation >50% in renal biopsy are the good indicators for recovery and good prognosis of cases of ATN, in addition debris <5% and >50% and vacuolation <5% are also good indicators for recovery and good prognosis of cases of ATN. On the other hand, flattening from 6% to 25% and from 26% to 50%, dilatation from 6% to 25%, debris from 26% to 50% and vacuolation >50% are also indicators for delayed recovery and poor prognosis of cases of ATN. Renal biopsy in AKI with the diagnosis of ATN with scoring system of flattening, dilatation, debris, and vacuolation can point to indication of recovery or progression of these cases.

Using Japanese big data to investigate novel factors and their high-risk combinations that affect vancomycin-induced nephrotoxicity

AIMS

Several factors related to vancomycin-induced nephrotoxicity (VIN) have not yet been clarified. In the present study, we used Japanese big data to investigate novel factors and their high-risk combinations that influence VIN.

METHODS

We employed a large Japanese electronic medical record database and included patients who had been administered intravenous vancomycin between June 2000 and December 2020. VIN was defined as an increase in serum creatinine ≥0.5 mg/dL or 1.5-fold higher than the baseline. The outcomes were: (1) factors affecting VIN that were identified using multiple logistic regression analysis, and (2) combinations of factors that affect the risk of VIN according to a decision tree analysis, which is a typical machine learning method.

RESULTS

Of the 7,306 patients that were enrolled, VIN occurred in 14.2% of them (1,035). A multivariate analysis extracted 22 variables as independent factors. Concomitant ramelteon use (odds ratio; 0.701, 95% confidence interval; 0.512-0.959), ward pharmacy service (0.741, 0.638-0.861), duration of VCM <7 days (0.748, 0.623-0.899) and trough concentrations 10-15 mg/L (0.668, 0.556-0.802) reduce the risk of VIN. Meanwhile, concomitant piperacillin-tazobactam use (2.056, 1.754-2.409) and piperacillin use (2.868, 1.298-6.338) increase the risk. The decision tree analysis showed that a combination of vancomycin trough concentrations ≥20 mg/L and concomitant piperacillin-tazobactam use was associated with the highest risk.

CONCLUSIONS

We revealed that the concomitant ramelteon use and ward pharmacy service may decrease the risk of VIN, while the concomitant use of not only piperacillin-tazobactam but also piperacillin may increase the risk.

Impact of Linker Modification and PEGylation of Vancomycin Conjugates on Structure-Activity Relationships and Pharmacokinetics

As multidrug-resistant bacteria represent a concerning burden, experts insist on the need for a dramatic rethinking on antibiotic use and development in order to avoid a post-antibiotic era. New and rapidly developable strategies for antimicrobial substances, in particular substances highly potent against multidrug-resistant bacteria, are urgently required. Some of the treatment options currently available for multidrug-resistant bacteria are considerably limited by side effects and unfavorable pharmacokinetics. The glycopeptide vancomycin is considered an antibiotic of last resort. Its use is challenged by bacterial strains exhibiting various types of resistance. Therefore, in this study, highly active polycationic peptide-vancomycin conjugates with varying linker characteristics or the addition of PEG moieties were synthesized to optimize pharmacokinetics while retaining or even increasing antimicrobial activity in comparison to vancomycin. The antimicrobial activity of the novel conjugates was determined by microdilution assays on susceptible and vancomycin-resistant bacterial strains. VAN1 and VAN2, the most promising linker-modified derivatives, were further characterized in vivo with molecular imaging and biodistribution studies in rodents, showing that the linker moiety influences both antimicrobial activity and pharmacokinetics. Encouragingly, VAN2 was able to undercut the resistance breakpoint in microdilution assays on vanB and vanC vancomycin-resistant enterococci. Out of all PEGylated derivatives, VAN:PEG1 and VAN:PEG3 were able to overcome vanC resistance. Biodistribution studies of the novel derivatives revealed significant changes in pharmacokinetics when compared with vancomycin. In conclusion, linker modification of vancomycin-polycationic peptide conjugates represents a promising strategy for the modulation of pharmacokinetic behavior while providing potent antimicrobial activity.

Suprapubic Osteomyelitis in an Intravenous Drug User: A Case Report

We discuss a case of methicillin-resistant Staphylococcusaureus (MRSA) osteomyelitis pubis in a 45-year-old female patient with an active history of intravenous (IV) drug injection. While IV drug users are typically infected with Pseudomonas aeruginosa in cases of osteomyelitis of the pubic symphysis, our patient presented with a rare case of MRSA infection of the pubis symphysis. In this case, an investigation using magnetic resonance imaging (MRI), elevated levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and culture was consistent with the diagnosis of osteomyelitis. Osteomyelitis pubis is an infection that causes necrosis and destruction of the pubic bone. This condition remains a rarity, as less than 1% of osteomyelitis cases are reported to involve the pubic symphysis, thus contributing to the delays observed between onset of symptoms and diagnosis. The goal of this case report is to promote awareness of this phenomenon to hasten diagnosis and early treatment. The recommended treatment is with IV antibiotics for MRSA coverage for four to six weeks’ duration; however, our patient left against medical advice.

Urinary metabolomics study of vancomycin-associated nephrotoxicity based on ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry

Drug-induced nephrotoxicity is widespread and seriously affects human health. Vancomycin is a classical glycopeptide antibiotic. Vancomycin is widely used for severe infections caused by Gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus but its obvious nephrotoxicity affects the safety of its clinical application. However, the etiology of vancomycin induced kidney injury is not well understood. This study aimed to explore the potential mechanism of vancomycin-induced nephrotoxicity in rats. Vancomycin (400 mgkg^-1) was used to establish kidney injury models in rats. A metabonomic approach was employed using ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) to delineate metabolic alterations. As a result, 15, 22, and 37 biomarkers were identified in urine samples from the treatment group compared to the control model on D2, D4, and D7, respectively. Changes in the levels of these metabolites indicated that amino acid metabolism and energy metabolism were disturbed in rats with vancomycin-associated nephrotoxicity. This study revealed the kidney effect of vancomycin, which may provide novel and promising research approaches to vancomycin-induced renal toxicity.

Clinical Application Value of Pharmacokinetic Parameters of Vancomycin in Children Treated in the Pediatric Intensive Care Unit

OBJECTIVE

To explore the efficacy and safety of vancomycin as measured by pharmacokinetic/pharmacodynamic parameters in children with severe infection in the Pediatric Intensive Care Unit (PICU) and to determine the appropriate threshold for avoiding nephrotoxicity.

METHODS

The medical records of hospitalized children with severe infection treated with vancomycin in the PICU of a tertiary pediatric hospital from September 2018 to January 2021 were retrospectively collected. Univariate analysis was used to assess the correlation between vancomycin pharmacokinetic/pharmacodynamic parameters and therapeutic efficacy or vancomycin-related nephrotoxicity. Binary logistic regression was used to analyze the risk factors for vancomycin-related nephrotoxicity. The vancomycin area under the concentration-time curve over 24 h (AUC_0-24) threshold was determined by receiver operating characteristic (ROC) curve analysis.

RESULTS

One hundred and 10 patients were included in this study. Seventy-six patients (69.1%) exhibited clinically effective response, while the rest exhibited clinically ineffective response. There were no significant differences in APACHE II score, steady-state trough concentration, peak concentration or AUC_0-24 of vancomycin between the effective and ineffective groups. Among the 110 patients, vancomycin-related nephrotoxicity occurred in 15 patients (13.6%). Multivariate analysis showed that vancomycin treatment duration, trough concentration, and AUC_0-24 were risk factors for vancomycin-related nephrotoxicity. The ROC curve indicated that AUC_0-24 < 537.18 mg.h/L was a suitable cutoff point for predicting vancomycin-related nephrotoxicity.

CONCLUSION

No significant correlations were found between the trough concentration or AUC_0-24 of vancomycin and therapeutic efficacy when the daily dose of vancomycin was approximately 40 mg/kg d, while the trough concentration and AUC_0-24 were both closely related to vancomycin-related nephrotoxicity. The combination of AUC_0-24 and trough concentration for therapeutic drug monitoring may reduce the risk of nephrotoxicity.

Fatal Events Associated with Adverse Drug Reactions in the Korean National Pharmacovigilance Database

Adverse drug reactions (ADRs) pose a global public health threat, substantially contributing to death. Due to the relative paucity of clinical evidence regarding fatal ADRs, this study was performed to characterize the epidemiology of fatal ADRs in Korea. This was a retrospective, cross-sectional analysis of ADR cases reported to the Korea Adverse Event Reporting System from 2010 to 2019. All ADRs were coded using the World Health Organization-Adverse Reaction Terminology system and classified as either fatal or non-fatal events. Logistic regression was performed to identify factors associated with fatal events. Among 289,756 ADR records, 629 fatal events (0.2%) occurred. The most common causative agent of fatal ADRs was antibacterials (20.3%), followed by antimycobacterials (5.4%), analgesics (4.0%), and contrast media (1.9%). Among antimicrobials, vancomycin was most frequently implicated without significantly increasing the risk of fatal events. The risk for fatal ADRs was significantly increased with male sex; advanced age; polypharmacy; piperacillin/β-lactamase inhibitor; cefotetan; ceftriaxone; combination antimycobacterial therapy consisting of rifampicin, isoniazid, pyrazinamide, and ethambutol; morphine; and iopromide (reporting odds ratio > 1, p < 0.05 for all). Although fatal ADRs are uncommon (<1%) in Korea, they are primarily caused by commonly used medications including antibiotics, analgesics, and contrast media.

