Systematic review and meta-analysis of vancomycin-induced nephrotoxicity associated with dosing schedules that maintain troughs between 15 and 20 milligrams per liter. Antimicrob Agents Chemother. 2013;57:734-744. [PMID: 23165462 DOI: 10.1128/aac.01568-12]

Optimal Practice for Vancomycin Therapeutic Drug Monitoring: Position Statement From the Anti-infectives Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology

ABSTRACT

Individualization of vancomycin dosing based on therapeutic drug monitoring (TDM) data is known to improve patient outcomes compared with fixed or empirical dosing strategies. There is increasing evidence to support area-under-the-curve (AUC24)-guided TDM to inform vancomycin dosing decisions for patients receiving therapy for more than 48 hours. It is acknowledged that there may be institutional barriers to the implementation of AUC24-guided dosing, and additional effort is required to enable the transition from trough-based to AUC24-based strategies. Adequate documentation of sampling, correct storage and transport, accurate laboratory analysis, and pertinent data reporting are required to ensure appropriate interpretation of TDM data to guide vancomycin dosing recommendations. Ultimately, TDM data in the clinical context of the patient and their response to treatment should guide vancomycin therapy. Endorsed by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology, the IATDMCT Anti-Infectives Committee, provides recommendations with respect to best clinical practice for vancomycin TDM.

Therapeutic Drug Monitoring of Antibiotics: Defining the Therapeutic Range

PURPOSE

In the present narrative review, the authors aimed to discuss the relationship between the pharmacokinetic/pharmacodynamic (PK/PD) of antibiotics and clinical response (including efficacy and toxicity). In addition, this review describes how this relationship can be applied to define the therapeutic range of a particular antibiotic (or antibiotic class) for therapeutic drug monitoring (TDM).

METHODS

Relevant clinical studies that examined the relationship between PK/PD of antibiotics and clinical response (efficacy and response) were reviewed. The review (performed for studies published in English up to September 2021) assessed only commonly used antibiotics (or antibiotic classes), including aminoglycosides, beta-lactam antibiotics, daptomycin, fluoroquinolones, glycopeptides (teicoplanin and vancomycin), and linezolid. The best currently available evidence was used to define the therapeutic range for these antibiotics.

RESULTS

The therapeutic range associated with maximal clinical efficacy and minimal toxicity is available for commonly used antibiotics, and these values can be implemented when TDM for antibiotics is performed. Additional data are needed to clarify the relationship between PK/PD indices and the development of antibiotic resistance.

CONCLUSIONS

TDM should only be regarded as a means to achieve the main goal of providing safe and effective antibiotic therapy for all patients. The next critical step is to define exposures that can prevent the development of antibiotic resistance and include these exposures as therapeutic drug monitoring targets.

The Thirty-Day Mortality Rate and Nephrotoxicity Associated With Trough Serum Vancomycin Concentrations During Treatment of Enterococcal Infections: A Propensity Score Matching Analysis

The objective of this study was to evaluate the relationship between vancomycin trough levels in patients with documented enterococcal infections and mortality, clinical outcomes, microbiological outcomes, and nephrotoxicity. We conducted a retrospective cohort study of patients with enterococcus infections who were prescribed vancomycin with therapeutic drug monitoring during January 2010 and December 2019 at Chiang Mai University Hospital (CMUH). The study enrolled 300 participants who met the inclusion criteria and were prescribed vancomycin with therapeutic drug monitoring. The results of this study showed that, after propensity score matching, a vancomycin trough of ≥15 mg/L was associated with significant differences in 30-days mortality compared to a vancomycin trough of <15 mg/L (aHR: 0.41, 95% CI: 0.21–0.82; p = 0.011). Likewise, a vancomycin trough of ≥15 mg/L was associated with significant differences in the clinical response (aHR: 0.49, 95% CI: 0.26–0.94; p = 0.032), microbiological response (aHR: 0.32, 95% CI: 0.12–0.87; p = 0.025) and nephrotoxicity (aHR: 3.17, 95% CI: 1.39–7.23; p = 0.006), compared with a vancomycin trough of <15 mg/L. However, sub-group analysis found that very high trough levels (>20 mg/L) were also associated with a high rate of nephrotoxicity (aHR: 3.55, 95% CI 1.57–8.07, p = 0.002), when compared with a vancomycin trough of <15 mg/L. The target vancomycin trough concentration was ≥15 mg/L and this target can be an optimal alternative to the use of area under the curve (AUC) values for monitoring the treatment of enterococcal infection.

Associations Between Vancomycin Exposure and Acute Kidney Injury Within the Recommended Area Under the Curve Therapeutic Exposure Range Among Patients With Methicillin-Resistant Staphylococcus aureus Bloodstream Infections

Among patients with methicillin-resistant Staphylococcus aureus bacteremia, vancomycin-associated acute kidney injury increased as a function of the day 2 area under the curve (AUC), even for daily AUCs within the recommended therapeutic range (400–600). Further data are needed to determine if daily AUCs &lt;400 can be maintained without compromising efficacy.

Contribution of diafiltration and adsorption to vancomycin clearance in a continuous hemodiafiltration circuit model in vitro

BACKGROUND

Vancomycin (VCM) is eliminated mainly by diafiltration under continuous hemodiafiltration (CHDF), but the contribution of adsorption to CHDF clearance (CL_CHDF ) of VCM using a polyacrylonitrile and sodium methallyl sulfonate copolymer membrane coated with polyethylenimine (AN69ST) or a polymethylmethacrylate (PMMA) membrane is unknown. This study sought to investigate the contribution of diafiltration and adsorption to the CL_CHDF of VCM using AN69ST and PMMA membranes in vitro.

METHODS

An in vitro CHDF circuit model was developed. The initial concentration of VCM was 50 μg/mL and human serum albumin (HSA) was prepared at a concentration of 0, 2.5, or 5.0 g/dL. The effluent flow rate (Qe) was set at 800, 1500, or 3000 mL/h. The CL_CHDF , diafiltration rate, and adsorption rate of VCM were calculated.

RESULTS

Total CL_CHDF of VCM using the AN69ST membrane increased and decreased with increasing Qe and HSA concentration, respectively. Diafiltration and adsorption rates were 82.1 ± 9.8% and 12.1 ± 6.1% under all conditions, respectively. Total CL_CHDF using the PMMA membrane increased with increasing Qe. Diafiltration and adsorption rates were 89.2 ± 20.4% and 4.6 ± 17.0% under all conditions, respectively. The observed CL_CHDF values significantly correlated with the predicted CL_CHDF , calculated according to a previous study as the product of Qe and the plasma unbound fraction.

CONCLUSIONS

Diafiltration predominantly contributed to CL_CHDF of VCM using AN69ST and PMMA membranes. When diafiltration rather than adsorption mainly contributes to the CL_CHDF of VCM, the CL_CHDF could be predicted from the Qe and HSA concentration, at least in vitro.

