scholarly journals Pharmacokinetics of Daptomycin in Critically Ill Pediatric Patients

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
Charalampos Antachopoulos ◽  
Stavroula Ilia ◽  
Paschalis Kadiltzoglou ◽  
Eirini Baira ◽  
Aristides Dokoumetzidis ◽  
...  
Keyword(s):  
Critically Ill ◽  
Drug Exposure ◽  
Pediatric Patients ◽  
Plasma Concentrations ◽  
Therapeutic Drug ◽  
Burn Patients ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Optimal Drug

ABSTRACT The pharmacokinetics of daptomycin (10 mg/kg once daily) was studied in 4 critically ill pediatric patients aged 8 to 14 yrs. The area under the concentration-time curve from time zero to infinity (AUC 0–∞ ) of plasma concentrations on day 1 ranged between 123.8 to 663.9 μg · h/ml, with lower values observed in septic and burn patients; clearance ranged from 15.1 to 80.7 ml/h/kg. Higher-than-recommended doses of daptomycin may be needed in septic children to ensure optimal drug exposure. Interpatient variability may suggest a role for therapeutic drug monitoring.

scholarly journals Is the Recommended Dose of Efavirenz Optimal in Young West African Human Immunodeficiency Virus-Infected Children?

2009 ◽  
Vol 53 (10) ◽  
pp. 4407-4413 ◽  
Author(s):  
Déborah Hirt ◽  
Saik Urien ◽  
Mathieu Olivier ◽  
Hélène Peyrière ◽  
Boubacar Nacro ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Body Weight ◽  
Plasma Concentrations ◽  
Individual Characteristics ◽  
Population Pharmacokinetic ◽  
Ratio Test ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Immunodeficiency Virus

ABSTRACT We aimed in this study to describe efavirenz concentration-time courses in treatment-naïve children after once-daily administration to study the effects of age and body weight on efavirenz pharmacokinetics and to test relationships between doses, plasma concentrations, and efficacy. For this purpose, efavirenz concentrations in 48 children were measured after 2 weeks of didanosine-lamivudine-efavirenz treatment, and samples were available for 9/48 children between months 2 and 5 of treatment. Efavirenz concentrations in 200 plasma specimens were measured using a validated high-performance liquid chromatography method. A population pharmacokinetic model was developed with NONMEM. The influence of individual characteristics was tested using a likelihood ratio test. The estimated minimal and maximal concentrations of efavirenz in plasma (C min and C max, respectively) and the area under the concentration-time curve (AUC) were correlated to the decrease in human immunodeficiency virus type 1 RNA levels after 3 months of treatment. The threshold C min (and AUC) that improved efficacy was determined. The target minimal concentration of 4 mg/liter was considered for toxicity. An optimized dosing schedule that would place the highest percentage of children in the interval of effective and nontoxic concentrations was simulated. The pharmacokinetics of efavirenz was best described by a one-compartment model with first-order absorption and elimination. The mean apparent clearance and volume of distribution for efavirenz were 0.211 liter/h/kg and 4.48 liters/kg, respectively. Clearance decreased significantly with age. When the recommended doses were given to 46 of the 48 children, 19% (44% of children weighing less than 15 kg) had C mins below 1 mg/liter. A significantly higher percentage of children with C mins of >1.1 mg/liter or AUCs of >51 mg/liter·h than of children with lower values had viral load decreases greater than 2 log10 copies/ml after 3 months of treatment. Therefore, to optimize the percentage of children with C mins between 1.1 and 4 mg/liter, children should receive the following once-daily efavirenz doses: 25 mg/kg of body weight from 2 to 6 years, 15 mg/kg from 6 to 10 years, and 10 mg/kg from 10 to 15 years. These assumptions should be prospectively confirmed.

scholarly journals Achieving a physiological cortisol profile with once-daily dual-release hydrocortisone: a pharmacokinetic study

2016 ◽  
Vol 175 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Gudmundur Johannsson ◽  
Hans Lennernäs ◽  
Claudio Marelli ◽  
Kevin Rockich ◽  
Stanko Skrtic
Keyword(s):  
Replacement Therapy ◽  
Plasma Concentrations ◽  
Open Label ◽  
Post Dose ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Endogenous Cortisol ◽  
Dual Release ◽  
Dose Proportional

