Teicoplanin dosing strategy for treatment of Staphylococcus aureus in Korean patients with neutropenic fever

Population pharmacokinetics and model-based dosing optimization of teicoplanin in elderly critically ill patients with pneumonia

PURPOSE

To evaluate the population pharmacokinetics and pharmacodynamics of teicoplanin in elderly critically ill patients with pneumonia for optimal dosages.

METHODS

Fifteen critically ill patients (9 men) ≥ 60 years received teicoplanin 6 mg/kg for three doses followed by standard maintenance doses (6 mg/kg q24h) with renal dosing adjustment. Serial plasma samples from all patients were analyzed simultaneously by population pharmacokinetic modeling using NONMEM. Probability of target attainment (PTA) was calculated through Monte Carlo simulations for various dosing regimens to achieve adequate systemic exposures.

RESULTS

The median (interquartile range, IQR) age, body mass index, and creatinine clearance (CrCl) was 75 (64-78) years, 22.5 (20.8-25.4) kg/m2, and 64 (47-106) mL/min, respectively. The median (IQR) peak and trough concentration was 46.5 (42.7-51.0) and 8.7 (7.2-9.5) mg/L. The population pharmacokinetic model showed slower clearance (CL) and larger peripheral volume of distribution (V2) in patients with reduced CrCl: CL (L/h) = 0.629 × (CrCl/64)0.656, V2 (L) = 55.7 × (CrCl/64)-0.665. Model-based simulations showed PTAs ≥85% only for higher-dose regimens (12 mg/kg) up to an MIC of 0.5 mg/L.

CONCLUSIONS

Standard teicoplanin dosages for pneumonia may provide inadequate systemic exposures in elderly critically ill patients. High-dose regimens should be considered as empiric therapy or for less susceptible pathogens.

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.

Physiologically Based Pharmacokinetic Modeling and Dose Adjustment of Teicoplanin in Pediatric Patients With Renal Impairment

The pharmacokinetics of teicoplanin differs in children as compared with adults, and especially in renally impaired pediatric patients. Inappropriate empirical antibacterial therapy may lead to treatment-related antibacterial resistance and increased toxicity, making adjustment of the dosage regimen essential. In the present study, physiologically based pharmacokinetic (PBPK) models were developed to define the appropriate dosage regimen for pediatric patients with differing renal function. Our PBPK models accurately predicted teicoplanin exposures in both adult and pediatric subjects after single and multiple intravenous infusions, with a <1.36-fold error between predicted and observed data, and all observed data were within minimal and maximal data of the corresponding population simulation. The area under the plasma concentration-time curve was predicted to increase 1.25-fold, 1.95-fold, and 2.82-fold in pediatric patients with mild, moderate, and severe renal impairment, respectively, relative to that of healthy children. Subsequently, the results of Monte Carlo simulations indicated that the recommended dosing of 12, 9.5, 6, and 4 mg/kg at 12-hour intervals would be appropriate in pediatric patients with normal renal function and in those with mild, moderate, and severe renal impairment, respectively, at a susceptible minimum inhibitory concentration <2 mg/L. In conclusion, our PBPK model with an incorporated Monte Carlo simulation can provide improved guidance on dosing in pediatric patients with differing renal function and provide a basis for precision therapy with teicoplanin.

Population Pharmacokinetics and Model-Based Dosing Optimization of Teicoplanin in Pediatric Patients

