Proof of concept of physiologically based pharmacokinetic modelling in paediatric acute lymphoblastic leukaemia.

Physiologically based pharmacokinetic (PBPK) modelling is an alternative modelling technique that is increasingly used in pharmacokinetics. Due to its nature, it can be complementarily employed to population pharmacokinetics, especially when it comes to small population size. Here, we report the proof of concept of its application to accurately describe the pharmacokinetics of a recombinant L-asparaginase in paediatric patients with acute lymphoblastic leukaemia. Data from two randomized, double-blind, phase II/III clinical studies (MC-ASP.4/ALL; MC-ASP.5/ALL) were included to setup and evaluate the final model, respectively. Final population values for basic pharmacokinetic parameters were calculated (clearance: 0.0569 L/h/19.5 kg, volume of distribution: 1.251 L, half-life: 18.5 h, trough concentration: 140.9 IU/L). Pharmacokinetic parameter prediction as well as predictive performance of the model proofed to be comparable to a separately developed population pharmacokinetic model with 13% deviation in predicted median L-asparaginase trough levels. To the best of our knowledge, this is the first whole-body PBPK model of a non-antibody therapeutic protein.

Development and Validation of a High-Performance Liquid Chromatography With Ultraviolet Detection Method to Facilitate Therapeutic Monitoring of Teicoplanin Using Dried Blood Spots.

BACKGROUND: In neonatal and pediatric intensive care units, Gram-positive infections are a significant cause of morbidity and mortality. The increase in infections caused by methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococci have led to the increased use of glycopeptides, which treat invasive infections caused by Gram-positive organisms, particularly those resistant to beta-lactam antibiotics. Teicoplanin has bacteriostatic activity against Gram-positive bacteria, but its pharmacokinetics in children is highly variable, with most children failing to reach target levels at the recommended dose. This study aimed to develop a cost-effective method for determining concentrations using dried blood spot (DBS). METHODS: A method to determine the concentrations of teicoplanin in 20 µL blood or plasma using the Whatman 903 Protein Saver filter was evaluated. High-performance liquid chromatography with ultraviolet detection high-performance liquid chromatography with ultraviolet/vis was used, with internal standard ketoconazole. In addition, a method to quantify teicoplanin using 50 µL of liquid plasma was established to compare the results with the values obtained by DBS and dried plasma methods. RESULTS: The method was successfully developed and validated for 20 µL DBS. Furthermore, 50 µL of plasma was used to quantify teicoplanin with a lower limit of quantification of 10 mg/L. Precision and accuracy ranged from 2.3% to 10.7% and 95%-114.2%, respectively. A consistent factor (1.15) was used to calculate teicoplanin plasma concentrations from whole blood, indicating the reliability of the DBS method for therapeutic drug monitoring of teicoplanin. CONCLUSIONS: A simple, reliable, and cost-effective method using high-performance liquid chromatography with ultraviolet/vis was established to determine pediatric teicoplanin concentrations in both small plasma sample volumes and whole blood using DBS, and an accurate correlation factor for estimating teicoplanin plasma concentrations from DBS was identified. This method is suitable for the use in pediatrics.

Rationalising Optimal Dosing of Phytotherapeutics For Use In Children: Current Status - Potential Solutions - Actions Needed.

"Children are not small adults with respect to the treatment with medicinal products." This statement of the WHO was the basis for the initiative of the European Commission for the establishment of a paediatric regulation in 2007 to improve the health of children by facilitating the development of medicines for children and adolescents. Seventeen years later, in the field of herbal medicinal products, results are still sobering. Therefore, the Foundation Plants for Health, Society for Medicinal Plants and Natural Products Research, and German Society for Phytotherapy organised a symposium to assess the status quo for the paediatric use of herbal medicinal products (HMPs), to analyse the causes of the current situation, and to discuss strategies for establishing the proof of safe and efficacious HMPs for children.The current situation for HMPs and their use in children is not fulfilling the requirements of legislation. HMPs in paediatrics are effective and safe, but considering the needs of children is necessary. In European countries, the use, registration, and marketing of HMPs are different, depending on the respective national regulations and specific traditions. EU herbal monographs are the best common denominator for such procedures. Emerging safety discussions must be considered. New approaches with real-world data might be a solution. The regulatory framework is to be adapted. Defining rationalised dosing for HMPs can be achieved by the extrapolation of data from adults, by using existing clinical data for children, and by using RWD. Therefore, a strong need for revising restrictions for the use of HMPs in children and rationalising defined dosage regimes is obvious.