Vancomycin therapeutic monitoring by measured trough concentration versus Bayesian-derived area under the curve in critically ill patients with cancer

The updated vancomycin guideline and recent studies suggested that trough concentrations may result in underestimation of the actual area under the curve (AUC), leading to excessive dosing and nephrotoxicity. With limited data available on critically ill cancer patients, this study aimed to compare the two methods in this patient population. This was a 5‐year retrospective study on patients treated with vancomycin in the intensive care unit (ICU) of a comprehensive cancer center. The measured trough concentration was compared to Bayesian‐derived AUC/minimum‐inhibitory‐concentration (MIC), considering MIC as 1. Trough concentrations of 15–20 mg/L and AUC of 400–600 mg h/L were considered the targeted goal. Multivariate analysis was performed to identify factors associated with an AUC below the targeted goal. During the study period, 316 patients were included. The mean age was 54 years ±16 (SD); most patients had solid tumors (75%), and 11% had neutropenia. A targeted goal AUC and trough were recorded in 128 (41%) patients and in 64 (20%) patients, respectively. Of the 128 patients with targeted goal AUC, 31 (24%) had targeted goal trough concentrations and 91 (71%) had trough concentrations below 15 mg/L. Furthermore, among the patients with targeted goal trough concentration (n = 64), 33 (52%) had higher than targeted goal AUC. Augmented renal clearance (ARC), defined as a calculated creatinine‐clearance ≥130 ml/min, was associated with an AUC below the targeted goal. In a cohort of critically ill patients with cancer, over two‐thirds of the patients with a targeted goal Bayesian AUC/MIC had trough concentrations below the targeted goal. ARC was associated with AUC below the targeted goal.

Nephrotoxins and acute kidney injury - The consensus of the Taiwan acute kidney injury Task Force

The Taiwan Acute Kidney Injury (AKI) Task Force conducted a review of data and developed a consensus regarding nephrotoxins and AKI. This consensus covers: (1) contrast-associated AKI; (2) drug-induced nephrotoxicity; (3) prevention of drug-associated AKI; (4) follow up after AKI; (5) re-initiation of medication after AKI. Strategies for the avoidance of contrast media related AKI, including peri-procedural hydration, sodium bicarbonate solutions, oral N-acetylcysteine, and iso-osmolar/low-osmolar non-ionic iodinated contrast media have been recommended, given the respective evidence levels. Regarding anticoagulants, both warfarin and new oral anticoagulants have potential nephrotoxicity, and dosage should be reduced if renal pathology exam proves renal injury. Recommended strategies to prevent drug related AKI have included assessment of 5R/(6R) reactions - risk, recognition, response, renal support, rehabilitation and (research), use of AKI alert system and computerized decision support. In terms of antibiotics-associated AKI, avoiding concomitant administration of vancomycin and piperacillin-tazobactam, monitoring vancomycin trough level, switching from vancomycin to teicoplanin in high-risk patients, and replacing conventional amphotericin B with lipid-based amphotericin B have been shown to reduce drug related AKI. With respect to non-steroidal anti-inflammatory drug associated AKI, it is recommended to use these drugs cautiously in the elderly and in patients receiving renin-angiotensin-aldosterone system inhibitors/diuretics triple combinations.

Target serum concentration of vancomycin may be reached earlier with a loading dose

BACKGROUND

Vancomycin treatment failure against vancomycin-susceptible gram-positive cocci is not rare in the intensive care unit (ICU). One of the reasons for this is the substandard drug trough concentration. We aimed to examine the hypothesis that the target serum concentration could be reached earlier with a loading dose of vancomycin.

METHODS

This retrospective cohort study was conducted at our ICU between June 2018 and June 2020 and involved patients who were suspected of having, or confirmed to have, gram-positive cocci infection and treated with vancomycin. One group of the patients was administered a loading dose of vancomycin (loading group) and compared with the group that did not receive a loading dose (control group). The baseline characteristics, vancomycin serum concentrations, and clinical outcomes were collected and analyzed.

RESULTS

Fifty-five patients were finally included, of which 29 received a loading dose of vancomycin. The serum concentration of vancomycin before the second dose was significantly higher for the loading group than for the control group (10.3 ± 6.1 mg/L vs. 5.7 ± 4.4 mg/L, P = 0.002). The results for both groups were similar before the fifth dose (12.4 ± 7.3 mg/L vs. 10.3 ± 6.3 mg/L in the loading and the control groups, respectively; P = 0.251). The 28-day mortality was lower for the loading group than for the control group (6.7% vs. 34.6% in the loading and control groups, respectively; P = 0.026). No significant differences were observed in serum creatinine (Cr) concentrations of the two groups.

CONCLUSION

With the loading dose of vancomycin, the target serum concentration of vancomycin may be reached earlier without increasing the risk of acute kidney injury.

TRIAL REGISTRATION

https://www.chictr.org.cn; ChiCTR2000035369.

N-acetylcysteine Ameliorates Vancomycin-induced Nephrotoxicity by Inhibiting Oxidative Stress and Apoptosis in the in vivo and in vitro Models

Background: Oxidative stress-related apoptosis is considered as the key mechanism implicated in the pathophysiology of nephrotoxicity with vancomycin (VCM) therapy. We evaluated the possible effects of N-acetylcysteine (NAC) on VCM-induced nephrotoxicity and the underlying mechanism. Methods: VCM-induced nephrotoxicity was established using HK-2 cells and SD rats and observed by measuring cell survival, kidney histological changes, renal function and kidney injury related markers (KIM-1 and NGAL). Oxidative stress, renal cell apoptosis and the involved signaling pathways were also evaluated. Results: In model rats, NAC could protect against VCM-induced acute kidney injury with histological damage, renal dysfunction, and increased Cre and BUN levels. In HK-2 cells, VCM-induced decreased cell viability was restored by NAC. In addition, increased expression of caspase-3, KIM-1 and NGAL suffering from VCM was also reversed by NAC in vivo and in vitro. NAC inhibited ROS production, decreased cell apoptosis by decreasing the Bax/Bcl-2 ratio and caspase-3 expression in HK-2 cells and regulated oxidative stress indicators in the kidney by decreasing GSH, SOD and CAT activity and increasing MDA levels. Furthermore, NAC could effectively reverse VCM-associated increased P38 MAPK/JNK phosphorylation. Conclusions: The results demonstrated that NAC had a protective effect against nephrotoxicity from VCM by inhibiting oxidative stress and apoptosis via P38 MAPK/JNK.

Vancomycin area under the curve/minimum inhibitory concentration and trough level concordance–evaluation on an urban health unit

Background:

A vancomycin AUC/MIC (area under the curve/minimum inhibitory concentration) of 400–600 mg•h/L is associated with improved clinical outcomes for the treatment of methicillin resistant Staphylococcus aureus (MRSA) infections. Currently, there are still limited studies evaluating the relationship between vancomycin trough and AUC.

Objectives:

To evaluate the correlation between vancomycin trough and AUC/MIC and determine if trough-guided monitoring is an adequate predictor of AUC/MIC in the Urban Health population at St Paul’s Hospital.

