Therapeutic Monitoring Of Vancomycin Research Articles

Practices, Knowledge, and Attitudes of Nephrologists Towards Prescribing and Monitoring Vancomycin at Dialysis Centers

ABSTRACT Background Vancomycin dosing protocols are varied in the literature for hemodialysis patients. This study sought to determine nephrologists’ practices, knowledge, attitudes, and barriers toward prescribing and monitoring vancomycin at dialysis centers. Methods A cross-sectional and multi-center study was conducted in Kuwait using a validated self-administered questionnaire among 168 nephrologists. Descriptive and comparative analyses were performed using SPSS (version 28). Results The response rate was 75% (n = 126). Over half of nephrologists frequently prescribed a vancomycin loading dose of 1000 mg (53.2%) and a maintenance dose of 500 mg (51.6%) to all patients. Their overall median (IQR) percentage knowledge about the therapeutic monitoring of vancomycin was 66.7% (33.3) and was found to be higher in nephrologists aged ≤ 40 years and in registrars/senior registrars (p < 0.05). Their overall median (IQR) attitude score was 4.0 (1.0) [positive attitude]. Nephrologists with > 15 years of practice experience expressed higher attitudes (p < 0.05). The top two perceived barriers were a lack of clear local hospital/national guidelines (60.3%) for vancomycin dosing in dialysis and inconsistencies among different dosing references and guidelines (51.6%). Conclusion Findings showed that nephrologists have varying practices, moderate knowledge, and positive attitudes toward prescribing and monitoring vancomycin and highlight the need for interventions to overcome the perceived barriers.

Case report: therapeutic monitoring of vancomycin in an acute liver failure patient with anuria under high-flow continuous hemodiafiltration

BackgroundHigh-flow continuous hemodiafiltration (HF-CHDF) combines diffusive and convective solute removal and is employed for artificial liver adjuvant therapy. However, there is no report on dosage planning of vancomycin (VCM) in patients with acute liver failure under HF-CHDF.Case presentationA 20-year-old woman (154 cm tall, weighing 50 kg) was transferred to the intensive care unit (ICU) with acute liver failure associated with autoimmune liver disease. On the following day, HF-CHDF was started due to elevated plasma ammonia concentration. On ICU day 8, VCM was started for suspected pneumonia and meningitis (30 mg/kg loading dose, then 20 mg/kg every 12 hrs). However, on ICU day 10, VCM blood concentration was under the limit of detection (< 3.0 μg/mL) and the patient developed anuria. The VCM dose was increased to 20 mg/kg every 6 hrs. Calculation with a one-compartment model using the HF-CHDF blood flow rate as a surrogate for VCM clearance, together with hematocrit and protein binding ratio, predicted a trough VCM blood concentration of 15 μg/mL. The observed concentration was about 12 μg/mL. The difference may represent non-HF-CHDF clearance. Finally, living donor liver transplantation was performed.ConclusionWe report an acute liver failure patient with anuria under HF-CHDF in whom VCM administration failed to produce an effective blood concentration, likely due to HF-CHDF-enhanced clearance. VCM dosage adjustment proved successful, and was confirmed by calculation using a one-compartment model.

175. Assessment of Institutional Uptake of Vancomycin AUC Monitoring One-Year Post Guideline Publication in Hospitals Across the United States