[Use of strongly acting sustained-release opioids in pediatrics : Pitfalls and solutions for morphine and hydromorphone]. / Anwendung stark wirksamer retardierter Opioide in der Pädiatrie : Fallstricke und Lösungen für Morphin und Hydromorphon.

BACKGROUND: In pediatrics, adequate treatment with potent opioids requires the administration of sustained-release preparations for many patients; however, the dosing and administration of sustained-release morphine and hydromorphone preparations via gastrointestinal tubes confronts providers with a major hurdle, especially as the company Mundipharma GmbH has discontinued the production and distribution of the preparation MST retard granules in 2019, which has been proven for these purposes in pediatrics. The aim of this study was to establish a production technique for available sustained-release opioid preparations, which are particularly suitable for use in the low-dose range required in pediatrics and which can also be administered via gastrointestinal tubes. METHOD: Low-dose preparations were produced by opening of morphine and hydromorphone capsules and weighing of the sustained-release pellets. To evaluate the partition, an analysis of the drug content via high performance liquid chromatography (HPLC) was conducted. Moreover, the administration via gastrointestinal tubes (charrière, Ch 8-Ch 10) was examined by an ex vivo experiment. RESULTS: The examination showed a practicable method to produce low dosages of sustained-release morphine and hydromorphone. The preparations are in accordance with the test for content uniformity of the European Pharmacopoeia (Ph. Eur.). Furthermore, the pellets were administered to gastrointestinal tubes Ch 8 (morphine) and Ch 10 (hydromorphone) by a syringe application technique and passed the tubes completely. CONCLUSION: The production technique can be considered as safe and enables the off-label oral application or application via gastrointestinal tubes of sustained-release opioids in pediatrics.

Systematic Evaluation of Pharmacokinetic Models for Model-Informed Precision Dosing of Meropenem in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy.

The altered pharmacokinetics of renally cleared drugs such as meropenem in critically ill patients receiving continuous renal replacement therapy (CRRT) might impact target attainment. Model-informed precision dosing (MIPD) is applied to individualize meropenem dosing. However, most population pharmacokinetic (PopPK) models developed to date have not yet been evaluated for MIPD. Eight PopPK models based on adult CRRT patients were identified in a systematic literature research and encoded in NONMEM 7.4. A data set of 73 CRRT patients from two different study centers was used to evaluate the predictive performance of the models using simulation and prediction-based diagnostics for i) a priori dosing based on patient characteristics only and ii) Bayesian dosing by including the first measured trough concentration. Median prediction error (MPE) for accuracy within |20%| (95% confidence intervals including zero) and median absolute prediction error (MAPE) for precision ≤ 30% were considered clinically acceptable. For a priori dosing, most models (n = 5) showed accuracy and precision MPE within |20%| and MAPE <35%. The integration of the first measured meropenem concentration improved the predictive performance of all models (median MAPE decreased from 35.4 to 25.0%; median MPE decreased from 21.8 to 4.6%). The best predictive performance for intermittent infusion was observed for the O'Jeanson model, including residual diuresis as covariate (a priori and Bayesian dosing MPE within |2%|, MAPE <30%). Our study revealed the O'Jeanson model as the best-predicting model for intermittent infusion. However, most of the selected PopPK models are suitable for MIPD in CRRT patients when one therapeutic drug monitoring sample is available.

Developing a Method for Quantifying Meropenem in Children-Volumetric Adsorptive Microsampling Versus Plasma Sampling.

BACKGROUND: Meropenem is a carbapenem antibiotic often used in pediatric intensive care units due to its broad spectrum of activity. Therapeutic drug monitoring (TDM) is a useful tool to increase the effectiveness of meropenem by adjusting the dose based on plasma levels; however, the relatively large sample volume required for TDM can limit its use in children. Therefore, this study aimed to determine meropenem concentrations and consequently perform TDM effectively using the smallest possible sample volume. Volumetric absorptive microsampling (VAMS) is a sampling technology developed to collect a small, precise volume of blood. For the applicability of VAMS in TDM, plasma concentrations must be reliably calculated from whole blood (WB) collected by VAMS. METHODS: VAMS technology using 10 µL of WB was evaluated and compared with EDTA-plasma sampling. High-performance liquid chromatography with UV detection was applied to quantify meropenem in VAMS and plasma samples after the removal of proteins by precipitation. Ertapenem was used as the internal standard. Samples were collected simultaneously from critically ill children receiving meropenem using VAMS and traditional sampling. RESULTS: It was found that no consistent factor could be determined to calculate meropenem plasma concentrations from the WB, indicating that VAMS was not reliable in the TDM of meropenem. Therefore, to reduce the required sample amount in pediatric patients, a method for quantifying meropenem from 50 µL of plasma with a lower limit of quantification of 1 mg/L was developed and successfully validated. CONCLUSIONS: A simple, reliable, and low-cost method was established using high-performance liquid chromatography-UV to determine the concentration of meropenem in 50 µL of plasma. VAMS using WB does not seem to be suitable for TDM of meropenem.

