scholarly journals Population Pharmacokinetics of High-Dose Continuous-Infusion Meropenem and Considerations for Use in the Treatment of Infections Due to KPC-Producing Klebsiella pneumoniae

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Piergiorgio Cojutti ◽  
Assunta Sartor ◽  
Elda Righi ◽  
Claudio Scarparo ◽  
Matteo Bassetti ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Renal Function ◽  
Klebsiella Pneumoniae ◽  
Monte Carlo Simulations ◽  
Continuous Infusion ◽  
Population Pharmacokinetics ◽  
University Hospital ◽  
Therapeutic Drug ◽  
High Dose ◽  
Content Type

ABSTRACT We assessed the population pharmacokinetics of high-dose continuous-infusion (HDCI) meropenem in a cohort of patients with Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) infections. Monte Carlo simulations were used to define the permissible HDCI meropenem regimens that could be safely considered for the treatment of KPC-Kp infections due to meropenem-resistant strains. Permissible doses were arbitrarily defined as those associated with a ≤10% to 15% likelihood of meropenem steady-state concentrations (C ss) of >100 mg/liter. Probabilities of target attainment (PTA) of four incremental pharmacodynamic determinants for meropenem efficacy (100% T>1×MIC, 100% T>2×MIC, 100% T>3×MIC, and 100% T>4×MIC, where “T>MIC” represents the time during which the plasma concentration of this time-dependent antibacterial agent is maintained above the MIC for the pathogen) in relation to different classes of renal function were calculated. The cumulative fractions of response (CFR) for the permissible HDCI meropenem regimens were calculated against the MIC distribution of the KPC-Kp clinical isolates that were collected routinely at our University Hospital between 2013 and 2016 (n = 169). Ninety-seven meropenem C ss were included in the analysis. The final model included creatinine clearance (CrCL) as a covariate and explained 94% of the population variability. Monte Carlo simulations based on licensed dosages of up to 6 g/day predicted an acceptable PTA (>80%) of 100% T>1×MIC against KPC-Kp with a meropenem MIC of ≤32 mg/liter in patients with a CrCL level of <130 ml/min. Dosages of 8 g/day were needed for achieving the same target in patients with CrCL at levels of 130 to 200 ml/min. In dealing with pathogens with a meropenem MIC of 64 mg/liter, HDCI regimens using meropenem at higher than licensed levels should be considered. In these cases, real-time therapeutic drug monitoring could be a useful adjunct for optimized care. The predicted CFR were >75% in all of the classes of renal function.

scholarly journals Population Pharmacokinetics and Pharmacodynamics of Levofloxacin in Acutely Hospitalized Older Patients with Various Degrees of Renal Function

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Pier Giorgio Cojutti ◽  
Virginia Ramos-Martin ◽  
Isabella Schiavon ◽  
Paolo Rossi ◽  
Massimo Baraldo ◽  
...  
Keyword(s):  
Renal Function ◽  
Clinical Outcome ◽  
Creatinine Clearance ◽  
Population Pharmacokinetics ◽  
Older Patients ◽  
Classification And Regression Tree ◽  
Therapeutic Drug ◽  
Time Curve ◽  
Content Type ◽  
Cart Analysis

