The effect of body mass index and creatinine clearance on serum trough concentration of vancomycin in adult patients

Vancomycin therapeutic drug monitoring: focus on patients with hematological malignancies

OBJECTIVE

This study aimed to identify key factors influencing vancomycin serum concentrations in adult patients with hematological malignancies by analyzing various physiological and biochemical indicators, to assess the impact on vancomycin levels and provide a basis for judicious clinical application.

METHODS

A retrospective analysis was conducted from January 2013 to April 2022. Statistical analyses were performed using SPSS 25.0, including correlation analysis, collinearity diagnostics, multiple linear regression, and receiver operating characteristic curves construction.

RESULTS

The study included 115, with 72.2% exhibited sub-therapeutic vancomycin trough concentrations (<10 mg/L). A significant positive correlation was observed between vancomycin trough concentrations and variables of age, blood cells, platelets, alkaline phosphatase, blood urea nitrogen, and serum creatinine. In contrast, a significant negative correlation was noted with weight, C-reactive protein, creatinine clearance, and estimated glomerular filtration rate. Among patients with hematological malignancies, cystatin C, creatinine clearance, gender, and neutrophil counts were identified as the main determinants of vancomycin trough concentrations. The combined assessment of these factors achieved high predictive accuracy, with 92.9% sensitivity and 82.5% specificity.

CONCLUSION

Cystatin C, creatinine clearance, gender, and neutrophil counts emerged as the principal determinants affecting vancomycin trough concentrations in patients with hematological malignancies. Pharmacists can optimize vancomycin therapy by tailoring pharmaceutical care based on individual patient characters and therapeutic drug monitoring.

Multiple linear regression model was constructed based on the influencing factors of vancomycin trough concentration

Objective: To evaluate the influencing factors of Vancomycin trough concentration in blood, construct an individualized Vancomycin administration model for rational use of Vancomycin. Methods: The clinical data of Vancomycin trough concentration in blood from June 2020 to December 2022 in our hospital were analyzed retrospectively. The effects of age, sex, Vancomycin administration and cumulative dose, albumin, total bilirubin, alanine aminotransferase, Creatinine (CR), urea (Bun), Creatinine clearance rate (Ccr), and time of blood sample collection on Vancomycin trough concentration were analyzed. A linear regression equation for the influencing factors of Vancomycin trough concentration in blood was constructed. Results: Sixty-six patients (82.5%) were treated with Vancomycin by intravenous drip. Significant differences existed in the influence of patients' age, Vancomycin administration, CR, Bun and Ccr on Vancomycin trough concentration (P < 0.05). Vancomycin trough concentration in blood showed negative correlated with Ccr (P < 0.05). The regression model of Vancomycin trough concentration in blood was y = 40.911 - 10.971 × method of administration - 1.715 × collection time + 1.018 × cumulative dose - 0.178 × Ccr, the model could predict 41.30% Vancomycin trough concentration in blood. Conclusion: The influencing factors of Vancomycin trough concentration in blood were complex. The constructed regression model of Vancomycin concentration in plasma may provide a scientific reference for individualized administration of Vancomycin in clinical practice.

Decreased Kidney Function Explains Higher Vancomycin Exposure in Older Adults

INTRODUCTION

Older adults face a higher risk of vancomycin-related toxicity given their (patho)-physiological changes, making early management of supratherapeutic exposure crucial. Yet, data on vancomycin exposure in older adults is scarce. This study aims to compare vancomycin concentrations between older and younger patients, emphasizing supratherapeutic concentrations and the effect of patient characteristics.

METHODS

This observational retrospective study was conducted in the University Hospital of Leuven (EC Research S65213). We analyzed early (first) vancomycin concentrations between older (≥ 75 years) and younger patients. Multivariable analyses were conducted to evaluate the association between baseline patient characteristics with supratherapeutic exposure (logistic regression), and dose-normalized concentrations (linear regression).

RESULTS

We included 449 patients aged ≥ 75 years (median 80) and 1609 aged < 75 years (median 61). In univariable analysis, the first-measured vancomycin concentrations were significantly higher in older adults (p < 0.001), who more frequently reached supratherapeutic concentrations (30.7% versus 21%; p < 0.001). In multivariable analysis, factors associated with supratherapeutic concentrations were decreased the estimated glomerular filtration rate calculated by using the Chronic Kidney Disease Epidemiology Collaboration equation (eGFRCKD-EPI) [odds ratio (OR) of 0.98, confidence interval (CI) 0.97-0.98]. Supratherapeutic concentrations had inverse association with giving lower loading dose (OR of 0.59, CI 0.39-0.90), and lower maintenance dose (OR of 0.45, CI 0.26-0.77). Factors that predicted increased dose-normalized concentrations included decreased eGFRCKD-EPI (coefficient of -0.05, CI -0.06 to -0.04), lower body weight (coefficient of -0.04, CI -0.05 to -0.03), increased blood urea nitrogen (coefficient of 0.02, CI 0.01-0.03), and delayed time to therapeutic drug monitoring (TDM) sampling (coefficient of 0.08, CI 0.06-0.09).