Validation of a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide and N-monomethylacetamide in pediatric plasma.

N,N-dimethylacetamide is an excipient used in intravenous busulfan formulations, a drug used in hematopoietic stem cell transplantation conditioning. The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide, and its metabolite N-monomethylacetamide in plasma from children receiving busulfan. A 4 µl aliquot of patient plasma was extracted using 196 µl 50% methanol solution and quantified against calibrators prepared in the extraction solvent given negligible matrix effects across three concentrations. 9 [H2 ]-N,N-dimethylacetamide was used as an internal standard. Separation of N,N-dimethylacetamide and N-monomethylacetamide was achieved using a Kinetex EVO C18 stationary phase (100 mm × 2.1 mm × 2.6 µm) running an isocratic mobile phase of 30% methanol containing 0.1% formic acid at a flow of 0.2 ml/min over 3.0 min. The injection volume was 1 µl. Calibration curves for N,N-dimethylacetamide and N-monomethylacetamide were linear up to 1200 and 200 µg/L, respectively, with a lower limit of quantification 1 µg/L for both analytes. Calibrator accuracy and precision were within ± 10% of the test parameters across four concentration levels. Analytes were stable over 14 days at three different storage conditions. This method was successfully applied to measure N,N-dimethylacetamide and N-monomethylacetamide concentrations in a total of 1265 plasma samples from 77 children.

Voriconazole plasma concentrations and dosing in paediatric patients below 24 months of age.

Voriconazole (VCZ) is an important first-line option for management of invasive fungal diseases and approved in paediatric patients ≥24 months at distinct dosing schedules that consider different developmental stages. Information on dosing and exposures in children <24 months of age is scarce. Here we report our experience in children <24 months who received VCZ due to the lack of alternative treatment options. This retrospective analysis includes 50 distinct treatment episodes in 17 immunocompromised children aged between 3 and <24 months, who received VCZ between 2004 and 2022 as prophylaxis (14 patients; 47 episodes) or as empirical treatment (3 patients; 3 episodes) by mouth (46 episodes) or intravenously (4 episodes) based on contraindications, intolerance or lack of alternative options. Trough concentrations were measured as clinically indicated, and tolerability was assessed based on hepatic function parameters and discontinuations due to adverse events (AEs). VCZ was administered for a median duration of 10 days (range: 1-138). Intravenous doses ranged from 4.9 to 7.0 mg/kg (median: 6.5) twice daily, and oral doses from 3.8 to 29 mg/kg (median: 9.5) twice daily, respectively. The median trough concentration was 0.63 mg/L (range: 0.01-16.2; 38 samples). Only 34.2% of samples were in the recommended target range of 1-6 mg/L; 57.9% had lower and 7.9% higher trough concentrations. Hepatic function parameters analysed at baseline, during treatment and at end of treatment did not show significant changes during VCZ treatment. There was no correlation between dose and exposure or hepatic function parameters. In three episodes, VCZ was discontinued due to an AE (6%; three patients). In conclusion, this retrospective analysis reveals no signal for increased toxicity in paediatric patients <24 months of age. Empirical dosing resulted in mostly subtherapeutic exposures which emphasises the need for more systematic study of the pharmacokinetics of VCZ in this age group.

Pharmacokinetic modelling of caspofungin to develop an extended dosing regimen in paediatric patients.

