Pharmacokinetic Assessment of Vancomycin Loading Dose in Critically Ill Patients

A Systematic Review on Clinical Safety and Efficacy of Vancomycin Loading Dose in Critically Ill Patients

Background: The clinical significance of utilizing a vancomycin loading dose in critically ill patients remains unclear. Objective: The main aim of this systematic review is to evaluate the clinical safety and efficacy of the vancomycin loading dose in critically ill patients. Methods: We performed a systematic review using PRISMA guidelines. PubMed, the Web of Science, MEDLINE, Scopus, Google Scholar, the Saudi Digital Library and other databases were searched. Studies that reported clinical outcomes among patients receiving the vancomycin LD were considered eligible. Data for this study were collected using PubMed, the Web of Science, MEDLINE, Scopus, Google Scholar and the Saudi Digital Library using the following terms: “vancomycin”, “safety”, “efficacy” and “loading dose” combined with the Boolean operator “AND” or “OR”. Results: A total of 17 articles, including 2 RCTs, 11 retrospective cohorts and 4 other studies, met the inclusion/exclusion criteria out of a total 1189 studies. Patients had different clinical characteristics representing a heterogenous group, including patients in critical condition, with renal impairment, sepsis, MRSA infection and hospitalized patients for hemodialysis or in the emergency department. Conclusions: The study shows that the target therapeutic level is achieved more easily among patients receiving a weight-based LD as compared to patients received the usual dose without an increased risk of new-onset adverse drug reactions.

Clinical Practice Guidelines for Therapeutic Drug Monitoring of Vancomycin in the Framework of Model-Informed Precision Dosing: A Consensus Review by the Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring

Background: To promote model-informed precision dosing (MIPD) for vancomycin (VCM), we developed statements for therapeutic drug monitoring (TDM). Methods: Ten clinical questions were selected. The committee conducted a systematic review and meta-analysis as well as clinical studies to establish recommendations for area under the concentration-time curve (AUC)-guided dosing. Results: AUC-guided dosing tended to more strongly decrease the risk of acute kidney injury (AKI) than trough-guided dosing, and a lower risk of treatment failure was demonstrated for higher AUC/minimum inhibitory concentration (MIC) ratios (cut-off of 400). Higher AUCs (cut-off of 600 μg·h/mL) significantly increased the risk of AKI. Although Bayesian estimation with two-point measurement was recommended, the trough concentration alone may be used in patients with mild infections in whom VCM was administered with q12h. To increase the concentration on days 1–2, the routine use of a loading dose is required. TDM on day 2 before steady state is reached should be considered to optimize the dose in patients with serious infections and a high risk of AKI. Conclusions: These VCM TDM guidelines provide recommendations based on MIPD to increase treatment response while preventing adverse effects.

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.

Exploring population pharmacokinetic models in patients treated with vancomycin during continuous venovenous haemodiafiltration (CVVHDF)

BACKGROUND

Therapeutic antibiotic dose monitoring can be particularly challenging in septic patients requiring renal replacement therapy. Our aim was to conduct an exploratory population pharmacokinetic (PK) analysis on PK of vancomycin following intermittent infusion in critically ill patients receiving continuous venovenous haemodiafiltration (CVVHDF); focussing on the influence of dialysis-related covariates.

METHODS

This was a retrospective single-centre tertiary level intensive care unit (ICU) study, which included patients treated concurrently with vancomycin and CVVHDF between January 2015 and July 2016. We extracted clinical, laboratory and dialysis data from the electronic healthcare record (EHR), using strict inclusion criteria. A population PK analysis was conducted with a one-compartment model using the PMetrics population PK modelling package. A base structural model was developed, with further analyses including clinical and dialysis-related data to improve model prediction through covariate inclusion. The final selected model simulated patient concentrations using probability of target attainment (PTA) plots to investigate the probability of different dosing regimens achieving target therapeutic concentrations.

