Teicoplanin therapy for Staphylococcus aureus septicaemia: relationship between pre-dose serum concentrations and outcome

Model-informed precision dosing of teicoplanin for the rapid achievement of the target area under the concentration-time curve: A simulation study

Teicoplanin, a glycopeptide antimicrobial, is recommended for therapeutic drug monitoring, but it remains unclear how to target the area under the concentration-time curve (AUC). This simulation study purposed to demonstrate the potential of the Bayesian forecasting approach for the rapid achievement of the target AUC for teicoplanin. We generated concordant and discordant virtual populations against a Japanese population pharmacokinetic model. The predictive performance of the Bayesian posterior AUC in limited sampling on the first day against the reference AUC was evaluated as an acceptable target AUC ratio within the range of 0.8-1.2. In the concordant population, the probability for the maximum a priori or Bayesian posterior AUC on the first day (AUC_0-24 ) was 61.3% or more than 77.0%, respectively. The Bayesian posterior AUC on the second day (AUC_24-48 ) was more than 75.1%. In the discordant population, the probability for the maximum a priori or Bayesian posterior AUC_0-24 was 15.5% or 11.7-80.7%, respectively. The probability for the maximum a priori or Bayesian posterior AUC_24-48 was 23.4%, 30.2-82.1%. The AUC at steady-state (AUC_SS ) was correlated with trough concentration at steady-state, with a coefficient of determination of 0.930; the coefficients on days 7 and 4 were 0.442 and 0.125, respectively. In conclusion, this study demonstrated that early sampling could improve the probability of AUC_0-24 and AUC_24-48 but did not adequately predict AUC_SS . Further studies are necessary to apply early sampling-based model-informed precision dosing in the clinical settings.

Population pharmacokinetic analysis and dosing regimen optimization of teicoplanin in critically ill patients with sepsis

Objectives: Teicoplanin has been extensively used in the treatment for infections caused by gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). However, current teicoplanin treatment is challenging due to relatively low and variable concentrations under standard dosage regimens. This study aimed to investigate the population pharmacokinetics (PPK) characteristics of teicoplanin in adult sepsis patients and provide recommendations for optimal teicoplanin dosing regimens. Methods: A total of 249 serum concentration samples from 59 septic patients were prospectively collected in the intensive care unit (ICU). Teicoplanin concentrations were detected, and patients' clinical data were recorded. PPK analysis was performed using a non-linear, mixed-effect modeling approach. Monte Carlo simulations were performed to evaluate currently recommended dosing and other dosage regimens. The optimal dosing regimens were defined and compared by different pharmacokinetic/pharmacodynamic parameters, including trough concentration (C_min), the ratio of 24-h area under the concentration-time curve to the minimum inhibitory concentration (AUC_0-24/MIC), as well as the probability of target attainment (PTA) and the cumulative fraction of response (CFR) against MRSA. Results: A two-compartment model adequately described the data. The final model parameter estimates for clearance, central compartment volume of distribution, intercompartmental clearance and peripheral compartment volume were 1.03 L/h, 20.1 L, 3.12 L/h and 101 L, respectively. Glomerular filtration rate (GFR) was the only covariate that significantly affected teicoplanin clearance. Model-based simulations revealed that 3 or 5 loading doses of 12/15 mg/kg every 12 h followed by a maintenance dose of 12/15 mg/kg every 24 h-72 h for patients with different renal functions were required to achieve a target C_min of 15 mg/L and a target AUC_0-24/MIC of 610. For MRSA infections, PTAs and CFRs were not satisfactory for simulated regimens. Prolonging the dosing interval may be easier to achieve the target AUC_0-24/MIC than reducing the unit dose for renal insufficient patients. Conclusion: A PPK model for teicoplanin in adult septic patients was successfully developed. Model-based simulations revealed that current standard doses may result in undertherapeutic C_min and AUC, and a single dose of at least 12 mg/kg may be needed. AUC_0-24/MIC should be preferred as the PK/PD indicator of teicoplanin, if AUC estimation is unavailable, in addition to routine detection of teicoplanin C_min on Day 4, follow-up therapeutic drug monitoring at steady-state is recommended.

Pharmacokinetics and pharmacodynamics of peptide antibiotics

Antimicrobial resistance is a major global health challenge. As few new efficacious antibiotics will become available in the near future, peptide antibiotics continue to be major therapeutic options for treating infections caused by multidrug-resistant pathogens. Rational use of antibiotics requires optimisation of the pharmacokinetics and pharmacodynamics for the treatment of different types of infections. Toxicodynamics must also be considered to improve the safety of antibiotic use and, where appropriate, to guide therapeutic drug monitoring. This review focuses on the pharmacokinetics/pharmacodynamics/toxicodynamics of peptide antibiotics against multidrug-resistant Gram-negative and Gram-positive pathogens. Optimising antibiotic exposure at the infection site is essential for improving their efficacy and minimising emergence of resistance.

Therapeutic Drug Monitoring of Antibiotics: Defining the Therapeutic Range

PURPOSE

In the present narrative review, the authors aimed to discuss the relationship between the pharmacokinetic/pharmacodynamic (PK/PD) of antibiotics and clinical response (including efficacy and toxicity). In addition, this review describes how this relationship can be applied to define the therapeutic range of a particular antibiotic (or antibiotic class) for therapeutic drug monitoring (TDM).

METHODS

Relevant clinical studies that examined the relationship between PK/PD of antibiotics and clinical response (efficacy and response) were reviewed. The review (performed for studies published in English up to September 2021) assessed only commonly used antibiotics (or antibiotic classes), including aminoglycosides, beta-lactam antibiotics, daptomycin, fluoroquinolones, glycopeptides (teicoplanin and vancomycin), and linezolid. The best currently available evidence was used to define the therapeutic range for these antibiotics.

RESULTS

The therapeutic range associated with maximal clinical efficacy and minimal toxicity is available for commonly used antibiotics, and these values can be implemented when TDM for antibiotics is performed. Additional data are needed to clarify the relationship between PK/PD indices and the development of antibiotic resistance.

CONCLUSIONS

TDM should only be regarded as a means to achieve the main goal of providing safe and effective antibiotic therapy for all patients. The next critical step is to define exposures that can prevent the development of antibiotic resistance and include these exposures as therapeutic drug monitoring targets.

Clinical practice guidelines for therapeutic drug monitoring of teicoplanin: a consensus review by the Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring

Background

Owing to its low risk of adverse effects, teicoplanin has been extensively used in patients with infections caused by MRSA. To promote the better management of patients receiving teicoplanin, we have updated the guidelines for therapeutic drug monitoring (TDM).

Methods

The guidelines were developed by a committee following the methodology handbook published by the Japanese Medical Information Distribution Service. Nine clinical questions were selected. The committee conducted a systematic review and meta-analysis to establish evidence-based recommendations for the target trough concentration (C_min). An initial electronic database search returned 515 articles, and 97 articles qualified for a full review. Four and five studies were included for the efficacy evaluation of cut-off C_min values of 15 and 20 mg/L, respectively.

Results

Compared with C_min < 15 mg/L, a target C_min value of 15–30 mg/L resulted in increased clinical efficacy in patients with non-complicated MRSA infections (OR = 2.68; 95% CI = 1.14–6.32) without an increase in adverse effects. Although there was insufficient evidence, target C_min values of 20–40 mg/L were suggested in patients with complicated or serious MRSA infections. A 3 day loading regimen followed by maintenance treatment according to renal function was recommended to achieve the target trough concentrations. Because of the prolonged half-life of teicoplanin, measurement of the C_min value on Day 4 before reaching steady state was recommended.