Outpatient vancomycin therapy: Acute kidney injury in individualized AUC-based goal trough ranges versus traditional trough dosing

BACKGROUND

Recent changes to vancomycin guidelines recommend area under the curve concentration (AUC) monitoring in most patients, owing to similar effectiveness and reduced rates of acute kidney injury (AKI).

OBJECTIVE

The purpose of this study was to assess the incidence of AKI in patients receiving vancomycin dosed by AUC-based goal troughs and vancomycin dosed by traditional trough goals (15-20 mcg/mL) in the outpatient setting.

METHODS

Patients were included if they received vancomycin outpatient for at least 1 week. The primary objective was comparing the incidence of AKI in patients receiving vancomycin as an outpatient with trough goals derived from patient-specific AUC calculations determined as an inpatient with that of patients receiving vancomycin by traditional goal troughs. Secondary objectives included assessing the rate of treatment failure, AUC estimated trough range, and number of regimen changes required.

RESULTS

There were 65 patients in the traditional trough dosing group and 53 patients in the AUC trough dosing group. The incidence of AKI was lower in the AUC trough group (5.7% vs. 23.1%; P = 0.01). There were no differences in the incidence of treatment failure. The median AUC estimated trough range was 11.4-17.1 mcg/mL. There were statistically significant less average regimen changes required in the AUC dosing group (1.13 vs. 1.64; P = 0.006).

CONCLUSION

There was a statistically significant lower incidence of AKI in patients receiving vancomycin dosed by individualized AUC-based trough ranges compared with that of patients receiving traditional trough dosing. Developing a process for individualized AUC-based trough ranges can facilitate a convenient monitoring method to use the benefits of vancomycin AUC dosing as an outpatient.

A Comparison Between Cefepime and Piperacillin-Tazobactam in the Management of Septic Shock

Introduction Septic shock is defined as a dysregulated host response to infection characterized by hemodynamic instability. Concern for the increased risk of acute kidney injury (AKI) with piperacillin-tazobactam in combination with vancomycin may prompt more use of alternative broad-spectrum antipseudomonal beta-lactam antibiotics, such as cefepime. This study assessed whether cefepime was associated with improved outcomes compared to piperacillin-tazobactam in patients with septic shock. Methods This retrospective cohort study included veterans treated for septic shock between September 1, 2008, and August 31, 2018. This study compared cefepime and piperacillin-tazobactam as initial antibiotic management for septic shock. Outcomes included AKI, Clostridioides difficile infection (CDI), hospital length of stay, intensive care unit mortality, and mortality within 30 days of hospitalization. Results In total, 240 patients were included in this study (120 in each cohort). The proportion of AKI was 60.0% in the piperacillin-tazobactam cohort compared to 58.3% in the cefepime cohort (p = 0.90). Mortality was significantly higher in the cefepime cohort. There were no significant differences in CDI or hospital length of stay. Conclusion The results of this study do not suggest that the use of the antipseudomonal beta-lactam antibiotic used in the initial management of septic shock is associated with differences in the AKI or CDI. The higher mortality observed with cefepime may warrant further investigation.

Intraperitoneal pharmacokinetics of vancomycin in patients on automated peritoneal dialysis

It is unclear if the pharmacokinetics of vancomycin are the same during automated peritoneal dialysis (APD), where cycler exchanges may affect the systemic, peritoneal, and urinary disposition of drug. We conducted a prospective pharmacokinetic study evaluating the pharmacokinetics of vancomycin in plasma, dialysis fluid, and urine in peritonitis‐negative patients on APD. Patients underwent four drug‐free exchanges with 1.5% or 2.5% dextrose following the initial dwell period. Plasma, dialysis fluid, and urine was collected over the course of 7 days for pharmacokinetic analysis. Four patients completed the study with no adverse events. Following a median (range) dwell of 14.6 (14.2–17.6 h), the mean (±SD) observed maximum plasma concentration was 28.7 ± 4.9 mg/L with a mean bioavailability of 98.5 ± 1.4% prior to starting the cycler. The overall mean total plasma clearance estimated from study start to completion was 7.6 ± 1.2 ml/min. Mean total clearance during the dialytic exchange was 13.6 ± 4.9 ml/min. In patients with residual renal function, the mean vancomycin renal clearance was 3.1 ± 1.5 ml/min, representing 21.4%–58.9% of the overall total plasma clearance during the study period. Despite the small sample size, this pilot study suggests that the dwell time has important implications for systemic vancomycin exposure, time to therapeutic plasma concentration, and dosing. Dose is driven by dwell time, whereas the cycler determines the dosing interval. Rapid exchanges from APD will determine the frequency of dosing rather than the adequacy of absorption when vancomycin is given in the peritoneum.

Intra-articular administration of vancomycin and tobramycin during primary cementless total knee arthroplasty : determination of intra-articular and serum elution profiles

AIMS

Intra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA.

METHODS

A prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml.

RESULTS

A total of 22 patients were included in final analysis. At one, four, and 24 hours postoperatively, mean (95% confidence interval (CI)) serum concentrations were 2.4 (0.7 to 4.1), 5.0 (3.1 to 6.9), and 4.8 (2.8 to 6.9) for vancomycin and 4.9 (3.4 to 6.3), 7.0 (5.8 to 8.2), and 1.3 (0.8 to 1.8) for tobramycin; intra-articular concentrations were 1,900.6 (1,492.5 to 2,308.8), 717.9 (485.5 to 950.3), and 162.2 (20.5 to 304.0) for vancomycin and 2,105.3 (1,389.9 to 2,820.6), 403.2 (266.6 to 539.7), and 98.8 (0 to 206.5) for tobramycin.

CONCLUSION

Intra-articular administration of 1 g of vancomycin and 600 mg of tobramycin as a solution after closure of the arthrotomy in primary cementless TKA achieves therapeutic intra-articular concentrations over the first 24 hours postoperatively and does not reach sustained toxic levels in peripheral blood. Cite this article: Bone Joint J 2021;103-B(11):1702-1708.

Vancomycin Nephrotoxicity Causing Renal Transplant Acute Kidney Injury

Nephrotoxicity is a rather frequent side effect of vancomycin treatment. Attributes of vancomycin nephrotoxicity (VN) are well documented, including its clinical manifestations and renal morphologic changes. However, VN has not been emphasized as the cause of acute kidney injury (AKI) in the renal transplant setting. We report the first 3 such cases. In each of these cases, AKI developed concurrently with vancomycin treatment and resolved after its cessation. As compared with the general population, VN in the renal transplant setting displayed some unusual clinical behaviors. Its development was rather capricious, being noted in some but not every episode of vancomycin treatment, even in the same individual. AKI developed gradually in conjunction with protracted vancomycin treatment, in contrast to a precipitous course in the nontransplant setting. However, renal transplant biopsies showed typical features of VN in each case. VN is an unusual but now well-documented cause of AKI in renal transplant recipients. VN in this setting may display some atypical features, setting it apart from that in the general population. However, renal transplant biopsy changes are characteristic and are amenable to a definitive diagnosis.

Folate Functionalized Lipid Nanoparticles for Targeted Therapy of Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA), commonly called a superbug, is a highly alarming antibiotic-resistant population of Staphylococcus aureus (S. aureus) bacteria. Vancomycin (VAN) was first approved by the FDA in 1988, and it is still regarded as the treatment of choice for MRSA. The efficacy of VAN treatment has become less effective due to the development of VAN resistance in MRSA and the potential for nephrotoxicity. This study aims to improve the efficacy of VAN treatment by identifying the folate receptor for MRSA infected tissues and developing folate decorated lipid nanoparticles containing VAN (LVAN). In comparison to conventional VAN, LVAN showed a higher bactericidal effect and a superior ability to inhibit biofilm in MRSA with an enhanced accumulation in MRSA infected thigh tissues and a reduced accumulation in kidney. The results suggested that LVAN is a promising candidate to overcome the current limitations of bacterial resistance and adverse side effects in kidneys found in VAN.