RESULTS

A total of 106 vancomycin dosing intervals (155 levels) in 24 patients were examined. An acceptable 1-compartment base model was produced (Plots of observed vs. population predicted concentrations (Obs-Pred) R² = 0.78). No continuous covariates explored resulted in a clear improvement over the base model. Inclusion of anticoagulation modality and vasopressor use as categorical covariates resulted in similar PK parameter estimates, with a trend towards lower parameter estimate variability when using regional citrate anti-coagulation or without vasopressor use. Simulations using PTA plots suggested that a 2 g loading dose followed by 750 mg 12 hourly as maintenance dose, commencing 12 h after loading, is required to achieve adequate early target trough concentrations of at least 15 mg/L.

CONCLUSIONS

PTA simulations suggest that acceptable trough vancomycin concentrations can be achieved early in treatment with a 2 g loading dose and maintenance dose of 750 mg 12 hourly for critically ill patients on CVVHDF.

Impact of a vancomycin loading dose on the achievement of target vancomycin exposure in the first 24 h and on the accompanying risk of nephrotoxicity in critically ill patients

Background

The advocated pharmacokinetic/pharmacodynamic (PK/PD) target for vancomycin, AUC/MIC ≥ 400 mg·h/L, may not be reached with a conventional fixed starting dose of 1000 mg in critically ill patients, but increasing the dose may cause nephrotoxicity.

Objectives

To evaluate the effect of a weight-based loading dose of 25 mg/kg vancomycin on PK/PD target attainment in the first 24 h (AUC_0–24) in critically ill patients and to evaluate whether this increases the risk of acute kidney injury (AKI).

Patients and methods

A prospective observational before/after study was performed in ICU patients, comparing the percentage of vancomycin courses with AUC_0–24 ≥ 400 mg·h/L and the incidence of AKI, defined as worsening of the risk, injury, failure, loss of kidney function and end-stage kidney disease (RIFLE) score. The conventional dose group received 1000 mg of vancomycin as initial dose; the loading dose group received a weight-based loading dose of 25 mg/kg. A population PK model developed using non-linear mixed-effects modelling was used to estimate AUC_0–24 in all patients.

Results

One hundred and four courses from 82 patients were included. With a loading dose, the percentage of courses achieving AUC_0–24 ≥ 400 mg·h/L increased significantly from 53.8% to 88.0% (P = 0.0006). The percentage of patients with new-onset AKI was not significantly higher when receiving a 25 mg/kg loading dose (28.6% versus 37.8%; P = 0.48). However, the risk of AKI was significantly higher in patients achieving AUC_0–24 > 400 mg·h/L compared with patients achieving AUC < 400 mg·h/L (39.0% versus 14.8%; P = 0.031).

Conclusions

A weight-based loading dose of 25 mg/kg vancomycin led to significantly more patients achieving AUC_0–24 ≥ 400 mg·h/L without increased risk of AKI. However, some harm cannot be ruled out since higher exposure was associated with increased risk of AKI.

Evidence-based Guideline for Therapeutic Drug Monitoring of Vancomycin: 2020 Update by the Division of Therapeutic Drug Monitoring, Chinese Pharmacological Society

BACKGROUND

Clinical practice guidelines or recommendations often require timely and regular updating as new evidence emerges, because this can alter the risk-benefit trade-off. The scientific process of developing and updating guidelines accompanied by adequate implementation can improve outcomes. To promote better management of patients receiving vancomycin therapy, we updated the guideline for the therapeutic drug monitoring (TDM) of vancomycin published in 2015.

METHODS

Our updated recommendations complied with standards for developing trustworthy guidelines, including timeliness and rigor of the updating process, as well as the use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We also followed the methodology handbook published by the National Institute for Health and Clinical Excellence and the Spanish National Health System.

RESULTS

We partially updated the 2015 guideline. Apart from adults, the updated guideline also focuses on pediatric patients and neonates requiring intravenous vancomycin therapy. The guideline recommendations involve a broadened range of patients requiring TDM, modified index of TDM (both 24-hour area under the curve and trough concentration), addition regarding the necessity and timing of repeated TDM, and initial dose for specific subpopulations. Overall, 1 recommendation was deleted and 3 recommendations were modified. Eleven new recommendations were added, and no recommendation was made for 2 clinical questions.

CONCLUSIONS

We updated an evidence-based guideline regarding the TDM of vancomycin using a rigorous and multidisciplinary approach. The updated guideline provides more comprehensive recommendations to inform rational and optimized vancomycin use and is thus of greater applicability.