Conclusions

The new guideline recommendations indicate the target C_min value for TDM and the dosage regimen to achieve this concentration and suggest practices for specific subpopulations.

Teicoplanin Therapeutic Drug Monitoring and Treatment Outcomes in Children With Gram-Positive Infections

This is a retrospective audit of teicoplanin dosing, drug-level monitoring, and outcomes in 29 children who received 31 courses of teicoplanin. Our study of noncritically ill children showed that the majority (35/43, 81%) of trough concentrations were within the therapeutic range (10-30 mg/L) contrasting previous studies in children. Overall, 21 of the 24 (88%) children with Gram-positive infections achieved cure.

Optimal trough concentration of teicoplanin for the treatment of methicillin-resistant Staphylococcus aureus infection: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

It has been recommended that the trough concentration (C_min ) of teicoplanin should be maintained at ≥20 μg/ml for difficult-to-treat complicated infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Conversely, C_min of teicoplanin of at least 10 μg/ml is required for non-complicated MRSA infections. Considering the low incidence of nephrotoxicity for teicoplanin, C_min  = 15-30 μg/ml has been suggested for most MRSA infections. Thus, we assessed the clinical efficacy and adverse effects of teicoplanin at this target C_min .

METHODS

We searched electronic databases (PubMed, Cochrane Central Register of Controlled Trials and Ichushi-Web) to identify eligible studies. Studies were included if they provided the incidence of treatment success, mortality in patients with MRSA infection, and/or hepatotoxicity and nephrotoxicity according to the C_min range.

RESULTS AND DISCUSSION

Four trials assessing clinical success (n = 299) and three studies assessing adverse effects (n = 546) were included. C_min  = 15-30 μg/ml significantly increased the probability of treatment success compared with C_min  < 15 μg/ml (odds ratio [OR] = 2.68, 95% confidence interval [CI] = 1.14-6.32, p = 0.02). The all-cause mortality rate did not differ between the groups (OR = 0.46, 95% CI = 0.13-1.61, p = 0.22). C_min  = 15-30 μg/ml did not increase the risks of nephrotoxicity (OR = 0.91, 95% CI = 0.49-1.69, p = 0.76) or hepatotoxicity (OR = 0.67, 95% CI = 0.18-2.44, p = 0.54).

WHAT IS NEW AND CONCLUSION

Teicoplanin therapy using a C_min target of 15-30 μg/ml is likely to be associated with better clinical responses than C_min  < 15 μg/ml without increasing the risk of adverse effects.

Population Pharmacokinetics of Unbound and Total Teicoplanin in Critically Ill Pediatric Patients

BACKGROUND AND OBJECTIVES

Teicoplanin is a highly protein-bound antibiotic, increasingly used to treat serious Gram-positive infections in critically ill children. Maturational and pathophysiological intensive care unit-related changes often lead to altered pharmacokinetics. In this study, the objectives were to develop a pediatric population-pharmacokinetic model of unbound and total teicoplanin concentrations, to investigate the impact of plasma albumin levels and renal function on teicoplanin pharmacokinetics, and to evaluate the efficacy of the current weight-based dosing regimen.

METHODS

An observational pharmacokinetic study was performed and blood samples were collected for quantification of unbound and total concentrations of teicoplanin after the first dose and in assumed steady-state conditions. A population-pharmacokinetic analysis was conducted using a standard sequential approach and Monte Carlo simulations were performed for a probability of target attainment analysis using previously published pharmacokinetic-pharmacodynamic targets.

RESULTS

A two-compartment model with allometric scaling of pharmacokinetic parameters and non-linear plasma protein binding best described the data. Neither the inclusion of albumin nor the renal function significantly improved the model and no other covariates were supported for inclusion in the final model. The probability of target attainment analysis showed that the standard dosing regimen does not satisfactory attain the majority of the proposed targets.

CONCLUSIONS

We successfully characterized the pharmacokinetics of unbound and total teicoplanin in critically ill pediatric patients. The highly variable unbound fraction of teicoplanin could not be predicted using albumin levels, which may support the use of therapeutic drug monitoring of unbound concentrations. Poor target attainment was shown for the most commonly used dosing regimen, regardless of the pharmacokinetic-pharmacodynamic target evaluated.

Clinical efficacy and safety in patients treated with teicoplanin with a target trough concentration of 20 μg/mL using a regimen of 12 mg/kg for five doses within the initial 3 days

Background

A trough concentration (C_min) ≥20 μg/mL of teicoplanin is recommended for the treatment of serious methicillin-resistant Staphylococcus aureus (MRSA) infections. However, sufficient clinical evidence to support the efficacy of this target C_min has not been obtained. Even though the recommended high C_min of teicoplanin was associated with better clinical outcome, reaching the target concentration is challenging.

Methods

Pharmacokinetics and adverse events were evaluated in all eligible patients. For clinical efficacy, patients who had bacteremia/complicated MRSA infections were analyzed. The primary endpoint for clinical efficacy was an early clinical response at 72–96 h after the start of therapy. Five dosed of 12 mg/kg or 10 mg/kg was administered as an enhanced or conventional high loading dose regimen, respectively. The C_min was obtained at 72 h after the first dose.

Results

Overall, 512 patients were eligible, and 76 patients were analyzed for treatment efficacy. The proportion of patients achieving the target C_min range (20–40 μg/mL) by the enhanced regimen was significantly higher than for the conventional regimen (75.2% versus 41.0%, p < 0.001). In multivariate analysis, C_min ≥ 20 μg/mL was an independent factor for an early clinical response (odds ratio 3.95, 95% confidence interval 1.25–12.53). There was no significant difference in the occurrence of adverse events between patients who did or did not achieve a C_min ≥ 20 μg/mL.

Conclusion

A target C_min ≥ 20 μg/mL might improve early clinical responses during the treatment of difficult MRSA infections using 12 mg/kg teicoplanin for five doses within the initial 3 days.

Therapeutic drug monitoring of the teicoplanin trough level after the loading doses in patients receiving venoarterial extracorporeal membrane oxygenation

BACKGROUND

The optimal loading dose of teicoplanin in patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) has never been determined by therapeutic drug monitoring. This study investigated the appropriateness of proposed loading dose regimens of teicoplanin when administered to patients receiving VA-ECMO by using a previously proposed loading dosage and measuring the teicoplanin trough concentration (C_trough).

METHODS

Patients who initiated teicoplanin therapy while receiving VA-ECMO were enrolled. Every included patient received four loading doses of teicoplanin at a dose of 12 mg/kg. The first three doses were administered 12 h apart, and the fourth dose was administered 24 h after the third dose. Blood samples were collected before administering the maintenance dose (i.e., the fifth dose), and the teicoplanin C_trough was measured. Serum teicoplanin levels were determined using an Agilent 1290 ultra-high performance liquid chromatography system.

RESULTS

The teicoplanin C_trough was successfully tested in 11 patients. Their median age was 68.2 years, and 81.8% of them were men. The median of each loading dose was 11.6 (range, 10.7-12.8) mg/kg. The median teicoplanin C_trough was 22.01 (range, 14.85-44.84) mg/L. All patients had a C_trough of more than 10 mg/L, whereas 90.9% (10/11) of the patients achieved a C_trough of more than 15 mg/L.

CONCLUSION

The loading dosage consisting of four doses of teicoplanin administered within the first 72 h at a dose of 12 mg/kg/dose could achieve an adequate therapeutic C_trough of teicoplanin in patients receiving VA-ECMO.