Vancomycin-induced nephrotoxicity in non-intensive care unit pediatric patients

Previous data suggested several risk factors for vancomycin-induced nephrotoxicity (VIN), including higher daily dose, long-term use, underlying renal disease, intensive care unit (ICU) admission, and concomitant use of nephrotoxic medications. We conducted this study to investigate the prevalence and risk factors of VIN and to estimate the cut-off serum trough level for predicting acute kidney injury (AKI) in non-ICU pediatric patients. This was a retrospective, observational, single-center study at Samsung Medical Center tertiary hospital, located in Seoul, South Korea. We reviewed the medical records of non-ICU pediatric patients, under 19 years of age with no evidence of previous renal insufficiency, who received vancomycin for more than 48 h between January 2009 and December 2018. The clinical characteristics were compared between patients with AKI and those without to identify the risk factors associated with VIN, and the cut-off value of serum trough level to predict the occurrence of VIN was calculated by the Youden's index. Among 476 cases, 22 patients (4.62%) developed AKI. The Youden's index indicated that a maximum serum trough level of vancomycin above 24.35 μg/mL predicted VIN. In multivariate analysis, longer hospital stay, concomitant use of piperacillin-tazobactam and serum trough level of vancomycin above 24.35 μg/mL were associated independently with VIN. Our findings suggest that concomitant use of nephrotoxic medication and higher serum trough level of vancomycin might be associated with the risk of VIN. This study suggests that measuring serum trough level of vancomycin can help clinicians prevent VIN in pediatric patients.

Transcriptome and microbiome analyses of the mechanisms underlying antibiotic-mediated inhibition of larval development of the saprophagous insect Musca domestica (Diptera: Muscidae)

Antibiotics are designed to treat bacterial infections in humans and animals; however, the overuse of various antibiotics and consequent contamination in the environment can have adverse effects on aquatic, soil, and saprophytic organisms. The house fly, an important decomposer in ecosystems, has been used for bioconversion of human and animal waste. Vermireactors have been used to remove antibiotics from waste for pollution control, but the effects of antibiotics on fly larvae are unclear. In the present work, we aimed to reveal the mechanism underlying the effects of antibiotics on larval growth in house flies at the transcriptome and microbiome levels and the relationships between genes and the microbiota. Observation of house flies after antibiotic exposure showed that gentamicin sulfate and levofloxacin hydrochloride inhibited larval development to a greater extent than amoxicillin. Transcriptome analysis revealed that biological pathways related to protein synthesis and the metabolism of fatty acids, pentose, and glucuronate were significantly enriched in flies exposed to gentamicin sulfate and levofloxacin hydrochloride. Crucial genes in these pathways were identified as candidates for future study. Microbiome analysis revealed three key bacteria that were closely correlated with gentamicin sulfate and levofloxacin hydrochloride exposure. The correlation network between the differentially expressed genes and bacteria identified an important microbic effector, Pseudomonas and its associated genes. This work will improve the knowledge about the mechanism underlying the effects of antibiotics on the larval development of house flies in the environment and provide guidance for improving the application of house fly bioconversion.

Population pharmacokinetics of vancomycin in paediatric patients with febrile neutropenia and augmented renal clearance: development of new dosing recommendations

OBJECTIVES

The purpose of this study was to evaluate the influence of augmented renal clearance (ARC) on vancomycin clearance and provide dosage recommendations for paediatric patients with febrile neutropenia following HSCT.

METHODS

A population pharmacokinetic analysis was performed based on a two-compartment model structure using a non-linear mixed-effect modelling approach. Monte Carlo simulations were conducted as a target attainment analysis of AUC between 400 mg·h/L and 650 mg·h/L for MRSA at an MIC of 1 mg/L.

RESULTS

A total of 165 paediatric patients and 276 vancomycin serum concentrations were analysed in this study. Age, body weight, estimated glomerular filtration rate (eGFR) and fever (≥38.0°C) were identified as factors that significantly influenced vancomycin clearance. The median eGFR of the population was 143 mL/min/1.73 m2 and 34% of patients showed an eGFR ≥160 mL/min/1.73 m2, which may be classified as ARC. Our simulations showed that current dosing recommendations result in poor target attainment. In particular, children aged 6 months old to 6 years old with ARC require an initial vancomycin dose up to 35%-65% higher than the current dosing guidelines.

CONCLUSIONS

ARC is frequently observed in paediatric patients with post-HSCT febrile neutropenia, resulting in a significant increase in vancomycin clearance. We propose a vancomycin dosing strategy for children with febrile neutropenia following HSCT based on eGFR, age, weight and body temperature.

Functional Impacts of Aminoglycoside Treatment on Speech Perception and Extended High-Frequency Hearing Loss in a Pediatric Cystic Fibrosis Cohort

Purpose The purpose of this study is to better understand the prevalence of ototoxicity-related hearing loss and its functional impact on communication in a pediatric and young adult cohort with cystic fibrosis (CF) and individuals without CF (controls). Method We did an observational, cross-sectional investigation of hearing function in children, teens, and young adults with CF (n = 57, M = 15.0 years) who received intravenous aminoglycoside antibiotics and age- and gender-matched controls (n = 61, M = 14.6 years). Participants completed standard and extended high-frequency audiometry, middle ear measures, speech perception tests, and a hearing and balance questionnaire. Results Individuals with CF were 3-4 times more likely to report issues with hearing, balance, and tinnitus and performed significantly poorer on speech perception tasks compared to controls. A higher prevalence of hearing loss was observed in individuals with CF (57%) compared to controls (37%). CF and control groups had similar proportions of slight and mild hearing losses; however, individuals with CF were 7.6 times more likely to have moderate and greater degrees of hearing loss. Older participants displayed higher average extended high-frequency thresholds, with no effect of age on average standard frequency thresholds. Although middle ear dysfunction has not previously been reported to be more prevalent in CF, this study showed that 16% had conductive or mixed hearing loss and higher rates of previous otitis media and pressure equalization tube surgeries compared to controls. Conclusions Individuals with CF have a higher prevalence of conductive, mixed, and sensorineural hearing loss; poorer speech-in-noise performance; and higher rates of multiple symptoms associated with otologic disorders (tinnitus, hearing difficulty, dizziness, imbalance, and otitis media) compared to controls. Accordingly, children with CF should be asked about these symptoms and receive baseline hearing assessment(s) prior to treatment with potentially ototoxic medications and at regular intervals thereafter in order to provide otologic and audiologic treatment for hearing- and ear-related problems to improve communication functioning.

Impact of ascorbic acid in reducing the incidence of vancomycin associated nephrotoxicity in critically ill patients: A preliminary randomized controlled trial

Background Antioxidants show nephroprotective effect against vancomycin associated nephrotoxicity (VAN) in animals. This study aimed to assess the ascorbic acid nephro-protective role against VAN clinically.

Methods Forty-one critically ill patients were randomly assigned to one of two groups: intervention group (vancomycin IV plus ascorbic acid, n=21) or control group (vancomycin IV only, n=20). Primary outcomes were the incidence of VAN and the absolute change in creatinine parameters, while mortality rate was the secondary outcome. Nephrotoxicity was defined as an increase in serum creatinine (S.cr) by at least 0.5 mg/dL or 50% of baseline for at least two successive measurements. This study is registered at Clinicaltrials.gov (NCT03921099), April 2019.

Results Mean absolute S.cr increase was significant when compared between both groups, P-value = 0.036, where S.cr increased by 0.05(0.12) and 0.34(0.55) mg/dL in the intervention and control groups, respectively. Mean absolute Cr.cl decline was significant when compared between both groups, P-value = 0.04, where Cr.cl was decreased by 5.9(17.8) and 22.3(30.4) ml/min in the intervention and control groups, respectively. Incidence of VAN was 1/21(4.7%) versus 5/20(25%) in the intervention and control groups, respectively (RR: 0.19; CI: 0.024–1.49; P-value = 0.093). Mortality was higher in the control group; however, it was not statistically significant, P-value = 0.141.

Conclusion Co-administration of ascorbic acid with vancomycin preserved renal function and reduced the absolute risk of VAN by 20.3%, however, the reduction in VAN incidence didn’t reach statistical significance level. Further large multicenter prospective trials are recommended.

Development of a new pharmacokinetic model for target-concentration controlled infusion of vancomycin in critically ill patients

The aim of this prospective study was to construct a new pharmacokinetic model of vancomycin for target-concentration controlled infusion (TCI). As the first loading dose, 25 mg/kg of vancomycin was administered during 60-90 min. Arterial blood samples were obtained at pre-set intervals to measure the serum concentrations of vancomycin. Population pharmacokinetic analysis was performed using the NONMEM software (ICON Development Solutions). In total, 197 serum concentration measurements from 22 patients were used to characterise the pharmacokinetics of vancomycin. A three-compartment mammillary model best described the pharmacokinetics of vancomycin in critically ill patients. The ideal body weight was a significant covariate for the central and slow peripheral volume of distribution. The weight and age converted to categorical variables at a cut-off of 65 years were a significant covariate for the clearance. Based on the results of stochastic simulation, the TCI method maintained the therapeutic concentration range for the longest duration. In addition, assuming that vancomycin was administered by the TCI method for 7 days, the dose was reduced by about 15% compared with the standard administration methods. The daily area under the curve values were maintained between 500 mg·h/L and 600 mg·h/L. TCI has the potential to become a new infusion method for patient-tailored dosing in critically ill patients. To administer vancomycin via TCI in clinical practice, the newly constructed pharmacokinetic model should undergo proper external validation.

