Pharmacokinetics of teicoplanin in children

Age and Sex-Related Differences in Teicoplanine Isoform Concentrations in SARS-CoV-2 Patients

Teicoplanin, a glycopeptide antibiotic commonly used to treat bacterial infections, was discovered to be active in vitro against SARS-CoV-2. The aim of this study was to assess the levels of teicoplanin and its components in a cohort of adult and pediatric SARS-CoV-2 patients, evaluating the effect of sex and age on analyte concentrations. The levels of AST, ALT and leukocytes were shown to be higher in females, while the C reactive protein was higher in males. Evaluating the absence/presence of teicoplanin isoforms, we observed that A2-2_3 is the only one consistently present in pediatrics and adults. In adult men and all pediatrics, A2-4_5 is always present. In pediatrics, except for A3-1, median isoform concentrations were higher in females; on the contrary, in adult patients, males showed higher levels. This is the first study to describe levels of teicoplanin isoforms in SARS-CoV-2 infected patients in males and females, and pediatrics and adults, despite the small sample size of our cohort. The observed results imply that additional testing, via therapeutic drug monitoring, may be helpful to more effectively manage infections, particularly those caused by the most recent viruses.

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.

Contribution of Population Pharmacokinetics of Glycopeptides and Antifungals to Dosage Adaptation in Paediatric Onco-hematological Malignancies: A Review

The response to medications in children differs not only in comparison to adults but also between children of the different age groups and according to the disease. This is true for anti-infectives that are widely prescribed in children with malignancy. In the absence of pharmacokinetic/pharmacodynamic paediatric studies, dosage is frequently based on protocols adapted to adults. After a short presentation of the drugs, we reviewed the population pharmacokinetic studies available for glycopeptides (vancomycin and teicoplanin, n = 5) and antifungals (voriconazole, posaconazole, and amphotericin B, n = 9) currently administered in children with onco-hematological malignancies. For each of them, we reported the main study characteristics including identified covariates affecting pharmacokinetics and proposed paediatric dosage recommendations. This review highlighted the very limited amount of data available, the lack of consensus regarding PK/PD targets used for dosing optimization and regarding dosage recommendations when available. Additional PK studies are urgently needed in this specific patient population. In addition to pharmacokinetics, efficacy may be altered in immunocompromised patients and prospective clinical evaluation of new dosage regimen should be provided as they are missing in most cases.

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.

Pharmacokinetics of multiple doses of teicoplanin in Chinese elderly critical patients

BACKGROUND

The dose-effect relationship of teicoplanin has been a hot topic of clinical concern, but there was lack of the evidence of Chinese patients to optimize dosage, especially in elderly critical patients, whose plasma protein, liver and kidney function are greatly different from ordinary patients.

METHODS

Elderly critical patients were divided into high-dose(800mg), medium-dose (600mg) and low-dose (400mg) groups, which consisted of 6 cases of each group. Three groups were taken intravenous blood at different times after the last administration of teicoplanin to measure teicoplanin plasma concentration.

RESULTS

The t_1/2 of high-dose, middle-dose and low-dose groups were 70.76 ± 11.72h, 73.60 ± 9.48h, 80.24 ± 6.75h, respectively; CL were 0.14 ± 0.09mL ∙ h^-1 ∙ kg^-1, 0.11 ± 0,05mL ∙ h^-1 ∙ kg^-1, 0.12 ± 0.06mL ∙ h^-1 ∙ kg^-1 respectively. The Cmax and AUC_0-t of the three dose groups were linearly correlated with the dose.

CONCLUSIONS

In Chinese elderly critical patients, t_1/2 of teicoplanin was consistent with that of literatures published, however, CL were higher. The pharmacokinetics of teicoplanin at the range of 400 ~ 800mg is linear pharmacokinetics, indicating that the dosage regimens for patients were more simply and accurately adjusted according to therapeutic drug monitoring.

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.

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.).