ABSTRACT A retrospective study was conducted in a large sample of acutely hospitalized older patients who underwent therapeutic drug monitoring during levofloxacin treatment. The aim was to assess the population pharmacokinetics (popPK) and pharmacodynamics of levofloxacin among older patients. PopPK and Monte Carlo simulation were performed to define the permissible doses in older patients according to various degrees of renal function. Classification and regression tree (CART) analysis was used to detect the cutoff 24-hour area under the concentration-time curve (AUC24)/MIC ratio that best correlated with the clinical outcome. The probability of target attainment (PTA) of this value was calculated against different pathogens. A total of 168 patients were included, and 330 trough and 239 peak concentrations were used for the popPK analysis. Creatinine clearance (CrCL) was the only covariate that improved the model fit (levofloxacin CL = 0.399 + 0.051 × CrCLCKD-EPI [creatinine clearance estimated by means of the chronic kidney disease epidemiology]). Drug doses ranged between 500 mg every 48 h and 500 mg every 12 h in relation to different renal functions. The identified cutoff AUC24/MIC ratio (≥95.7) was the only covariate that correlated with a favorable clinical outcome in multivariate regression analysis (odds ratio [OR], 20.85; 95% confidence interval [CI], 1.56 to 186.73). PTAs were optimal (>80%) against Escherichia coli and Haemophilus influenzae, borderline against Staphylococcus aureus, and suboptimal against Pseudomonas aeruginosa. The levofloxacin doses defined in our study may be effective for the treatment of infections due to bacterial pathogens, with an MIC of ≤0.5 mg/liter in older patients with various degrees of renal function, while minimizing the toxicity risk. Conversely, the addition of another active antimicrobial should be considered whenever treating infections caused by less susceptible pathogens.

scholarly journals High-Dosage Cefazolin Achieves Sufficient Cerebrospinal Diffusion To Treat an External Ventricular Drainage-Related Staphylococcus aureus Ventriculitis

2018 ◽  
Vol 63 (2) ◽  
pp. e01844-18 ◽  
Author(s):  
Matthieu Grégoire ◽  
Benjamin Gaborit ◽  
Colin Deschanvres ◽  
Raphaël Lecomte ◽  
Guillaume Deslandes ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cerebrospinal Fluid ◽  
Continuous Infusion ◽  
External Ventricular Drainage ◽  
High Dose ◽  
Ventricular Drainage ◽  
Content Type

ABSTRACT A patient received continuous infusion of cefazolin 10 g then 8 g daily for an external ventricular drainage-related methicillin-susceptible Staphylococcus aureus (MSSA) ventriculitis. Median free concentrations in the cerebrospinal fluid were 11.9 and 6.1 mg/liter after 10- and 8-g doses, respectively. Free concentrations in the cerebrospinal fluid were always above the MIC usually displayed by methicillin-susceptible Staphylococcus aureus (MSSA) isolates. These results support the use of high-dose cefazolin to achieve sufficient meningeal concentrations.

scholarly journals Population Pharmacokinetics of Continuous-Infusion Meropenem in Febrile Neutropenic Patients with Hematologic Malignancies: Dosing Strategies for Optimizing Empirical Treatment against Enterobacterales and P. aeruginosa

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 785
Author(s):  
Pier Giorgio Cojutti ◽  
Anna Candoni ◽  
Davide Lazzarotto ◽  
Carla Filì ◽  
Maria Zannier ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Continuous Infusion ◽  
Hematologic Malignancies ◽  
Population Pharmacokinetic Analysis ◽  
Empirical Treatment ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Dosing Strategies ◽  
Neutropenic Patients

A population pharmacokinetic analysis of continuous infusion (CI) meropenem was conducted in a prospective cohort of febrile neutropenic (FN) patients with hematologic malignancies. A non-parametric approach with Pmetrics was used for pharmacokinetic analysis and covariate evaluation. Monte Carlo simulations were performed for identifying the most appropriate dosages for empirical treatment against common Enterobacterales and P. aeruginosa. The probability of target attainment (PTA) of steady-state meropenem concentration (Css)-to-minimum inhibitory concentration (MIC) ratio (Css/MIC) ≥1 and ≥4 at the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoint of 2 mg/L were calculated. Cumulative fraction of response (CFR) against Enterobacterales and P. aeruginosa were assessed as well. PTAs and CFRs ≥ 90% were considered optimal. A total of 61 patients with 178 meropenem Css were included. Creatinine clearance (CLCR) was the only covariate associated with meropenem clearance. Monte Carlo simulations showed that dosages of meropenem ranging between 1 g q8h and 1.25 g q6h by CI may grant optimal PTAs of Css/MIC ≥4 at the EUCAST clinical breakpoint. Optimal CFRs may be granted with these dosages against the Enterobacterales at Css/MIC ≥ 4 and against P. aeruginosa at Css/MIC ≥ 1. When dealing against P. aeruginosa at Css/MIC ≥ 4, only a dosage of 1.5 g q6h by CI may grant quasi-optimal CFR (around 80–87%). In conclusion, our findings suggest that dosages of meropenem ranging between 1 g q8h and 1.25 g q6h by CI may maximize empirical treatment against Enterobacterales and P. aeruginosa among FN patients with hematologic malignancies having different degree of renal function.

