scholarly journals Pharmacokinetics of remdesivir and GS-441524 in two critically ill patients who recovered from COVID-19

2020 ◽  
Vol 75 (10) ◽  
pp. 2977-2980 ◽  
Author(s):  
Massimo Tempestilli ◽  
Priscilla Caputi ◽  
Valeria Avataneo ◽  
Stefania Notari ◽  
Olindo Forini ◽  
...  
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Drug Exposure ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Loading Dose ◽  
Blood Samples ◽  
Csf Concentration ◽  
Pharmacokinetic Evaluation

Abstract Background Remdesivir is a prodrug of the nucleoside analogue GS-441524 and is under evaluation for treatment of SARS-CoV-2-infected patients. Objectives To evaluate the pharmacokinetics of remdesivir and GS-441524 in plasma, bronchoalveolar aspirate (BAS) and CSF in two critically ill COVID-19 patients. Methods Remdesivir was administered at 200 mg loading dose on the first day followed by 12 days of 100 mg in two critically ill patients. Blood samples were collected immediately after (C0) and at 1 (C1) and 24 h (C24) after intravenous administration on day 3 until day 9. BAS samples were collected on Days 4, 7 and 9 from both patients while one CSF on Day 7 was obtained in one patient. Remdesivir and GS-441524 concentrations were measured in these samples using a validated UHPLC-MS/MS method. Results We observed higher concentrations of remdesivir at C0 (6- to 7-fold higher than EC50 from in vitro studies) and a notable decay at C1. GS-441524 plasma concentrations reached a peak at C1 and persisted until the next administration. Higher concentrations of GS-441524 were observed in the patient with mild renal dysfunction. Mean BAS/plasma concentration ratios of GS-441524 were 2.3% and 6.4% in Patient 1 and Patient 2, respectively. The CSF concentration found in Patient 2 was 25.7% with respect to plasma. GS-441524 levels in lung and CNS suggest compartmental differences in drug exposure. Conclusions We report the first pharmacokinetic evaluation of remdesivir and GS-441524 in recovered COVID-19 patients. Further study of the pharmacokinetic profile of remdesivir, GS-441524 and the intracellular triphosphate form are required.

scholarly journals New Colistin Population Pharmacokinetic Data in Critically Ill Patients Suggesting an Alternative Loading Dose Rationale

2014 ◽  
Vol 58 (12) ◽  
pp. 7324-7330 ◽  
Author(s):  
N. Grégoire ◽  
O. Mimoz ◽  
B. Mégarbane ◽  
E. Comets ◽  
D. Chatelier ◽  
...  
Keyword(s):  
Steady State ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Plasma Concentrations ◽  
Multidrug Resistant ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Data ◽  
Loading Dose ◽  
Liquid Chromatography Tandem Mass

ABSTRACTColistin is an old antibiotic that has recently gained a considerable renewal of interest as the last-line defense therapy against multidrug-resistant Gram-negative bacteria. It is administered as colistin methanesulfonate (CMS), an inactive prodrug, and it was shown that due to slow CMS conversion, colistin plasma concentrations increase very slowly after treatment initiation, which constitutes the rationale for a loading dose in critically ill patients. However, faster CMS conversion was observed in healthy volunteers but using a different CMS brand, which may also have a major impact on colistin pharmacokinetics. Seventy-three critically ill patients not undergoing dialysis received multiple doses of CMS. The CMS concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a pharmacokinetic analysis was conducted using a population approach. We confirmed that CMS renal clearance and colistin concentrations at steady state are mostly governed by creatinine clearance, but we predict a typical maximum concentration of drug in serum (Cmax) of colistin close to 2 mg/liter, occurring 3 h after an initial dose of 2 million international units (MIU) of CMS. Accordingly, the estimated colistin half-life (t1/2) was relatively short (3.1 h), with rapid attainment of steady state. Our results are only partially consistent with other recently published results. We confirm that the CMS maintenance dose should be adjusted according to renal function in critically ill patients. However, much higher than expected colistin concentrations were observed after the initial CMS dose, with rapid steady-state achievement. These discrepancies challenge the pharmacokinetic rationale for a loading dose, which may still be appropriate for rapid bacterial eradication and an improved clinical cure rate.

scholarly journals High-Dose Continuous Oxacillin Infusion Results in Achievement of Pharmacokinetics Targets in Critically Ill Patients with Deep Sternal Wound Infections following Cardiac Surgery

2014 ◽  
Vol 58 (9) ◽  
pp. 5448-5455 ◽  
Author(s):  
Nicolas Nesseler ◽  
Marie-Clémence Verdier ◽  
Yoann Launey ◽  
Alexandre Malherbe ◽  
Marine Dermu ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Continuous Infusion ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Plasma Concentrations ◽  
High Dose ◽  
Loading Dose ◽  
Wound Infections ◽  
Sternal Wound Infections ◽  
Deep Sternal Wound Infections

