Vancomycin serum concentration during febrile neutropenia in patients with acute myeloid leukemia

Dried blood spot analysis for the quantification of vancomycin and creatinine using liquid chromatography - tandem mass spectrometry: Method development and validation

BACKGROUND

Vancomycin is a widely used antibiotic for the treatment of gram-positive bacterial infections, especially for methicillin-resistant Staphylococcus aureus (MRSA) infections. Due to a small therapeutic range and large inter-patient variability, therapeutic drug monitoring (TDM) of vancomycin is required to minimize toxicity and maximize treatment efficacy. Venous blood sampling is mostly applied for TDM of vancomycin, although this widely used sampling method is more invasive compared to less painful alternatives, such as the dried blood spot (DBS) method, which can be performed at home.

METHOD

We developed an UPLC-MS/MS method for the quantification of vancomycin and creatinine in DBS. A fast sample preparation and short analysis run time of 5.2 min were applied, which makes this method highly suitable for clinical settings. Validation was performed according to international (FDA and EMA) guidelines.

RESULTS

The validated concentration range was found linear for creatinine from 41.8 µmol/L to 722 µmol/L and for vancomycin from 3.8 mg/L to 76.6 mg/L (r2 > 0.990) and the inaccuracies, imprecisions, hematocrit effects, and recoveries were < 15 % for both compounds. No significant carryover effect was observed.

CONCLUSION

Hence, we successfully validated a quantification method for the simultaneous determination of creatinine and vancomycin in DBS.

Advances in antibacterial treatment of adults with high-risk febrile neutropenia

BACKGROUND

High-risk febrile neutropenia (HR-FN) is a life-threatening complication in patients with haematological malignancies or receiving myelosuppressive chemotherapy. Since the last international guidelines were published over 10 years ago, there have been major advances in the understanding and management of HR-FN, including on antibiotic pharmacokinetics and discontinuation/de-escalation strategies.

OBJECTIVES

Summarizing major advances in the field of antibacterial therapy in patients with HR-FN: empirical therapy, pharmacokinetics of antibiotics and antibiotic stewardship.

SOURCES

Narrative review based on literature review from PubMed. We focused on studies published between 2010 and 2023 about the pharmacokinetics of antimicrobials, management of antimicrobial administration, and discontinuation/de-escalation strategies. We did not address antimicrobial prophylaxis, viral or fungal infections.

CONTENT

Several high-quality publications have highlighted important modifications of antibiotic pharmacokinetics in HR-FN, with standard dosages exposing patients to underdosing. These recent clinical and population pharmacokinetics studies help improve management protocols with optimized initial dosing and infusion rules for β-lactams, vancomycin, daptomycin and amikacin; they highlight the potential benefits of therapeutic drug monitoring. A growing body of evidence also shows that antibiotic discontinuation/de-escalation strategies are beneficial for bacterial ecology and patients' outcome. We further discuss methods and limitations for implementation of such protocols in haematology.

IMPLICATIONS

We highlight recent information about the management of antibacterial therapy in HR-FN that might be considered in updated guidelines for HR-FN management.

Impact of Underlying Comorbidities on Outcomes of Patients Treated with Ceftaroline Fosamil for Complicated Skin and Soft Tissue Infections: Pooled Results from Three Phase III Randomized Clinical Trials

Introduction

In three phase III randomized controlled trials, ceftaroline fosamil was shown to be non-inferior to vancomycin plus aztreonam for the treatment of complicated skin and soft tissue infections (cSSTIs). This exploratory analysis evaluated the impact of underlying comorbidities on clinical outcomes in patients with cSSTI pooled from these three studies.

Methods

CANVAS 1 and 2 and COVERS evaluated ceftaroline fosamil (600 mg every 12 h [q12h]; 600 mg every 8 h [q8h; COVERS]) versus vancomycin plus aztreonam (1 g q12h each [CANVAS 1 and 2]; vancomycin 15 mg/kg q12h and aztreonam 1 g q8h [COVERS]) in hospitalized adults with cSSTI. The primary efficacy variable in each trial was clinical response at the test-of-cure (TOC) visit. Subgroup analyses were performed on the pooled clinically evaluable (CE) population, exploring the impact of age and various baseline comorbidities.