Methods:

This was a retrospective chart review of 29 patients from November 2019 to February 2021. Patient demographics and laboratory data were collected from electronic medical records. The two-level equation-based approach was used to calculate AUC/MIC. The proportion of AUC/MIC values within target (400–600 mg•h/L) despite subtherapeutic troughs, and the proportion of AUC/MIC values supratherapeutic when trough is within target (15–20 mg/L) were the primary endpoints.

Main Results:

Fifty-seven sets of levels were collected and 75% of vancomycin troughs and AUC24 were found to be discordant. When trough was 10–14.9 mg/L, AUC24 was > 400 mg•h/L in 94% of cases and when trough was 15–20 mg/L, AUC24 was > 600 mg•h/L in 69% of cases. There was a moderate correlation between vancomycin trough and AUC24h ( R2 = 0.57; p < 0.001).

Conclusion:

A vancomycin trough between 15 and 20 mg/L may result in an AUC/MIC greater than necessary for clinical efficacy. Considering these findings and the practical concerns of AUC-guided monitoring, a modest reduction in target troughs to prevent vancomycin toxicity warrants clinical consideration and further evaluation.

Vancomycin Area Under the Curve to Predict Timely Clinical Response in the Treatment of Methicillin-resistant Staphylococcus aureus Complicated Skin and Soft Tissue Infections

INTRODUCTION

Although recent guidelines have recommended monitoring vancomycin (VAN) area under the curve (AUC)/minimum inhibitory concentration (MIC) to ensure clinical efficacy and minimize toxicity in methicillin-resistant Staphylococcus aureus (MRSA) for various infections, there are no recommendations regarding complicated skin and soft tissue infections (cSSTIs). We aimed to evaluate the association between VAN AUC and clinical outcomes in MRSA cSSTIs.

METHODS

This was a retrospective cohort study of adult patients treated with ≥72 hours of VAN for MRSA cSSTI from 2008 to 2013 at Detroit Medical Center. The primary outcome was timely clinical success (TCS) defined as (1) resolution of signs and symptoms of infection within 72 hours, (2) stabilization and/or reduction in lesion size, (3) alternative agents not required due to VAN failure or toxicity as elected by the prescribing clinician. Classification and regression tree (CART) analysis was performed to determine the AUC associated with TCS in the cohort. Multivariable logistic regression was used to evaluate the association between VAN-AUC and the primary outcome.

RESULTS

A total of 154 patients were included in this analysis. CART identifed an AUC ≥435 mg*hr/L for TCS. Overall, 60.9% of patients experienced TCS; 69.7% in the target-AUC group versus 52.5% in the below-target AUC group, (P = .013). Target-AUC attainment was independently associated with increased odds of TCS (adjusted odds ratio [aOR], 2.208; 95% confidence interval [CI], 1.047-4.659).

CONCLUSIONS

In adults treated with VAN for MRSA cSSTI, target-AUC attainment was independently associated with improved clinical outcomes and maybe most warranted for patients at high risk of VAN failure or VAN-associated toxicity.

Treatment of MRSA infections in India: Clinical insights from a Delphi analysis

PURPOSE

International and Indian guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections are available, but the local guidelines are not MRSA-specific. This study aimed to provide clinical insights for the treatment of MRSA infections in India.

METHODS

We used a three-step modified Delphi method to obtain insights. Ten experts comprising infectious disease specialists, microbiologists, pulmonologists, and critical care experts agreed to participate in the analysis. In round 1, a total of 161 statements were circulated to the panel and the experts were asked to 'agree' or 'disagree' by responding 'yes' or 'no' to each statement and provide comments. The same process was used for 73 statements in round 2. Direct interaction with the experts was carried out in round 3 wherein 35 statements were discussed. At least 80% of the experts had to agree for a statement to reach concordance.

RESULTS

Eighty-eight statements in round 1, thirty-eight statements in round 2, and eight statements in round 3 reached concordance and were accepted without modification. The final document comprised 152 statements on the management of various syndromes associated with MRSA such as skin and soft tissue infections, bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system infections.

CONCLUSIONS

This analysis will assist clinicians in India to choose an appropriate course of action for MRSA infections.

Degradation of vancomycin in external quality assessment samples is a factor to underestimate its concentration

Aim: To compare the difference between the measured and target values in vancomycin external quality assessment (EQA) samples and to investigate the factors for underestimating its concentration. Materials & methods: A retrospective analysis of 195 international vancomycin EQA results was performed. Deviations of the concentrations determined by TDx fluorescence polarization immunoassay (FPIA), Axsym FPIA and Architect chemiluminescence microparticle immunoassay (CMIA) method were -2.43, -16.28 and -10.53%, respectively. Chromatographic peaks of the crystalling degradation products appeared in samples with large deviations. Vancomycin were degraded after long-term transporting and high temperature. Conclusion: Vancomycin concentrations measured by Axsym FPIA and Architect CMIA methods were likely to be underestimated. Long-term transporting resulted in low EQA results, suggesting that establishing a local EQA system for vancomycin is essential.

Risk Factors Associated With Nephrotoxicity During Outpatient Intravenous Vancomycin Administration

Background: Many studies have described an association between intravenous vancomycin and nephrotoxicity; however, the majority have evaluated incidence and risk factors among hospitalized patients. Outpatient administration of intravenous antibiotics is a growing practice and presents its own set of unique challenges. Objective: The aim of this study was to identify risk factors for vancomycin-associated nephrotoxicity in the outpatient setting. Methods: A case-control study of patients who received intravenous vancomycin through an Outpatient Parenteral Antimicrobial Therapy (OPAT) program was conducted. Patients were identified who developed an acute kidney injury (AKI) during treatment. The primary outcome was the incidence of AKI during treatment. Results: A total of 37 out of 130 patients (28.5%) met the criteria for AKI. AKI was more likely to occur in patients with a longer duration of therapy, higher maximum trough concentration, co-administration of a fluoroquinolone or metronidazole, and those who received another potentially nephrotoxic medication. Co-administration of a fluoroquinolone (OR = 5.96, P = 0.009, [CI: 1.59, 24.38]), any nephrotoxic medication (OR = 11.17, P < 0.001, [CI 3.14, 51.23]), and a higher maximum vancomycin trough (OR = 1.29, P < 0.001, [CI 1.17, 1.44]) were all indicative of a higher odds of an AKI. Conclusion: In this cohort, vancomycin-associated nephrotoxicity was common during outpatient intravenous antibiotic therapy. Co-administration of a fluoroquinolone, any nephrotoxic medication, and a higher maximum vancomycin trough were associated with AKI development. Further study is needed to determine how this impacts long-term clinical outcomes and what measures can be taken to reduce nephrotoxicity risk.

Risk of antimicrobial-associated organ injury among the older adults: a systematic review and meta-analysis

Background

Older adults (aged 65 years and above) constitute the fastest growing population cohort in the western world. There is increasing evidence that the burden of infections disproportionately affects older adults, and hence this vulnerable population is frequently exposed to antimicrobials. There is currently no systematic review summarising the evidence for organ injury risk among older adults following antimicrobial exposure. This systematic review and meta-analysis examined the relationship between antimicrobial exposure and organ injury in older adults.