BackgroundA new therapeutic monitoring of vancomycin for serious methicillin resistant Staphylococcus aureus infections guideline was published in March 2020. The guideline recommends a change in monitoring from trough to AUC/MIC based to improve patient outcomes. The purpose of this study was to determine institutional uptake of vancomycin AUC monitoring 1-year post guideline publication in hospitals across the U.S.MethodsAn electronic survey was created to assess vancomycin AUC monitoring practices and distributed to the American College of Clinical Pharmacy Infections Diseases Practice and Research Network (ACCP IDprn) and American Society of Health System Pharmacists (ASHP). Initial survey distribution (phase 1) occurred May-June 2020 and aimed to serve as baseline data. The survey was re-distributed (phase 2) to the ACCP IDprn and ASHP one year later, May-June 2021. Prior to re-distribution the survey was updated to assess the impact of COVID-19 on uptake. Results were analyzed and reported using descriptive statistics. Chi-Square tests were used to compare categorical data.ResultsA total of 202 responses to phase 1 and 138 responses to phase 2 were recorded. Significantly more respondents implemented AUC monitoring 1-year post guideline than at baseline (42.8% vs 29.8%, p= 0.013). In both phases, 57% of those who had not implemented AUC monitoring had plans to do so over the next year. Additionally, 46.2% phase 2 respondents reported COVID-19 impacted their ability to transition to AUC monitoring citing issues such as lack of time and inadequate resources. The most common AUC monitoring programs utilized at baseline and 1-year post guideline were purchased Bayesian software (38.3% vs. 35.6%) and homemade software (26.1% vs 23.7%). Perceived challenges to implementing AUC monitoring included cost, difficult use and integration.ConclusionIncreased uptake of vancomycin AUC monitoring occurred from baseline to 1-year post guideline publication. However, less than half of hospitals implemented this recommendation. Although COVID-19 impacted a large portion respondents’ ability to implement AUC monitoring, majority plan to transition to vancomycin AUC monitoring over the next year. AUC monitoring should be adapted by all hospitals to optimize vancomycin efficacy and safety.Disclosures All Authors: No reported disclosures

Predictive Performance of Bayesian Vancomycin Monitoring in the Critically Ill.

It is recommended that therapeutic monitoring of vancomycin should be guided by 24-hour area under the curve concentration. This can be done via Bayesian models in dose-optimization software. However, before these models can be incorporated into clinical practice in the critically ill, their predictive performance needs to be evaluated. This study assesses the predictive performance of Bayesian models for vancomycin in the critically ill. Retrospective cohort study. Single-center ICU. Data were obtained for all patients in the ICU between 1 January, and 31 May 2020, who received IV vancomycin. The predictive performance of three Bayesian models were evaluated based on their availability in commercially available software. Predictive performance was assessed via bias and precision. Bias was measured as the mean difference between observed and predicted vancomycin concentrations. Precision was measured as the sd of bias, root mean square error, and 95% limits of agreement based on Bland-Altman plots. None. A total of 466 concentrations from 188 patients were used to evaluate the three models. All models showed low bias (-1.7 to 1.8 mg/L), which was lower with a posteriori estimate (-0.7 to 1.8 mg/L). However, all three models showed low precision in terms of sd (4.7-8.8 mg/L) and root mean square error (4.8-8.9 mg/L). The models underpredicted at higher observed vancomycin concentrations (bias 0.7-3.2 mg/L for < 20 mg/L; -5.1 to -2.3 for ≥ 20 mg/L) and the Bland-Altman plots showed a great deviation between observed and predicted concentrations. Bayesian models of vancomycin show not only low bias, but also low precision in the critically ill. Thus, Bayesian-guided dosing of vancomycin in this population should be used cautiously.

Continued professional development: A comparison of online vs. in-person workshops

IntroductionPharmacy practice continues to change and therefore requires lifelong health professions education. These practice changes require academics and leaders in pharmacy to identify how to best teach and train pharmacists to manage patient care services. This study assessed whether an online training module is as effective as an in-person workshop to train pharmacists to apply dosing and therapeutic monitoring of vancomycin. MethodsThe primary endpoint measured the difference in average assessment score change between pre- and post-training between intervention groups. All pharmacists completed: (1) a baseline pretest, (2) Session 1 online, (3) Session 2 (an online training module or in-person workshop), (4) a posttest, and (5) a voluntary survey of perceptions on training. ResultsA total of 56 pharmacists completed the training, 43% online and 57% in-person. The multiple linear regression included pretest, training method, and pharmacists' role on posttest (R2 = 0.1041 and P = .34). A voluntary anonymous survey about perceptions on the training was completed by 20 participants. On average, perceptions were agreeable on an eight-item Likert scale between groups (Cronbach's alpha = 0.77). The total scores for the Likert scale were 27 ± 3.3 vs. 23 ± 1.6, P = .001, in the online and in-person sessions, respectively. More participants in the online group agreed that they had enough time to comprehend and apply the material, 4 vs. 3 (on the Likert scale). ConclusionsAn online training module is as effective as an in-person workshop at training pharmacists to apply vancomycin dosing and monitoring.