Results

Overall, 1808 patients were included in the CE population (1005 ceftaroline fosamil; 803 vancomycin plus aztreonam). Clinical cure rates at TOC were 89.7% (ceftaroline fosamil) and 90.8% (vancomycin plus aztreonam) (difference [95% confidence interval] − 1.13 [− 3.87, 1.67]). Clinical response rates were similar between treatment groups, regardless of age (≤ 65 years or > 65 years), and in subgroups of patients with and without diabetes mellitus, peripheral vascular disease, cancer/malignancy, renal impairment, and obesity; within these subgroups, efficacy and safety results were generally consistent with those of the overall cSSTI population.

Conclusions

This analysis provides supportive evidence of the efficacy of ceftaroline fosamil in patients with cSSTI and underlying comorbidities.

Trial Registration

CANVAS 1, NCT00424190 and CANVAS 2, NCT00423657 (both trials first posted on ClinicalTrials.gov 18/01/2007); COVERS, NCT01499277 (first posted on ClinicalTrials.gov 26/12/2011).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00557-w.

Causes of vancomycin dosing error; problem detection and practical solutions; a retrospective, single-center, cross-sectional study

Vancomycindosing error and inappropriate monitoring is a common problem in hospital daily practice. In King Abdulaziz Medical City (KAMC) in Jeddah, a high percentage of abnormal vancomycin trough levels is still detected despite using the recommended dose. Therefore, the current research objective is to study the major causes of vancomycin dosing errors. This retrospective, single-center, cross-sectional study was carried out at KAMC hospital in Jeddah from January 1st until December 31st 2019. All adult patients (≥15 years) who received vancomycin and had an initial abnormal trough level at the measured steady-state were included in this study. 472 patients have met the study inclusion criteria.

The current study evaluated the factors that play a role in causing vancomycin trough level abnormalities such as sampling time, vancomycin dosing, and patient’s pharmacokinetic and pharmacodynamic variations.

In this study, we found that pharmacokinetic and pharmacodynamic variability was attributed to 65% of vancomycin's abnormal trough level. Also, the result showed a significantly increased odds of the low trough in the non-elderly group (OR 6, 95% CI 2.48 – 14.9, P < 0.001) and febrile neutropenic patients (OR 2.21, 95% CI 1.119 – 4.365, P < 0.05). However, the odds of high trough levels were significantly elevated among patients who have CrCl < 50 ml/min (OR 5, 95% CI 1.262–20.539, P < 0.05). In addition, the present investigation revealed that the occurrence of abnormal vancomycin levels was not affected by daily duty time or working days (p > 0.05). The current study indicated that vancomycin dosing errors were common in KAMC patients; thus, there is an unmet need to evaluate the causes of vancomycin abnormal trough level and optimize a strategy that would enhance the therapeutic effectiveness and minimize the potential toxicity.

A Systematic Review of Vancomycin Dosing in Patients with Hematologic Malignancies or Neutropenia

Objective

To provide a comprehensive review of vancomycin dosing in patients with hematologic malignancies or neutropenia.

Methods

PubMed, Embase and the Cochrane Library were searched through April 2, 2020. Original studies relevant to vancomycin dosing regimen in adults with hematologic malignancies or neutropenia were included. No restriction was applied in study design and language. A descriptive analysis was performed.