Methodology

We searched for original research articles in PubMed, Embase.com, Web of Science core collection, Web of Science BIOSIS citation index, Scopus, Cochrane Central Register of Controlled Trials, ProQuest, and PsycINFO databases, using key words in titles and abstracts, and using MeSH terms. We searched for all available articles up to 31 May 2021. After removing duplicates, articles were screened for inclusion into or exclusion from the study by two reviewers. The Newcastle-Ottawa scale was used to assess the risk of bias for cohort and case-control studies. We explored the heterogeneity of the included studies using the Q test and I² test and the publication bias using the funnel plot and Egger’s test. The meta-analyses were performed using the OpenMetaAnalyst software.

Results

The overall absolute risks of acute kidney injury among older adults prescribed aminoglycosides, glycopeptides, and macrolides were 15.1% (95% CI: 12.8–17.3), 19.1% (95% CI: 15.4–22.7), and 0.3% (95% CI: 0.3–0.3), respectively. Only 3 studies reported antimicrobial associated drug-induced liver injury. Studies reporting on the association of organ injury and antimicrobial exposure by age or duration of treatment were too few to meta-analyse. The funnel plot and Egger’s tests did not indicate evidence of publication bias.

Conclusion

Older adults have a significantly higher risk of sustaining acute kidney injury when compared to the general adult population. Older adults prescribed aminoglycosides have a similar risk of acute kidney injury to the general adult population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02512-3.

Effectiveness and antimicrobial susceptibility profiles during primary antimicrobial prophylaxis for pediatric acute myeloid leukemia

Limited data are available on antimicrobials exposure and microbiology evolution in pediatric acute myeloid leukemia (AML) patients underwent antimicrobials prophylaxis. To assess the effectiveness of antimicrobials prophylaxis, antibiotic susceptibilities of bacteria, and exposure of antimicrobials during intensive chemotherapy for AML patients, 90 consecutive de novo AML patients aged 0-18 years between January 1, 1997 and March 31, 2018 were enrolled. Vancomycin, ciprofloxacin and voriconazole prophylaxis was administered from January 1, 2010. During the preprophylaxis period, January 1997 to December 2009, 62 patients experienced a total of 87 episodes of bloodstream infection (BSI) and 17 episodes of invasive fungal infection (IFI) among 502 courses of chemotherapy. In contrast, 16 episodes of BSI occurred and no IFIs were reported to occur in 28 patients who received 247 courses of chemotherapy in the prophylaxis period. Patients who received antimicrobial prophylaxis had a significant reduction of BSI, IFI, and febrile neutropenia in comparison with patients without prophylaxis. Exposure to amikacin, carbapenem, amphotericin B was reduced in the prophylaxis period. Imipenem susceptibility of Enterobacter cloacae as well as vancomycin susceptibility of Enterococcus species were reduced in the prophylaxis period. At the time of the last follow up, patients with prophylaxis had a better subsequent 5-year overall survival rate than those without prophylaxis. Prophylactic antimicrobials administration in children with AML who undergo chemotherapy can significantly reduce the rates of life-threatening infection, exposure to antimicrobials, and might result in a better outcome.

Acute kidney injury associated with area under the curve versus trough monitoring of vancomycin in obese patients

Vancomycin is a first-line agent used in the treatment of methicillin-resistant Staphylococcus aureus; however, vancomycin is associated with acute kidney injury (AKI). Previous literature demonstrates decreased incidence of AKI using 24-hour area under the concentration-time curve (AUC₂₄) monitoring, but its safety is unknown in obese populations. Patients ≥18 years, with Body Mass Indices (BMI) ≥30 kg/m², admitted between August 2015-July 2017 or October 2017-September 2019, who received vancomycin for ≥72 hours and had level(s) drawn within 96 hours of initiation were included. The primary outcome was incidence of AKI. Secondary outcomes included inpatient mortality rate, median inpatient length of stay, median vancomycin trough concentration, and median vancomycin AUC₂₄. AKI was identified using the highest serum creatinine value compared to the value immediately prior to vancomycin initiation based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. Overall, 1024 patients met inclusion criteria, with 142 out of 626 patients in the trough group and 65 out of 398 patients in the AUC₂₄ group meeting criteria for AKI (22.7% vs. 16.3%, p=0.008). Logistic regression of the data to account for confounding factors maintained significance for the reduction in incidence of AKI with AUC₂₄ monitoring compared to trough monitoring (p=0.010). Monitoring of vancomycin with AUC₂₄ was associated with a decreased risk of AKI when compared with trough monitoring in obese patients.

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.

Therapeutic Drug Monitoring of Vancomycin in Adult Patients with Methicillin-Resistant Staphylococcus aureus Bacteremia or Pneumonia

Background

Vancomycin remains widely used for methicillin-resistant Staphylococcus aureus (MRSA) infections; however, treatment failure rates up to 50% have been reported. At the authors' institution, monitoring of trough concentration is the standard of care for therapeutic drug monitoring of vancomycin. New guidelines support use of the ratio of 24-hour area under the concentration-time curve to minimum inhibitory concentration (AUC₂₄/MIC) as the pharmacodynamic index most likely to predict outcomes in patients with MRSA-associated infections.

Objectives

To determine the discordance rate between trough levels and AUC₂₄/MIC values and how treatment failure and nephrotoxicity outcomes compare between those achieving and not achieving their pharmacodynamic targets.

Methods

This retrospective cohort study involved patients with MRSA bacteremia or pneumonia admitted to the study hospital between March 1, 2014, and December 31, 2018, and treated with vancomycin. Data for trough concentrations were collected, and minimum concentrations (C _min) were extrapolated. The AUC₂₄/MIC values were determined using validated population pharmacokinetic models. The C _min and AUC₂₄/MIC values were characterized as below, within, or above pharmacodynamic targets (15-20 mg/L and 400-600, respectively). Discordance was defined as any instance where a patient's paired C _min and AUC₂₄/MIC values fell in different ranges (i.e., below, within, or above) relative to the target ranges. Predictors of treatment failure and nephrotoxicity were determined using logistic regression.

Results

A total of 128 patients were included in the analyses. Of these, 73 (57%) received an initial vancomycin dose less than 15 mg/kg. The discordance rate between C _min and AUC₂₄/MIC values was 21% (27/128). Rates of treatment failure and nephrotoxicity were 34% (43/128) and 18% (23/128), respectively. No clinical variables were found to predict discordance. Logistic regression identified initiation of vancomycin after a positive culture result (odds ratio [OR] 4.41, 95% confidence interval [CI] 1.36-14.3) and achievement of target AUC₂₄/MIC after 4 days (OR 3.48, 95% CI 1.39-8.70) as modifiable predictors of treatment failure.