Effect of vancomycin loading dose on clinical outcome in critically ill patients with methicillin-resistant Staphylococcus aureus pneumonia

Background

Vancomycin is the treatment of choice for serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Current guidelines recommend giving an initial loading dose (LD) of 25–30 mg/kg to rapidly increase the serum concentration. However, high-quality evidence for the clinical benefit of LD is lacking. Herein, we aim to examine the association between vancomycin LD and clinical outcome.

Methods

A retrospective cohort study was conducted on adult patients treated for MRSA pneumonia with vancomycin in medical intensive care units from April 2016 to August 2018. MRSA pneumonia was defined by the Centers for Disease Control and National Healthcare Safety Network definition. The primary outcome was the clinical cure of pneumonia. Secondary outcome measures included time to pharmacokinetic (PK) target attainment, microbiological cure, acute kidney injury, and all-cause mortality.

Results

A total of 81 patients were included; of these 22 (27.2%) received LD. The mean initial dose was significantly higher in the LD group. Clinical cure was similar in both groups (68.2% vs. 66.1% in the LD and non-LD groups, respectively; P=0.860). No significant difference was observed in the microbiological cure, all-cause mortality, and incidence of acute kidney injury. Furthermore, no difference was observed in terms of time to PK target attainment (69.2 vs. 63.4 h in the LD and non-LD groups, respectively; P=0.624). Vancomycin minimum inhibitory concentration of <2 mg/L was identified as an independent predictive factor for clinical cure in multivariable analysis, whereas vancomycin LD was not.

Conclusions

Initial LD is not associated with better clinical outcome or rapid pharmacological target attainment in critically ill patients with MRSA pneumonia. Further studies are warranted to provide better evidence for this widely recommended practice.

Evaluation of a Pilot Vancomycin Precision Dosing Advisory Service on Target Exposure Attainment Using an Interrupted Time Series Analysis

This study evaluated the ability of a pilot therapeutic drug monitoring (TDM) Advisory Service to facilitate vancomycin therapeutic target attainment within a real-world clinical setting. The Service provided area under the concentration-time curve (AUC)-guided vancomycin dose recommendations, using Bayesian forecasting software and clinical expertise, to prescribers at an Australian hospital. A retrospective audit of intravenous vancomycin therapy (> 48 hours) in adults (≥ 18 years old) was undertaken over a 54-month period to evaluate attainment of established vancomycin pharmacokinetic/pharmacodynamic targets (AUC over 24 hours / minimum inhibitory concentration: 400-600) before (36-month period) and after (18-month period) Service implementation. Interrupted time series analysis was employed to evaluate monthly measures of the median proportion of therapy spent within the target range. Indices of time to target attainment were also assessed before and after Service implementation. The final cohort comprised 1,142 courses of vancomycin (816 patients); 835 courses (596 patients) and 307 courses (220 patients) administered before and after Service implementation, respectively. Prior to piloting the Service, the median proportion of time in the target range was 40.1% (95% CI, 34.3-46.0%); this increased by 10.4% (95% CI, 1.2-19.6%, P = 0.03) after the Service, and was sustained throughout the post-Service evaluation period. Post-Service target attainment at 48-72 hours after initiation of therapy was increased (7.8%, 95% CI, 1.3-14.3%, P = 0.02). The findings of this study provide evidence that a consultative TDM Service can facilitate attainment of vancomycin therapeutic targets; however, optimization of the Service may further improve the use of vancomycin.

Population pharmacokinetic meta-analysis of individual data to design the first randomized efficacy trial of vancomycin in neonates and young infants

OBJECTIVES

In the absence of consensus, the present meta-analysis was performed to determine an optimal dosing regimen of vancomycin for neonates.

METHODS

A 'meta-model' with 4894 concentrations from 1631 neonates was built using NONMEM, and Monte Carlo simulations were performed to design an optimal intermittent infusion, aiming to reach a target AUC0-24 of 400 mg·h/L at steady-state in at least 80% of neonates.