Optimal teicoplanin loading regimen to rapidly achieve target trough plasma concentration in critically ill patients

Teicoplanin is used for the treatment of Methicillin-resistant Staphylococcus aureus infection. It has been demonstrated that conventional loading regimen was insufficient for teicoplanin to achieve target trough plasma concentration (C_min  > 10 mg/L). Therefore, a Chinese expert group recommended an optimal loading dose regimen of teicoplanin to treat severe Gram-positive infection. However, there was no report about the teicoplanin concentration, and the safety and efficacy of teicoplanin therapy in Chinese patients since the consensus was published. The objective of this study was to compare the teicoplanin C_min and clinical response in critically ill Chinese patients after the administration of conventional or optimal loading regimen, and to reveal the potential factors that may affect teicoplanin C_min in addition to loading regimen. Fifty-five patients were retrospectively divided into two groups based on teicoplanin loading regimen: (a) CD group (conventional loading dose group, n = 18, loading dose was 400 mg); (b) OD group (optimal loading dose group, n = 37, loading dose was 800 mg). Initially, three loading doses were administered every 12 hours, while the fourth loading dose was injected 24 hours after the third dose. The maintenance dose was 400 mg (CD group) or 800 mg (OD group), respectively. The mean teicoplanin C_min on day 2 and day 4 in the OD group was significantly higher than those in the CD group, which were 14.75 ± 5.93 mg/L vs 8.26 ± 4.87 mg/L (P < .001) and 14.90 ± 5.20 mg/L vs 9.13 ± 4.75 mg/L (P = .019), respectively. The percentages of patients in the OD group achieving the target teicoplanin C_min on day 2 and day 4 were also significantly higher than those in the CD group, which were 83.7% vs 33.3% (P < .001) and 82.4% vs 28.6% (P = .0013), respectively. Furthermore, multivariate linear regression analysis showed that body-weight exerted significant effect on teicoplanin C_min in the OD group. The percentage of favourable clinical response in the OD group was significantly higher than that in the CD group (83.8% vs 55.6%, P = .025). There was no difference between teicoplanin adverse effects in the two groups. The study demonstrated that the optimal loading dose regimen of teicoplanin can rapidly reach target C_min , and result in a good clinical efficacy and low adverse effect in critically ill Chinese patients.

Evaluating the optimal dose of teicoplanin with therapeutic drug monitoring: not too high for adverse event, not too low for treatment efficacy

Therapeutic drug monitoring (TDM) of teicoplanin is aimed at minimizing the clinical impact of pharmacokinetic variability; however, its benefits are still being defined. We performed a retrospective study of teicoplanin TDM focusing on the dose-serum concentration relationship and clinical outcomes in a clinical setting. From January 2017 to December 2018, patients receiving teicoplanin ≥ 72 h with TDM were enrolled. Patients were divided into three groups: non-loading (NL) group, low-dose loading (LD) group (loading dose < 9 mg/kg), and high-dose loading (HD) group (≥ 9 mg/kg). Serum teicoplanin trough concentration (C_min) and adverse events (AEs) were evaluated in each regimen. A subgroup of patients with bacteremia was analyzed to evaluate clinical efficacy. Among 65 patients, 12, 18, and 35 were grouped in NL, LD, and HD, respectively. Achievement rates of C_min > 20 mg/L within 10 days were significantly different among the groups (25.0%, 38.9%, and 68.6% in the NL, LD, and HD groups, respectively; P = 0.014). Fourteen patients (21.5%) had AEs, and higher C_min over 10 days (adjusted odds ratio 2.08 per every 20 mg/L increases, 95% CI 1.13-3.84, P = 0.019) and age ≥ 65 years (P = 0.009) were identified as independent risk factors. In the subgroup analysis, HD regimen (P = 0.050) and high mean C_min over 10 days (P = 0.025) were significantly associated with treatment success. Although HL regimen could achieve C_min targets and improve clinical outcome during teicoplanin treatment, high C_min was associated with AEs during treatment. Routine TDM can be helpful to optimize teicoplanin administration.

Comparative efficacy and safety of vancomycin versus teicoplanin in febrile neutropenic patients receiving hematopoietic stem cell transplantation

WHAT IS KNOWN AND OBJECTIVE

Patients who receive hematopoietic stem cell transplantation (HSCT) are usually administered a calcineurin inhibitor. Because vancomycin is associated with an increased incidence of nephrotoxicity, neutropenic patients receiving HSCT are considered a high-risk population for nephrotoxicity with vancomycin. We retrospectively compared the efficacy and safety of vancomycin and teicoplanin in febrile neutropenic patients receiving HSCT.

METHODS

A single-centre, retrospective cohort study was conducted at the 614-bed Gifu University Hospital in Japan. Patients who received HSCT and were administered vancomycin or teicoplanin by injection for febrile neutropenia from 1 January 2012 to 31 August 2017 were enrolled. Time to attain an effective trough concentration, clinical efficacy and adverse events were compared between the two groups.

RESULTS

Time to attain an effective trough concentration of over 10 μg/mL tended to be shorter in the teicoplanin group than in the vancomycin group (median 3, 95% confidence interval [CI] 2.4-3.6 days vs median 6, 95% CI 1.5-10.5 days; hazard ratio [HR] 0.4, 95% CI 0.15-1.06; P = .066). The rate of clinical failure was lower in the teicoplanin group than in the vancomycin group (18.8% vs 53.8%, P = .113). In addition, the overall incidence of nephrotoxicity was significantly lower in the teicoplanin group (0% vs 46.2%, P = .004).

WHAT IS NEW AND CONCLUSION

Our findings suggest that administration of teicoplanin may lead to early attainment of the effective concentration with a lower rate of clinical failure and incidence of nephrotoxicity compared to vancomycin in febrile neutropenic patients receiving HSCT.

Measurement of Teicoplanin Concentration With Liquid Chromatography-Tandem Mass Spectrometry Method Demonstrates the Usefulness of Therapeutic Drug Monitoring in Hematologic Patient Populations

BACKGROUND

Teicoplanin is a glycopeptide antibiotic that has become increasingly popular with the spread of methicillin-resistant Staphylococcus aureus. The aim of the study was to develop and validate an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for teicoplanin, and analyze trough teicoplanin concentrations achieved in patients with hematological diseases.

METHODS

The UHPLC-MS/MS method for teicoplanin was developed, validated, and applied in a retrospective analysis of trough plasma teicoplanin concentrations from 305 patients receiving standard dose, and 17 patients receiving therapeutic drug monitoring (TDM)-guided individualized dose.

RESULTS

The linear range was 3.9-52.9 mg/L. The imprecision was less than 12%, the limits of detection and quantification were less than 0.13 and 0.72 mg/L, respectively. The sample carry-over and ion suppression were insignificant. In the standard dose group, the median teicoplanin concentrations were 7.5 mg/L (days 3-5) and 8.9 mg/L (on days 6-8); and the proportion of trough levels achieving ≥10 mg/L was 20% (days 3-5) and 38% (days 6-8), respectively. In the TDM-guided individualized dose group, median teicoplanin concentration was higher (16.9 mg/L), and the proportion of trough levels ≥10 mg/L was also higher (77%) when compared with the standard dose group.

CONCLUSIONS

Based on these results, the present UHPLC-MS/MS method can be considered suitable for routine TDM of teicoplanin. Also, based on the insufficient trough teicoplanin concentrations achieved with standard dose regimen, and the higher trough teicoplanin concentrations achieved with TDM-guided individualized dose regimen, this study highlights the importance of TDM of teicoplanin, especially in high-risk patient groups.