BACKGROUND: Echinocandins are commonly used in treatment and prophylaxis of invasive fungal diseases. Intravenous daily dosing for prophylaxis in the outpatient setting can however become a hurdle for adequate compliance in the paediatric population. OBJECTIVES: Simulations were performed to assess extended twice-weekly dosing for antifungal prophylaxis using caspofungin. METHODS: A population pharmacokinetic model was developed based on previously published data from children aged 3 months to 17 years. Using the final model, Monte Carlo simulations were performed to assess the dose needed for adequate exposure in a twice-weekly setting. Mean weekly AUC0-24 h/MIC together with reported AUC0-24 h from previously reported paediatric trials were used to guide adequate exposure. RESULTS AND CONCLUSIONS: A two-compartment model with linear elimination and allometric scaling using fixed exponents was found most adequate to describe the given paediatric populations. Simulations showed that a 200 mg/m2 twice-weekly regimen with maximal 200 mg total dose should result in exposures matching registered daily dosing as well as commonly used pharmacokinetic/pharmacodynamic targets.

Pre-existing antibodies against polyethylene glycol reduce asparaginase activities on first administration of pegylated E. coli asparaginase in children with acute lymphocytic leukemia.

Antibodies against polyethylene glycol (PEG) in healthy subjects raise concerns about the efficacy of pegylated drugs. We evaluated the prevalence of antibodies against PEG among patients with acute lymphoblastic leukemia (ALL) prior to and/or immediately after their first dose of pegylated E.coli asparaginase (PEG-ASNase). Serum samples of 701 children, 673 with primary ALL, 28 with relapsed ALL, and 188 adults with primary ALL were analyzed for anti-PEG IgG and IgM. Measurements in 58 healthy infants served as reference to define cut-points for antibody-positive and -negative samples. Anti-PEG antibodies were detected in ALL patients prior the first PEG-ASNase with a prevalence of 13.9% (anti-PEG IgG) and 29.1% (anti-PEG IgM). After administration of PEG-ASNase the prevalence of anti-PEG antibodies decreased to 4.2% for anti-PEG IgG and to 4.5% for anti-PEG IgM. Pre-existing anti-PEG antibodies did not inhibit PEG-ASNase activity but significantly reduced PEGASNase activity levels in a concentration dependent manner. Although pre-existing anti-PEG antibodies did not boost, pre-existing anti-PEG IgG were significantly associated with firstexposure hypersensitivity reactions (CTCAE grade 2) (p.

Pharmacodynamics of Posaconazole in Experimental Invasive Pulmonary Aspergillosis: Utility of Serum Galactomannan as a Dynamic Endpoint of Antifungal Efficacy.

Aspergillus galactomannan antigenemia is an accepted tool for the diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Little is known, however, about the utility of this biomarker to assess the efficacy of antifungal therapies. The pharmacokinetics (PK) and pharmacodynamics (PD) of posaconazole in treatment and prophylaxis were investigated in the persistently neutropenic rabbit model of Aspergillus fumigatus IPA at doses between 2 and 20 mg/kg per day. Sparse plasma sampling was used to obtain PK data at steady state, and the serum galactomannan index (GMI), as a dynamic endpoint of antifungal response, was obtained every other day, in addition to conventional outcome parameters including survival and fungal tissue burden. Nonparametric PK/PD model building was performed using the Pmetrics package in R. A one-compartment model with linear elimination best described the PK of posaconazole. The PD effect of posaconazole exposure in plasma on the GMI in serum was best described by dynamic Hill functions reflecting growth and killing of the fungus. Through calculations of the area under the concentration-time curve from 0 to 24 h (AUC0-24) at steady state, the exposure-response relationship between posaconazole and the GMI for treatment followed a sigmoidal function with an asymptote forming above an AUC0-24 of 30 mg · h/liter. All prophylactic doses were able to control the fungal burden. A nonparametric population PK/PD model adequately described the effect of posaconazole in prophylaxis and treatment of experimental IPA. An AUC0-24 greater than 30 mg · h/liter was associated with adequate resolution of the GMI, which well supports previously suggested exposure-response relationships in humans.

Population pharmacokinetic evaluation of cefuroxime in perioperative antibiotic prophylaxis during and after cardiopulmonary bypass.