Conclusions

The relationship between vancomycin monitoring and outcome is likely confounded by inadequate empiric or initial dosing. Before any modification of practice with respect to vancomycin monitoring, empiric vancomycin dosing should be optimized.

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.

Optimization of Vancomycin Dosing to Achieve Target Area Under the Curve in Pediatrics

OBJECTIVE

Vancomycin dosing requirements to achieve a target area under curve/minimum inhibitory concentration (AUC/MIC) of 400 to 600 mg•hr/L have not been established in pediatrics. Dose modeling studies and recent guidelines suggest dosing higher than historical recommendations. This study examines dosing requirements to achieve target AUC/MIC in human pediatric patients.

METHODS

This retrospective study includes 77 patients, aged 1 month to 18 years, at a single center, who received at least 2 days of intravenous vancomycin with a pharmacokinetic monitoring note and calculated AUC/MIC. Dosing to achieve target AUC/MIC was evaluated by age and indication. Nephrotoxicity was also assessed.

RESULTS

The mean dose required to achieve target AUC/MIC for all patients was 67.7 mg/kg/day. Adjusting for age, the mean dose required to achieve target AUC/MIC of 400 to 600 mg•hr/L was found to be statistically significantly different among 3 age cohorts: 1 month to 5 years, 6 to 12 years, and 13 to 18 years [F(2,74) = 15.32, p < 0.001], with mean requirements of 79 ± 14.1, 65.6 ± 21.1, and 53.9 ± 17.1 mg/kg/day, respectively. Dosing requirements were also found to be statistically significantly different across indications [F(6,70) = 4.84, p < 0.001]. Acute kidney injury was identified in 5 patients (6.5%).

CONCLUSIONS

The vancomycin dose required to achieve target AUC/MIC in pediatrics was significantly higher in younger pediatric patients and ranged from 53.9 to 79 mg/kg/day, confirming recent guideline recommendations. Doses can be further adjusted for indication. Nephrotoxicity rates remain low compared with historical rates with single trough monitoring.

Vancomyxins: Vancomycin-Polymyxin Nonapeptide Conjugates That Retain Anti-Gram-Positive Activity with Enhanced Potency against Gram-Negative Strains

Vancomycin functions by binding to lipid II, the penultimate bacterial cell wall building block used by both Gram-positive and Gram-negative species. However, vancomycin is generally only able to exert its antimicrobial effect against Gram-positive strains as it cannot pass the outer membrane (OM) of Gram-negative bacteria. To address this challenge, we here describe efforts to conjugate vancomycin to the OM disrupting polymyxin E nonapeptide (PMEN) to yield the hybrid “vancomyxins”. In designing these hybrid antibiotics, different spacers and conjugation sites were explored for connecting vancomycin and PMEN. The vancomyxins show improved activity against Gram-negative strains compared with the activity of vancomycin or vancomycin supplemented with PMEN separately. In addition, the vancomyxins maintain the antimicrobial effect of vancomycin against Gram-positive strains and, in some cases, show enhanced activity against vancomycin-resistant strains. The hybrid antibiotics described here have reduced nephrotoxicity when compared with clinically used polymyxin antibiotics. This study demonstrates that covalent conjugation to an OM disruptor contributes to sensitizing Gram-negative strains to vancomycin while retaining anti-Gram-positive activity.

Exploratory Cost-Effectiveness Analysis for Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections: Is Linezolid or Daptomycin Favored Over Vancomycin?

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus bloodstream infections (MRSAB) cause significant mortality, and often require extended antibiotic therapy. Vancomycin, the most common initial MRSAB treatment, carries significant monitoring burden and nephrotoxicity risks. Our objective was to compare the cost-effectiveness of vancomycin and other antibiotic regimens against MRSAB.

METHODS

We estimated the cost-effectiveness of intravenous antibiotics (vancomycin, daptomycin, linezolid, ceftaroline/daptomycin) for Veterans Health Administration patients with MRSAB using an exploratory decision-tree model. Primary effectiveness outcome was composite of microbiological failure at 7 days and adverse drug event (ADE)-related discontinuation after at least 7 days.

RESULTS

In base-case analyses, intravenous linezolid was the least expensive regimen at 4 and 6 weeks. Daptomycin was more expensive and more effective than linezolid, with an incremental cost-effectiveness ratio (ICER) of ~$13,000 (4 weeks) per composite failure avoided. With 6 weeks of treatment, daptomycin was more expensive and more effective than vancomycin (ICER ~$21,000 per composite failure avoided). Vancomycin and ceftaroline/daptomycin were dominated strategies at both 4 and 6 weeks. In one-way sensitivity analyses, vancomycin was favored when its microbiological failure risk was less than 20.1% (base-case: 27.2%), assuming a willingness to pay (WTP) threshold of $40,000/composite treatment failure avoided. In two-way sensitivity analyses, intravenous linezolid was favored if linezolid microbiological failure and ADE-related discontinuation rates were < 22.5% and < 17.3%, respectively. Daptomycin, vancomycin, and linezolid were favored in 50%, 31%, and 17% of 4-week probabilistic iterations, respectively, at $40,000 WTP.

CONCLUSION

Daptomycin is likely less expensive and more effective than vancomycin or other initial regimens for MRSAB. More data are needed on the safety of linezolid against MRSAB.

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.

Involvement of the effect of renal hypoperfusion medications on vancomycin trough concentration: A secondary analysis using a retrospective observational data

This study examined the association between vancomycin (VCM) trough concentration and confounding factors including renal hypoperfusion medications which include angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, loop/thiazide diuretics, or non-steroidal anti-inflammatory drugs. This secondary analysis included patients aged >15 years who were administered VCM intravenously between June 2015 and August 2017 at the Tokyo Women's Medical University Medical Center East. We investigated predictors for three (initial, mean, and final) dose-normalized VCM trough concentration (dose-normalized VCM_trough ) as outcome using a multiple linear regression analysis. In total, 208 patients were analysed (use of loop/thiazide diuretics: 48 [23%]). Multiple linear regression analysis revealed that the initial dose-normalized VCM_trough was negatively correlated with estimated glomerular filtration rate (eGFR) (p = 0.028) and positively correlated with the use of loop/thiazide diuretics (p = 0.003). Meanwhile, there was a positive correlation between the mean dose-normalized VCM_trough and age (p = 0.023). The mean dose-normalized VCM_trough was negatively correlated with eGFR (p < 0.001) and serum albumin (p < 0.001). The final dose-normalized VCM_trough was positively associated with age (p = 0.034) and negatively associated with eGFR (p = 0.032) and serum albumin (p = 0.007). Clinicians should closely monitor VCM trough concentration while receiving VCM and loop/thiazide diuretics.

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.