RESULTS

A two-compartment model best fitted the data. Current weight, postmenstrual age (PMA) and serum creatinine were the significant covariates for CL. After model validation, simulations showed that a loading dose (25 mg/kg) and a maintenance dose (15 mg/kg q12h if <35 weeks PMA and 15 mg/kg q8h if ≥35 weeks PMA) achieved the AUC0-24 target earlier than a standard 'Blue Book' dosage regimen in >89% of the treated patients.

CONCLUSIONS

The results of a population meta-analysis of vancomycin data have been used to develop a new dosing regimen for neonatal use and to assist in the design of the model-based, multinational European trial, NeoVanc.

Development, Evaluation, and Pharmacokinetic Assessment of Polymeric Microarray Patches for Transdermal Delivery of Vancomycin Hydrochloride

Methicillin-resistant Staphylococcus aureus (MRSA) can cause harmful and potentially deadly infections. Vancomycin remains the first-line antibiotic treatment for MRSA-derived infections. Nevertheless, as a peptide drug, it is poorly absorbed when administered orally because of its high molecular weight and low permeability in the gastrointestinal tract and is therefore administered intravenously for the treatment of systemic diseases. In order to circumvent some of the many drawbacks associated with intravenous injection, other routes of drug delivery should be investigated. One of the strategies which has been employed to enhance transdermal drug delivery is based on microarray patches (MAPs). This work, for the first time, describes successful transdermal delivery of vancomycin hydrochloride (VCL) using dissolving MAPs (DMAPs) and hydrogel-forming MAPs (HFMAPs). VCL was formulated into DMAPs and reservoirs [film dosage forms, lyophilized wafers, and compressed tablets (CSTs)] using excipients such as poly(vinyl pyrrolidone), poly(vinyl alcohol), sodium hyaluronate, d-sorbitol, and glycerol. In this study, HFMAPs were manufactured using aqueous blends containing poly(methylvinyl ether-co-maleic acid) cross-linked by esterification with poly(ethylene glycol). The VCL-loaded CSTs (60% w/w VCL) were the most promising reservoirs to be integrated with HFMAPs based on the physicochemical evaluations performed. Both HFMAPs and DMAPs successfully delivered VCL in ex vivo studies with the percentage of drug that permeated across the neonatal porcine skin recorded at 46.39 ± 8.04 and 7.99 ± 0.98%, respectively. In in vivo studies, the area under the plasma concentration time curve from time zero to infinity (AUC_0-∞) values of 162.04 ± 61.84 and 61.01 ± 28.50 μg h/mL were achieved following the application of HFMAPs and DMAPs, respectively. In comparison, the AUC_0-∞ of HFMAPs was significantly greater than that of the oral administration control group, which showed an AUC_0-∞ of 30.50 ± 9.18 μg h/mL (p < 0.05). This work demonstrates that transdermal delivery of VCL is feasible using DMAPs and HFMAPs and could prove effective in the treatment of infectious diseases caused by MRSA, such as skin and soft tissue infections, lymphatic-related infections, and neonatal sepsis.

Weight-based vancomycin loading strategy may not improve achievement of optimal vancomycin concentration in patients with preserved renal function

We performed a retrospective study to evaluate clinical effectiveness of vancomycin loading strategy and factors associated with achieving optimal C _min. Patients administered vancomycin for ≥72 h from January to June 2018 were enrolled. Patients were divided into two groups: loading (LD) and non-loading (NLD). LD was defined as initial vancomycin dose ≥20 mg/kg and ≥120% of maintenance dose. During study period, 70 and 71 received initial LD (24.2 ± 2.5 mg/kg) and NLD (17.3 ± 3.3 mg/kg) doses of vancomycin, respectively (p < .001). Achievement of optimal C _min was not different before administration of the third dose (24.4% in LD versus 18.2% in NLD, p = .484) and within 72 h (22.9% versus 28.2%, p = .759). Risk factors for failure to achieve optimal C _min before administration of the third dose were higher creatinine clearance and higher level of serum albumin. Therefore, more sufficient loading or patient-specific dose strategies should be used to achieve optimal serum vancomycin C _min.