In Silico Pharmacokinetic Study of Vancomycin Using PBPK Modeling and Therapeutic Drug Monitoring.

Vancomycin has been in clinical use for nearly 50 years and remains the first-line treatment option for Gram-positive infections, including methicillin-resistant Staphylococcus aureus (MRSA). There are multiple strategies to monitor therapy and adjust the dose of this antibiotic. AUC24/MIC ratio has been demonstrated to be the best parameter to predict the effectiveness and safety of vancomycin, and a target ratio of ≥400 is recommended. Still, trough and peak serum levels at steady-state conditions have been used in clinical settings as an accurate and practical method to monitor vancomycin. In this work, we collected and analyzed clinical information of patients being treated in a hospital center in Porto (Portugal) and studied the pharmacokinetics of vancomycin in silico, developing several physiologically based pharmacokinetic (PBPK) models using simulation software GastroPlus™. Different dosages and treatment regimens were studied, and the influence of patients' age, weight and renal function was evaluated; a simulation population was also performed. A linear effect of dose and a significant influence of weight and renal function in plasmatic levels of vancomycin was observed. The results of this work corroborate the accumulation of vancomycin in plasma and identify some parameters that influence the pharmacokinetics of this antibiotic. The importance of therapeutic monitoring of vancomycin is highlighted, and the usefulness of in silico tools, namely PBPK modeling, is demonstrated.

Should Therapeutic Monitoring of Vancomycin Based on Area under the Curve Become Standard Practice for Patients with Confirmed or Suspected Methicillin-Resistant Staphylococcus aureus Infection? The “Pro” Side: Correction

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Implementation of a vancomycin therapeutic monitoring protocol in adults

Background and objectives: Therapeutic Drug Monitoring (TDM) is an important tool in optimizing vancomycin therapy, a drug used to treat serious infections caused by grampositive bacteria. The aim of this study was to implement a protocol for the therapeutic monitoring of vancomycin in hospitals and to describe the clinical, laboratory and use characteristics of this drug after its implementation. Methods: The international consensus on vancomycin TDM was used for protocol development. Patient data were collected from medical records and pharmacokinetic software estimates. Results: The vancomycin protocol was implemented at a hospital and made available to the clinical staff. We evaluated 49 patients. Vancomycin was prescribed mainly to treat pneumonia 15 (30.6%). Among the identified microorganisms, Staphylococcus aureus was the most common with 8 cases (50%), and 9 (56.3%) patients were resistant to oxacillin. The average use of vancomycin was 10.6 (± 6.6) days and the loading dose was administered in 33 (67.3%) patients. A total of 5 (11.1%) patients had acute renal failure. Monitoring of Minimal Concentrations in the vancomycin valley (Cmin) occurred in 43 (87.8%) patients. In the first measurement, 16 of them (37.2%) presented Cmin below 10 mcg/dL and 11 (25.6%) above 20 mcg/dL, data considered outside the therapeutic range. Conclusion: The elaboration of an MTF protocol for vancomycin guides the rational and safe use of this antibiotic. Continued training in human resources and investment in dose-adjusting pharmacokinetic software may contribute to the optimization of vancomycin therapy.

The Pharmacokinetics, Optimal Dose and Therapeutic Monitoring of Vancomycin in Severe Burn Patients

The Pharmacokinetics, Optimal Dose and Therapeutic Monitoring of Vancomycin in Severe Burn Patients

PKP-006 Comparison between the use of total/ideal/adjusted body weight for empirical vancomycin dosing in obese patients