Vitamin C reduces vancomycin-related nephrotoxicity through the inhibition of oxidative stress, apoptosis, and inflammation in mice

Background

Vancomycin (VCM) is an antibiotic widely used to treat a range of serious bacterial infections; however, it is associated with nephrotoxicity. Vitamin C (VC) is a classical antioxidant that can alleviate various organ injuries and inflammatory responses by reducing inflammation and oxidative stress. This study aimed to examine the effect of VC on VCM-related nephrotoxicity in mice.

Methods

Mice were randomized into four groups: control, VCM (400 mg/kg/day), VCM (400 mg/kg/day) + VC (200 mg/kg/day), and VC (200 mg/kg/day) groups. Both VCM and VC were administered via intraperitoneal injection for 7 d, after which kidney and blood samples were collected and evaluated. Creatinine (Cr), blood urea nitrogen (BUN), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and nuclear factor-κB (NF-κB) were measured.

Results

In the VCM group, kidney index, renal injury score, cell apoptosis, serum Cr and BUN, and kidney Cr, BUN, MDA, IL-1β, IL-6, TNF-α, and NF-κB were higher compared to the control group (all P<0.05), while body weight and kidney SOD activity were lower (both P<0.05). By contrast, no differences were observed between the control and VC groups (VC and VCM + VC groups) for all these indicators.

Conclusions

The antioxidant VC reduces VCM-related renal injury by reducing oxidative stress, cell apoptosis, and inflammation.

Lowered Risk of Nephrotoxicity through Intervention against the Combined Use of Vancomycin and Tazobactam/Piperacillin: A Retrospective Cohort Study

The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We sought to evaluate interventions against the combined use of VCM and TAZ/PIPC. This retrospective cohort study involved patients who considered the combined use of VCM and TAZ/PIPC as a treatment. Patients that had either or both antimicrobials replaced were assigned to the intervention group, whereas those who were continued on combination therapy were assigned to the comparison group. The primary endpoint was the incidence of acute kidney injury (AKI). The survival rate of patients on day 30 was evaluated as the secondary endpoint. The comparison and intervention groups were composed of 65 and 68 patients, respectively, and the incidence rates of AKI were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified the intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). For the incidence of AKI of grade greater than 1, the hazard ratio was 0.114 (95% CI, 0.025 to 0.497). The survival rates on day 30 in the comparison and intervention groups were 92.3% and 91.2%, respectively, with a relative risk of 0.988 (95% CI, 0.892 to 1.094). The trough VCM concentration was not associated with the incidence of AKI in patients receiving the combination therapy. This study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity. IMPORTANCE The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We retrospectively evaluated interventions against the combined use of VCM and TAZ/PIPC. Patients for whom either or both antimicrobials were replaced were assigned to the intervention group (65 patients), whereas those who were continued on combination therapy were assigned to the comparison group (68 patients). The primary endpoint was the incidence of acute kidney injury (AKI). The incidence rates of AKI in the intervention and comparison groups were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). In conclusion, this study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity.

Incidence of acute kidney injury after teicoplanin- or vancomycin- and piperacillin/tazobactam combination therapy: A comparative study using propensity score matching analysis

INTRODUCTION

Combination therapy with vancomycin (VCM) and piperacillin/tazobactam (PIPC/TAZ) increases the risk of acute kidney injury (AKI). Teicoplanin (TEIC) has a lower risk of AKI than VCM. Currently, the difference in AKI risk after TEIC-PIPC/TAZ combination therapy and VCM-PIPC/TAZ combination therapy is controversial. This study aimed to compare AKI incidence after treatment with these two drug combinations using propensity score matching analysis.

METHODS

This single-center cohort study used data extracted from patients' medical records. We included patients who received TEIC-PIPC/TAZ therapy (TEIC group) or VCM-PIPC/TAZ therapy (VCM group). After propensity score matching, AKI incidence, AKI stage, 30-day mortality, and time to AKI incidence were compared between the groups.

RESULTS

After propensity score matching, 94 patients were matched in each group. AKI incidence was significantly lower in the TEIC group than in the VCM group (10.6% vs. 23.4%, odds ratio [95% confidence interval]: 0.39 [0.17-0.88], p = 0.03). AKI stage, 30-day mortality, and time to AKI incidence were not significantly different between the groups.

CONCLUSIONS

This study suggested that AKI incidence may be lower in patients undergoing combination therapy with TEIC-PIPC/TAZ than in those receiving therapy with VCM-PIPC/TAZ. To prevent the occurrence of AKI, clinicians may need to choose TEIC instead of VCM for patients receiving PIPC/TAZ.

Comparative incidence of acute kidney injury in patients on vancomycin therapy in combination with cefepime, piperacillin-tazobactam or meropenem

Recent studies have shown that the incidence of nephrotoxicity increases when vancomycin is combined with a beta-lactam antibiotic. The objective of this study was to compare the incidence of acute kidney injury (AKI) in adult patients who received vancomycin with either piperacillin-tazobactam (VPT), cefepime (VC), or meropenem (VM). This was a single center retrospective chart review. Patients were included if they were 18 years or older, received 48 hours of combination therapy and antibiotics were started within 24 hours of each other. Exclusion criteria were receiving more than one combination of antibiotics, serum creatinine > 1.2 mg/dL, AKI at the time of inclusion, or any form of renal replacement therapy. Two hundred patients met inclusion criteria. A total of 27 (13%) patients experienced AKI. The incidence of AKI was 21.6%, 9%, and 7.4% in the VPT, VC and VM groups, respectively. A patient who received VPT was 5 times more likely to develop AKI when compared to a patient who received VC (adjusted OR 5.09 95% CI (1.51-17.08), p = 0.008) and 7 times more likely to develop AKI when compared to VM (adjusted OR 7.03 95% CI (1.97-28.08), p = 0.002). This study found a statistically significant difference in the incidence of AKI in patient receiving VPT when compared to VC or VM. This finding supports the need for careful monitoring of renal function in patients receiving VPT therapy and routine evaluation for de-escalation of antimicrobial therapy.

Renoprotective Effects of Melatonin against Vancomycin-Related Acute Kidney Injury in Hospitalized Patients: a Retrospective Cohort Study

Vancomycin is associated with nephrotoxicity, and the mechanism may in part be related to oxidative stress. In vitro and preclinical studies suggest that melatonin supplementation decreases oxidative stress. The objective of this study was to evaluate concomitant use of melatonin and vancomycin and the incidence of acute kidney injury (AKI). We performed a retrospective cohort study at a large community medical center. All consecutive patients admitted to the medical center between January 2016 and September 2020 who received vancomycin therapy alone or concomitantly with melatonin as part of ordinary care were considered for inclusion. The primary endpoint was the development of AKI, defined as an absolute increase in serum creatinine of ≥0.3 mg/dl or a ≥50% increase in serum creatinine. All data were analyzed using descriptive statistics. A multivariable logistic regression was constructed to account for potential confounding variables. We identified a total of 303 adult patients meeting inclusion and exclusion criteria treated with vancomycin, 101 of which received melatonin concomitantly. Overall baseline characteristics were similar between the two groups except for the incidence of bacteremia/sepsis. After controlling for the vancomycin area under the curve, baseline creatinine clearance, and intensive care unit admission in a multivariable logistic regression analysis, melatonin use was associated with a 63% decrease in AKI (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.14 to 0.96; P = 0.041). Melatonin use was associated with a significant reduction in vancomycin-related AKI. Although this was a retrospective study with a small sample size, given the magnitude of the difference seen, further large prospective studies are warranted.

Candidates for area under the concentration-time curve (AUC)-guided dosing and risk reduction based on analyses of risk factors associated with nephrotoxicity in vancomycin-treated patients

OBJECTIVES

Compared with vancomycin trough concentration (C_min)-guided dosing, area under the concentration-time curve (AUC)-guided dosing is associated with decreased acute kidney injury (AKI). However, whether C_min-guided or AUC-guided dosing should be used in patients other than those with serious MRSA infections remains uncertain. The purposes of this multicentre study were to identify risk factors for early- and late-phase vancomycin-induced AKI and to identify candidates for AUC-guided dosing, rather than C_min-guided dosing, who require a more accurate dose titration to reduce the AKI risk.

METHODS

A multivariate logistic regression analysis was applied to identify risk factors for AKI. Additionally, the cut‑off day for AKI onset, cut-off C_min for AKI, safe C_min for reduced AKI risk and probability of AKI were calculated.