Impact of teicoplanin maintenance dose and MIC values on the clinical outcomes of patients treated for methicillin-resistant Staphylococcus aureus bacteremia

Objectives

Teicoplanin, a glycopeptide, is regarded as among the drug choices for methicillin-resistant Staphylococcus aureus (MRSA) infections. Few studies have evaluated the relationship between teicoplanin minimal inhibitory concentrations (MICs) and outcomes among patients with serious MRSA infections.

Subjects and methods

We investigated the relationship between teicoplanin maintenance dose and clinical outcomes, on the completion of teicoplanin therapy, in bacteremia patients with MRSA infection, with different teicoplanin MICs. A total of 146 adult patients with MRSA bacteremia were enrolled at Kaohsiung Chang Gung Memorial Hospital between September 2012 and September 2015.

Results

A higher number of patients in the high-dose regimen group (6 mg/kg/12 h) had favorable outcomes than those in the standard-dose regimen group (6 mg/kg/24 h) (84.1% vs 41.2%; p<0.01), regardless of the teicoplanin MICs. In the multivariate analysis, a Pittsburgh bacteremia score ≥4 (OR, 0.07, 95% CI, 0.03–0.19) was a risk factor for an unfavorable final clinical response, whereas high-dose teicoplanin maintenance therapy for MRSA bacteremia was significantly associated with a favorable final response (OR, 25.3 [95% CI, 4.43–144.03] for isolates with a teicoplanin MIC ≥1.5 mg/L and OR, 5.6 [95% CI, 1.57–19.91] for isolates with a teicoplanin MIC <1.5 mg/L). Survival at 30 days was significantly better for patients receiving high-dose teicoplanin maintenance treatment, regardless of the teicoplanin MICs of the MRSA isolates. Patients were selected using propensity score matching, based on the independent predictors of a favorable final outcome. After appropriate propensity score matching, patients in the high-dose regimen group still had a statistically significant favorable outcome at the end of treatment (84.1% vs 40.9%; p<0.01).

Conclusion

The results suggested that high-dose teicoplanin maintenance treatment is associated with more favorable outcomes than standard-dose teicoplanin maintenance treatment, for patients with MRSA bacteremia, regardless of the teicoplanin MIC.

Pharmacodynamics of teicoplanin against MRSA

Objectives

The overall study aim was to identify the relevant preclinical teicoplanin pharmacokinetic (PK)/pharmacodynamic (PD) indices to predict efficacy and suppression of resistance in MRSA infection.

Methods

A hollow-fibre infection model and a neutropenic murine thigh infection model were developed. The PK/PD data generated were modelled using a non-parametric population modelling approach with Pmetrics. The posterior Bayesian estimates derived were used to study the exposure-effect relationships. Monte Carlo simulations from previously developed population PK models in adults and children were conducted to explore the probability of target attainment (PTA) for teicoplanin dosage regimens against the current EUCAST WT susceptibility range.

Results

There was a concentration-dependent activity of teicoplanin in both the in vitro and in vivo models. A total in vivo AUC/MIC of 610.4 (total AUC of 305.2 mg·h/L) for an MRSA strain with an MIC of 0.5 mg/L was needed for efficacy (2 log10 cell kill) against a total bacterial population. A total AUC/MIC ratio of ∼1500 (total AUC of ∼750 mg·h/L) was needed to suppress the emergence of resistance. The PTA analyses showed that adult and paediatric patients receiving a standard regimen were only successfully treated for the in vivo bactericidal target if the MIC was ≤0.125 mg/L in adults and ≤0.064 mg/L in children.

Conclusions

This study improves our understanding of teicoplanin PD against MRSA and defines an in vivo AUC/MIC target for efficacy and suppression of resistance. Additional studies are needed to further corroborate the PK/PD index in a variety of infection models and in patients.

Therapeutic Drug Monitoring of Teicoplanin in Haematological Malignancy Patients with Febrile Neutropenia and Optimizing Dosage Regimens

This study used high-performance liquid chromatography to measure 202 teicoplanin plasma trough concentrations (C_min ) in 114 haematological malignancy patients with febrile neutropenia. Patients were divided into two groups according to the mean initial dose (MID) over the first 3 days of treatment: (i) MID = 533.33 mg/day (loading dose group, 400 mg q12h for three doses followed by 400 mg qd, n = 62) and (ii) MID < 533.33 mg/day (unloaded or underloaded group, n = 52). During the first 3 days after treatment, the overall C_min was higher in group 1 than in group 2 (10.96 ± 5.44 mg/L versus 6.31 ± 3.73 mg/L, mean ± S.D.; p = 0.002), as was the qualifying rate of C_min > 10 mg/L (54.5% versus 11.1%, p = 0.001), and the probability of C_min < 5 mg/L was lower in group 1 than in group 2 (13.6% versus 40.7%, p = 0.037). After 3 days, the average C_min and qualifying rates did not differ significantly between the two groups, and the average C_min was <10 mg/L in both groups. Binary logistic regression analysis revealed that creatinine clearance (p = 0.004) and MID (p = 0.010) could affect C_min during the first 3 days of treatment and that age (p = 0.022) only could affect C_min after 3 days. In conclusion, it is necessary to apply loading dose to achieve teicoplanin C_min > 10 mg/L rapidly and, from a pharmacokinetic/pharmacodynamic perspective, 600 mg is recommended as loading and maintenance dose for these patients when AUC₂₄ /minimum inhibitory concentration > 345.

Optimal Trough Concentration of Teicoplanin in Febrile Neutropenic Patients with Hematological Malignancy

BACKGROUND

Teicoplanin is a glycopeptide antibiotic currently used for the treatment of methicillin-resistant Staphylococcus aureus. The need for therapeutic drug monitoring of teicoplanin has been increasingly highlighted as important. It is generally accepted that whereas a plasma trough concentration (Cmin) of ≥10 mg/L is appropriate for the majority of infections, it should exceed 20 mg/L for severe infections. The target Cmin of teicoplanin in patients with febrile neutropenia (FN) has not been reported. The aim of this study was to estimate the target Cmin for the treatment of FN in patients with hematological malignancy.

METHODS

In this retrospective, single-center, observational cohort study, the records of 52 hospitalized patients with hematological malignancy who were treated with teicoplanin for FN due to bacteriologically documented or presumptive gram-positive infections were analyzed.

RESULTS

A significant difference in the first Cmin of teicoplanin was observed between the response and nonresponse groups in patients with bacteremia. The areas under the receiver operating characteristic curves were 0.80 for clinical efficacy. The cut-off value of teicoplanin Cmin on days 4-6 was 15.2 mg/L (sensitivity 80.0%, specificity 75.0%).

CONCLUSIONS

The authors propose a target teicoplanin Cmin of ≥15.2 mg/L for FN in patients with hematological malignancy.