Objectives: The pharmacokinetics (PK) of teicoplanin differs in children compared with adults. Our aim was to determine the PK of teicoplanin in an Asian pediatric population and to optimize dosage regimens. Methods: This was a retrospective PK study and all the data were collected from hospitalized children. We developed a population PK model using sparse data, and Monte Carlo simulation was used to assess the ability of standard teicoplanin regimen and other different dosage regimens. The optimal dosing regimens were defined as achieving the target trough concentration (C _min) of 10 mg/L and pharmacokinetic/pharmacodynamic (PK/PD, [AUC₂₄/MIC]) of 125 for moderate infection. For severe infection, the optimal dosing regimens were defined as achieving the target 15 mg/L and AUC₂₄/MIC of 345. Results: 159 children were included and 1.5 samples/children on average were provided. Estimated clearance of teicoplanin was 0.694 L/h (0.784/L/h/70 kg) and volume of distribution was 1.39 L. Teicoplanin standard loading dose was adequate for moderate infection, while 13 mg/kg was needed for severer infection. With standard maintenance doses, both patients with moderate and severe infection failed to achieve the target C _min. 12 and 16 mg/kg/day were required to achieve a C _min ≥ 10 and 15 mg/L, respectively. However, standard maintenance dose was adequate to achieve AUC₂₄/MIC ≥ 125 for moderate infection, and 12 mg/kg/day was needed to achieve AUC₂₄/MIC ≥ 345 for severe infection. Lower weight and serum creatinine were associated with higher dose. Conclusion: Optimal doses based on the target C _min were higher than that based on the PK/PD target. To achieve the C _min and PK/PD targets simultaneously, a standard loading dose was adequate for moderate infection based on simulation, while dosing higher than standard doses were required in other situation. Further clinical studies with rich sampling from children is required to confirm our findings.

Population Pharmacokinetics and Dosage Optimization of Teicoplanin in Children With Different Renal Functions

Objective

The purposes of our study were to investigate the population pharmacokinetics of teicoplanin in Chinese children with different renal functions and to propose the appropriate dosing regimen for these pediatric patients.

Methods

We performed a prospective pharmacokinetic research on children aged 0-10 years, with different renal functions. The population pharmacokinetics model of teicoplanin was developed using NLME program. The individualized optimal dosage regimen was proposed on the basis of the obtained population pharmacokinetics parameters.

Results

To achieve the target trough level of 10-30 mg/L, optimal dosing regimen for children with different renal functions are predicted as follows based on the population PK simulations: children with moderate renal insufficiency need three loading doses of 6 mg/kg q12h followed by a maintenance dose of 5 mg/kg qd; children with mild renal insufficiency require three loading doses of 12 mg/kg q12h followed by a maintenance dose of 8 mg/kg qd; children with normal or augmented renal function should be given three loading doses of 12 mg/kg q12h followed by a maintenance doses of 10 mg/kg qd.

Conclusion

The first study on the population pharmacokinetics of teicoplanin in Chinese children with different renal functions was performed. Individualized dosing regimen was recommended for different renal function groups based on population PK model prediction.

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 (Cmin) 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 Cmin > 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 Cmin 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 Cmin over 10 days (P = 0.025) were significantly associated with treatment success. Although HL regimen could achieve Cmin targets and improve clinical outcome during teicoplanin treatment, high Cmin was associated with AEs during treatment. Routine TDM can be helpful to optimize teicoplanin administration.

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.

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 teicoplanin dosage regimens for methicillin-resistant Staphylococcus aureus infections in endocarditis patients and renal failure patients

This study aimed to assess whether traditional initial loading and maintenance doses of teicoplanin were appropriate in endocarditis and renal failure patients with methicillin-resistant Staphylococcus aureus (MRSA) infections and to recommend optimal dosage regimens. Pharmacokinetic parameters and physicochemical properties of teicoplanin were performed to develop pharmacokinetic models using GastroPlus^TM. Concentration-time curves of teicoplanin in endocarditis and renal failure patients with MRSA infections were simulated by changing clearance (CL) and volume of distribution of the central compartment (V_c). Different teicoplanin dosage regimens were assessed according to the target trough concentration, and optimal teicoplanin dosage regimens were recommended. Dosage regimen of four teicoplanin doses of 6 mg/kg q12 h followed by 6 mg/kg qd is recommended for renal failure patients infected by MRSA. And optimal dosage regimen is five teicoplanin doses of 15 mg/kg q12 h followed by doses of 12 mg/kg qd for endocarditis patients infected by MRSA.

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.