AIMS: The purpose of this study was to explore pharmacokinetic and pharmacodynamic aspects of a contemporary dosing scheme of cefuroxime as perioperative prophylaxis in cardiac surgery using cardiopulmonary bypass (CPB). METHODS: Cefuroxime plasma concentrations were measured in 23 patients. A 1.5-g dose of cefuroxime was administered at start of surgery and CPB, followed by 3 additional doses every 6 hours postoperative. Drug levels were used to build a population pharmacokinetic model. Target attainment for Staphylococcus aureus (2-8 mg/L) and Escherichia coli (8-32 mg/L) were evaluated and dosing strategies for optimization were investigated. RESULTS: A dosing scheme of 1.5 g cefuroxime preoperatively with a repetition at start of CPB achieves plasma unbound concentrations of 8 mg/L in almost all patients during surgery. The second administration is critical to provide this level of coverage. Simulations indicate that higher unbound concentrations up to 32 mg/L are reached by a continuous infusion rate of 1 g/h after a bolus of 1 g. In the postoperative phase, most patients do not reach unbound concentrations above 2 mg/L. To improve target attainment up to 8 mg/L, the continuous application of cefuroxime with infusion rates of 0.125-0.25 g/h is simulated and shown to be an alternative to bolus dosing. CONCLUSION: Dosing recommendations for cefuroxime as perioperative antibiotic prophylaxis in cardiac surgery are sufficient to reach plasma unbound concentration to cover S. aureus during the operation. Target attainment is not achieved in the postoperative period. Continuous infusion of cefuroxime may optimize target attainment.

Population pharmacokinetics of vancomycin in patients with external ventricular drain-associated ventriculitis.

BACKGROUND: To determine the distribution of vancomycin into the cerebrospinal fluid (CSF) in patients with external ventricular drain (EVD)-associated ventriculitis, the pharmacokinetics of vancomycin were evaluated and covariate relationships explored. METHODS: For the population pharmacokinetic model patients were recruited in a neurocritical care unit at the University Hospital of Muenster in the period between January 2014 and June 2015. All patients had a clinical evidence of EVD-associated ventriculitis. Population pharmacokinetic analysis of vancomycin was performed using NONMEM. RESULTS: A total of 184 blood and 133 CSF samples were collected from 29 patients. The final population pharmacokinetic model is a three-compartment model with linear elimination. Creatinine clearance (ClCr ) and CSF-lactate were detected as significant covariates, showing that the total vancomycin plasma clearance (Cl) depends on ClCr and furthermore the clearance (Cldif ) between the central and CSF compartment correlates with CSF lactate concentration. Based on the final model, the following values were estimated by NONMEM: Cl = 5.15 L/h, Q (intercompartmental clearance) = 3.31 L/h, Cldif  = 0.0031 L/h, Vcentral  = 42.1 L, VCSF  = 0.32 L and the value of Vperipheral was fixed to 86.2 L. With the developed pharmacokinetic model, area under the curve (AUC) values as well as CSF trough levels were simulated. CONCLUSION: Based on our analysis, the dosing of vancomycin should be referred to the degree of inflammation (derived from the CSF lactate concentration) and renal function (derived from ClCr ).

Extended Dosing Regimens for Fungal Prophylaxis.

Invasive fungal diseases carry high morbidity and mortality in patients undergoing chemotherapy for hematological malignancies or allogeneic hematopoietic stem cell transplantation. In order to prevent these life-threatening infections, antifungal chemoprophylaxis plays an important role in daily clinical practice. Broad-spectrum antifungal triazoles are widely used but exhibit disadvantages such as relevant drug-drug interactions. Therefore, amphotericin B products or echinocandins can be an alternative in selected patient populations. As these compounds are available as intravenous formulations only, there is growing interest in extended dosing regimens. Although not approved for these agents, this strategy is a rational option, as these compounds have properties suitable for this strategy, including dose-proportional pharmacokinetics, prolonged elimination half-life, and a large therapeutic window. As the use of extended dosing regimens in antifungal prophylaxis is expanding in clinical practice, we reviewed the pharmacokinetic and pharmacodynamic rationale for this strategy, animal model data, dose escalation studies, and clinical trials supporting this concept.

Modelling Age-Related Changes in the Pharmacokinetics of Risperidone and 9-Hydroxyrisperidone in Different CYP2D6 Phenotypes Using a Physiologically Based Pharmacokinetic Approach.

