Evaluation of the variability and safety of serum trough concentrations of vancomycin in patients admitted to the intensive care unit

Engineered Aptamer-Derived Fluorescent Aptasensor: the Label-Free, Single-Step, Rapid Detection of Vancomycin in Clinical Samples

Currently, the reported vancomycin (VCM) aptamers, including the 3- (Kd  =  9.13 × 10-6 m) and 4-truncated variants (Kd = 45.5 × 10-6 m), are engineered via stem truncation of the VCM parent aptamer, which inevitably compromises their affinities, thus affecting their clinical application within the VCM therapeutic window of 6.9-13.8 × 10-6 m. Herein, the binding pocket of the VCM parent aptamer is elucidated for the first time and we implemented the Post-SELEX modification strategy involving truncation and mutagenesis to refined the VCM parent aptamer. This yielded a VCM aptamer (ABC20-11) with an intramolecular G-triplex, an enhanced thioflavin T (ThT) fluorescence intensity, and an improved affinity (Kd = 0.591 × 10-6 m) and specificity (one-methyl level) for VCM. Utilizing a portable fluorescence detector specifically designed for rapidly detecting VCM concentration and leveraging the competitive binding between VCM and ThT to ABC20-11, a label-free fluorescent aptasensor is developed. This aptasensor exhibits exceptional analytical performances across various clinical samples (serum, cerebrospinal fluid, and joint fluid), with corresponding linear ranges of 0.5-50, 0.5-40, and 0.5-50 × 10-6 m and detection limits at 0.11, 0.12, and 0.16 × 10-6 m, respectively. Consequently, the proposed VCM aptasensor displays considerable clinical value and potential for use in rapid VCM detection.

Is It Still Beneficial to Monitor the Trough Concentration of Vancomycin? A Quantitative Meta-Analysis of Nephrotoxicity and Efficacy

This study conducted a quantitative meta-analysis to investigate the association of vancomycin indicators, particularly area under the curve over 24 h (AUC24) and trough concentrations (Ctrough), and their relationship with both nephrotoxicity and efficacy. Literature research was performed in PubMed and Web of Science on vancomycin nephrotoxicity and efficacy in adult inpatients. Vancomycin Ctrough, AUC24, AUC24/minimum inhibitory concentration (MIC), nephrotoxicity evaluation and treatment outcomes were extracted. Logistic regression and Emax models were conducted, stratified by evaluation criterion for nephrotoxicity and primary outcomes for efficacy. Among 100 publications on nephrotoxicity, 29 focused on AUC24 and 97 on Ctrough, while of 74 publications on efficacy, 27 reported AUC24/MIC and 68 reported Ctrough. The logistic regression analysis indicated a significant association between nephrotoxicity and vancomycin Ctrough (odds ratio = 2.193; 95% CI 1.582-3.442, p < 0.001). The receiver operating characteristic curve had an area of 0.90, with a cut-off point of 14.55 mg/L. Additionally, 92.3% of the groups with a mean AUC24 within 400-600 mg·h/L showed a mean Ctrough of 10-20 mg/L. However, a subtle, non-statistically significant association was observed between the AUC24 and nephrotoxicity, as well as between AUC24/MIC and Ctrough concerning treatment outcomes. Our findings suggest that monitoring vancomycin Ctrough remains a beneficial and valuable approach to proactively identifying patients at risk of nephrotoxicity, particularly when Ctrough exceeds 15 mg/L. Ctrough can serve as a surrogate for AUC24 to some extent. However, no definitive cut-off values were identified for AUC24 concerning nephrotoxicity or for Ctrough and AUC24/MIC regarding efficacy.

Assessment of an institutional guideline for vancomycin dosing and identification of predictive factors associated with dose and drug trough levels

OBJECTIVES

To evaluate the effectiveness of an antimicrobial guideline for vancomycin prescribing deployed using electronic prescribing aid and web/phone-based app. To define factors associated with guideline compliance and drug levels, and to investigate if antimicrobial dosing recommendations can be refined using routinely collected electronic healthcare record data.

METHODS

We used data from Oxford University Hospitals between 01-January-2016 and 01-June-2021 and multivariable regression models to investigate factors associated with dosing compliance, drug levels and acute kidney injury (AKI).