Objective Oral once-daily dual-release hydrocortisone (DR-HC) replacement therapy was developed to provide a cortisol exposure−time profile that closely resembles the physiological cortisol profile. This study aimed to characterize single-dose pharmacokinetics (PK) of DR-HC 5–20mg and assess intrasubject variability. Methods Thirty-one healthy Japanese or non-Hispanic Caucasian volunteers aged 20−55 years participated in this randomized, open-label, PK study. Single doses of DR-HC 5, 15 (3×5), and 20mg were administered orally after an overnight fast and suppression of endogenous cortisol secretion. After estimating the endogenous cortisol profile, PK of DR-HC over 24h were evaluated to assess dose proportionality and impact of ethnicity. Plasma cortisol concentrations were analyzed using liquid chromatography−tandem mass spectrometry. PK parameters were calculated from individual cortisol concentration−time profiles. Results DR-HC 20mg provided higher than endogenous cortisol plasma concentrations 0−4h post-dose but similar concentrations later in the profile. Cortisol concentrations and PK exposure parameters increased with increasing doses. Mean maximal serum concentration (Cmax) was 82.0 and 178.1ng/mL, while mean area under the concentration−time curve (AUC)0−∞ was 562.8 and 1180.8h×ng/mL with DR-HC 5 and 20mg respectively. Within-subject PK variability was low (<15%) for DR-HC 20mg. All exposure PK parameters were less than dose proportional (slope <1). PK differences between ethnicities were explained by body weight differences. Conclusions DR-HC replacement resembles the daily normal cortisol profile. Within-subject day-to-day PK variability was low, underpinning the safety of DR-HC for replacement therapy. DR-HC PK were less than dose proportional – an important consideration when managing intercurrent illness in patients with adrenal insufficiency.

scholarly journals Pharmacodynamic Evaluation of RWJ-270201, a Novel Neuraminidase Inhibitor, in a Lethal Murine Model of Influenza Predicts Efficacy for Once-Daily Dosing

2001 ◽  
Vol 45 (7) ◽  
pp. 2115-2118 ◽  
Author(s):  
G. L. Drusano ◽  
S. L. Preston ◽  
D. Smee ◽  
K. Bush ◽  
K. Bailey ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Proportional Hazards ◽  
Explanatory Power ◽  
Neuraminidase Inhibitor ◽  
Cox Proportional Hazards ◽  
Time Data ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Drug Challenge

ABSTRACT We examined RWJ-270201 in a lethal model of influenza in BALB/c mice. The aim was to delineate the pharmacodynamically linked variable for the drug. Challenge was performed with influenza virus A/Shongdong/09/93 (H3N2). Treatment was administered by gavage. Five doses (1 to 10 mg/kg of body weight) and three schedules (every 24, 12, and 8 h) were evaluated with 10 mice per group. There were 39 placebo-treated mice. Drug exposure was evaluated for infected mice. Exposures were calculated after population modeling of all the plasma concentration-time data simulataneously using the NPEM3 program. Evaluation of dose and schedule with Kaplan-Meier analysis and Cox proportional hazards modeling demonstrated that schedule offered no explanatory power relative to dose alone. Evaluation of peak concentration, trough concentration, and area under the concentration-time curve (AUC) by the same methods revealed that AUC was the dynamically linked variable. Again, schedule offered no further explanatory power when included in the model with AUC. This indicates that AUC is the linked variable and that the anti-influenza effect of RWJ-270201 is independent of schedule. We conclude that once-daily dosing of RWJ-270201 should be evaluated in clinical trials of influenza therapy.

scholarly journals Relationship between Plasma Concentrations of Afatinib and the Onset of Diarrhea in Patients with Non-Small Cell Lung Cancer

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1054
Author(s):  
Hayato Yokota ◽  
Kazuhiro Sato ◽  
Sho Sakamoto ◽  
Yuji Okuda ◽  
Mariko Asano ◽  
...  
Keyword(s):  
Single Point ◽  
Plasma Concentrations ◽  
Small Cell ◽  
Therapeutic Drug ◽  
Small Cell Lung ◽  
Time Curve ◽  
Concentration Time ◽  
Kaplan Meier ◽  
Daily Dose ◽  
Plasma Concentration Time Curve