Pharmacokinetic/pharmacodynamic modelling approaches in paediatric infectious diseases and immunology

Pharmacokinetic/pharmacodynamic (PKPD) modelling is used to describe and quantify dose-concentration-effect relationships. Within paediatric studies in infectious diseases and immunology these methods are often applied to developing guidance on appropriate dosing. In this paper, an introduction to the field of PKPD modelling is given, followed by a review of the PKPD studies that have been undertaken in paediatric infectious diseases and immunology. The main focus is on identifying the methodological approaches used to define the PKPD relationship in these studies. The major findings were that most studies of infectious diseases have developed a PK model and then used simulations to define a dose recommendation based on a pre-defined PD target, which may have been defined in adults or in vitro. For immunological studies much of the modelling has focused on either PK or PD, and since multiple drugs are usually used, delineating the relative contributions of each is challenging. The use of dynamical modelling of in vitro antibacterial studies, and paediatric HIV mechanistic PD models linked with the PK of all drugs, are emerging methods that should enhance PKPD-based recommendations in the future.

Teicoplanin pharmacokinetics in critically ill paediatric patients

Twenty-one critically ill children aged between 7 days and 12 years were treated with teicoplanin (three loading dosages of 10 mg/kg at 12 h intervals, followed by a maintenance dosage of 10 mg/kg/day). Serum teicoplanin concentrations were monitored by HPLC. Mean concentrations in plasma 30 min after drug administration were 20 +/- 16.1 mg/L. The volume of distribution was 0.30 L/kg and the terminal half-life was 17.41 h. Only 11% of trough values were >10 mg/L (established as desirable values). In critically ill children a dosage of 10 mg/kg/day does not assure serum trough values >10 mg/L.

Teicoplanin pharmacokinetics in pediatric patients

BACKGROUND

The incidence of methicillin-resistant Gram-positive bacteria infections in febrile neutropenic children is high. Teicoplanin is an alternative treatment to vancomycin in these patients but few pharmacokinetic studies of teicoplanin in children have been conducted and optimal dosages have not been well-established.

OBJECTIVES

To assess the pharmacokinetics of teicoplanin in combination with another antibiotic in Gram-positive infections in pediatric patients undergoing bone marrow transplantation and to determine the most appropriate dosage regimen for this type of patient.

METHODS

We studied 21 patients divided into 2 groups. In Group A (n = 9) the dosage regimen consisted of 3 loading doses of 10 mg/kg at 12-h intervals, followed by a maintenance dosage of 10 mg/kg/day. Group B (n = 12) received the same loading dose and a maintenance dosage of 20 mg/kg/day. Plasma teicoplanin concentrations were monitored in all patients from the second day after the start of treatment and periodically thereafter. Serum concentrations above 10 mg/l were established as desirable trough values.

RESULTS

In Group A trough values > 10 mg/l were not reached in five patients and treatment was modified owing to persistent fever. In Group B all patients attained trough values > 10 mg/l. Tolerance to treatment was excellent.

CONCLUSION

In febrile neutropenic pediatric patients undergoing bone marrow transplantation, maintenance dosages of teicoplanin between 15 and 20 mg/kg/day assure serum concentrations above 10 mg/l. Dosages of 10 mg/kg/day do not assure serum through values above 10 mg/l.

Pharmacokinetics of anti-infective agents in paediatric patients

Various differences in drug disposition exist between children and adults. For example, the volume of distribution (Vd) for many drugs is larger in children than in adults. Other parameters, including excretion and elimination may be altered in children compared with adults. The penicillins and cephalosporins are used commonly for the treatment of infection in paediatric patients. The increased Vd in children contributes to the increased elimination half-life of these agents. Clearance of the acylureido-penicillins is increased in children with cystic fibrosis, a disease that decreases the elimination half-life for these drugs. Aminoglycosides distribute into extracellular fluid and their pharmacokinetic profile is affected by changes in Vd. The Vd for aminoglycosides is slightly higher in children than in adults. Children with cystic fibrosis, burns, or cancer have higher clearance rates and larger Vd values for aminoglycosides. Few data in the literature address the pharmacokinetics of other anti-infective agents, including vancomycin, teicoplanin, erythromycin, metronidazole, chloramphenicol, and cotrimoxazole (trimethoprim-sulfamethoxazole), in children. Similarly, there is little information regarding the pharmacokinetic profile of antivirals and antifungals in children. Dosage guidelines are available to enable the clinician to initiate anti-infective therapy in children. Subsequent dosage requirements may change based on the patient's current clinical condition. Although several studies have investigated the pharmacokinetics of anti-infectives in neonates and adults, data for children are limited. Therefore, further studies are required so that the ever growing arsenal of anti-infectives can be administered appropriately to children.