scholarly journals Evaluation by Monte Carlo Simulation of the Pharmacokinetics of Two Doses of Meropenem Administered Intermittently or as a Continuous Infusion in Healthy Volunteers

2005 ◽  
Vol 49 (5) ◽  
pp. 1881-1889 ◽  
Author(s):  
Wolfgang A. Krueger ◽  
Jurgen Bulitta ◽  
Martina Kinzig-Schippers ◽  
Cornelia Landersdorfer ◽  
Ulrike Holzgrabe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Monte Carlo ◽  
Liquid Chromatography ◽  
Healthy Volunteers ◽  
Continuous Infusion ◽  
Intravenous Infusion ◽  
High Dose ◽  
Loading Dose ◽  
Group A ◽  
Group B

ABSTRACT Meropenem is a broad-spectrum carbapenem antibacterial agent. In order to optimize levels in plasma relative to the MICs, the ideal dose level and dosage regimen need to be determined. The pharmacokinetics of meropenem were studied in two groups, each comprising eight healthy volunteers who received the following doses: 500 mg as an intravenous infusion over 30 min three times a day (t.i.d.) versus a 250-mg loading dose followed by a 1,500 mg continuous infusion over 24 h for group A and 1,000 mg as an intravenous infusion over 30 min t.i.d. versus a 500-mg loading dose followed by a 3,000-mg continuous infusion over 24 h for group B. Meropenem concentrations in plasma and urine were determined by liquid chromatography-mass spectrometry/mass spectrometry and high-performance liquid chromatography with UV detection, respectively. Pharmacokinetic calculations were done by use of a two-compartment open model, and the data were extrapolated by Monte Carlo simulations for 10,000 simulated subjects for pharmacodynamic evaluation. There were no significant differences in total clearance and renal clearance between group A and group B or between the intermittent treatment and the continuous infusion. The analyses of the probability of target attainment by MIC for the high- and low-dose continuous infusions were robust up to MICs of 4 mg/liter and 2 mg/liter, respectively. The corresponding values for intermittent infusions were only 0.5 mg/liter and 0.25 mg/liter. When these observations were correlated with MICs obtained from the MYSTIC database, intermittent infusion results in adequate activity against two of the most common nosocomially acquired pathogens, Klebsiella pneumoniae and Enterobacter cloacae. However, against Pseudomonas aeruginosa, the evaluation shows a clear advantage of high-dose therapy administered as a continuous infusion. We believe that in the empirical therapy situation, the continuous-infusion mode of administration is most worth the extra efforts. We conclude that clinical trials for evaluation of the continuous infusions of meropenem in critically ill patients are warranted.

scholarly journals Risk of higher dose methotrexate for renal impairment in patients with rheumatoid arthritis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Keigo Hayashi ◽  
Ken-Ei Sada ◽  
Yosuke Asano ◽  
Sumie Hiramatsu Asano ◽  
Yuriko Yamamura ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Renal Function ◽  
Renal Impairment ◽  
Disease Duration ◽  
Linear Regression Analysis ◽  
University Hospital ◽  
High Dose ◽  
Concomitant Treatment ◽  
Confounding Factors ◽  
Dose Methotrexate