Background Pharmacokinetic studies have suggested that total body weight (TBW) could be the optimal approach to calculate the dose of intravenous vancomycin (15–20 mg/kg TBW every 8–12 h) for target achievement (Css > 15 mg/L). 1 However, recent data concluded that the use of adjusted body weight (ABW) might be a better approach in obese patients. 2 Purpose To determine which is the preferred method (TBW, ideal body weight (IBW) or ABW) to optimise vancomycin treatment in obese patients. Material and methods Retrospective, non-interventional, observational study. Inclusion criteria: >18 years-old, body-mass-index (BMI) ≥30 kg/m 2 , creatinine clearance ≥60 mL/min, and vancomycin TDM at steady-state. Non-obese patients were included as a control group. Patients were identified by reviewing TDM reports. Vancomycin theoretical total daily doses (15–20 mg/kg) were calculated using TBW, IBW and ABW for each patient. They were compared with the dose used in our patients after TDM (Bayesian forecasting; PKSAbbot Software; target: Css > 15 mg/L) (TDM dose). Dose differences greater than 10–12.5% of the TDM dose were considered unsuitable, since they could be related to clinical failure. Wilcoxon’s test analysis was performed using SPSS; (p Results Forty obese patients: 35% men; 60.4 ± 12.6 years-old; BMI: 33.3 ± 2.7 kg/m 2 . Compared to the TDM dose and considering 15–20 mg/kg: (i) Overdosage was observed in 72.5 (95%), 25 (47.5%) and 32.5 (72.5%) patients for TBW, IBW and ABW, respectively. Statistically significant differences were seen, with mean dose differences higher than 500 mg in the 20 mg/kg group. (ii) Underdosage was seen in: 22.5 (5.0%), 75 (45%) and 67.5 (27.5%) respectively. Statistically significant differences were seen with mean dose differences lower than 400 mg in the 15 mg/kg group. No relevant differences were observed in the control group. Conclusion Compared to the TDM dose, a high incidence of overdosage would be observed by using TBW. In our obese patient cohort, ABW might be the best approach to set the dose of intravenous vancomycin (15–20 mg/kg), as already seen in previous literature. 2 References Rybak M, Lomaestro B, Rotschafer JC, et al . Therapeutic monitoring of vancomycin in adult patients: a consensus review of the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists. Am J Health Syst Pharm 2009;66:82–98 Leong JV, Boro MS, Winter M, et al . Determining vancomycin clearance in an overweight and obese population. Am J Health Syst Pharm 2011;68:599–603 No conflict of interest.

Questioning the accuracy of trough concentrations as surrogates for area under the curve in determining vancomycin safety.

Questioning the accuracy of trough concentrations as surrogates for area under the curve in determining vancomycin safety.

Underestimation of the Calculated Area Under the Concentration-Time Curve Based on Serum Creatinine for Vancomycin Dosing

BackgroundThe ratio of the steady-state 24-hour area under the concentration-time curve (ssAUC24) to the MIC (AUC24/MIC) for vancomycin has been recommended as the preferred pharmacodynamic index. The aim of this study was to assess whether the calculated AUC24 (cAUC24) using the creatinine clearance (CLcr) differs from the ssAUC24 based on the individual pharmacokinetic data estimated by a commercial software.Materials and MethodsThe cAUC24 was compared with the ssAUC24 with respect to age, body mass index, and trough concentration of vancomycin and the results were expressed as median and interquartile ranges. A correlation between the cAUC24 and ssAUC24 and the trough concentration of vancomycin was evaluated. The probability of reaching an AUC24/MIC of 400 or higher was compared between the cAUC24 and ssAUC24 for different MICs of vancomycin and different daily doses by simulation in a subgroup with a trough concentration of 10 mg/L and higher.ResultsThe cAUC24 was significantly lower than the ssAUC24 (392.38 vs. 418.32 mg·hr/L, P < 0.0001) and correlated weakly with the trough concentration (r = 0.649 vs. r = 0.964). Assuming a MIC of 1.0 mg/L, the probability of reaching the value of 400 or higher was 77.5% for the cAUC24/MIC and 100% for the ssAUC24/MIC in patients with a trough concentration of 10 mg/L and higher. If the MIC increased to 2.0 mg/L, the probability was 57.7% for the cAUC24/MIC and 71.8% for the ssAUC24/MIC at a daily vancomycin dose of 4,000 mg.ConclusionsThe cAUC24 using the calculated CLcr is usually underestimated compared with the ssAUC24 based on individual pharmacokinetic data. Therefore, to obtain a more accurate AUC24, therapeutic monitoring of vancomycin rather than a simple calculation based on the CLcr should be performed, and a more accurate biomarker for renal function is needed.