PURPOSE: Dose-optimization strategies for risperidone are gaining in importance, especially in the elderly. Based on the genetic polymorphism of cytochrome P 450 (CYP) 2D6 genetically and age-related changes cause differences in the pharmacokinetics of risperidone and 9-hydroxyrisperidone. The goal of the study was to develop physiologically based pharmacokinetic (PBPK) models for the elderly aged 65+ years. Additionally, CYP2D6 phenotyping using metabolic ratio were applied and different pharmacokinetic parameter for different age classes predicted. METHODS: Plasma concentrations of risperidone and 9-hydroxyrisperidone were used to phenotype 17 geriatric inpatients treated under naturalistic conditions. For this purpose, PBPK models were developed to examine age-related changes in the pharmacokinetics between CYP2D6 extensive metabolizer, intermediate metabolizer, poor metabolizer, (PM) and ultra-rapid metabolizer. RESULTS: PBPK-based metabolic ratio was able to predict different CYP2D6 phenotypes during steady-state. One inpatient was identified as a potential PM, showing a metabolic ratio of 3.39. About 88.2% of all predicted plasma concentrations of the inpatients were within the 2-fold error range. Overall, age-related changes of the pharmacokinetics in the elderly were mainly observed in Cmax and AUC. Comparing a population of young adults with the oldest-old, Cmax of risperidone increased with 24-44% and for 9-hydroxyrisperidone with 35-37%. CONCLUSIONS: Metabolic ratio combined with PBPK modelling can provide a powerful tool to identify potential CYP2D6 PM during therapeutic drug monitoring. Based on genetic, anatomical and physiological changes during aging, PBPK models ultimately support decision-making regarding dose-optimization strategies to ensure the best therapy for each patient over the age of 65 years.

Challenges at the Time of COVID-19: Opportunities and Innovations in Antivirals from Nature.

As viral infections are an increasing threat to human societies, the need for new therapeutic strategies is becoming even more obvious. As no vaccine is available for COVID-19, the development of directly acting antiviral agents and preventive strategies have to be considered. Nature provides a huge reservoir of anti-infectious compounds, from which we can deduce innovative ideas, therapies, and products. Anti-adhesive natural products interact with the receptor-mediated recognition and early interaction of viruses with the host cells, leading to a reduced internalisation of the virus and reduced infections (e.g., procyanidin-B-2-di-O-gallate against influenza and herpes virus). Lignans like podophyllotoxin and bicyclol show strong antiviral activities against different viruses, and essential oils can directly interact with viral membranes and reduce the host's inflammatory responses (e.g., 1,8-cineol). Echinacea extracts stimulate the immune system, and bioavailable alkamides are key players by interacting with immunomodulating cannabinoid receptors. COVID-19 and SARS-CoV-2 infections have, in part, successfully been treated in China by preparations from traditional Chinese medicine and, while it is too early to draw conclusions, some promising data are available. There is huge potential, but intensified research is needed to develop evidence-based medicines with a clearly defined chemical profile. Intensified research and development, and therefore funding, are needed for exploiting nature's reservoir against viral infections. Combined action for basic research, chemistry, pharmacognosy, virology, and clinical studies, but also supply chain, sustainable sourcing, and economic aspects have to be considered. This review calls for intensified innovative science on natural products for the patients and for a healthier world!

Improving medication appropriateness in nursing homes via structured interprofessional medication-review supported by health information technology: a non-randomized controlled study.

BACKGROUND: In nursing home residents (NHRs), polypharmacy is widespread, accompanied by elevated risks of medication related complications. Managing medication in NHRs is a priority, but prone to several challenges, including interprofessional cooperation. Against this background, we implemented and tested an interprofessional intervention aimed to improve medication appropriateness for NHRs. METHODS: A non-randomized controlled study (SiMbA; "Sicherheit der Medikamentherapie bei AltenheimbewohnerInnen", Safety of medication therapy in NHRs) was conducted in six nursing homes in Austria (2016-2018). Educational training, introduction of tailored health information technology (HIT) and a therapy check process were combined in an intervention aimed at healthcare professionals. Medication appropriateness was assessed using the Medication Appropriateness Index (MAI). Data was collected before (t0), during (t1, month 12) and after (t2, month 18) intervention via self-administered assessments and electronic health records. RESULTS: We included 6 NHs, 17 GPs (52.94% female) and 240 NHRs (68.75% female; mean age 85.0). Data of 159 NHRs could be included in the analysis. Mean MAI-change was - 3.35 (IG) vs. - 1.45 (CG). In the subgroup of NHRs with mean MAI ≥23, MAI-change was - 10.31 (IG) vs. -3.52 (CG). The intervention was a significant predictor of improvement in MAI when controlled for in a multivariable regression model. CONCLUSIONS: Improvement of medication appropriateness was clearest in residents with inappropriate baseline MAI-scores. This improvement was independent of variances in certain covariates between the intervention and the control group. We conclude that our intervention is a feasible approach to improve NHRs' medication appropriateness. TRIAL REGISTRATION: DRKS Data Management, ID: DRKS00012246 . Registered 16.05.2017 - Retrospectively registered.