Tools for the Individualized Therapy of Teicoplanin for Neonates and Children

The aim of this study was to develop a population pharmacokinetic (PK) model for teicoplanin across childhood age ranges to be used as Bayesian prior information in the software constructed for individualized therapy. We developed a nonparametric population model fitted to PK data from neonates, infants, and older children. We then implemented this model in the BestDose multiple-model Bayesian adaptive control algorithm to show its clinical utility. It was used to predict the dosages required to achieve optimal teicoplanin predose targets (15 mg/liter) from day 3 of therapy. We performed individual simulations for an infant and a child from the original population, who provided early first dosing interval concentration-time data. An allometric model that used weight as a measure of size and that also incorporated renal function using the estimated glomerular filtration rate (eGFR), or the ratio of postnatal age (PNA) to serum creatinine concentration (SCr) for infants <3 months old, best described the data. The median population PK parameters were as follows: elimination rate constant (Ke) = 0.03 · (wt/70)^−0.25 · Renal (h⁻¹); V = 19.5 · (wt/70) (liters); Renal = eGFR^0.07 (ml/min/1.73 m²), or Renal = PNA/SCr (μmol/liter). Increased teicoplanin dosages and alternative administration techniques (extended infusions and fractionated multiple dosing) were required in order to achieve the targets safely by day 3 in simulated cases. The software was able to predict individual measured concentrations and the dosages and administration techniques required to achieve the desired target concentrations early in therapy. Prospective evaluation is now needed in order to ensure that this individualized teicoplanin therapy approach is applicable in the clinical setting. (This study has been registered in the European Union Clinical Trials Register under EudraCT no. 2012-005738-12.)

Improvement of Predictivity of Teicoplanin Serum Trough Concentrations at Steady State Calculated by Vancomycin Pharmacokinetic Parameter

 According to a recent study and meta-analysis, trough levels of >10 μg/mL teicoplanin (TEIC) may be acceptable for the treatment of uncomplicated infection, but no method of TEIC personalized medicine has been established. Vancomycin (VCM) and TEIC are glycopeptide antibiotic agents effective against methicillin-resistance Staphyloccocus aureus. This study aimed to establish TEIC personalized medicine at a steady state calculated by VCM pharmacokinetic parameters. Bayesian forecasting and population mean methods were employed to estimate individual total VCM clearance (CL) using existing population pharmacokinetics (PPK) parameter, and the differences between the CL calculated by these two methods were defined as ΔCL. Serum drug concentration data for patients treated with TEIC were collected at a steady state concentration (>96 h post infusion). There was a significant relationship between the prediction error of TEIC trough level and ΔCL. The relation between ΔCL and TEIC trough concentration at steady state was used to develop the following equation to determine the maintenance dose: TEIC (μg/mL)=1.1119X-6.124ΔCL+3.9164 (X is defined as TEIC trough concentration calculated from the PPK parameter). The results of this study indicated that it is possible to improve the prediction error of TEIC trough concentration at a steady state for patients who have received VCM therapy.

Teicoplanin-based antimicrobial therapy in Staphylococcus aureus bone and joint infection: tolerance, efficacy and experience with subcutaneous administration

Background

Staphylococci represent the first etiologic agents of bone and joint infection (BJI), leading glycopeptides use, especially in case of methicillin-resistance or betalactam intolerance. Teicoplanin may represent an alternative to vancomycin because of its acceptable bone penetration and possible subcutaneous administration.

Methods

Adults receiving teicoplanin for S. aureus BJI were included in a retrospective cohort study investigating intravenous or subcutaneous teicoplanin safety and pharmacokinetics.

Results

Sixty-five S. aureus BJIs (orthopedic device-related infections, 69 %; methicillin-resistance, 17 %) were treated by teicoplanin at the initial dose of 5.7 mg/kg/day (IQR, 4.7–6.5) after a loading dose of 5 injections 12 h apart. The first trough teicoplanin level (C_min) reached the therapeutic target (15 mg/L) in 26 % of patients, only. An overdose (C_min >25 mg/L) was observed in 16 % patients, 50 % of which had chronic renal failure (p = 0.049). Seven adverse events occurred in 6 patients (10 %); no predictive factor could be highlighted. After a 91-week follow-up (IQR, 51–183), 27 treatment failures were observed (42 %), associated with diabetes (OR, 5.1; p = 0.057), systemic inflammatory disease (OR, 5.6; p = 0.043), and abscess (OR, 4.1; p < 10⁻³). A normal CRP-value at 1 month was protective (OR, 0.2; p = 0.029). Subcutaneous administration (n = 14) showed no difference in pharmacokinetics and tolerance compared to the intravenous route.

Conclusions

Teicoplanin constitutes a well-tolerated therapeutic alternative in S. aureus BJI, with a possible subcutaneous administration in outpatients. The loading dose might be increase to 9–12 mg/kg to quickly reach the therapeutic target, but tolerance of such higher doses remains to be evaluated, especially if using the subcutaneous route.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1955-7) contains supplementary material, which is available to authorized users.

Change of teicoplanin loading dose requirement for incremental increases of systemic inflammatory response syndrome score in the setting of sepsis

Background Target trough concentrations are recommended for teicoplanin (TEIC) to minimize its adverse effects and to maximize efficacy in sepsis caused by grampositive cocci, including methicillin-resistant Staphylococcus aureus infection. However, optimal doses to attain proper trough values in patients with sepsis have not yet been well established for TEIC. Objective This study investigated whether the systemic inflammatory response syndrome (SIRS) score could predict the pharmacokinetics of TEIC in patients with sepsis. Setting This study was conducted at Fukuoka University Hospital in Japan. Methods We retrospectively reviewed the records of patients using TEIC between April 2012 and March 2015. SIRS positive was defined as infection with a SIRS score ≥2. Estimates of pharmacokinetic parameters were calculated using a Bayesian method. Creatinine clearance rates were estimated by the Cockcroft-Gault formula (eCcr). Main outcome measure Change of TEIC loading dose requirement for incremental increases of SIRS score. Results In total, 133 patients were enrolled: 50 non-SIRS patients and 83 patients with SIRS. The TEIC plasma trough concentration was significantly lower in SIRS than non-SIRS patients (15.7 ± 7.1 vs. 20.1 ± 8.6 μg/mL; P < 0.01), although there was no significant difference in the loading dose administered. Moreover, SIRS scores were increasingly predictive of eCcr and TEIC clearance in a stepwise manner. To achieve the target trough concentration (15-30 μg/mL), the optimal doses required in non-SIRS versus SIRS patients were 12-24 versus 18-30 mg/kg/day, respectively, during the first 48 h. Conclusions These findings suggest that the pharmacokinetics of TEIC are altered in SIRS patients, who required higher doses than non-SIRS patients to achieve the target trough concentration. We suggest that the SIRS score can become a new modality to determine the initial TEIC loading dose.

Therapeutic drug monitoring of anti-infective agents in critically ill patients

Initial adequate anti-infective therapy is associated with significantly improved clinical outcomes for patients with severe infections. However, in critically ill patients, several pathophysiological and/or iatrogenic factors may affect the pharmacokinetics of anti-infective agents leading to suboptimal drug exposure, in particular during the early phase of therapy. Therapeutic drug monitoring (TDM) may assist to overcome this problem. We discuss the available evidence on the use of TDM in critically ill patient populations for a number of anti-infective agents, including aminoglycosides, β-lactams, glycopeptides, antifungals and antivirals. Also, we present the available evidence on the practices of anti-infective TDM and describe the potential utility of TDM to improve treatment outcome in critically ill patients with severe infections. For aminoglycosides, glycopeptides and voriconazole, beneficial effects of TDM have been established on both drug effectiveness and potential side effects. However, for other drugs, therapeutic ranges need to be further defined to optimize treatment prescription in this setting.