GRP-092 Implementation of Recommendations Arising from Therapeutic Monitoring of Vancomycin Trough Levels in a Tertiary Hospital

BackgroundIn 2009 we established a consensus review of therapeutic monitoring of vancomycin by several societies including the American Society of Health-System Pharmacists (ASHP), the Infectious Diseases Society of America (IDSA)...

Therapeutic monitoring of vancomycin

The present study aimed to characterize admitted patients in a public hospital in the Northwestern region of Parana State, which were subject to therapeutic monitoring of vancomycin during 2007 and 2008. The data were obtained by a retrospective study of patients' medical records, from where we separated the laboratory results, medical prescriptions, gender, age, and diagnosis of patients submitted to therapeutic monitoring. Of the total of 38 patients, only eight (21.1%) presented serum concentrations within recommended range, varying from 1.3 to 47.9 mg L -1 . Concentrations above the reference value were observed in 22 patients (57.9%), and below the reference, in other eight patients (21.1%). The recommended serum concentrations at peak were obtained in only four patients (11.4%), higher than the recommended value in seven patients (20.0%), and lower, in 24 patients (68.6%). Only one patient (2.6%) presented serum concentration within the reference values at both high and low dosages. Therefore, the results evidenced the importance of therapeutic monitoring of vancomycin, individualizing the dose for each patient, and reducing toxic or subtherapeutic effects of this antimicrobial substance.

Therapeutic monitoring of vancomycin according to initial dosing regimen in pediatric patients

PurposeThis study aimed to determine the optimal initial vancomycin dose to achieve appropriate trough levels in pediatric patients.MethodsWe analyzed clinical data for 309 children treated with intravenous vancomycin between 2004 and 2009 at 2 different hospitals in South Korea. The patients were 1-16 years old and exhibited normal renal function. Patient data, including reason for treatment and initial dosing regimen, were reviewed. Two subgroups were identified and compared according to initial vancomycin dose: 40 (35-45) mg/kg/day and 60 (55-65) mg/kg/day. Trough levels were obtained at steady state after at least 4 doses of vancomycin.ResultsPatients who received vancomycin had post-operation or wound-related infections (37.2%), localized infection (12.9%), catheter-related infections (9.4%), meningitis (8.7%), or endocarditis (6.8%). Pathogens were confirmed in 79 cases: 28 cases of methicillin-resistant Staphylococcus epidermidis (35.4%) and 25 of methicillin-resistant Staphylococcus aureus (31.6%). Out of the 309 patients, 201 (65%) received vancomycin at 40 mg/kg/day and 108 (35%) at 60 mg/kg/day. Average trough concentrations were significantly different between the groups (P<0.001). Trough levels over 10 mg/L were less likely to be achieved in the 40 mg/kg/day group (14%) than in the 60 mg/kg/day group (49%) (P<0.001). There were no differences in renal function deterioration between the groups.ConclusionA common vancomycin dosing regimen, 40 mg/kg/day, was not high enough to achieve trough levels of over 10 mg/L in pediatric patients. Careful drug monitoring must be performed, and increasing initial dose of vancomycin should be considered in pediatric patients.

Therapeutic Monitoring of Vancomycin in Adults

Target Population: Clinicians who treat adult patients with intravenous vancomycin; pharmacistsSponsoring Organizations: The American Society of

Therapeutic monitoring of vancomycin in adult patients: A consensus review of the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists

Vancomycin is a glycopeptide antibiotic that has been in clinical use for nearly 50 years as a penicillin alternative to treat penicillinase-producing strains of Staphylococcus aureus . It is one of the most widely used antibiotics in the United States for the treatment of serious gram-positive

A review of vancomycin therapeutic drug monitoring recommendations in Scotland

Letter regarding the therapeutic monitoring of vancomycin. Most clinicians would agree that the analysis of peak concentrations is of limited value due to both the pharmacodynamic (time-dependency) and pharmacokinetic (multiexponential decline) properties of vancomycin.1 However, there is still a lack of uniformity with respect to trough concentrations.