Pharmacotherapy in Children and Adolescents: Oncology.

Pharmacotherapy in paediatric oncology is a difficult task. It is challenging to determine the optimal dose in children of different age groups. In addition, anticancer drugs display severe side effects reducing the quality of life. Late effects like secondary tumours and cardiotoxicity can be apparent years after treatment and must be taken into account when planning treatment schedules. Classical cytoreducing agents are still of great importance in treating children with leukaemia and solid tumours. In addition, drugs developed by rational drug design (targeted drugs) are a very important part of many treatment protocols, and newer drugs are emerging in several types of cancer. Unfortunately, there is only limited experience with newer drugs in children, because new drugs are mostly developed for adults. Complicated therapy regimens require a solid knowledge of the pharmacology of the drugs applied. This chapter attempts to introduce some pharmacological knowledge for the most important anticancer drugs in children with a focus on side effects and age-specific considerations.

Integration of physiological changes during the postpartum period into a PBPK framework and prediction of amoxicillin disposition before and shortly after delivery.

The objective of this study was to develop a physiologically based pharmacokinetic (PBPK) model for amoxicillin for non-pregnant, pregnant and postpartum populations by compiling a database incorporating reported changes in the anatomy and physiology throughout the postpartum period. A systematic literature search was conducted to collect data on anatomical and physiological changes in postpartum women. Empirical functions were generated describing the observed changes providing the basis for a generic PBPK framework. The fraction unbound ([Formula: see text]) of predominantly albumin-bound drugs was predicted in postpartum women and compared with experimentally observed values. Finally, a specific amoxicillin PBPK model was newly developed, verified for non-pregnant populations and translated into the third trimester of pregnancy (29.4-36.9 gestational weeks) and early postpartum period (drug administration 1.5-3.8 h after delivery). Pharmacokinetic predictions were evaluated using published clinical data. The literature search yielded 105 studies with 1092 anatomical and physiological data values on 3742 postpartum women which were used to generate various functions describing the observed trends. The [Formula: see text] could be adequately scaled to postpartum women. The pregnancy PBPK model predicted amoxicillin disposition adequately as did the postpartum PBPK model, although clearance was somewhat underestimated. While more research is needed to establish fully verified postpartum PBPK models, this study provides a repository of anatomical and physiological changes in postpartum women that can be applied to future modeling efforts. Ultimately, structural refinement of the developed postpartum PBPK model could be used to investigate drug transfer to the neonate via breast-feeding in silico.

Physiologically based pharmacokinetic evaluation of cefuroxime in perioperative antibiotic prophylaxis.

AIMS: Adequate plasma concentrations of antibiotics during surgery are essential for the prevention of surgical site infections. We examined the pharmacokinetics of 1.5 g cefuroxime administered during induction of anaesthesia with follow-up doses every 2.5 hours until the end of surgery. We built a physiologically based pharmacokinetic model with the aim to ensure adequate antibiotic plasma concentrations in a heterogeneous population. METHODS: A physiologically based pharmacokinetic model (PK-Sim® /MoBi® ) was developed to investigate unbound plasma concentrations of cefuroxime. Blood samples from 25 thoracic surgical patients were analysed with high-performance liquid chromatography. To evaluate optimized dosing regimens, physiologically based pharmacokinetic model simulations were conducted. RESULTS: Dosing simulations revealed that a standard dosing regimen of 1.5 g every 2.5 hours reached the pharmacokinetic/pharmacodynamic target for Staphylococcus aureus. However, for Escherichia coli, >50% of the study participants did not reach predefined targets. Effectiveness of cefuroxime against E. coli can be improved by administering a 1.5 g bolus immediately followed by a continuous infusion of 3 g cefuroxime over 3 hours. CONCLUSION: The use of cefuroxime for perioperative antibiotic prophylaxis to prevent staphylococcal surgical site infections appears to be effective with standard dosing of 1.5 g preoperatively and follow-up doses every 2.5 hours. In contrast, if E. coli is relevant in surgeries, this dosing regimen appears insufficient. With our derived dose recommendations, we provide a solution for this issue.