An ultra-high pressure liquid chromatography-tandem mass spectrometry method for the quantification of teicoplanin in plasma of neonates

The development and validation of an ultra-high pressure liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) method was performed with the aim to be applied for the quantification of plasma teicoplanin concentrations in neonates. Pharmacokinetic data of teicoplanin in the neonatal population is very limited, therefore, a sensitive and reliable method for the determination of all isoforms of teicoplanin applied in a low volume of sample is of real importance. Teicoplanin main components were extracted by a simple acetonitrile precipitation step and analysed on a C18 chromatographic column by a triple quadrupole MS with electrospray ionization. The method provides quantitative data over a linear range of 25-6400ng/mL with LOD 8.5ng/mL and LOQ 25ng/mL for total teicoplanin. The method was applied in plasma samples from neonates to support pharmacokinetic data and proved to be a reliable and fast method for the quantification of teicoplanin concentration levels in plasma of infants during therapy in Intensive Care Unit.

Population pharmacokinetics and dosing optimization of teicoplanin in children with malignant haematological disease

AIM

Children with haematological malignancy represent an identified subgroup of the paediatric population with specific pharmacokinetic parameters. In these patients, inadequate empirical antibacterial therapy may result in infection-related morbidity and increased mortality, making optimization of the dosing regimen essential. As paediatric data are limited, our aim was to evaluate the population pharmacokinetics of teicoplanin in order to define the appropriate dosing regimen in this high risk population.

METHODS

The current dose of teicoplanin was evaluated in children with haematological malignancy. Population pharmacokinetics of teicoplanin were analyzed using nonmem software. The dosing regimen was optimized based on the final model.

RESULTS

Eighty-five children (age range 0.5 to 16.9 years) were included. Therapeutic drug monitoring and opportunistic samples (n = 143) were available for analysis. With the current recommended dose of 10 mg kg(-1) day(-1) , 41 children (48%) had sub-therapeutic steady-state trough concentrations (Css,min <10 mg l(-1) ). A two compartment pharmacokinetic model with first order elimination was developed. Systematic covariate analysis identified that bodyweight (size) and creatinine clearance significantly influenced teicoplanin clearance. The model was validated internally. Its predictive performance was further confirmed in an external validation. In order to reach the target AUC of 750 mg l(-1)  h 18 mg kg(-1) was required for infants, 14 mg kg(-1) for children and 12 mg kg(-1) for adolescents. A patient-tailored dose regimen was further developed and reduced variability in AUC and Css,min values compared with the mg kg(-1) basis dose, making the modelling approach an important tool for dosing individualization.

CONCLUSIONS

This first population pharmacokinetic study of teicoplanin in children with haematological malignancy provided evidence-based support to individualize teicoplanin therapy in this vulnerable population.

Glycopeptide antibiotics: evolving resistance, pharmacology and adverse event profile

The first glycopeptide antibiotic was vancomycin, isolated from the soil in the 1950s; since then, the class has expanded to include teicoplanin and the new semisynthetic glycopeptides dalbavancin, oritavancin and telavancin. They are bactericidal, active against most Gram-positive organisms, and in a concentration-dependent manner, inhibit cell wall synthesis. Resistance to vancomycin has emerged, especially among enterococci and Staphylococcus aureus through a variety of mechanisms. This emerging resistance to vancomycin makes proper dosing and monitoring of the area under the curve/MIC critically important. The chief adverse effect of vancomycin is nephrotoxicity, which is also intricately related to its dose. The efficacy of the semisynthetic glycopeptides has been demonstrated in skin and soft-tissue infections, but remains to be seen in serious methicillin-resistant Staphylococcus aureus infections.

Teicoplanin use in adult patients with haematological malignancy: Exploring relationships between dose, trough concentrations, efficacy and nephrotoxicity

In 2010, our hospital introduced a higher target teicoplanin trough concentration of ≥20 mg/L by Day 3 for haematological malignancy patients. This study aimed to explore whether target trough concentrations were achieved, to identify factors associated with trough concentrations attained, and to assess clinical efficacy with teicoplanin treatments and nephrotoxicity. This was a retrospective, single-centre, cohort study of 172 teicoplanin treatments in 104 adults with haematological malignancy. Mixed-effects regression was used to evaluate factors affecting trough concentrations, and logistic regression was used to assess the relationship between trough concentrations and treatment outcomes. Nephrotoxicity was assessed using the RIFLE criteria. Considerable variability in trough concentrations was observed, with trough concentrations ≥20 mg/L rarely achieved early in therapy. A mixed-effects regression model explaining 52% of the variation in trough concentrations was developed. Dose and day of therapy were positively associated with trough concentration, whilst estimated renal function and, interestingly, acute myeloid leukaemia diagnosis were negatively associated (P<0.05). Results suggested a positive relationship between trough concentration and the likelihood of a favourable outcome for coagulase-negative staphylococcal central line-associated bloodstream infections. Elucidation of a specific target concentration requires further investigation. Teicoplanin was well tolerated renally. Findings suggest a risk of underexposure if conventional teicoplanin doses are used in haematological malignancy patients. Given the variability in trough concentrations observed, the identified factors affecting trough concentrations attained and the suggested link with clinical outcome, individualised initial dosing followed by therapeutic drug monitoring is recommended to ensure early adequate exposure in this vulnerable patient group.

Changes in the pharmacokinetics of teicoplanin in patients with hyperglycaemic hypoalbuminaemia: Impact of albumin glycosylation on the binding of teicoplanin to albumin

There is large interindividual variability in serum teicoplanin (TEIC) concentrations after administration of a loading dose, and the factors that influence the pharmacokinetics of TEIC are disputed. The aim of this study was to clarify changes in the pharmacokinetics of TEIC that occur in patients with hyperglycaemia as well as the impact of albumin glycosylation on the pharmacokinetics of TEIC. This study consisted of retrospective and prospective investigations. The pharmacokinetic parameters of TEIC were retrospectively compared between patients receiving TEIC treatment. Ninety-four patients were divided into four groups according to their serum albumin and blood glucose concentrations [(i) hyperglycaemic hypoalbuminaemia (albumin<3.0g/dL) (n=16); (ii) non-hyperglycaemic hypoalbuminaemia (n=29); (iii) hyperglycaemic normoalbuminaemia (albumin≥3.0g/dL) (n=9); and (iv) non-hyperglycaemic normoalbuminaemia (n=40)]. In addition, the concentration of glycosylated albumin was prospectively determined in 28 patients. At 12h after administration of a loading dose, patients with hyperglycaemic hypoalbuminaemia displayed significantly lower serum TEIC concentrations (P<0.05) and higher TEIC volume of distribution (Vd) (P<0.05) than the other three groups, whereas TEIC clearance did not differ significantly among the groups. In addition, the percentage of glycosylated albumin was significantly correlated with the association constant (Ka) of TEIC for albumin (r=0.53, P=0.004) and the Vd (r=0.41, P=0.031). These results suggest that hyperglycaemic hypoalbuminaemia lowers the serum TEIC concentration, which is attributable to the decreased Ka and increased Vd of TEIC by albumin glycosylation.