We evaluated the area under the plasma concentration–time curve (AUC) of afatinib required to avoid the onset of grade 2 or higher diarrhea. The C0 and AUC0–24 of afatinib were significant higher in patients with grade 2 diarrhea than in those with grade 0–1 diarrhea. The areas under the receiver operator curves were 0.795 with the highest sensitivity (89%) and specificity (74%) at an AUC0–24 threshold of 823.5 ng·h/mL, and 0.754 with the highest sensitivity (89%) and specificity (74%) at a C0 threshold of 28.5 ng/mL. In Kaplan–Meier analysis based on these cut-off AUC0–24 and C0 values, the median time to the incidence of grade 2 diarrhea was 16 days. The predicted AUC0–24 of afatinib from the single point of C6 showed the highest correlation with the measured AUC0–24 (r2 = 0.840); however, a significant correlation between the AUC0–24 and C0 was also observed (r2 = 0.761). C0 could be used as a marker of therapeutic drug monitoring because afatinib C0 was related to AUC0–24. Therefore, afatinib C0 should be monitored on day 8 after beginning therapy, and the daily dose of afatinib should be adjusted as an index with a cut-off value of 28.5 ng/mL.

scholarly journals Model-Informed Precision Dosing of Antibiotics in Pediatric Patients: A Narrative Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Alan Abdulla ◽  
Angela E. Edwina ◽  
Robert B. Flint ◽  
Karel Allegaert ◽  
Enno D. Wildschut ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Pediatric Patients ◽  
Significant Proportion ◽  
Patient Characteristics ◽  
Narrative Review ◽  
Therapeutic Drug ◽  
Analysis Model ◽  
Age Related ◽  
Co Morbidity ◽  
Optimal Drug

Optimal pharmacotherapy in pediatric patients with suspected infections requires understanding and integration of relevant data on the antibiotic, bacterial pathogen, and patient characteristics. Because of age-related physiological maturation and non-maturational covariates (e.g., disease state, inflammation, organ failure, co-morbidity, co-medication and extracorporeal systems), antibiotic pharmacokinetics is highly variable in pediatric patients and difficult to predict without using population pharmacokinetics models. The intra- and inter-individual variability can result in under- or overexposure in a significant proportion of patients. Therapeutic drug monitoring typically covers assessment of pharmacokinetics and pharmacodynamics, and concurrent dose adaptation after initial standard dosing and drug concentration analysis. Model-informed precision dosing (MIPD) captures drug, disease, and patient characteristics in modeling approaches and can be used to perform Bayesian forecasting and dose optimization. Incorporating MIPD in the electronic patient record system brings pharmacometrics to the bedside of the patient, with the aim of a consisted and optimal drug exposure. In this narrative review, we evaluated studies assessing optimization of antibiotic pharmacotherapy using MIPD in pediatric populations. Four eligible studies involving amikacin and vancomycin were identified from 418 records. Key articles, independent of year of publication, were also selected to highlight important attributes of MIPD. Although very little research has been conducted until this moment, the available data on vancomycin indicate that MIPD is superior compared to conventional dosing strategies with respect to target attainment. The utility of MIPD in pediatrics needs to be further confirmed in frequently used antibiotic classes, particularly aminoglycosides and beta-lactams.

scholarly journals Limited-Sampling Strategies for Anidulafungin in Critically Ill Patients

2014 ◽  
Vol 59 (2) ◽  
pp. 1177-1181 ◽  
Author(s):  
Marjolijn J. P. van Wanrooy ◽  
Johannes H. Proost ◽  
Michael G. G. Rodgers ◽  
Jan G. Zijlstra ◽  
Donald R. A. Uges ◽  
...  
Keyword(s):  
Linear Regression ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Sampling Strategies ◽  
Time Curve ◽  
Limited Sampling ◽  
Concentration Time

ABSTRACTEfficacy of anidulafungin is driven by the area under the concentration-time curve (AUC)/MIC ratio. Determination of the anidulafungin AUC along with MIC values can therefore be useful. Since obtaining a full concentration-time curve to determine an AUC is not always feasible or appropriate, limited-sampling strategies may be useful in adequately estimating exposure. The objective of this study was to develop a model to predict the individual anidulafungin exposure in critically ill patients using limited-sampling strategies. Pharmacokinetic data were derived from 20 critically ill patients with invasive candidiasis treated with anidulafungin. These data were used to develop a two-compartment model in MW\Pharm using an iterative 2-stage Bayesian procedure. Limited-sampling strategies were subsequently investigated using two methods, a Bayesian analysis and a linear regression analysis. The best possible strategies for these two methods were evaluated by a Bland-Altman analysis for correlation of the predicted and observed AUC from 0 to 24 h (AUC0–24) values. Anidulafungin exposure can be adequately estimated with the concentration from a single sample drawn 12 h after the start of the infusion either by linear regression (R2= 0.99; bias, 0.05%; root mean square error [RMSE], 3%) or using a population pharmacokinetic model (R2= 0.89; bias, −0.1%; RMSE, 9%) in critically ill patients and also in less severely ill patients, as reflected by healthy volunteers. Limited sampling can be advantageous for future studies evaluating the pharmacokinetics and pharmacodynamics of anidulafungin and for therapeutic drug monitoring in selected patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT01047267.)