CONCLUSIONS

The absence of age as a significant factor in the multivariable analysis suggests that eGFRCKD-EPI mediated the relationship between age and vancomycin exposure. Older adults may benefit more from vancomycin TDM.

Effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit

OBJECTIVE

This study aimed to assess the effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit (PICU).

METHODS

A retrospective cohort study was performed of 126 infants and toddlers (aged between 29 days and 3 years) from the PICU of a tertiary care hospital who were administered intravenous vancomycin between January 2019 and December 2022. Information about their demographic factors, duration of PICU stay, time of administration and trough levels of vancomycin were retrieved. Descriptive statistics were used for demographic factors and multivariable logistic regression analyses were conducted to assess the determining factors.

RESULTS

Based on the trough concentration of vancomycin, the participants were divided into three groups as follows: 4-5 mg/L, 5-15 mg/L and >15 mg/L. The serum vancomycin concentration was significantly related to body weight, albumin, cystatin C, urea nitrogen in serum, serum creatinine and creatinine clearance (p<0.05) in these patients. Multivariate analysis showed that body weight, albumin, cystatin C, urea nitrogen in serum and creatinine clearance were independent contributors to the trough vancomycin concentration. There was no difference in the effectiveness of different trough concentrations on patients (p=0.241). The cumulative incidence of acute kidney injury was highest in the group with a trough concentration of vancomycin >15 mg/L (p<0.01).

CONCLUSIONS

Patients with a vancomycin trough concentration of 4-5 mg/L in the PICU had a high cure rate (79.4%) and a low incidence of acute kidney injury (HR 18.3, 95% CI 5.135 to 87.621; p<0.001). Therefore, the serum trough concentration should be considered but it should also be combined with the treatment effect to achieve individualised administration for the clinical application of vancomycin.

A Brief Review of Pharmacokinetic Assessments of Vancomycin in Special Groups of Patients with Altered Pharmacokinetic Parameters

Vancomycin is considered the drug of choice against many Gram-positive bacterial infections. Therapeutic drug monitoring (TDM) is essential to achieve an optimum clinical response and avoid vancomycin-induced adverse reactions including nephrotoxicity. Although different studies are available on vancomycin TDM, still there are controversies regarding the selection among different pharmacokinetic parameters including trough concentration, the area under the curve to minimum inhibitory concentration ratio (AUC24h/MIC), AUC of intervals, elimination constant, and vancomycin clearance. In this review, different pharmacokinetic parameters for vancomycin TDM have been discussed along with corresponding advantages and disadvantages. Also, vancomycin pharmacokinetic assessments are discussed in patients with altered pharmacokinetic parameters including those with renal and/or hepatic failure, critically ill patients, patients with burn injuries, intravenous drug users, obese and morbidly obese patients, those with cancer, patients undergoing organ transplantation, and vancomycin administration during pregnancy and lactation. An individualized dosing regimen is required to guarantee the optimum therapeutic responses and minimize adverse reactions including acute kidney injury in these special groups of patients. According to the pharmacoeconomic data on vancomycin TDM, pharmacokinetic assessments would be cost-effective in patients with altered pharmacokinetics and are associated with shorter hospitalization period, faster clinical stability status, and shorter courses of inpatient vancomycin administration.

Chemotherapy and Anticancer Drugs Adjustment in Obesity: A Narrative Review

BACKGROUND

Obese individuals have higher rates of cancer incidence and cancer- related mortality. The worse chemotherapy outcomes observed in this subset of patients are multifactorial, including the altered physiology in obesity and its impact on pharmacokinetics, the possible increased risk of underdosing, and treatment-related toxicity.

AIMS

The present review aimed to discuss recent data on physiology, providing just an overall perspective and pharmacokinetic alterations in obesity concerning chemotherapy. We also reviewed the controversies of dosing adjustment strategies in adult and pediatric patients, mainly addressing the use of actual total body weight and ideal body weight.

METHODS

This narrative review tried to provide the best evidence to support antineoplastic drug dosing strategies in children, adolescents, and adults.

RESULTS

Cardiovascular, hepatic, and renal alterations of obesity can affect the distribution, metabolism, and clearance of drugs. Anticancer drugs have a narrow therapeutic range, and variations in dosing may result in either toxicity or underdosing. Obese patients are underrepresented in clinical trials that focus on determining recommendations for chemotherapy dosing and administration in clinical practice. After considering associated comorbidities, the guidelines recommend that chemotherapy should be dosed according to body surface area (BSA) calculated with actual total body weight, not an estimate or ideal weight, especially when the intention of therapy is the cure.

CONCLUSION

The actual total body weight dosing appears to be a better approach to dosing anticancer drugs in both adults and children when aiming for curative results, showing no difference in toxicity and no limitation in treatment outcomes compared to adjusted doses.

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.