Population pharmacokinetics of teicoplanin in children

Teicoplanin is frequently administered to treat Gram-positive infections in pediatric patients. However, not enough is known about the pharmacokinetics (PK) of teicoplanin in children to justify the optimal dosing regimen. The aim of this study was to determine the population PK of teicoplanin in children and evaluate the current dosage regimens. A PK hospital-based study was conducted. Current dosage recommendations were used for children up to 16 years of age. Thirty-nine children were recruited. Serum samples were collected at the first dose interval (1, 3, 6, and 24 h) and at steady state. A standard 2-compartment PK model was developed, followed by structural models that incorporated weight. Weight was allowed to affect clearance (CL) using linear and allometric scaling terms. The linear model best accounted for the observed data and was subsequently chosen for Monte Carlo simulations. The PK parameter medians/means (standard deviation [SD]) were as follows: CL, [0.019/0.023 (0.01)] × weight liters/h/kg of body weight; volume, 2.282/4.138 liters (4.14 liters); first-order rate constant from the central to peripheral compartment (Kcp), 0.474/3.876 h(-1) (8.16 h(-1)); and first-order rate constant from peripheral to central compartment (Kpc), 0.292/3.994 h(-1) (8.93 h(-1)). The percentage of patients with a minimum concentration of drug in serum (Cmin) of <10 mg/liter was 53.85%. The median/mean (SD) total population area under the concentration-time curve (AUC) was 619/527.05 mg · h/liter (166.03 mg · h/liter). Based on Monte Carlo simulations, only 30.04% (median AUC, 507.04 mg · h/liter), 44.88% (494.1 mg · h/liter), and 60.54% (452.03 mg · h/liter) of patients weighing 50, 25, and 10 kg, respectively, attained trough concentrations of >10 mg/liter by day 4 of treatment. The teicoplanin population PK is highly variable in children, with a wider AUC distribution spread than for adults. Therapeutic drug monitoring should be a routine requirement to minimize suboptimal concentrations. (This trial has been registered in the European Clinical Trials Database Registry [EudraCT] under registration number 2012-005738-12.).

Teicoplanin therapy for MRSA bacteraemia: a retrospective study emphasizing the importance of maintenance dosing in improving clinical outcomes

OBJECTIVES

To study the relationship between teicoplanin maintenance dosing and clinical outcomes in adults with MRSA bacteraemia.

METHODS

MRSA bacteraemic patients who received three teicoplanin loading doses (6 mg/kg/12 h) followed by maintenance doses of 6 mg/kg/24 h (Group 1) or 6 mg/kg/12 h (Group 2) were retrospectively analysed. Evaluated on day 7, an unfavourable early clinical response referred to the presence of septic shock, persistent fever, persistent leucocytosis and/or persistent bacteraemia. Assessed at completion of teicoplanin therapy, an unfavourable final clinical response referred to clinical treatment failure.

RESULTS

Compared with those in Group 1 (n = 122), patients in Group 2 (n = 82) had significantly higher rates of favourable early clinical response (P = 0.040) and final clinical response (P < 0.001) and a lower bloodstream-infection-related mortality rate (P = 0.018). Based on estimated ORs for favourable final clinical response in multivariate analysis, endocarditis (P < 0.001; OR 0.109, 95% CI 0.032-0.368), pneumonia (P < 0.001; OR 0.172, 95% CI 0.069-0.433), ICU admission (P < 0.001; OR 0.132, 95% CI 0.054-0.325) and high Pittsburgh bacteraemia score (P = 0.042; OR 0.187, 95% CI 0.021-0.457) were each a risk factor for an unfavourable final clinical response. Higher teicoplanin maintenance dosing contributed to a favourable final clinical response (P < 0.001; OR 8.800, 95% CI 3.602-21.502). Significantly higher favourable final clinical response rates were also found in patients with endocarditis (P = 0.007) and pneumonia (P < 0.001) in Group 2 compared with their counterparts in Group 1.

CONCLUSIONS

These data highlight the importance of higher teicoplanin maintenance dosing, especially for severe infections due to MRSA.

Therapeutic drug concentrations of teicoplanin in clinical settings

Background

Teicoplanin is a glycopeptide antibiotic that is widely used in clinical practice for the treatment of infections caused by drug-resistant Gram-positive bacteria. The aim of this study was to analyze plasma teicoplanin concentrations to determine the percentage of patients in whom therapeutic concentrations of teicoplanin were achieved in clinical practice.

Materials and Methods

The plasma teicoplanin concentrations of hospitalized patients receiving treatment at a teaching hospital were retrospectively analyzed. The target level was defined as a plasma teicoplanin concentration of 10 mg/L or greater, since this was generally regarded as the lower limit of the optimal concentration range required for the effective treatment of a majority of infections.

Results

Patients with sub-optimal (< 10 mg/L) plasma teicoplanin concentrations constituted nearly half of the total study population. The majority of these patients received the recommended loading dose, which were three 400 mg doses administered every 12 hours. Sub-group analysis showed a trend that the group receiving loading dose was more likely to reach the optimal teicoplanin concentration.

Conclusions

The data revealed that a significant proportion of patients in clinical practice achieved only sub-optimal teicoplanin concentrations, which emphasizes the importance of the mandatory use of loading dose and routine therapeutic drug monitoring. Treatment reassessment and simulation of individual dose regimens may also be necessary to achieve optimal drug concentrations.

Variability in protein binding of teicoplanin and achievement of therapeutic drug monitoring targets in critically ill patients: lessons from the DALI Study

The aims of this study were to describe the variability in protein binding of teicoplanin in critically ill patients as well as the number of patients achieving therapeutic target concentrations. This report is part of the multinational pharmacokinetic DALI Study. Patients were sampled on a single day, with blood samples taken both at the midpoint and the end of the dosing interval. Total and unbound teicoplanin concentrations were assayed using validated chromatographic methods. The lower therapeutic range of teicoplanin was defined as total trough concentrations from 10 to 20 mg/L and the higher range as 10-30 mg/L. Thirteen critically ill patients were available for analysis. The following are the median (interquartile range) total and free concentrations (mg/L): midpoint, total 13.6 (11.2-26.0) and free 1.5 (0.7-2.5); trough, total 11.9 (10.2-22.7) and free 1.8 (0.6-2.6). The percentage free teicoplanin for the mid-dose and trough time points was 6.9% (4.5-15.6%) and 8.2% (5.5-16.4%), respectively. The correlation between total and free antibiotic concentrations was moderate for both the midpoint (ρ = 0.79, P = 0.0021) and trough (ρ = 0.63, P = 0.027). Only 42% and 58% of patients were in the lower and higher therapeutic ranges, respectively. In conclusion, use of standard dosing for teicoplanin leads to inappropriate concentrations in a high proportion of critically ill patients. Variability in teicoplanin protein binding is very high, placing significant doubt on the validity of total concentrations for therapeutic drug monitoring in critically ill patients.

Nephrotoxicity of concomitant use of tacrolimus and teicoplanin in allogeneic hematopoietic stem cell transplant recipients

Both tacrolimus and glycopeptide antibiotics are known to be nephrotoxic, and are often concomitantly given after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation. The aim of this study is to evaluate the nephrotoxicity of concomitant use of tacrolimus and glycopeptide antibiotics in HSCT recipients. We retrospectively evaluated 67 patients who received intravenous tacrolimus and teicoplanin concomitantly for >4 days after allogeneic HSCT for hematologic diseases. Therapeutic drug monitoring (TDM) was performed in all patients for both tacrolimus and teicoplanin. The median age of the patients was 48 years (range: 16-62), and the median duration of the co-administration of tacrolimus and teicoplanin was 11 days (range: 4-40). The mean serum creatinine (sCr) level tended to be elevated after the co-administration (from 0.69 ± 0.26 to 0.75 ± 0.30 mg/dL; P = 0.08); however, a 2-fold or greater increase in sCr was observed only in 2 (3.0%) patients. Increased sCr was reversible, and no patient required hemodialysis. These results suggest that the incidence of clinically significant nephrotoxicity can be minimized if the TDM of each drug is properly applied.