Abstract Renal impairment is a major concern in patients taking high-dose methotrexate (MTX) for malignancy, but it has not been fully explored in rheumatoid arthritis (RA) patients taking low-dose MTX. This study aimed to elucidate the dose-dependent effects of MTX on the renal function of patients with RA. We retrospectively reviewed 502 consecutive RA patients who were prescribed MTX for ≥ 1 year at Okayama University Hospital between 2006 and 2018. The primary outcome was the change in estimated glomerular filtration rate (eGFR) over 1 year. The association between MTX dosage (< 8, 8–12, and ≥ 12 mg/week) and the change in eGFR was evaluated using multiple linear regression analysis with adjustment for possible confounding factors including age, sex, disease duration, body weight, comorbidity, baseline eGFR, concomitant treatment, and disease activity. Mean patient age was 63 years; 394 (78%) were female. Median disease duration was 77 months, while mean MTX dosage was 8.6 mg/week. The last 1-year change of eGFR (mean ± SD) in patients treated with MTX < 8 (n = 186), 8–12 (n = 219), ≥ 12 mg/week (n = 97) decreased by 0.2 ± 7.3, 0.6 ± 8.6, and 4.5 ± 7.9 mL/min/1.73 m2/year, respectively (p < 0.0001). After adjustment for the confounding factors, MTX ≥ 12 mg/week was still correlated with a decrease in 1-year eGFR (beta-coefficient: − 2.5; 95% confidence interval, − 4.3 to − 0.6; p = 0.0089) in contrast to MTX 8–12 mg/week. Careful monitoring of renal function is required in patients with MTX ≥ 12 mg/week over the course of RA treatment regardless of disease duration.

Ion Beam Induced Intermixing of Wsi0.45 on GaAs

1988 ◽  
Vol 128 ◽  
Author(s):  
S. J. Pearton ◽  
K. T. Short ◽  
K. S. Jones ◽  
A. G. Baca ◽  
C. S. Wu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Ion Beam ◽  
Dose Range ◽  
Device Fabrication ◽  
Electrical Activation ◽  
High Dose ◽  
Dislocation Loops ◽  
Semiconductor Interface ◽  
High Level

ABSTRACTThe systematics of ion beam induced intermixing of WSi0.45 on GaAs have been studied after through-implantation of Si or O in the dose range 1013 − 5 × 1016 cm−2. SIMS profiling shows significant knock-on of Si and W into the GaAs at the high dose range in accordance with Monte Carlo simulations, but there is virtually no electrical activation (≤0.1%) of this Si after normal implant annealing (900°C, 10 sec). This appears to be a result of the high level of disorder near the metal-semiconductor interface, which is not repaired by annealing. This damage consists primarily of dislocation loops extending a few hundred angstroms below the end of range of the implanted ions. Extrapolation of the ion doses used in this work to the usual doses used in GaAs device fabrication would imply that ion-induced intermixing of WSix will not be significant in through-implantation processes.

scholarly journals Evaluating Ciprofloxacin Dosing for Pseudomonas aeruginosa Infection by Using Clinical Outcome-Based Monte Carlo Simulations

2005 ◽  
Vol 49 (10) ◽  
pp. 4009-4014 ◽  
Author(s):  
Sheryl Zelenitsky ◽  
Robert Ariano ◽  
Godfrey Harding ◽  
Alan Forrest
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Monte Carlo ◽  
Clinical Outcome ◽  
Monte Carlo Simulations ◽  
Standard Dose ◽  
High Dose ◽  
Target Attainment ◽  
Real Patient ◽  
Dosing Regimens ◽  
Cure Rates