RESULTS

In total, 8.4% (159/1882) of patients developed AKI. AKI occurred within the first 7 days of therapy (early phase) in the vast majority of patients. Significant risk factors for AKI during the early phase were identified as C_min > 20 mg/L, ICU stay, concurrent diuretic or piperacillin/tazobactam use, and pre-existing renal dysfunction. A temporarily elevated C_min (>15-20 mg/L) was not associated with a greater risk of AKI. In patients with risk factors, the cut-off C_min for AKI and the estimated safe C_min for reduced AKI risk were 18.8-21.0 mg/L and <11.7-13.5 mg/L, respectively.

CONCLUSION

Patients with known AKI risk factors require a low target C_min. The presence of several risk factors for AKI may indicate a need for more accurate dose titration using AUC-guided dosing.

Iatrogenic Toxicities in the Intensive Care Unit

Drug-induced iatrogenic toxicities are common in critically ill patients and have been associated with increased morbidity and mortality. Early recognition and management of iatrogenic toxicities is essential; however, the diagnosis is usually complicated by the underlying critical illness, comorbidities, and administration of multiple medications. This article reviews several types of iatrogenic toxicities associated with medications that are commonly used in critically ill patients. The mechanism of the iatrogenic toxicities, clinical presentation, and diagnosis, as well as management are discussed.

Comparative evaluation of phosphatidylcholine and phosphatidylserine with different fatty acids on nephrotoxicity in vancomycin-induced mice

Phospholipids reportedly alleviate drug-induced acute kidney injury. However, no study has compared the effect of phospholipids with different fatty acids and polar heads on drug-induced nephrotoxicity. In the present study, we aimed to compare the possible nephroprotection afforded by phosphatidylcholine and phosphatidylserine with different fatty acids in a mouse model of vancomycin-induced nephrotoxicity. Pretreatment with phospholipids rich in docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) doubled the survival time when compared with the model group. Moreover, phospholipids rich in DHA/EPA significantly reduced the serum levels of renal function biomarkers and ameliorated kidney pathologies. In terms of alleviating renal damage, no significant differences were observed between different polar heads in DHA-enriched phospholipids, while phosphatidylserine from soybean was better than phosphatidylcholine in mitigating renal injury. Furthermore, DHA/EPA-enriched phospholipids inhibited vancomycin-induced nephrotoxicity mainly by inhibiting apoptosis and oxidative stress. These results provide a scientific basis for phospholipids as potential ingredients to prevent acute kidney injury.

Retrospective multicentre matched cohort study comparing safety and efficacy outcomes of intermittent-infusion versus continuous-infusion vancomycin

BACKGROUND

Patients with good renal function receiving intermittent-infusion vancomycin (IIV) may require total daily doses ≥4 g to achieve trough concentrations of 15-20 mg/L, increasing the risk of vancomycin-associated nephrotoxicity. Continuous-infusion vancomycin (CIV) may be associated with a lower risk of vancomycin-associated nephrotoxicity compared with IIV, but studies comparing safety of both dosing strategies are lacking.

OBJECTIVES

To compare the risk of nephrotoxicity with CIV versus IIV when target concentration ranges were the same with both dosing modalities.

METHODS

A retrospective multicentre matched cohort study of admitted patients between 1 January 2010 and 31 December 2016 was completed. Adult patients who received ≥48 h of vancomycin with at least one steady-state vancomycin concentration were eligible. The primary outcome was to compare the rates of nephrotoxic risk and renal injury, defined by the RIFLE criteria, between CIV and IIV.

RESULTS

Of 2136 patients who received vancomycin during the study period, 146 CIV patients were eligible and matched to 146 IIV patients. After adjustment of potential confounders, CIV was found to have a lower odds of developing nephrotoxic risk (OR 0.42, 95% CI 0.21-0.98, P = 0.025) and renal injury (OR 0.19, 95% CI 0.05-0.59, P = 0.004).

CONCLUSIONS

CIV is associated with a lower odds of nephrotoxicity compared with IIV when targeting the same concentration range and should be an alternative dosing strategy for patients who will receive prolonged therapy or require >4 g/day to achieve therapeutic levels.

Attributable nephrotoxicity of vancomycin in critically ill patients: a marginal structural model study

BACKGROUND

Although vancomycin nephrotoxicity is recognizable, critically ill patients have other potential reasons for acute kidney injury (AKI) and determining its attributable nephrotoxic risk in this population can be cumbersome.

OBJECTIVES

To determine the risk of AKI attributable to vancomycin, controlling for baseline and time-dependent confounders.

METHODS

Time-fixed and daily time-varying variables were extracted from a large public database. The exposures analysed were: (i) IV vancomycin; (ii) serum trough level greater than 15 and 20 mg/L; and (iii) concomitant exposure to vancomycin and piperacillin/tazobactam or other antipseudomonal β-lactams. Censoring and exposure inverse probability of treatment weighting were calculated. Marginal structural models were plotted to evaluate AKI, severe AKI (stage 2/3) and need of renal replacement therapy (RRT).

RESULTS

A total of 26 865 patients were included; 19.7% received vancomycin during ICU stay. After adjusting for fixed and time-variable confounders, vancomycin exposure was associated with AKI (HR = 1.24, 95% CI = 1.09-1.38), but not with severe AKI or need of RRT (HR = 1.05, 95% CI = 0.91-1.23 and HR = 0.97, 95% CI = 0.74-1.29, respectively). A serum trough level greater than 20 mg/L was associated with AKI (HR = 1.90, 95% CI = 1.52-2.30) and severe AKI (HR = 1.69, 95% CI = 1.31-2.19), but showed no statistically significant association with need of RRT (HR = 1.48, 95% CI = 0.92-2.56). The vancomycin + piperacillin/tazobactam combination was not associated with a greater risk than vancomycin alone.

CONCLUSIONS

The attributable nephrotoxicity of vancomycin in critically ill patients is significantly lower than previously suggested and severe AKI is related to vancomycin only when trough serum levels are greater than 20 mg/L.

Serum 5-Hydroxyindoleacetic Acid and Ratio of 5-Hydroxyindoleacetic Acid to Serotonin as Metabolomics Indicators for Acute Oxidative Stress and Inflammation in Vancomycin-Associated Acute Kidney Injury

The incidence of vancomycin-associated acute kidney injury (VAKI) varies from 5–43%, and early detection of VAKI is important in deciding whether to discontinue nephrotoxic agents. Oxidative stress is the main mechanism of VAKI, and serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) have been examined with respect to their involvement in ischemia/reperfusion damage in experimental animal models. In the current study, we assessed 5-HT and 5-HIAA as novel biomarkers for detecting VAKI in patients who have infections or compromised renal function, using a mass spectrometry–based metabolomics approach. We conducted amino acid profiling analysis and measurements of 5-HT and 5-HIAA using serum from subjects with VAKI (n = 28) and non-VAKI control subjects (n = 69), consisting of the infection subgroup (n = 23), CKD subgroup (n = 23), and healthy controls (HCs, n = 23). 5-HT was significantly lower in the VAKI group than in the non-VAKI groups, and the concentration of 5-HIAA and the ratio of 5-HIAA to 5-HT (5-HIAA/5-HT) showed higher values in the VAKI group. The infection subgroup presented a significantly greater 5-HIAA/5-HT ratio compared with the HC subgroup. Our study revealed that increased 5-HIAA/5-HT ratio has the potential to act as a VAKI surrogate marker, reflecting acute oxidative stress and inflammation.

Outcomes and Nephrotoxicity Associated with Vancomycin Treatment in Patients 80 Years and Older

Purpose

This retrospective observational study investigated the efficacy and safety of vancomycin to treat patients aged 80 years and older. In particular, the associations between vancomycin trough concentration (VTC) and treatment outcomes or nephrotoxicity were explored.

Patients and Methods

Patients aged ≥80 years had received ≥3 vancomycin treatments and ≥1 detection of VTC. Treatment outcomes were defined as success or failure. Nephrotoxicity was considered an increase in serum creatinine ≥ 44.2 mmol/L, or 50% above baseline, for ≥2 consecutive days. Univariate and multivariate analyses were performed to identify risk factors for treatment failure and nephrotoxicity.

Results

Of 349 patients, 120 (34.4%) experienced treatment failure. For patients with VTCs at <10, 10–15, 15–20, and ≥20 µg/mL, the clinical response rates were, respectively, 77.8, 77.0, 80.5, and 61.0%; the 30-day mortality rates were 2.8, 15.0, 15.3, and 37.8%; and the rates of persistent bacteremia were 16.7, 12.4, 11.9, and 11.0%. The multivariate analysis indicated that blood urea nitrogen ≥11 g/dL and heart failure were independently associated with treatment failure; but not VTC (P = 0.004, 0.016, 0.828, respectively). During vancomycin treatment, 42 (12.0%) patients experienced nephrotoxicity with recovery time 7.5 ± 4.5 days. Fewer than half of patients with nephrotoxicity recovered after suspending vancomycin application. The variables found independently associated with increased nephrotoxicity were: VTC ≥15 µg/mL; treatment duration ≥15 d; and concomitant aminoglycosides administration (P = 0.024, 0.035, 0.029).