Safety considerations with new antibacterial approaches for chronic bacterial prostatitis

Introduction: Chronic bacterial prostatitis (CBP) is a difficult-to-eradicate infection. Antibacterial therapy with currently licensed agents is hindered due to the increasing emergence of pathogen resistance worldwide and to frequent infection relapse. With limited treatment options, physicians are investigating new agents, which, however, may raise safety concerns.Areas covered: Antibacterial agents currently licensed for CBP were not considered. Available reports about the safety and efficacy of antibacterial agents that have been clinically tested or tentatively used to treat CBP in single cases were evaluated. This review also focused on agents targeting Gram-positive pathogens, whose prevalence as causative agents of CBP is increasing.Expert opinion: (i) Most antibacterial agents considered in this review have been administered off-label in the interest of patients, and their use requires particular caution. (ii) Reports describing the usage of many of the drugs reviewed here are still scant, and readers should be warned of the limited published evidence supporting therapy for CBP with these agents. (iii) As treatment must extend over several weeks, medium-term adverse events may occur and therapy should be individualized, taking into account the dosage and the potential toxicity of each specific antibiotic. Regarding dangerous drug-drug interactions, particular attention should be paid to the risk of ECG-QT-interval elongation.

Risk factors for acute kidney injury in vancomycin and piperacillin/tazobactam combination therapy: A retrospective study

INTRODUCTION

Combined use of vancomycin (VCM) and piperacillin/tazobactam (PIPC/TAZ) has been reported to increase the incidence of acute kidney injury (AKI). However, the risk factors associated with AKI after VCM and PIPC/TAZ (VPT) administration have not yet been identified. Therefore, we retrospectively assessed patients treated with VPT to investigate the risk factors for AKI development.

METHODS

The study involved patients who were treated with VPT from January 1, 2016 to March 31, 2020. The patients were divided into the AKI or non-AKI group. The clinical characteristics of patients and antimicrobial therapy were compared between the groups. Their association with AKI risk was evaluated using multivariate logistic regression analysis.

RESULTS

In total, 182 patients were included, with 118 in the non-AKI group and 64 in the AKI group. Therefore, the incidence of AKI was 35.2 %. The initiation of VPT combination therapy on the same day and concomitant use of vasopressors were associated with an increased risk of AKI (odds ratio [OR] 2.55, 95 % confidential interval [CI] 1.20-5.44 and OR 3.22, 95 % CI 1.31-7.89, respectively).

CONCLUSION

Our findings suggest that the concomitant use of vasopressors and initiating VPT combination therapy on the same day are likely risk factors for AKI development.

The case for precision dosing: medical conservatism does not justify inaction

The need for precision dosing has been challenged on the basis of insufficient evidence. Herein, we argue that adequate evidence exists to conduct therapeutic drug monitoring (TDM) and precisely target antibiotic exposures. While achievement of any antibiotic concentration does not guarantee efficacy sans toxicity for any single patient, stochastic control optimizes the probability of achieving favourable responses across patients. We argue that variability in targets (such as the organism's MIC) can be considered with models. That is, complexity alone does not relegate the decision-making framework to 'clinician intuition'. We acknowledge the exposure-response relationships are modified by patient-specific factors (other drugs, baseline organ functional status etc.) and describe how precision dosing can inform clinical decision making rather than protocolize it. Finally, we call for randomized, controlled trials; however, we suggest that these trials are not necessary to make TDM standard of care for multiple classes of antibiotics.

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.

Optimizing Antimicrobial Drug Dosing in Critically Ill Patients

A fundamental step in the successful management of sepsis and septic shock is early empiric antimicrobial therapy. However, for this to be effective, several decisions must be addressed simultaneously: (1) antimicrobial choices should be adequate, covering the most probable pathogens; (2) they should be administered in the appropriate dose, (3) by the correct route, and (4) using the correct mode of administration to achieve successful concentration at the infection site. In critically ill patients, antimicrobial dosing is a common challenge and a frequent source of errors, since these patients present deranged pharmacokinetics, namely increased volume of distribution and altered drug clearance, which either increased or decreased. Moreover, the clinical condition of these patients changes markedly over time, either improving or deteriorating. The consequent impact on drug pharmacokinetics further complicates the selection of correct drug schedules and dosing during the course of therapy. In recent years, the knowledge of pharmacokinetics and pharmacodynamics, drug dosing, therapeutic drug monitoring, and antimicrobial resistance in the critically ill patients has greatly improved, fostering strategies to optimize therapeutic efficacy and to reduce toxicity and adverse events. Nonetheless, delivering adequate and appropriate antimicrobial therapy is still a challenge, since pathogen resistance continues to rise, and new therapeutic agents remain scarce. We aim to review the available literature to assess the challenges, impact, and tools to optimize individualization of antimicrobial dosing to maximize exposure and effectiveness in critically ill patients.

Tolerance and microbiological efficacy of cefepime or piperacillin/tazobactam in combination with vancomycin as empirical antimicrobial therapy of prosthetic joint infection: a propensity-matched cohort study

BACKGROUND

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading us to propose cefepime as an alternative since 2017 in our reference centre.

OBJECTIVES

To compare microbiological efficacy and tolerance of these two EAT strategies.

METHODS

All adult patients with PJI empirically treated with vancomycin+cefepime (n = 89) were enrolled in a prospective observational study and matched with vancomycin+piperacillin/tazobactam-treated historical controls (n = 89) according to a propensity score including age, baseline renal function and concomitant use of other nephrotoxic agents. The two groups were compared using Kaplan-Meier curve analysis, and non-parametric tests regarding the proportion of efficacious empirical regimen and the incidence of empirical therapy-related adverse events (AE).

RESULTS

Among 146 (82.0%) documented infections, the EAT was considered efficacious in 77 (98.7%) and 65 (98.5%) of the piperacillin/tazobactam- and cefepime-treated patients, respectively (P = 1.000). The rate of AE, particularly AKI, was significantly higher in the vancomycin+piperacillin/tazobactam group [n = 27 (30.3%) for all AE and 23 (25.8%) for AKI] compared with the vancomycin+cefepime [n = 13 (14.6%) and 6 (6.7%)] group (P = 0.019 and <0.001, respectively), leading to premature EAT discontinuation in 20 (22.5%) and 5 (5.6%) patients (P = 0.002). The two groups were not significantly different regarding their comorbidities, and AKI incidence was not related to vancomycin plasma overexposure.

CONCLUSIONS

Based on the susceptibility profile of bacterial isolates from included patients, microbiological efficacy of both strategies was expected to be similar, but vancomycin + cefepime was associated with a significantly lower incidence of AKI.

Optimization of dosing regimens of vancomycin, teicoplanin, linezolid and daptomycin against methicillin-resistant Staphylococcus aureus in neutropenic patients with cancer by Monte Carlo simulations

The objective of this study was to evaluate the efficacy of various dosing regimens of vancomycin, teicoplanin, linezolid and daptomycin against methicillin-resistant Staphylococcus aureus (MRSA) in neutropenic patients with cancer. Monte Carlo simulations were conducted using pharmacokinetic parameters and pharmacodynamic data to determine cumulative fraction of response (CFRs) in terms of area under the concentration-time curve/minimum inhibition concentration target. Currently clinical standard dosing regimens of vancomycin, teicoplanin, linezolid and daptomycin were insufficient to provide expected CFRs against MRSA for neutropenic patients with cancer. The high dosing regimens of vancomycin (3500 mg/d), teicoplanin (800 mg/d) and daptomycin (8 mg/kg/d) could provide CFRs of ≥ 80%, showing a higher treatment success. However, the majority of CFRs with linezolid simulated dosing regimens reached < 80% against MRSA. Therefore, a strategy of high dosages of vancomycin, teicoplanin and daptomycin may be needed to attain optimal therapeutic efficacy against MRSA in neutropenic patients with cancer.