ABSTRACT Pseudomonas aeruginosa causes serious infections whose outcome is highly dependent on antimicrobial therapy. The goal of this study was to predict the relative efficacies of three ciprofloxacin dosing regimens for P. aeruginosa infection using clinical outcome-based Monte Carlo simulations (MCS) with “real patient” demographics, pharmacokinetics, MICs, and pharmacodynamics (PDs). Each cohort consisted of 1,000 simulated study subjects. Three ciprofloxacin dosing regimens were studied, including (i) the recommended standard dose of 400 mg given intravenously (i.v.) every 12 h (q12h), (ii) the recommended high dose of 400 mg i.v. q8h, and (iii) a novel, PD-targeted regimen to attain a ƒAUC/MIC value of >86. Probability of target attainment (PTA) and probability of cure (POC) were determined for each regimen. POC with the standard dose was at least 0.90 if pathogen MICs were ≤0.25 μg/ml but only 0.59 or 0.27 if MICs were 0.5 or 1 μg/ml, respectively. Predicted cure rates in these MIC categories were significantly higher at 0.72 and 0.40 with the high dose and 0.91 and 0.72 with the PD-targeted regimen(P < 0.0001). Analyses based on the local susceptibility profile produced PTA and POC estimates of 0.44 and 0.74 with the standard ciprofloxacin dose, 0.58 and 0.81 with the high dose, and 0.84 and 0.93 with the PD-targeted regimen, respectively. In conclusion, as demonstrated by clinical outcome-based MCSs, the highest recommended ciprofloxacin dose of 400 mg i.v. q8h should be used in the treatment of P. aeruginosa infection to improve PD target attainment and clinical cure. However, even this appears ineffective if pathogen MICs are 1 μg/ml, warranting the consideration of a lower MIC breakpoint, ≤0.5 μg/ml.

scholarly journals Prospective Evaluation of a Model-Based Dosing Regimen for Amikacin in Preterm and Term Neonates in Clinical Practice

2015 ◽  
Vol 59 (10) ◽  
pp. 6344-6351 ◽  
Author(s):  
A. Smits ◽  
R. F. W. De Cock ◽  
K. Allegaert ◽  
S. Vanhaesebrouck ◽  
M. Danhof ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Steady State ◽  
Monte Carlo Simulations ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Prospective Evaluation ◽  
Dosing Regimen ◽  
Model Based ◽  
Almost All ◽  
Trough Levels

ABSTRACTBased on a previously derived population pharmacokinetic model, a novel neonatal amikacin dosing regimen was developed. The aim of the current study was to prospectively evaluate this dosing regimen. First, early (before and after second dose) therapeutic drug monitoring (TDM) observations were evaluated for achieving target trough (<3 mg/liter) and peak (>24 mg/liter) levels. Second, all observed TDM concentrations were compared with model-predicted concentrations, whereby the results of a normalized prediction distribution error (NPDE) were considered. Subsequently, Monte Carlo simulations were performed. Finally, remaining causes limiting amikacin predictability (i.e., prescription errors and disease characteristics of outliers) were explored. In 579 neonates (median birth body weight, 2,285 [range, 420 to 4,850] g; postnatal age 2 days [range, 1 to 30 days]; gestational age, 34 weeks [range, 24 to 41 weeks]), 90.5% of the observed early peak levels reached 24 mg/liter, and 60.2% of the trough levels were <3 mg/liter (93.4% ≤5 mg/liter). Observations were accurately predicted by the model without bias, which was confirmed by the NPDE. Monte Carlo simulations showed that peak concentrations of >24 mg/liter were reached at steady state in almost all patients. Trough values of <3 mg/liter at steady state were documented in 78% to 100% and 45% to 96% of simulated cases with and without ibuprofen coadministration, respectively; suboptimal trough levels were found in patients with postnatal age <14 days and current weight of >2,000 g. Prospective evaluation of a model-based neonatal amikacin dosing regimen resulted in optimized peak and trough concentrations in almost all patients. Slightly adapted dosing for patient subgroups with suboptimal trough levels was proposed. This model-based approach improves neonatal dosing individualization.

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