RESULTS

3767 patients received intravenous vancomycin for ≥24 h. Compliance with recommended loading and initial maintenance doses reached 84% and 70% respectively; 72% of subsequent maintenance doses were correctly adjusted. However, only 26% first and 32% subsequent levels reached the target range, and for patients with ongoing vancomycin treatment, 55-63% achieved target levels at 5 days. Drug levels were independently higher in older patients. Incidence of AKI was low (5.7%). Model estimates were used to propose updated age, weight and eGFR specific guidelines.

CONCLUSION

Despite good compliance with guidelines for vancomycin dosing, the proportion of drug levels achieving the target range remained suboptimal. Routinely collected electronic data can be used at scale to inform pharmacokinetic studies and could improve vancomycin dosing.

Effect of Initial Vancomycin Dose and Creatinine Clearance on the Attainment of Target Trough Concentration in Children

BACKGROUND

Vancomycin is a glycopeptide antibiotic that is used to treat serious grampositive infections. However, therapeutic drug monitoring for vancomycin is not performed routinely in Vietnam in clinical practices. Monitoring of serum vancomycin concentration or trough levels is necessary to ensure the efficacy and safety of vancomycin therapy.

OBJECTIVE

This study aims to determine the impact of initial vancomycin dose and creatinine clearance on target trough attainment in hospitalized Vietnamese children.

METHODS

A prospective study with patients who received vancomycin for at least three days was conducted. Subsequently, demographic data, clinical diagnosis, vancomycin dosage, and serum creatinine levels were recorded. The vancomycin trough level was collected and creatinine clearance and adjusted vancomycin doses were calculated.

RESULTS

A total of 40 eligible patients were enrolled. Patients' mean age, body weight, and height were 1.4 years old, 9.8 kg, and 75.5 cm, respectively. The mean vancomycin dose was 55.83 ± 19.34 mg/kg/day. The mean creatinine clearance was 80.18 ± 29.14 ml/min. The median trough level was 11.09 (7.84 - 16.46) μg/ml. There was no significant difference in the mean initial and the adjusted vancomycin doses (p = 0.062). However, there were statistically significant differences of initial (p = 0.004) or adjusted doses (p = 0.016) between groups of creatinine clearance. The trough vancomycin concentration was not statistically significant (p = 0.406) between these groups.

CONCLUSION

Target trough vancomycin level may be associated with creatinine clearance but did not proportionally correspond to the vancomycin dose. Therefore, monitoring vancomycin trough levels is necessary to achieve the target trough and to ensure vancomycin efficacy and safety in treating severely infected Vietnamese children.

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.

An individualized administration model of vancomycin in elderly patients with sepsis and factors influencing augmented renal clearance

WHAT IS KNOWN AND OBJECTIVE

Vancomycin efficacy is dependent on appropriate dosing, which should aim to achieve a target serum trough level. The purpose of this study was to determine the variables that predicted vancomycin serum trough concentrations in elderly patients with sepsis.

METHODS

This retrospective cohort study, which was conducted in the medical ICU of a university-affiliated teaching hospital in China, included 87 medical patients with sepsis who were enrolled from January 2014 to December 2017.

RESULTS AND DISCUSSION

All the patients were at least 60 years old (mean age = 74.8 ± 8.2 years), and 51.7% (n = 45) of them were male. The most common primary site of infection was the lungs (67.8%), followed by the abdomen (12.6%). Patients with septic shock accounted for 21.8% (n = 19) of the cases. The proportion of patients with vancomycin serum trough concentrations reaching target concentrations (≥15 mg/L) was 47.1% (41 cases). Multivariate linear regression showed that the creatinine clearance rate (CCR) and the daily dosage of vancomycin were independent predictors of vancomycin serum trough concentrations (both p's < 0.05), and the model for predicting vancomycin trough concentrations should be: serum trough concentration (mg/L) = 15.942 - 0.101 × CCR (mL/min) + 0.347 × vancomycin daily doses (mg/kg/d). Augmented renal clearance (ARC) was present in 13 patients (14.9%), and logistic regression revealed body mass index (OR = 1.420, p = .002) and serum creatinine level (OR = 0.883, p = .002) were independent predictors of ARC.