Conclusion

In patients aged 80 years and older, elevated VTC level was not associated with favorable treatment outcomes. Patients with VTC ≥20 µg/mL appear to suggest a worsened prognosis compared with lower VTCs. The risk of nephrotoxicity increases with elevated VTC, longer treatment time, and concomitant aminoglycoside administration.

Vancomycin-Associated Tubular Casts and Vancomycin Nephrotoxicity

Introduction

Vancomycin nephrotoxicity is frequent and may be due to drug-induced acute tubular necrosis (ATN) or tubulointerstitial nephritis (TIN). Vancomycin-associated tubular cast (VTC) was recently described and may represent a novel cause of vancomycin nephrotoxicity. However, much is still unknown about VTC.

Materials and Methods

Thirty-seven kidney biopsy specimens from patients who were treated with vancomycin and developed acute kidney injury (AKI) were found among a total of 4673 biopsy samples between 2010 and 2019. These biopsy specimens were subjected to light microscopy, immunofluorescence, electron microscopy, and immunolocalization for vancomycin, uromodulin, myoglobin, tubular segment–specific markers, and examined for VTCs. The findings were correlated with the clinical course.

Results

VTCs displayed precipitated vancomycin casts in a background of uromodulin; the casts were limited to the distal tubules, and always associated with a background of more diffuse renal injury (ATN or TIN). The diagnosis of vancomycin nephrotoxicity was made in in 28 of 37 patients. VTC was noted in 25 of 28 biopsy samples from patients diagnosed with vancomycin nephrotoxicity and in one of nine biopsy samples from patients without this diagnosis. Vancomycin nephrotoxicity was diagnosed in 25 of 26 patients whose biopsy specimens showed VTC, but in only 3 of 11 patients without VTC in the biopsy samples.

Conclusions

VTC displays a characteristic morphologic profile amenable to ready recognition in biopsy specimens. It results from coprecipitation of vancomycin and uromodulin. It facilitates the biopsy diagnosis of vancomycin nephrotoxicity. It may have a nephrotoxic effect superimposing on and independent from the ATN or interstitial nephritis in the pathogenesis of vancomycin nephrotoxicity.

Competence Mining of Vancomycin (VAN) in the Management of Infections Due to Bacterial Strains With High VAN Minimum Inhibitory Concentrations (MICs): A Novel Dosing Strategy Based on Pharmacokinetic/Pharmacodynamic Modeling

The increasing emergence of bacterial strains with high VAN MICs (BS_H–VAN–M), such as Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus bovis, results in growing concern that VAN is not effective against these isolates. Due to the limited data on VAN against BS_H–VAN–M and the application limits of drugs currently considered to be effective for BS_H–VAN–M, exploration of “new usages for old drugs” is reasonable to improve and maximize the efficacy of existing antibiotics. This study aimed to construct a novel dosing strategy to mine the competence of VAN in the management of BS_H–VAN–M infections. Herein, we optimized the traditional intermittent i.v. infusion (TIII) method to create an optimal two-step infusion (OTSI). With pharmacokinetic (PK)/pharmacodynamic (PD) modeling at the targeted ratio of the daily area under the concentration-time curve (AUC_0–24) to the minimum inhibitory concentration (MIC) (AUC_0–24/MIC) of 400, we used Monte Carlo simulations to evaluate the efficacy of 25 VAN regimens (including 15 OTSI regimens and 10 TIII regimens with daily doses of up to 6 g) to treat pneumonia, meningitis, sternal osteomyelitis, mastitis, pleuritis, bacteremia, and bacterial pericarditis resulting from isolates with MICs of ≤64 mg/L and to the current E. faecalis, E. faecium, S. aureus, S. epidermidis, and S. bovis populations with a pooled MIC distribution. Our data indicated that 4 g/day VAN, with an OTSI but not a TIII, for mastitis, pleuritis, bacteremia, and bacterial pericarditis due to isolates with MICs of ≤4 mg/L or to the current E. faecalis, S. aureus, S. epidermidis, and S. bovis populations achieved the desired PK/PD exposure at the AUC_0–24/MIC target of 400. This study suggests the superiority and feasibility of OTSI relative to TIII for the competence mining of VAN against BS_H–VAN–M from the perspective of PK/PD and provides a new resource for understanding how PK/PD modeling shapes the performance of VAN to meet the growing challenges of BS_H–VAN–M infections.

Baseline kidney function is associated with vancomycin-induced acute kidney injury in children: a prospective nested case-control study

BACKGROUND

Children with kidney insufficiency are susceptible to vancomycin-induced acute kidney injury (VIAKI), but there is a lack of compelling clinical data. We conducted a nested case-control study to evaluate the relationship between kidney insufficiency and incidence of VIAKI in children.

METHODS

Patients were considered to have VIAKI if they met the criteria for eGFR change according to pRIFLE-I or p-RIFLE-F. Case group comprised patients who developed VIAKI. Case-control ratio was 1:3; patients were matched for age, severity, and nature of illness and initial vancomycin dose. Primary endpoint was incidence of VIAKI at three levels of kidney function, calculated using Kaplan-Meier curve and log-rank test. Secondary endpoint was treatment-related in-hospital mortality amongst case and control groups.

RESULTS

Amongst 386 children who fit study criteria, 31 developed VIAKI (8.03%). Thirty-one cases and 93 controls were selected from the observed cohort. Three risk factors were identified for VIAKI: moderate kidney insufficiency (OR 8.8, 2.4-32.8), vancomycin trough concentration ≥ 15 μg/mL (OR 7.7, 1.7-34.4), and furosemide use (OR 24.8, 6.4-98.2). A significant difference in time to VIAKI was noted between patients with moderate kidney insufficiency and patients with mild kidney insufficiency or normal kidney function (p < 0.001). In-hospital mortality rate in case group was 45.2%, compared to 18.3% in control group (p < 0.01).

CONCLUSIONS

Children with moderate kidney insufficiency are more likely to develop VIAKI than those with normal and mild kidney insufficiency. Patients who develop VIAKI have higher in-hospital mortality than those who do not develop VIAKI.

Safety of administering cefazolin versus other antibiotics in penicillin-allergic patients for surgical prophylaxis at a major Canadian teaching hospital

BACKGROUND

Cefazolin surgical prophylaxis is associated with better patient outcomes; however, its use in penicillin-allergic patients is controversial. We evaluated the safety of cefazolin as surgical prophylaxis in penicillin-allergic patients, including those with anaphylaxis histories.

METHODS

We conducted a pre and postintervention quality improvement evaluation of an institution-wide policy change at a tertiary-care hospital, before (October 2017-January 2018), during (February 2018-September 2018), and after (October 2018-October 2019) transition to routine cefazolin prophylaxis for penicillin-allergic patients, including those with anaphylaxis histories but excluding severe delayed reactions (eg, Stevens-Johnson syndrome). Retrospective data was collected on all surgical prophylaxis patients with penicillin-anaphylactic histories between October 2017 and September 2018. From October 2018, we prospectively reviewed adverse events with cefazolin. Primary outcome was adverse events in penicillin-allergic patients receiving cefazolin perioperatively.

RESULTS

From October 2017 to October 2019, 27,467 operations were performed. Of 220 patients with penicillin-anaphylactic histories reviewed prior to the full policy change, no statistically significant differences were reported in allergic reactions (P = .70), surgical site infections (P = 1.00), or adverse events (P = .32) with cefazolin compared to other antibiotics. Postpolicy implementation, cefazolin usage increased 18.2%, while vancomycin and clindamycin decreased by 11.4% and 62.0%, respectively. No anaphylaxis was documented in penicillin-allergic patients receiving cefazolin in either the review or quality assurance follow-up after the change. Of 3 patients developing reactions to cefazolin, none had histories of penicillin allergy. Surgical site infection rates were similar between pre and postpolicy time periods (P = .842).

CONCLUSION

Administration of cefazolin in penicillin-anaphylactic patients for surgical prophylaxis appears to be safe.

Correlates and Outcomes of Early Acute Kidney Injury after Hematopoietic Cell Transplantation

BACKGROUND

Patients undergoing hematopoietic cell transplantation (HCT) are at high risk for acute kidney injury (AKI). The etiology of AKI is often multifactorial and includes exposure to antibiotics and calcineurin inhibitors (CNI) for prevention of graft versus host disease.

METHODS

This is a retrospective, single center study which evaluated patients undergoing inpatient HCT at Froedtert Memorial Hospital, Milwaukee, Wisconsin from Jan 1 to Dec 31, 2016. AKI was defined as an increase in serum creatinine > 0.3 mg/dL from baseline value.

RESULTS

The total number of patients included in the study was 280, 64 had AKI and 216 were in the non-AKI group. AKI was noted in 23% patients. Exposure to CNI or vancomycin accounted for the majority of the cases (82%). The median pre-AKI vancomycin trough was elevated in the AKI group at 21.3 mcg/mL (range: 17.4-24.4 mcg/mL) while the pre-AKI CNI trough was lower in the AKI group at 12.3 ng/mL (range: 8.7-14.7 ng/mL).There were also a higher number of ICU transfers (19%) and higher 100 day mortality (15.6%) in the AKI group.