Vancomycin loading dose is associated with increased early clinical response without attainment of initial target trough concentration at a steady state in patients with methicillin-resistant Staphylococcus aureus infections

WHAT IS KNOWN AND OBJECTIVE

Vancomycin therapeutic guidelines suggest a loading dose of 25-30 mg/kg for seriously ill patients. However, high-quality data to guide the use of loading doses are lacking. We aimed to evaluate whether a loading dose (a) achieved a target trough concentration at steady state and (b) improved early clinical response.

METHODS

Patients with an estimated glomerular filtration rate ≥ 90 mL/min/1.73 m² were included. A loading dose of 25 mg/kg vancomycin followed by 15 mg/kg twice daily was compared with traditional dosing. A C_min sample was obtained before the fifth dose. An early clinical response 48-72 hours after the start of therapy and clinical success at end of therapy (EOT) was evaluated in patients with methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci or Enterococcus faecium.

RESULTS

There was no significant difference in C_min between the regimen with and without a loading dose (median: 10.4 and 10.2 µg/mL, P = .54). Proportions of patients achieving 10-20 and 15-20 µg/mL were 56.9% and 5.6%, respectively, in patients with a loading dose. Although there was no significant difference in success rate at EOT between groups, a loading dose was associated with increased early clinical response for all infections (adjusted odds ratio [OR]: 4.588, 95% confidence interval [CI]: 1.373-15.330) and MRSA infections (OR: 12.065, 95% CI: 1.821-79.959). Study limitations included no C_min measurements within 24 hours and the inclusion of less critically ill patients.

WHAT IS NEW AND CONCLUSION

A loading dose of 25 mg/kg followed by 15 mg/kg twice daily did not achieve the optimal Cmin at steady state in patients with normal renal function. However, more early clinical responses were obtained with a loading dose compared with traditional dosing, possibly because of a prompt albeit temporary achievement of a more effective concentration.

Antibiotic resistance: bioinformatics-based understanding as a functional strategy for drug design

The use of antibiotics to manage infectious diseases dates back to ancient civilization, but the lack of a clear distinction between the therapeutic and toxic dose has been a major challenge. This precipitates the notion that antibiotic resistance was from time immemorial, principally because of a lack of adequate knowledge of therapeutic doses and continuous exposure of these bacteria to suboptimal plasma concentration of antibiotics. With the discovery of penicillin by Alexander Fleming in 1924, a milestone in bacterial infections' treatment was achieved. This forms the foundation for the modern era of antibiotic drugs. Antibiotics such as penicillins, cephalosporins, quinolones, tetracycline, macrolides, sulphonamides, aminoglycosides and glycopeptides are the mainstay in managing severe bacterial infections, but resistant strains of bacteria have emerged and hampered the progress of research in this field. Recently, new approaches to research involving bacteria resistance to antibiotics have appeared; these involve combining the molecular understanding of bacteria systems with the knowledge of bioinformatics. Consequently, many molecules have been developed to curb resistance associated with different bacterial infections. However, because of increased emphasis on the clinical relevance of antibiotics, the synergy between in silico study and in vivo study is well cemented and this facilitates the discovery of potent antibiotics. In this review, we seek to give an overview of earlier reviews and molecular and structural understanding of bacteria resistance to antibiotics, while focusing on the recent bioinformatics approach to antibacterial drug discovery.

Understanding the evolution of antibiotic resistance at the molecular level as a functional tool for bioinformatic-based drug design.

Development and evaluation of a vancomycin dosing nomogram to achieve the target area under the concentration-time curve. A retrospective study

Although the superiority of vancomycin dosing based on area under the concentration-time curve (AUC_0-24) over that based on trough concentration has been reported, a dosing strategy to achieve the target AUC_0-24 has yet to be developed. The objective of this study was to develop a convenient useable nomogram for vancomycin dosing to obtain the target AUC_0-24 (400 μg h/mL). The nomogram was pharmacokinetically developed in a retrospective manner. The number of enrolled patients and concentrations was 166 and 309 for development of the nomogram, 99 and 181 for evaluation of the nomogram, respectively. The nomogram was developed as doses per personal body weight corresponding to each range of estimated glomerular filtration rate (eGFR), which was identified to be the covariate for vancomycin clearance by non-linear mixed effect modeling. The nomogram described the surrogate trough concentration for the target AUC_0-24 was calculatedly different for each eGFR range (9.3-15.0 μg/mL). The rate of attainment of therapeutic range using surrogate trough concentration to obtain the target AUC_0-24 was 63.8% in the evaluation period. We have developed and evaluated the first convenient useable nomogram of vancomycin dosing to obtain the target AUC_0-24.