WHAT IS NEW AND CONCLUSION

The CCR and daily dosage of vancomycin were significantly correlated with vancomycin serum trough concentrations in elderly patients with sepsis, and the individualized administration model should be verified through further clinical trials. BMI and serum creatinine level were identified to be independent predictors of ARC in elderly patients.

Vancomycin-associated nephrotoxicity in non-critically ill patients admitted in a Brazilian public hospital: A prospective cohort study

Introduction

Vancomycin is widely used to treat infections caused by Gram positive bacteria, mostly methicillin-resistant strains. Despite its therapeutic effectiveness, vancomycin is a nephrotoxic drug that has been associated with the occurrence of acute kidney injury (AKI). In this study, we sought to evaluate the variability of serum trough concentrations of vancomycin and to determine the incidence and risk factors of vancomycin-associated nephrotoxicity (VAN) in non-critically ill patients.

Methods

This was a prospective cohort including Brazilian public hospital inpatients from April 2017 to June 2018. The participants received intravenous vancomycin therapy for at least 48 hours for any suspected or confirmed infection by Gram positive bacteria. Demographic, clinical and laboratory data were collected. Information on vancomycin therapy and concomitant use of other nephrotoxic drugs were also recorded. Patients were followed up until discontinuation of vancomycin treatment or death, whatever occurred first. The primary outcome was the occurrence of AKI. We performed a Poisson regression to determine risk factors for AKI.

Results

Overall, 98 participants were included in the study. Median age was 55.9 (interquartile range [IQR] 40.6–66.8) years and 58 (59.2%) were men. Most of them showed subtherapeutic (<10mg/L) or supratherapeutic (>20mg/L) trough levels of vancomycin; 42.9% and 15.3%, respectively. A total of 19 (19.4%) patients developed AKI. Poisson regression showed that male sex (odds ratio [OR] 2.90; confidence interval [CI] 95% 1.28–6.53; p = 0.011), concomitant use of piperacillin-tazobactam (OR 4.66; CI 95% 2.26–9.58; p <0.001) and vancomycin trough levels above 20mg/mL (OR 4.21; CI 95% 1.57–11.278; p = 0.004) were independently associated with AKI.

Conclusions

Our study showed that usual doses of vancomycin did not reach recommended therapeutic serum trough levels of vancomycin in non-critically ill patients. Besides that, nephrotoxicity was common in this population, being associated with male sex, concomitant use of piperacillin-tazobactam and supra-therapeutic trough serum levels of vancomycin.

Risk factors for vancomycin nephrotoxicity and time course of renal function during vancomycin treatment

PURPOSE

Vancomycin (VCM) is used for the treatment of methicillin-resistant Staphylococcus aureus. Although the risk factors for VCM nephrotoxicity have been evaluated, the time course of renal function during VCM treatment is unknown. We assessed risk factors for VCM nephrotoxicity and how renal function varied over time.

METHODS

We conducted a retrospective analysis of patients receiving intravenous VCM treatment between June 2015 and August 2017 at Tokyo Women's Medical University, Medical Center East. VCM nephrotoxicity was defined as an increase in serum creatinine levels > 50%. We performed multivariate logistic regression analysis to assess risk factors for VCM nephrotoxicity. The time course of renal function with VCM nephrotoxicity was compared and stratified by risk factors for VCM nephrotoxicity. Clinical course of VCM nephrotoxicity and VCM trough concentration were assessed.

RESULTS

In total, 42 (17.3%) of 243 patients developed VCM nephrotoxicity. Risk factors for VCM nephrotoxicity were VCM trough concentration > 20 μg/mL and concomitant use of renal hypoperfusion medications (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, loop/thiazide diuretics, and non-steroidal anti-inflammatory drugs). Although time course of renal function stratified by renal hypoperfusion medications was comparable, the time course of renal function significantly deteriorated in patients with loop/thiazide diuretics. Focusing on patients continuing VCM treatment, VCM nephrotoxicity recovered in 40% of the patients and VCM trough concentration improved to 10-20 μg/mL in 75% of the patients.

CONCLUSIONS

VCM trough concentration > 20 μg/mL and concomitant use of renal hypoperfusion medications are associated with VCM nephrotoxicity. Recovery of VCM nephrotoxicity was poor compared to the improvement of VCM trough concentration.