Results

Twenty-three studies were included eventually, of which eighteen were case series studies, four were cohort studies and another one was a randomized controlled trial. Five case series studies made a clinical audit of conventional vancomycin dosing in patients with malignancies or neutropenia, showing that the proportion of patients with sub-therapeutic trough levels remained high, ranging from 32% to 88%. Seven case series studies and four cohort studies demonstrated that vancomycin clearance (CLva) tended to be higher in patients with hematologic malignancies or neutropenia, whereas volume of distribution (V) seemed to be comparable to the control group. Five studies proposed individualized initial dosing regimen per the pharmacokinetic changes; however, no prospective validation has been conducted in clinical setting. Additionally, four case series studies suggested that the correlation between vancomycin clearance and estimated creatinine clearance was relatively poor, bringing a great challenge to proper dosing strategy. A randomized controlled trial stated that therapeutic drug monitoring (TDM) of vancomycin could decrease the incidence of nephrotoxicity in immunocompromised febrile patients with hematologic malignancies.

Conclusion

The available evidence indicates that conventional vancomycin dosing leads to suboptimal concentration in patients with hematologic malignancy or neutropenia. TDM accompanied by pharmacokinetic interpretation can decrease the risk of nephrotoxicity. The individualization of the initial dosing regimen and mechanisms of augmented clearance require further research.

The effect of neutropenia on the clinical pharmacokinetics of vancomycin in adults

AIM

There is accumulating evidence that neutropenic patients require higher dosages of vancomycin. To prevent sub-therapeutic drug exposure, it is of utmost importance to obtain adequate exposure from the first dose onwards. We aimed to quantify the effect of neutropenia on the pharmacokinetics of vancomycin.

METHODS

Data were extracted from a matched patient cohort of patients known with (1) hematological disease, (2) solid malignancy, and (3) patients not known with cancer. Pharmacokinetic analysis was performed using non-linear mixed effects modeling with neutropenia investigated as a binary covariate on clearance and volume of distribution of vancomycin.

RESULTS

A total of 116 patients were included (39 hematologic patients, 39 solid tumor patients, and 38 patients not known with cancer). In total, 742 paired time-concentration observations were available for the pharmacokinetic analysis. Presence of neutropenia showed to significantly (p = 0.00157) increase the clearance of vancomycin by 27.7% (95% CI 10.2-46.2%), whereas it did not impact the volume of distribution (p = 0.704).

CONCLUSIONS

This study shows that vancomycin clearance is increased in patients with neutropenia by 27.7%. Therefore, the vancomycin maintenance dose should be pragmatically increased by 25% in neutropenic patients at the start of treatment. Since the volume of distribution appeared unaffected, no adjustment in loading dose is required. These dose adjustments do not rule out the necessity of further dose individualization by means of therapeutic drug monitoring.

Neutropenia is independently associated with sub-therapeutic serum concentration of vancomycin

BACKGROUND

We aimed to identify the impact of the presence of neutropenia on serum vancomycin concentration (SVC).

METHODS

A retrospective study was conducted from January 2005 to December 2015. The study population was comprised of adult patients who were performed serum concentration of vancomycin. Patients with renal failure or using non-conventional dosages of vancomycin were excluded.

RESULTS

A total of 1307 adult patients were included in this study, of whom 163 (12.4%) were neutropenic. Patients with neutropenia presented significantly lower SVCs than non-neutropenic patients (P<0.0001). Multiple linear regressions showed significant association between neutropenia and trough SVC (beta coefficients, -2.351; P=0.004). Multiple logistic regression analysis also revealed a significant association between sub-therapeutic vancomycin concentrations (trough SVC values<10mg/l) and neutropenia (odds ratio, 1.75, P=0.029) CONCLUSIONS: The presence of neutropenia is significantly associated with low SVC, even after adjusting for other variables. Therefore, neutropenic patients had a higher risk of sub-therapeutic SVC compared with non-neutropenic patients. We recommended that vancomycin therapy should be monitored with TDM-guided optimization of dosage and intervals, especially in neutropenic patients.

Guidelines for therapeutic drug monitoring of vancomycin: a systematic review

BACKGROUND AND OBJECTIVE

Despite the availability of clinical practice guidelines (CPGs) for therapeutic drug monitoring (TDM) of vancomycin, vancomycin serum concentrations still do not reach therapeutic concentrations in many patients. Thus, we sought to systematically review the quality and consistency of recommendations for an international cohort of CPGs regarding vancomycin TDM.