Relationship Status between Vancomycin Loading Dose and Treatment Failure in Patients with MRSA Bacteremia: It's Complicated

INTRODUCTION

A one-time vancomycin loading dose of 25-30 mg/kg is recommended in the current iteration of the vancomycin consensus guidelines in order to more rapidly achieve target serum concentrations and hasten clinical improvement. However, there are few clinical data to support this practice, and the extents of its benefits are largely unknown.

METHODS

A multicenter, retrospective, cohort study was performed to assess the impact of a vancomycin loading dose (≥ 20 mg/kg) on clinical outcomes and rates of nephrotoxicity in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. The study matched patients in a 1:1 fashion based on age, Pitt bacteremia score, and bacteremia source. The primary outcome was composite treatment failure (30-day mortality, bacteremia duration ≥ 7 days after vancomycin initiation, persistent signs and symptoms of infection ≥ 7 days after vancomycin initiation, or switch to an alternative antimicrobial agent). Secondary outcomes included duration of bacteremia, length of stay post-bacteremia onset, and nephrotoxicity.

RESULTS

A total of 316 patients with MRSA bacteremia were included. Median first doses in the loading dose and non-loading dose groups were 23.0 mg/kg and 14.3 mg/kg, respectively (P < 0.001). No difference was found in composite failure rates between the non-loading dose and loading dose groups (40.5% vs. 36.7%; P = 0.488) or in the incidence of nephrotoxicity (12.7% vs. 16.5%; P = 0.347). While multivariable regression modeling showed receipt of a vancomycin loading dose on a mg/kg basis was not significantly associated with composite failure [aOR 0.612, 95% CI (0.368-1.019)]; post hoc analyses demonstrated that initial doses ≥ 1750 mg were independently protective against failure [aOR 0.506, 95% CI (0.284-0.902)] without increasing the risk for nephrotoxicity [aOR 0.909, 95% CI (0.432-1.911)].

CONCLUSION

These findings suggest that initial vancomycin doses above a certain threshold may decrease clinical failures without increasing toxicity and that weight-based dosing might not be the optimal strategy.

The clinical efficacy and safety of vancomycin loading dose: A systematic review and meta-analysis

BACKGROUND

The clinical significance of using vancomycin loading dose remains controversial. A systematic review and meta-analysis were performed to assess the clinical efficacy and safety of vancomycin loading dose in the treatment of infections.

METHODS

The Pubmed, Embase, Web of Science, and Cochrane Library databases were searched from their inception up to 5 May 2019. Randomized controlled trials (RCTs) and other observational studies were included if they provided clinical outcomes or trough concentrations of vancomycin loading dose (20-30 mg/kg) and conventional-dose (10-20 mg/kg) in the treatment of infections. Achievement of therapeutic concentration (serum trough concentrations of vancomycin reached 15-20 mg/L before the second dose), clinical response (clinical improvement or culture-negative), nephrotoxicity (serum creatinine increase ≥0.5 mg/dL or ≥50% increasing from the baseline), other adverse events (including pruritus, flushing, rash, and/or red man syndrome), and mortality were analyzed. Heterogeneity was identified using the Cochrane I statistic, and P-value <.10 or I-values >50% indicated significant heterogeneity. Pooled estimates of the intervention effects were determined by the odds ratios (ORs) and 95% confidence intervals (CIs) in Review Manager program, version 5.3.5.

RESULTS

Two RCTs and 7 cohort studies including 2816 infected patients were selected for the analysis, in which serum trough concentrations of vancomycin following the use of vancomycin loading dose or other outcomes were available. Loading dose group had a significantly higher compliance rate of serum trough concentration of 15 to 20 mg/L (OR = 3.06; 95% CI = 1.15-8.15; P = .03) and significantly lower incidence of nephrotoxicity (OR = 0.59, 95% CI = 0.40-0.87; P = .008; I = 29%) compared with control group. No significant difference was noted between loading dose group and control group in terms of other adverse events and clinical response (OR = 1.98, 95% CI = 0.80-4.93; P = .14; I = 0%). The use of vancomycin loading doses in patients can indeed increase the achievement of therapeutic concentration.