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.

Impact of combining vancomycin with piperacillin/tazobactam or with meropenem on vancomycin-induced nephrotoxicity

Vancomycin (VAN) is a broad-spectrum antibiotic against Gram-positive cocci used empirically with other broad-spectrum antibiotics, such as piperacillin/tazobactam (TZP), cefepime, or meropenem (MEM). Conflicting literature on the rates of acute kidney injury (AKI) of VAN with TZP is reported, and studies on AKI rate with MEM are limited. This study aimed to evaluate AKI rates in patients receiving VAN with either TZP or MEM. This was a retrospective cohort study of patients received either VAN-TZP or VAN-MEM for ≥ 72 h. Patients with a baseline serum creatinine (SCr) of ≥ 1.5 mg/dL were excluded. The primary outcome was rate of AKI as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. SCr was recorded at baseline and 3-5 days post antibiotics initiation. 158 patients were included, 77 in the VAN-TZP group versus 81 in the VAN-MEM group. While the percentage of patients meeting AKI definition was numerically higher in the VAN-MEM group, the difference was not significant (10.4% vs. 21%; P = 0.07). As such, change in SCr was not significantly different between the two groups (- 7.4 vs. - 6.1%; P = 0.7). In-hospital mortality was higher in the VAN-MEM group (23.4% vs. 39.5%; P = 0.03) possibly because the majority of this group's patients were critically ill. This study showed that combining MEM with VAN did not offer the benefit of a lower rate of AKI compared with a combination with TZP. Therefore, patients with no risk factors for infections resistant to TZP can continue to receive TZP with VAN without risking AKI development.

Pediatric Antibiotic Stewardship: Optimization of Vancomycin Therapy Based on Individual Pharmacokinetics

BACKGROUND

Vancomycin has been a first-line treatment for Gram-positive infections for decades. However, strategies for therapeutic drug monitoring (TDM) and dose-optimization in pediatrics remain controversial. In this study, we analyzed the impact of specific antibiotic stewardship interventions on efficacy and safety of vancomycin therapy.

METHODS

From September 2014 to May 2017, we conducted a prospective study to compare a control and a TDM intervention group in our tertiary care center. As part of an antibiotic stewardship program, we implemented internal guidelines on correct vancomycin dosing, TDM timing, as well as targeted trough level range and installed a pharmacokinetic (PK) consultation service to adapt vancomycin dosing to individually calculated PK parameters. As primary clinical outcomes, the percentage of patients with sustained therapeutic vancomycin trough levels and treatment days with therapeutic vancomycin trough levels, that is, 10-15 mg/L were analyzed. Secondary outcomes included nephrotoxicity, readmission rate and mortality. Median daily dose required to achieve therapeutic trough levels was examined.

RESULTS

Clinical outcomes for 90 control patients were compared with outcomes for 19 patients guided by a PK consultation service. Percentage of patients with sustained therapeutic vancomycin trough levels increased from 17.8% to 94.7% (P < 0.001) and percentage of treatment days with therapeutic vancomycin trough levels increased from 18.4% (117/637) to 665% (155/233, P < 0.001). Readmission rate decreased from 24.4% to 5.3% (P = 0.07). No differences in nephrotoxicity or mortality rate were observed between groups. A median daily dose of 72 mg/kg/d was required to achieve therapeutic trough levels.

CONCLUSIONS

Our data demonstrate that implementation of internal guidelines and a PK consultation service was associated with a profound improvement of vancomycin therapy and, therefore, patient safety.

Protective Effects of Hydroalcoholic Extract of Rosa canina Fruit on Vancomycin-Induced Nephrotoxicity in Rats

Vancomycin-induced nephrotoxicity (VIN) has been reported to occur in 5–35% of recipient patients. The aims of the study were to evaluate protective effects of Rosa canina (RC) on VIN in rats. Rats were randomly divided into five groups as follows: control group I, group II (received VAN 400 mg/kg/day, every 12 h at doses of 200 mg/kg/day, for 7 consecutive days), group III (VAN + RC 250 mg/kg/day, for 7 consecutive days), group IV (VAN + RC 500 mg/kg/day, for consecutive days), and group V (received RC 500 mg/kg/day, for consecutive 7 days). On the eighth day after anesthetizing the animals, blood samples were taken from the heart, and then, the kidneys were removed to investigate kidney function, oxidative stress, and histopathological marker. Also, the chemical composition of RC extract was identified by GC-MS analysis. Oral dose of 500 mg/kg RC extract significantly reduced the serum levels of blood urea nitrogen (BUN), creatinine (Cr), malondialdehyde (MDA), and nitric oxide (NO) and also the kidney tissue MDA, protein carbonyl, and NO metabolites (nitrite) levels compared to the VAN-treated group (P < 0.05). Based on histopathological analysis, RC extract at the dose of 500 mg/kg inhibited the destructive effects of VAN on kidney tissues. GC-MS analysis indicated that the main compositions were found to be lactose (21.96%), 3-t-butyloxaziridine (20.91%), and 5-oxymethylfurfurole (16.75%). The results indicated that oral administration of RC was able to reduce VAN-induced nephrotoxicity in rats, possibly through antioxidant pathways.

Should Therapeutic Drug Monitoring Based on the Vancomycin Area Under the Concentration-Time Curve Be Standard for Serious Methicillin-Resistant Staphylococcus aureus Infections?-No

In this counterpoint we critically appraise the evidence supporting therapeutic drug monitoring based on the vancomycin 24-hour area under the concentration-time curve (AUC24) for serious methicillin-resistant Staphylococcus aureus infections. We reveal methodologically weaknesses and inconsistencies in the data and suggest that, in the absence of clear and convincing evidence of benefit compared with modestly reducing trough targets, alternative strategies are more likely to result in superior safety and efficacy. These include focusing on fundamental antibiotic stewardship to limit vancomycin exposure overall, achieving earlier and more complete source control, and establishing alternative therapeutic options to vancomycin. Implementation of AUC24-based therapeutic drug monitoring will take resources away from these more promising, alternative solutions.

Population Pharmacokinetics of Vancomycin Under Continuous Renal Replacement Therapy Using a Polymethylmethacrylate Hemofilter

BACKGROUND

Although continuous hemodiafiltration (CHDF) is often performed in critically ill patients during sepsis treatment, the pharmacokinetics of vancomycin (VCM) during CHDF with a polymethylmethacrylate hemofilter (PMMA-CHDF) have not been revealed. In this study, the authors aimed to describe the population pharmacokinetics of VCM in critically ill patients undergoing PMMA-CHDF and clarify its hemofilter clearance (CLhemofilter).