CONCLUSION

AKI is a frequent complication following HCT and is associated with a higher risk of ICU transfer and higher mortality post HCT. While a higher vancomycin trough level may be indicative of a higher risk of AKI, the risk following CNI exposure may not be related to trough levels alone. There may be underlying pharmacogenetic factors which may alter the risk of AKI with CNI use.

Alteration in Acute Kidney Injury Potential with the Combination of Vancomycin and Imipenem-Cilastatin/Relebactam or Piperacillin/Tazobactam in a Preclinical Model

The risk of vancomycin (VAN)-associated acute kidney injury (AKI) may be altered with combination regimens. The specific AKI risk when VAN is combined with imipenem-cilastatin/relebactam (IMP-C/REL) or piperacillin/tazobactam (TZP) has not been clearly defined. We sought to quantify the dose-AKI relationships of VAN alone and in combination with TZP or IMP-C/REL. Male C57BL/6J mice (Charles River Laboratory) aged 10 to 12 weeks were dosed with study drug regimens in three stages. Stage 1 consisted of a VAN dose-ranging design (0 to 600 mg/kg daily) over a 7-day period to identify the VAN monotherapy dose-AKI relationship in the murine model. Stage 2 evaluated the approximate VAN dose eliciting 50% AKI response in stage 1 in combination with the highest human equivalent doses (HEDs) used in preclinical murine models (2.5 and 320 mg/kg daily for TZP and IMP-C/REL, respectively). Stage 3 tested these combinations with fractionated doses of TZP or IMP-C/REL administered at 6- and 12-h intervals. In these studies, AKI was defined with biomarkers (serum creatinine [SCr], blood urea nitrogen [BUN]) and with histopathological assessment by a treatment-blinded pathologist. VAN doses of 300 to 500 mg/kg daily reproducibly led to development of AKI within 4 days of dosing. Mice treated with VAN alone had a near doubling of their baseline SCr and BUN levels compared with mice treated with control, IMP-C/REL alone, or TZP alone. Both VAN+IMP-C/REL and VAN+TZP had significantly (P < 0.05) lower SCr and BUN values than VAN alone when dosed once daily. This nephroprotective effect was retained with VAN+IMP-C/REL but not VAN+TZP when IMP-C/REL and TZP were administered every 6 h. Biomarker results were concordant with histopathological findings. The VAN dose-AKI relationship can be attenuated with single daily HEDs of TZP or IMP-C/REL in mice. IMP-C/REL, but not TZP, retained a nephroprotective effect compared with VAN monotherapy when administered as fractionated doses.

Kidney biopsy findings in vancomycin-induced acute kidney injury: a pooled analysis

BACKGROUND

Acute kidney injury represents a major adverse effect of vancomycin administration. The aim of the present study is to accumulate all biopsy-proven cases of vancomycin nephrotoxicity and assess the association of histopathological features with renal prognosis.

METHODS

Medline, Scopus, CENTRAL, Web of Science, and Clinicaltrials.gov were systematically searched from inception to 29 September 2020. All case reports/series providing individual data of patients with biopsy-proven vancomycin nephrotoxicity were held eligible. A time-to-event analysis was performed evaluating the effects of histological diagnosis on renal recovery.

RESULTS

Overall, 18 studies were included, comprising 21 patients. Acute tubulointerstitial nephritis was the predominant pattern in 9 patients and was associated with a significantly higher risk of permanent renal dysfunction (HR: 5.08, 95% CI: [1.05-24.50)] compared to acute tubular necrosis. Tubulitis and eosinophilic infiltration were the most common histopathological findings, while interstitial fibrosis was linked to significantly worse renal prognosis (HR: 5.55, 95% CI: 1.13-27.27). Immunofluorescence and electron microscopy features were non-specific. Obstruction by tubular casts composed of vancomycin aggregates and uromodulin has been identified as a new mechanism of nephrotoxicity.

CONCLUSIONS

Acute tubular necrosis and tubulointerstitial nephritis represent the main histological patterns of vancomycin-induced acute kidney injury. The presence of fibrosis in the context of interstitial inflammation may be linked to lower recovery rates and worse long-term renal outcomes. A novel cast nephropathy obstructive mechanism has been suggested, necessitating further confirmation. Large-scale studies should define the exact indications of kidney biopsy in cases with suspected vancomycin nephrotoxicity.

Individualized Vancomycin Dosing with Therapeutic Drug Monitoring and Pharmacokinetic Consultation Service: A Large-Scale Retrospective Observational Study

Background

To date, outcome data with a large sample size and data regarding the clinical outcomes of pharmacokinetic-guided (PK) dosing of vancomycin are limited.

Aim

We evaluated the pharmacokinetic and clinical outcomes of a PK-guided dosing advisory program, pharmacokinetic consultation service (PKCS), in vancomycin treatment.

Methods

We investigated vancomycin therapeutic drug monitoring (TDM) and PKCS use through a retrospective review of patients who had serum vancomycin trough concentration data from October 2017 to November 2018. Among these patients, we selected non-critically ill adult patients satisfying our selection criteria to evaluate the effect of PKCS. Target trough attainment rate, time to target attainment, vancomycin-induced nephrotoxicity (VIN), vancomycin treatment failure rate, and duration of vancomycin therapy were compared between patients whose dosing was adjusted according to PKCS (PKCS group), and those whose dose was adjusted at the discretion of the attending physician (non-PKCS group).

Results

A total of 280 patients met the selection criteria for the VIN analysis (PKCS, n=134; non-PKCS, n=146). The incidence of VIN was similar between the two groups (PKCS, n=5; non-PKCS, n=5); however, the target attainment rate was higher in the PKCS group (75% vs 60%, P = 0.012). The time to target attainment was similar between the two groups. Further exclusions yielded 112 patients for the clinical outcome evaluation (PKCS, n=51; non-PKCS, n=61). The treatment failure rate was similar, and the duration of vancomycin therapy was longer in the PKCS group (12 vs 8 days, P = 0.008).

Conclusion

In non-critically ill patients, an increase in target trough achieved by PKCS did not lead to decreased vancomycin treatment failures, shorter vancomycin treatment, or decreased nephrotoxicity in vancomycin treatment. Considering the excessive amount of effort currently put into vancomycin dosing and monitoring, more selective criteria for individualized pharmacokinetic-guided dosing needs to be applied.

Association Between Vancomycin Area Under the Curve and Nephrotoxicity: a single center, retrospective cohort study in a veteran population

Background

It is unclear which vancomycin area under the curve (AUC) values are most associated with risk for acute kidney injury (AKI).

Methods

This retrospective cohort study was undertaken to determine if vancomycin AUC >550 is associated with a higher rate of AKI than an AUC <550. Patients treated with vancomycin for at least 4 days at the VA St. Louis Health Care System from 1/1/2016 to 9/31/2018 were included. The primary outcome was AKI (defined as an increase in serum creatinine by 0.3 mg/dL or 50% from baseline). Secondary outcomes included length of stay, readmission in 30 days, and mortality in 30 days. A bivariate analysis was used to determine other potential factors affecting AKI rate, with significant variables (P < .2) to be included in the multivariate logistic regression analysis to determine independent risk for AKI.

Results

Two hundred patients were included in the analysis; 100 patients with an AUC ≥550 and 100 with an AUC <550. Only mean vancomycin dose (1722.50 mg vs 2361.25 mg; P < .05), mean AUC (465.88 vs 696.45; P < .05), and peak SCr (1.22 mg/dL vs 1.48 mg/dL; P = .015) were significantly different between groups (AUC <550 vs AUC ≥550, respectively). AKI occurred in 42% (42/100) of patients with AUC ≥550 compared with 2% (2/100) of patients with AUC <550 (P < .05). Secondary outcomes were not different between the groups. In the bivariate analysis, age ≥70, CrCl <50 mL/min, and AUC ≥550 (odds ratio, 49.5; 95% CI, 10.1-242.3; P < .05) were found to be independently associated with risk for developing AKI.

Conclusions

Patients with a vancomycin AUC ≥550 were found to have a significantly higher rate of AKI compared with those with an AUC <550.