High-dose regimen to achieve novel target trough concentration in teicoplanin

In the treatment of severe MRSA infections such as endocarditis, more than 20 mg/L of plasma trough concentration (C(min)) is recommended for teicoplanin; however, in the treatment of common MRSA infections, recommended C(min) remains more than 10 mg/L. In this study, we set C(min) as 15-30 mg/L to obtain a favorable clinical outcome in the treatment of common MRSA infections, and investigated the optimal loading regimen that achieved the target C(min) in patients with normal renal function. Seventy-eight patients received the high-dose regimen A (6 mg/kg every 12-h for initial two days) and 60 patients received the high-dose regimen B (the first five loading doses of 10-12 mg/kg at 12-h intervals for initial three days, followed by 6 mg/kg once daily). The mean C(min) on the 4th day was 13.7 ± 5.3 mg/L in regimen A, and 20.0 ± 6.6 mg/L in regimen B (P < 0.001), and the proportion of patients achieving the 15-30 mg/L was 25.6% and 68.3% (P < 0.001). Clinical response at end-of treatment were 66.7% and 85.0% (P = 0.014). The patients of initial C(min) with ≥15 mg/L had tended to be higher clinical response than those with <15 mg/L (80.9% vs 68.6%, P = 0.084). There were no significant differences in the occurrence of adverse effects in regimen A and B (nephrotoxicity; 1.3% vs 3.3%, P = 0.413, hepatotoxicity; 5.1% vs 3.3%, P = 0.608). In conclusion, to obtain C(min) 15-30 mg/L, the first five loading doses of 10-12 mg/kg at 12-h intervals was required in patients with normal renal function.

Current trends in the management of cardiac implantable electronic device (CIED) infections

Cardiac implantable electronic device (CIED) infections are an emerging clinical problem. A growing number of dedicated and high quality clinical studies are currently being generated. We here review the most recent advances in the diagnosis and treatment of patients with CIED infection including intracardiac lead endocarditis. We discuss the current etiology and risk factors, and appraise the major diagnostic issues, describing our center's therapeutic approach. We also address the management of CIED infection complications.

[Inter-individual and intra-individual pharmacokinetic variability during teicoplanin therapy in geriatric patients]

OBJECTIVES

The authors had for aim to assess the inter- and intra-individual variability of teicoplanin pharmacokinetic parameters in geriatric patients.

METHODS

A cohort of 90 geriatric patients, treated with teicoplanin, was used to build two models describing the pharmacokinetics of teicoplanin, at the beginning and at the end of treatment respectively.

RESULTS

The inter- and intra-individual variability of parameters were important as shown respectively by the coefficients of variation of pharmacokinetic parameters ranging from 125 to 694% and the half-life change during the treatment (by a factor of three to more than 30) for 60% of patients.

CONCLUSIONS

The results revealed that elderly patients presented significant variability, which was only partly explained by the renal function. Therapeutic monitoring of teicoplanin in geriatric patients should be undertaken at the end of the loading dose and repeatedly during the maintenance phase to prevent over- or underexposure.

Age- and gender-related differences in teicoplanin levels in paediatric patients

OBJECTIVES

Teicoplanin is a glycopeptide antibiotic active against Gram-positive bacteria, including methicillin-resistant staphylococci. While teicoplanin trough levels (TTLs) >10 mg/L are commonly considered appropriate, levels >20 mg/L are aimed for in the treatment of severe infections. Due to toxicity, it is recommended to avoid levels >60 mg/L.

PATIENTS AND METHODS

In our institution, the initial dosing schedule of teicoplanin (10-15 mg/kg every 12 h for three loading doses and every 24 h thereafter) is adapted according to TTLs analysed by a fluorescence polarization immunoassay on treatment days 2 to 4. Teicoplanin peak levels (TPLs) are analysed in selected cases 30 min after the end of infusion. In a retrospective analysis we evaluated 1357 TTLs and 333 TPLs from 410 treatment episodes from 2005 to 2011.

RESULTS

Initial TTLs were <10 mg/L in 14.1% and <20 mg/L in 72.6% of episodes. Toddlers had significantly lower TTLs, with a 2-fold and 2.5-fold increased risk of having levels <10 mg/L (24.6%) and <20 mg/L (82.6%), respectively. For the entire cohort, follow-up TTLs were less likely to be <10 mg/L and more likely to be >20 mg/L when compared with initial TTLs (P < 0.001, each). Adolescent girls had significantly higher initial TPLs (P = 0.001) and significantly higher follow-up TTLs (P = 0.016) than adolescent boys. In parallel, adolescent girls had initial TPLs >60 mg/L significantly more frequently (P = 0.012) and follow-up TTLs <10 mg/L significantly less frequently (P = 0.005).

CONCLUSIONS

More tailored dosing regimens with higher loading doses, especially for toddlers, should be considered. While further pharmacokinetic data in paediatric patients are pending, therapeutic drug monitoring is mandatory.

Prognosis of patients with methicillin-resistant Staphylococcus aureus bloodstream infection treated with teicoplanin: a retrospective cohort study investigating effect of teicoplanin minimum inhibitory concentrations

Background

The present study was designed to investigate whether teicoplanin minimum inhibitory concentrations (MICs) of methicillin-resistant Staphylococcus aureus (MRSA) isolates play a role in the prognosis of patient with teicoplanin-treated MRSA bloodstream infection (BSI).

Methods

Between 1 January 2006 and 31 December 2009, adult patients with teicoplanin-treated MRSA BSI in two Taiwan medical centers were retrospectively enrolled. Their blood MRSA isolates were submitted for determination of MICs to various antibiotics and multi-locus sequence types. All-cause mortalities on Days 14 and 30, as well as clinical response at the end of teicoplanin therapy were treated as endpoints.

Results

Two hundred seventy adult patients were enrolled and 210 blood MRSA isolates were available. Independent risk factors for un-favorable outcome at the end of teicoplanin therapy included septic shock (p < 0.0001) and an elevated C-reactive protein level (p = 0.0064). The independent risk factors for all-cause Day 14 mortality (13.0%) included the presence of auto-immune diseases (p = 0.0235), septic shock (p = 0.0253) and thrombocytopenia (p = 0.0018). The independent risk factors for all-cause Day 30 mortality (26.3%) included age (p = 0.0102), septic shock (p < 0.0001) and thrombocytopenia (p = 0.0059).

Conclusions

The current study didn’t find a significant role for teicoplanin MICs in the prognosis of adult patients with teicoplanin-treated MRSA BSI.

Timing of initiating glycopeptide therapy for methicillin-Resistant Staphylococcus aureus bacteremia: the impact on clinical outcome

When a Staphylococcus-like organism (SLO) is microscopically found in Gram staining of blood culture (BC) specimen, it seems reasonable to administrate a glycopeptide (GP) for empirical therapy. The paper investigates the risk factors for 14-day mortality in patients with methicillin-resistance Staphylococcus aureus bacteremia (MRSAB) and clarifies the impact of the timing for initiating GP therapy. A retrospective study identifies patients with MRSAB (endocarditis was excluded) between 2006 and 2009. Patients were categorized as receiving GP at the interval before a preliminary BC report indicating the growth of SLO and the onward 24 hours or receiving GP 24 h after a preliminary BC report indicating the growth of SLO. Total 339 patients were enrolled. There was no difference on the 14-day overall or infection-related mortality rates at the time to administer GP. Multivariate analysis disclosed pneumonia (OR = 4.47; of 95% CI; of 2.09–9.58; P < 0.01) and high APACHE II score (OR, 2.81, with 95% CI, 1.19–6.65; P = 0.02) were independent risk factors for infection-related mortality. The mortality rate did not decrease following administrating GP immediately after a preliminary BC indicating SLO growth. An additional research for the optimal timing for initiating GP treatment is warranted.