METHODS

This single-center, retrospective study enrolled patients who underwent intravenous VCM therapy during PMMA-CHDF at the intensive care unit of Chiba University Hospital between 2008 and 2016. A population analysis was performed, and CLhemofilter was assessed.

RESULTS

Twenty-five patients were enrolled. Median body weight (BW) and Sequential Organ Failure Assessment (SOFA) score were 63 kg and 15, respectively. Mean conditions for CHDF were 107.5 ± 18.3 mL/min for blood flow rate and 26.3 ± 6.3 mL/kg/h for effluent flow rate. The mean parameter estimates were distribution volume of the central compartment (V1), 59.1 L; clearance of the central compartment (CL1), 1.35 L/h; distribution volume of the peripheral compartment (V2), 56.1 L; and clearance of the peripheral compartment (CL2), 3.65 L/h. BW and SOFA score were significantly associated with V1 (P < 0.05) and CL1 (P < 0.05), respectively, and were thus selected as covariates in the final model. The estimated dosage of VCM to achieve a target area under the concentration-time curve/minimum inhibitory concentration ≥400 was 27.1 mg/kg for loading and 9.7 mg/kg every 24 hours for maintenance; these dosages were affected by BW and SOFA score. Mean CLhemofilter obtained from 8 patients was 1.35 L/h, which was similar to CL1.

CONCLUSIONS

The authors clarified the pharmacokinetics and CLhemofilter of VCM in PMMA-CHDF patients. The PK of VCM in patients undergoing CHDF appeared to vary not only with the CHDF setting and BW but also with SOFA score.

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.

Assessment of the Implementation of AUC Dosing and Monitoring Practices With Vancomycin at Hospitals Across the United States

INTRODUCTION

The latest vancomycin therapeutic drug monitoring guidelines for serious MRSA infections have made a pivotal change in dosing, switching from targeting trough levels to AUC dosing. Because of these new recommendations, antimicrobial stewardship programs across the country are tasked with implementing AUC based dosing.

OBJECTIVES

To assess plans for institutional adoption of vancomycin AUC dosing programs and perceptions of currently used programs in hospitals across the US.

METHODS

An electronic survey was distributed to members of the American College of Clinical Pharmacy IDprn Listserv and American Society of Health-System Pharmacists between May and June 2020 to assess current institutional vancomycin dosing. Institutional program use and multiple software user parameters were analyzed using descriptive statistics.

RESULTS

Two hundred two pharmacists responded to the survey with the majority practicing in institutions with 251-500 beds. Most respondents have yet to implement AUC dosing (142/202, 70.3%) with many of them planning to do so in the next year (81/142, 57.0%). Of those that already implemented AUC dosing programs, purchased Bayesian software (23/60, 38.3%) and homemade software (21/60, 35.0%) were the 2 methods most frequently utilized. Purchased Bayesian software users were more likely to recommend their software to other institutions and ranked user friendliness higher compared to non-purchased software.

CONCLUSION

Most respondents have not made the switch to vancomycin AUC dosing, but there is a growing interest with many institutions looking to adopt a program within the next year.

Outcomes of a pharmacist-driven vancomycin monitoring initiative in a community hospital

WHAT IS KNOWN AND OBJECTIVE

Vancomycin, an antibiotic commonly used to treat MRSA infections, can be nephrotoxic. Administering vancomycin requires close monitoring of serum vancomycin levels and appropriate dosing based on patients' renal function, underlying infection type and serum concentration levels. This article discusses the results and implications of a pharmacist-driven vancomycin monitoring initiative, which was implemented at Mercy Catholic Medical Center's Philadelphia Campus (MPC) in July 2016.

METHODS

MPC pharmacists were trained on how to give appropriate vancomycin dosing recommendations based on patients' vancomycin trough levels, renal function and underlying infection. This retrospective observational study consisted of patients who presented to MPC and were administered vancomycin over a 3-month period in 2015 for pre-implementation cohort and over a 3-month period in 2018 for post-implementation cohort. Patients with age ≥18 and receiving vancomycin for a minimum of 48 hours were included, whereas ESRD patients were excluded. Primary goal evaluated whether the incidence of AKI decreased with the pharmacist-driven initiative. Secondary goal assessed whether vancomycin level monitoring and achievement of goal serum levels improved with the initiative.

RESULTS AND DISCUSSION

A total of 214 patients were included in the final data analysis, with 110 patients in the pre-implementation cohort and 104 patients in the post-implementation cohort. Although not statistically significant, a higher incidence of AKI was observed in the post-implementation cohort. However, compared to pre-implementation cohort, post-implementation group had higher percentage of patients with underlying comorbidities (such as CKD), higher number of cases of severe sepsis and septic shock, and greater number of patients with concomitant exposure to CT contrast and piperacillin-tazobactam-all of which were confounding factors that likely increased the AKI incidence in post-implementation cohort. With the initiative, there was a significant increase in the number of patients with appropriate vancomycin trough level monitoring (27.3% vs 55.8%, p value < 0.001) in the post-implementation cohort and a decrease in the number of patients with no trough level monitoring (30% vs. 7.6%, p value < 0.001).

WHAT IS NEW AND CONCLUSION

Pharmacist-driven vancomycin monitoring significantly improved the monitoring compliance of vancomycin trough levels. In patients who developed AKI during their hospital course, pharmacist interventions improved the total percentage of patients attaining desired trough goals and helped reduce further renal insult from supratherapeutic vancomycin level. Incorporation of AUC-guided dosing and monitoring has the potential to further optimize vancomycin efficacy and safety.

Efficacy and Safety of Vancomycin Therapy After the Transition to AUC/MIC Monitoring in a Primary Facility

BACKGROUND

New guidance recommends area under the curve/minimum inhibitory concentration (AUC/MIC) instead of trough-based monitoring for vancomycin therapy. While this transition has demonstrated improved safety and efficacy in large, tertiary centers, this has not been assessed in the primary hospital setting.

OBJECTIVE

The primary objectives were to evaluate the efficacy and safety of AUC/MIC monitoring in inpatient veterans treated with intravenous vancomycin for ≥72 hours compared to a historical cohort of trough-based monitoring.

METHODS

This was a retrospective, quasi-experimental study over 2 five-month study periods. Efficacy was evaluated by comparing clinical failure rates as defined by a persistent fever, clinical deterioration, or escalation of gram-positive therapy. Safety was determined by the incidence of acute kidney injury (AKI) defined by an acute increase in serum creatinine ≥0.3 mg/dL over 48 hours.

RESULTS

25 patients met the criteria in the before group and 19 in the after group. Efficacy was equivalent between groups; no patients exhibited clinical failure of vancomycin therapy. In the before group, 2 patients (8%) met defined criteria for AKI, while none in the after group experienced AKI (P = 0.21). Total vancomycin exposure was similar between groups (P = 0.56).

CONCLUSION

AUC-based monitoring was equally efficacious as trough-based monitoring with similarly low rates of AKI.