Urinary Exosomes Identify Inflammatory Pathways in Vancomycin Associated Acute Kidney Injury

Background: Vancomycin is commonly used as a first line therapy for gram positive organisms such as methicillin resistant Staphylococcusaureus. Vancomycin-induced acute kidney injury (V-AKI) has been reported in up to 43% of patients, especially in those with higher targeted trough concentrations. The precise mechanism of injury in humans remains elusive, with recent evidence directed towards proximal tubule cell apoptosis. In this study, we investigated the protein contents of urinary exosomes in patients with V-AKI to further elucidate biomarkers of mechanisms of injury and potential responses. Methods: Urine samples from patients with V-AKI who were enrolled in the DIRECT study and matched healthy controls from the UAB-UCSD O’Brien Center Biorepository were included in the analysis. Exosomes were extracted using solvent exclusion principle and polyethylene glycol induced precipitation. Protein identity and quantification was determined by label-free liquid chromatography mass spectrometry (LC/MS). The mean peak serum creatinine was 3.7 ± 1.4 mg/dL and time to kidney injury was 4.0 ± 3.0 days. At discharge, 90% of patients demonstrated partial recovery; 33% experienced full recovery by day 28. Proteomic analyses on five V-AKI and 7 control samples revealed 2009 proteins in all samples and 251 proteins significantly associated with V-AKI (Pi-score > 1). The top discriminatory proteins were complement C3, complement C4, galectin-3-binding protein, fibrinogen, alpha-2 macroglobulin, immunoglobulin heavy constant mu and serotransferrin. Conclusion: Urinary exosomes reveal up-regulation of inflammatory proteins after nephrotoxic injury in V-AKI. Further studies are necessary in a large patient sample to confirm these findings for elucidation of pathophysiologic mechanisms and validation of potential injury biomarkers.

Vancomycin Associated Acute Kidney Injury: A Longitudinal Study in China

Background: Vancomycin-associated acute kidney injury (VA-AKI) is a recognizable condition with known risk factors. However, the use of vancomycin in clinical practices in China is distinct from other countries. We conducted this longitudinal study to show the characteristics of VA-AKI and how to manage it in clinical practice.

Patients and Methods: We included patients admitted to hospital, who received vancomycin therapy between January 1, 2016 and June 2019. VA-AKI was defined as a patient having developed AKI during vancomycin therapy or within 48 h following the withdrawal of vancomycin therapy.

Results: A total of 3719 patients from 7058 possible participants were included in the study. 998 patients were excluded because of lacking of serum creatinine measurement. The incidence of VA-AKI was 14.3%. Only 32.3% (963/2990) of recommended patients performed therapeutic drug monitoring of vancomycin. Patients with VA-AKI were more likely to concomitant administration of cephalosporin (OR 1.55, 95% CI 1.08–2.21, p = 0.017), carbapenems (OR 1.46, 95% CI 1.11–1.91, p = 0.006) and piperacillin-tazobactam (OR 3.12, 95% CI 1.50–6.49, p = 0.002). Full renal recovery (OR 0.208, p = 0.005) was independent protective factors for mortality. Compared with acute kidney injury stage 1, AKI stage 2 (OR 2.174, p = 0.005) and AKI stage 3 (OR 2.210, p = 0.005) were independent risk factors for fail to full renal recovery.

Conclusion: Lack of a serum creatinine measurement for the diagnosis of AKI and lack of standardization of vancomycin therapeutic drug monitoring should be improved. Patient concomitant with piperacillin-tazobactam are at higher risk. Full renal recovery was associated with a significantly reduced morality.

Evaluation of bone and kidney toxicity of BT2-peg2, a potential carrier for the targeted delivery of antibiotics to bone

Previous studies have demonstrated that the bone targeting agent BT2-peg2 (BT2-minipeg2, 9), when conjugated to vancomycin and delivered systemically by intravenous (IV) or intraperitoneal (IP) injection accumulates in bone to a greater degree than vancomycin alone, but that this accumulation is associated with severe nephrotoxicity. To determine whether this nephrotoxicity could be attributed to BT2-peg2 itself, we used a rat model to assess the distribution and toxicity of BT2-peg2 after IP injection of 11 mg/kg twice daily for 21 days. The results demonstrated that BT2-peg2 accumulates in bone but there was no evidence of nephrotoxicity or any histopathological abnormalities in the bone. This suggests the nephrotoxicity observed in previous studies is likely due to the altered pharmacokinetics of vancomycin when conjugated to BT2-peg2 rather than to BT2-peg2 itself. Thus, BT2-peg2 may be a safe carrier for the enhanced delivery of antibiotics other than vancomycin to the bone as a means of combating bone infection. However, the data also emphasizes the need to carefully examine the pharmacokinetic characteristics of any BT2-peg2-antibiotic conjugate utilized for treatment of bone infections.

The efficiency of pomegranate (Punica granatum) peel ethanolic extract in attenuating the vancomycin-triggered liver and kidney tissues injury in rats

This study evaluated the potential of Punica granatum peel ethanol extract (PPEE) in attenuating the liver and kidney tissue injury induced by vancomycin (VM) treatment in rats. Fifty rats were distributed equally into five groups: control group, PPEE-administered group (100 mg/kg BW/day for 2 weeks; orally), VM-treated group (443.6 mg/kg BW, every alternate day for 2 weeks; intraperitoneally), pre-treated group, and concomitant-treated group. The biochemical response and the histopathology of the hepatic and renal tissue of the treated animals were assessed. The results showed that VM treatment induced substantial hepatotoxicity and nephrotoxicity, evidenced by a significant elevation in tissue injury and lipid oxidative (malondialdehyde) and inflammatory response (C-reactive protein) biomarkers, with lowered antioxidants and protein levels. Additionally, VM treatment induced various morphological, cytotoxic, vascular, and inflammatory perturbations as well as upregulation in the immune-expression of Caspase-3 and downregulation of BCL-2. Moreover, PPEE co-treatment was found to reduce the VM-induced toxicity by protecting the tissue against reactive oxygen species (ROS)-mediated oxidative damage, and inflammation as well as hinder the apoptotic cell death by modulating the expression of apoptosis-related proteins. Thus, we conclude that the PPEE administration showed more restoring efficacy when administered prior to VM medication.

Effect of vancomycin loading dose on clinical outcome in critically ill patients with methicillin-resistant Staphylococcus aureus pneumonia

Background

Vancomycin is the treatment of choice for serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Current guidelines recommend giving an initial loading dose (LD) of 25–30 mg/kg to rapidly increase the serum concentration. However, high-quality evidence for the clinical benefit of LD is lacking. Herein, we aim to examine the association between vancomycin LD and clinical outcome.

Methods

A retrospective cohort study was conducted on adult patients treated for MRSA pneumonia with vancomycin in medical intensive care units from April 2016 to August 2018. MRSA pneumonia was defined by the Centers for Disease Control and National Healthcare Safety Network definition. The primary outcome was the clinical cure of pneumonia. Secondary outcome measures included time to pharmacokinetic (PK) target attainment, microbiological cure, acute kidney injury, and all-cause mortality.

Results

A total of 81 patients were included; of these 22 (27.2%) received LD. The mean initial dose was significantly higher in the LD group. Clinical cure was similar in both groups (68.2% vs. 66.1% in the LD and non-LD groups, respectively; P=0.860). No significant difference was observed in the microbiological cure, all-cause mortality, and incidence of acute kidney injury. Furthermore, no difference was observed in terms of time to PK target attainment (69.2 vs. 63.4 h in the LD and non-LD groups, respectively; P=0.624). Vancomycin minimum inhibitory concentration of <2 mg/L was identified as an independent predictive factor for clinical cure in multivariable analysis, whereas vancomycin LD was not.

Conclusions

Initial LD is not associated with better clinical outcome or rapid pharmacological target attainment in critically ill patients with MRSA pneumonia. Further studies are warranted to provide better evidence for this widely recommended practice.

Emergency department methicillin-resistant Staphylococcus aureus nare screen effect on pneumonia treatment duration

STUDY OBJECTIVE

The objective of this study was to determine if performing a methicillin-resistant Staphylococcus aureus (MRSA) nasal screen in the emergency department (ED) decreased general medicine patient exposure to anti-MRSA antibiotics for pneumonia.

METHODS

This was a single-center, retrospective study evaluating patients who had a diagnosis of pneumonia and were initiated on anti-MRSA therapy (vancomycin or linezolid) in the ED and subsequently admitted to a general medicine floor. Patients were divided into two groups: 1) did not receive a MRSA nares screen in the ED (No MRSA screen group) or 2) received a MRSA nares screen in the ED (MRSA screen group). The primary outcome was anti-MRSA antibiotic duration. Secondary outcomes included vancomycin level evaluation, hospital survival, and acute kidney injury.

RESULTS

Of the 116 patients included, 37 patients received a MRSA nares screen in the ED and 79 patients did not. Median duration of antibiotic exposure was similar for both groups (No MRSA screen, 30.5 h [interquartile range (IQR) 20.5-52.5] vs. MRSA screen, 24.5 h [IQR 20.6-40.3]; p = 0.28). Of patients who were screened, 35 were negative and 2 were positive. Secondary outcomes were similar.

CONCLUSION

Performing a MRSA nares screen in the ED for patients diagnosed with pneumonia, initiated on anti-MRSA antibiotics, and admitted to a general medicine floor did not decrease duration of anti-MRSA antibiotics. At this time, ED providers do not need to consider a MRSA nasal screen in the ED for patients being admitted to general medicine, although larger studies could be considered.