scholarly journals Voriconazole Pharmacokinetics in Liver Transplant Recipients

2009 ◽  
Vol 54 (2) ◽  
pp. 852-859 ◽  
Author(s):  
H. J. Johnson ◽  
K. Han ◽  
B. Capitano ◽  
D. Blisard ◽  
S. Husain ◽  
...  
Keyword(s):  
Liver Transplant ◽  
Drug Exposure ◽  
Plasma Concentrations ◽  
Fixed Dose ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Prophylactic Regimen ◽  
Time Curve ◽  
Transplant Patients ◽  
Concentration Time

ABSTRACT The objective of this study was to evaluate the pharmacokinetics of voriconazole and the potential correlations between pharmacokinetic parameters and patient variables in liver transplant patients on a fixed-dose prophylactic regimen. Multiple blood samples were collected within one dosing interval from 15 patients who were initiated on a prophylactic regimen of voriconazole at 200 mg enterally (tablets) twice daily starting immediately posttransplant. Voriconazole plasma concentrations were measured using high-pressure liquid chromatography (HPLC). Noncompartmental pharmacokinetic analysis was performed to estimate pharmacokinetic parameters. The mean apparent systemic clearance over bioavailability (CL/F), apparent steady-state volume of distribution over bioavailability (V ss/F), and half-life (t 1/2) were 5.8 ± 5.5 liters/h, 94.5 ± 54.9 liters, and 15.7 ± 7.0 h, respectively. There was a good correlation between the area under the concentration-time curve from 0 h to infinity (AUC0-∞) and trough voriconazole plasma concentrations. t 1/2, maximum drug concentration in plasma (C max), trough level, AUC0-∞, area under the first moment of the concentration-time curve from 0 h to infinity (AUMC0-∞), and mean residence time from 0 h to infinity (MRT0-∞) were significantly correlated with postoperative time. t 1/2, λ, AUC0-∞, and CL/F were significantly correlated with indices of liver function (aspartate transaminase [AST], total bilirubin, and international normalized ratio [INR]). The C max, last concentration in plasma at 12 h (C last), AUMC0-∞, and MRT0-∞ were significantly lower in the presence of deficient CYP2C19*2 alleles. Donor characteristics had no significant correlation with any of the pharmacokinetic parameters estimated. A fixed dosing regimen of voriconazole results in a highly variable exposure of voriconazole in liver transplant patients. Given that trough voriconazole concentration is a good measure of drug exposure (AUC), the voriconazole dose can be individualized based on trough concentration measurements in liver transplant patients.

scholarly journals Therapeutic Drug Monitoring of Linezolid: a Retrospective Monocentric Analysis

2010 ◽  
Vol 54 (11) ◽  
pp. 4605-4610 ◽  
Author(s):  
Federico Pea ◽  
Mario Furlanut ◽  
Piergiorgio Cojutti ◽  
Francesco Cristini ◽  
Eleonora Zamparini ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
High Performance ◽  
Drug Exposure ◽  
Plasma Concentrations ◽  
Hplc Method ◽  
Therapeutic Drug ◽  
Time Curve ◽  
Standard Dosage ◽  
Wide Variability