METHODS

PubMed, Embase, guidelines' websites and Google were searched for CPGs for vancomycin TDM. Two independent assessors rated the quality of each CPG using the Appraisal of Guidelines for Research & Evaluation II (AGREEII) instrument and data were independently extracted.

RESULTS

Twelve guidelines were evaluated and the overall quality of guidelines for vancomycin TDM was moderate. The highest score was recorded in the domain of clarity of presentation, and the lowest score was recorded in the domain of rigor of development and stakeholder involvement. The specific recommendations for vancomycin TDM were moderately consistent and guidelines varied in trough concentration monitoring, frequency of TDM, and serum concentration targets.

CONCLUSION

The overall guideline quality for vancomycin TDM was not optimal and effort is needed to improve guideline quality, especially in the domain of rigor of development and stakeholder involvement.

Antimicrobial treatment of febrile neutropenia: pharmacokinetic-pharmacodynamic considerations

Patients with cancer or hematologic diseases are particularly at risk of infection leading to high morbidity, mortality and costs. Extensive data show that optimization of the administration of antimicrobials according to their pharmacokinetic and pharmacodynamic parameters improves clinical outcome. Evidence is growing that when pharmacokinetic and pharmacodynamic parameters are used to target not only clinical cure but also eradication, the selection resistance is also contained. This is of particular importance in patients with neutropenia in whom increasing rates of drug-resistant Gram-negative bacteria have been reported, particularly Pseudomonas aeruginosa. Based on experimental and clinical studies, pharmacokinetic and pharmacodynamic parameters are discussed in this review for each antibiotic used in febrile neutropenia in order to help physicians improve dosing and optimization of antimicrobial agents.

Benefits of therapeutic drug monitoring of vancomycin: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The necessity of therapeutic drug monitoring (TDM) for vancomycin is controversial. The objective of the current review was to evaluate the available evidence for the necessity of TDM in patients given vancomycin to treat Gram-positive infections.

METHODS

Medline, Embase, Web of Sciences, the Cochrane Library and two Chinese literature databases (CNKI, CBM) were searched. Randomized controlled studies and observational studies that compared the clinical outcomes of TDM groups vs. non-TDM groups were included. Two reviewers independently extracted the data. The primary outcome was clinical efficacy of therapy. Secondary outcomes included vancomycin associated nephrotoxicity, duration of vancomycin therapy, length of hospital stay, and mortality. Meta-analysis was performed using the Mantel-Haenszel fixed effect method (FEM). Odds ratios (ORs) or weighted mean differences (WMD) with 95% confidence intervals (95%CIs) were calculated for categorical and continuous outcomes, respectively.

RESULTS

One randomized controlled trial (RCT) and five cohort studies were included in the meta-analysis. Compared with non-TDM groups, TDM groups had significantly higher rates of clinical efficacy (OR = 2.62, 95%CI 1.34-5.11 P = 0.005) and decreased rates of nephrotoxicity (OR = 0.25, 95%CI 0.13-0.48 P<0.0001). Subgroup analyses showed that TDM group had significantly higher rates of clinical efficacy in both cohort studies subgroup (OR = 3.04, 95%CI 1.34-6.90) and in Asian population subgroup (OR = 3.04, 95%CI 1.34-6.90). TDM group had significantly decreased rates of nephrotoxicity in all subgroup. There was no significant difference in duration of vancomycin therapy (WMD = -0.40, 95%CI -2.83-2.02 P = 0.74) or length of stay (WMD = -1.01, 95%CI -7.51-5.49 P = 0.76) between TDM and non-TDM groups. Subgroup analyses showed there were no differences in duration of vancomycin therapy. Only one study reported mortality rates.

CONCLUSIONS

Studies to date show that TDM significantly increases the rate of clinical efficacy and decreases the rate of nephrotoxicity in patients treated with vancomycin.