Clinical pharmacokinetics of teicoplanin

Teicoplanin is a recently introduced glycopeptide antibiotic for the treatment of a variety of aerobic and anaerobic Gram-positive infections. It is a mixture of 5 closely related components, of similar polarity and biological activity, and 1 or more polar hydrolysis products. Teicoplanin is rapidly and extensively absorbed from muscle and the peritoneal cavity but very poorly absorbed from the gastrointestinal tract. Following intravenous administration, the disposition kinetics are best described by a tri-exponential equation, and the majority of drug is excreted unchanged, by glomerular filtration. In patients with normal renal function, the half-lives of the first, second and terminal phases are 35 minutes, 10 hours and 87 hours, respectively. The initial volume of distribution is 0.089 L/kg, the volume of distribution at steady-state is 0.86 L/kg, clearance is 0.0114 L/h/kg and renal clearance is 0.0083 L/h/kg. Teicoplanin is highly bound in plasma to albumin (fraction unbound = 0.1) and in tissues. The pharmacokinetics are linear over a wide dose range (2 to 26 mg/kg). The minor differences in the pharmacokinetics of the components of teicoplanin can be accounted for by differences in lipophilicity. The events following multiple dosing are predicted from single dose data; renal clearance decreases in patients with renal insufficiency in a predictable manner. Negligible drug is lost during haemodialysis. As expected, clearance per kilogram is higher in children than in adults, and lower in the elderly, associated with a decrease in glomerular filtration rate with advancing years. Tissue distribution data are limited. Concentrations, relative to those in plasma, are high in lung and bone tissue and low in fat. Animal data show high concentrations in most tissues, and particularly high in liver and kidneys. Teicoplanin penetrates slowly and poorly into cerebrospinal fluid, but relatively rapidly and effectively in synovial and pleural fluids and in soft tissue. The manufacturer's recommended intravenous or intramuscular dosage regimens rapidly achieve and maintain adequate plasma concentrations of teicoplanin; the dosing interval is usually 1 day. The maintenance dosing rate, but not the loading dose (if needed), must be reduced in patients with poor renal function and in the elderly. For those patients on continuous ambulatory peritoneal dialysis, the peritoneal cavity offers a convenient alternative route of drug administration.

Teicoplanin pharmacokinetics in patients undergoing continuous ambulatory peritoneal dialysis after intravenous and intraperitoneal dosing

The pharmacokinetics of teicoplanin after single 6-mg/kg intravenous and intraperitoneal doses were studied in five noninfected patients undergoing continuous ambulatory peritoneal dialysis. Biological samples were assayed for teicoplanin content by a microbiological assay technique. Terminal disposition half-life (266.4 +/- 51.9 h [mean +/- standard error of the mean]) was prolonged and total body clearance (0.040 +/- 0.004 ml/min per kg) was reduced compared with values previously reported in subjects with normal renal function. The volume of distribution at steady state (1.15 +/- 0.19 liters/kg) was higher than values previously reported in subjects with normal renal function (0.56 to 0.72 liter/kg). Peritoneal dialysis clearance (0.007 +/- 0.001 ml/min per kg) accounted for only 16.1% of total body clearance. The absolute systemic bioavailability of teicoplanin after intraperitoneal administration was 81.5 +/- 10.7%.