CONCLUSION

Vancomycin loading dose increases the achievement of therapeutic concentration without bringing extra risk of nephrotoxicity. However, well-designed large-scale RCTs remain needed to validate the clinical efficacy of vancomycin loading dose and to further evaluate other adverse reactions and mortality.PROSPERO registration number CRD42018093927.

Yunnan Baiyao reduces hospital-acquired pressure ulcers via suppressing virulence gene expression and biofilm formation of Staphylococcus aureus

Yunnan Baiyao (YB) as a kind of famous Chinese herbal medicine, possessed hemostatic, invigorating the circulation of blood, and anti-inflammatory effects. Identifying strategies to protect patients at risk for hospital-acquired pressure ulcers (HAPU) is essential. Herein, our results showed that YB treatment can effectively reduce the acne wound area and improve efficacy in a comparative study of 60 cases HAPU patients with S. aureus positive of acne wound pathogens. Furthermore, YB inhibited HIa expression and suppressed accessory gene regulator (agr) system controlled by regulatory RNA II and RNA III molecule using pALC1740, pALC1742 and pALC1743 S. aureus strain linked to gfp_uvr reporter gene. Moreover, YB downregulated cao mRNA expression and inhibited coagulase activity by RT-PCR, slide and tube coagulase test. Additionally, YB downregulated seb, sec, sed, and tsst-1 mRNA expression to suppress enterotoxin and tsst-1 secretion and adhesion function related genes sarA, icaA, and cidA mRNA expression. Taken together, the data suggest that YB may reduce HAPU via suppressing virulence gene expression and biofilm formation of S. aureus.

The dosing and monitoring of vancomycin: what is the best way forward?

We have evaluated the literature to review optimal dosing and monitoring of intravenous vancomycin in adults, in response to evolving understanding of targets associated with efficacy and toxicity. The area under the total concentration-time curve (0-24 h) divided by the minimum inhibitory concentration (AUC₂₄/MIC) is the most commonly accepted index to guide vancomycin dosing for the treatment of Staphylococcus aureus infections, with a value of 400 h a widely recommended target for efficacy. Upper limits of AUC₂₄ exposure of around 700 (mg/L).h have been proposed, based on the hypothesis that higher exposures of vancomycin are associated with an unacceptable risk of nephrotoxicity. If AUC₂₄/MIC targets are used, sources of variability in the assessment of both AUC₂₄ and MIC need to be considered. Current consensus guidelines recommend measuring trough vancomycin concentrations during intermittent dosing as a surrogate for the AUC₂₄. Trough concentrations are a misleading surrogate for AUC₂₄ and a poor end-point in themselves. AUC₂₄ estimation using log-linear pharmacokinetic methods based on two plasma concentrations, or Bayesian methods are superior. Alternatively, a single concentration measured during continuous infusion allows simple AUC₂₄ estimation and dose-adjustment. All of these methods have logistical challenges which must be overcome if they are to be adopted successfully.

The current role of glycopeptides in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in not neutropenic adults: the viewpoint of a group of Italian experts

Staphylococcus aureus is still an important problem in clinical and therapeutic area, worldwide. In Italy, in recent years, methicillin resistance remained stable, yet considerably high, the percentage of strains of MRSA being around 40%. It was deemed interesting and timely to carry out a consensus conference using the RAND/UCLA method to collect the opinion of a group of experts in infectious diseases on the role of glycopeptides in the management of MRSA infections within several clinical scenarios and namely in pneumonia, bacteremia and endocarditis, joint replacement infections, skin and soft tissue infections, diabetic foot, abdominal infections and central nervous system infections. The scenarios proposed by the Scientific Committee have been validated by a group of experts in infectious diseases and then voted in three meetings of infectious disease specialists. The results obtained on each individual condition were analyzed and therapeutic recommendations on each of these were released.