ABSTRACT The objective of the present retrospective observational study carried out in patients receiving a standard dosage of linezolid and undergoing routine therapeutic drug monitoring (TDM) was to assess the interindividual variability in plasma exposure, to identify the prevalence of attainment of optimal pharmacodynamics, and to define if an intensive program of TDM may be warranted in some categories of patients. Linezolid plasma concentrations (trough [C min] and peak [C max] levels) were analyzed by means of a high-performance liquid chromatography (HPLC) method, and daily drug exposure was estimated (daily area under the plasma concentration-time curve [AUC24]). The final database included 280 C min and 223 C max measurements performed in 92 patients who were treated with the fixed 600-mg dose every 12 h (q12h) intravenously (n = 58) or orally (n = 34). A wide variability was observed (median values [interquartile range]: 3.80 mg/liter [1.75 to 7.53 mg/liter] for C min, 14.70 mg/liter [10.57 to 19.64] for C max, and 196.08 mg·h/liter [144.02 to 312.10 mg·h/liter] for estimated AUC24). Linezolid C min was linearly correlated with estimated AUC24 (r 2 = 0.85). Optimal pharmacodynamic target attainment (defined as C min of ≥2 mg/liter and/or AUC24/MIC90 ratio of >80) was obtained in about 60 to 70% of cases, but potential overexposure (defined as C min of ≥10 mg/liter and/or AUC24 of ≥400 mg·h/liter) was documented in about 12% of cases. A significantly higher proportion of cases with potential overexposure received cotreatment with omeprazole, amiodarone, or amlodipine. Our study suggests that the application of TDM might be especially worthwhile in about 30% of cases with the intent of avoiding either the risk of dose-dependent toxicity or that of treatment failure.

scholarly journals Association between voriconazole exposure and Sequential Organ Failure Assessment (SOFA) score in critically ill patients

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260656
Author(s):  
Anne-Lise Bienvenu ◽  
Pierre Pradat ◽  
Alexandra Plesa ◽  
Vincent Leclerc ◽  
Vincent Piriou ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Critically Ill ◽  
Sofa Score ◽  
Critically Ill Patients ◽  
Drug Exposure ◽  
Therapeutic Drug ◽  
Multicenter Cohort Study ◽  
Large Variability ◽  
Optimal Drug ◽  
The Impact

Therapeutic drug monitoring (TDM) is essential for voriconazole to ensure optimal drug exposure, mainly in critically ill patients for whom voriconazole demonstrated a large variability. The study aimed at describing factors associated with trough voriconazole concentrations in critically ill patients and evaluating the impact of voriconazole concentrations on adverse effects. A 2-year retrospective multicenter cohort study (NCT04502771) was conducted in six intensive care units. Adult patients who had at least one voriconazole TDM were included. Univariable and multivariable linear regression analyses were performed to identify predictors of voriconazole concentrations, and univariable logistic regression analysis, to study the relationship between voriconazole concentrations and adverse effects. During the 2-year study period, 70 patients were included. Optimal trough voriconazole concentrations were reported in 37 patients (52.8%), subtherapeutic in 20 (28.6%), and supratherapeutic in 13 (18.6%). Adverse effects were reported in six (8.6%) patients. SOFA score was identified as a factor associated with an increase in voriconazole concentration (p = 0.025), mainly in the group of patients who had SOFA score ≥ 10. Moreover, an increase in voriconazole concentration was shown to be a risk factor for occurrence of adverse effects (p = 0.011). In that respect, critically ill patients who received voriconazole treatment must benefit from a TDM, particularly if they have a SOFA score ≥ 10. Indeed, identifying patients who are overdosed will help to prevent voriconazole related adverse effects. This result is of utmost importance given the recognized COVID-19-associated pulmonary aspergillosis in ICU patients for whom voriconazole is among the recommended first-line treatment.

scholarly journals Validation of Heel Stick Microsampling To Optimize Micafungin Doses in Neonates and Young Infants

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Cinzia Auriti ◽  
Bianca Maria Goffredo ◽  
Maria Paola Ronchetti ◽  
Fiammetta Piersigilli ◽  
Sara Cairoli ◽  
...  
Keyword(s):  
Dose Adjustment ◽  
Plasma Concentrations ◽  
Therapeutic Drug ◽  
Strongly Correlated ◽  
Time Curve ◽  
Young Infants ◽  
Concentration Time ◽  
Critically Ill Neonates ◽  
The Mean ◽  
Neonates And Infants

ABSTRACT Major gaps exist in our knowledge of antimicrobial pharmacokinetics in critically ill neonates and infants that require validated microsampling and bioanalysis methods to support therapeutic drug monitoring. We compared serially collected intravenous (i.v.) and heel stick capillary (HSC)-sampled plasma concentrations of micafungin (8 mg/kg) in eight infants born preterm with systemic candidiasis. The mean (standard deviation) micafungin area under the plasma concentration-time curve to infinity (AUCinf) was 316 (65.0) h · mg/liter based on HSC concentrations that strongly correlated (R2 = 0.92) with i.v. values to support dose adjustment.

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