ABSTRACTKnowledge regarding antimicrobial therapy strategies in deep sternal wound infections (DSWI) following cardiac surgery is limited. Therefore, we aimed to determine the steady-state plasma and mediastinal concentrations of oxacillin administered by continuous infusion in critically ill patients with DSWI and to compare these concentrations with the susceptibility of staphylococci recovered. A continuous infusion of oxacillin (150 to 200 mg/kg of body weight/24 h) was administered after a loading dose (50 mg/kg). Plasma and mediastinal concentrations of total and unbound oxacillin were determined 4 h after the loading dose (H4) and then at day 1 (H24) and day 2 (H48). Twelve patients were included. Nine patients exhibited bacteremia, 5 were in septic shock, 8 were positive forStaphylococcus aureus, and 4 were positive for coagulase-negative staphylococci. The median MIC (first to third interquartile range) was 0.25 (0.24 to 0.41) mg/liter. Median plasma concentrations of total and unbound oxacillin at H4, H24, and H48 were, respectively, 64.4 (41.4 to 78.5) and 20.4 (12.4 to 30.4) mg/liter, 56.9 (31.4 to 80.6) and 21.7 (6.5 to 27.3) mg/liter, and 57.5 (32.2 to 85.1) and 20 (14.3 to 35.7) mg/liter. The median mediastinal concentrations of total and unbound oxacillin at H4, H24, and H48 were, respectively, 2.3 (0.7 to 25.9) and 0.9 (<0.5 to 15) mg/liter, 29.1 (19.7 to 38.2) and 12.6 (5.9 to 19.8) mg/liter, and 31.6 (14.9 to 42.9) and 17.1 (6.7 to 26.7) mg/liter. High-dose oxacillin delivered by continuous infusion is a valuable strategy to achieve our pharmacokinetic target (4× MIC) at the site of action at H24. But concerns remain in cases of higher MICs, emphasizing the need for clinicians to obtain the MICs for the bacteria and to monitor oxacillin concentrations, especially the unbound forms, at the target site.

scholarly journals Application of a Loading Dose of Colistin Methanesulfonate in Critically Ill Patients: Population Pharmacokinetics, Protein Binding, and Prediction of Bacterial Kill

2012 ◽  
Vol 56 (8) ◽  
pp. 4241-4249 ◽  
Author(s):  
Ami F. Mohamed ◽  
Ilias Karaiskos ◽  
Diamantis Plachouras ◽  
Matti Karvanen ◽  
Konstantinos Pontikis ◽  
...  
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Half Life ◽  
Equilibrium Dialysis ◽  
Compartment Model ◽  
Pharmacokinetic Data ◽  
Loading Dose ◽  
Content Type ◽  
Colistin Methanesulfonate

ABSTRACTA previous pharmacokinetic study on dosing of colistin methanesulfonate (CMS) at 240 mg (3 million units [MU]) every 8 h indicated that colistin has a long half-life, resulting in insufficient concentrations for the first 12 to 48 h after initiation of treatment. A loading dose would therefore be beneficial. The aim of this study was to evaluate CMS and colistin pharmacokinetics following a 480-mg (6-MU) loading dose in critically ill patients and to explore the bacterial kill following the use of different dosing regimens obtained by predictions from a pharmacokinetic-pharmacodynamic model developed from anin vitrostudy onPseudomonas aeruginosa. The unbound fractions of colistin A and colistin B were determined using equilibrium dialysis and considered in the predictions. Ten critically ill patients (6 males; mean age, 54 years; mean creatinine clearance, 82 ml/min) with infections caused by multidrug-resistant Gram-negative bacteria were enrolled in the study. The pharmacokinetic data collected after the first and eighth doses were analyzed simultaneously with the data from the previous study (total, 28 patients) in the NONMEM program. For CMS, a two-compartment model best described the pharmacokinetics, and the half-lives of the two phases were estimated to be 0.026 and 2.2 h, respectively. For colistin, a one-compartment model was sufficient and the estimated half-life was 18.5 h. The unbound fractions of colistin in the patients were 26 to 41% at clinical concentrations. Colistin A, but not colistin B, had a concentration-dependent binding. The predictions suggested that the time to 3-log-unit bacterial kill for a 480-mg loading dose was reduced to half of that for the dose of 240 mg.

Design, Synthesis, and Pharmacokinetic Evaluation of O-Carbamoyl Tizoxanide Prodrugs

2020 ◽  
Vol 16 ◽  
Author(s):  
Xi He ◽  
Wenjun Hu ◽  
Fanhua Meng ◽  
Xingzhou Li
Keyword(s):  
Plasma Concentration ◽  
Broad Spectrum ◽  
Plasma Concentrations ◽  
Antiviral Drug ◽  
Systemic Exposure ◽  
Pharmacokinetic Profile ◽  
Hydroxyl Group ◽  
First Pass

Background: The broad-spectrum antiparasitic drug nitazoxanide (N) has been repositioned as a broad-spectrum antiviral drug. Nitazoxanide’s in vivo antiviral activities are mainly attributed to its metabolitetizoxanide, the deacetylation product of nitazoxanide. In reference to the pharmacokinetic profile of nitazoxanide, we proposed the hypotheses that the low plasma concentrations and the low system exposure of tizoxanide after dosing with nitazoxanide result from significant first pass effects in the liver. It was thought that this may be due to the unstable acyloxy bond of nitazoxanide. Objective: Tizoxanide prodrugs, with the more stable formamyl substituent attached to the hydroxyl group rather than the acetyl group of nitazoxanide, were designed with the thought that they might be more stable in plasma. It was anticipated that these prodrugs might be less affected by the first pass effect, which would improve plasma concentrations and system exposure of tizoxanide. Method: These O-carbamoyl tizoxanide prodrugs were synthesized and evaluated in a mouse model for pharmacokinetic (PK) properties and in an in vitro model for plasma stabilities. Results: The results indicated that the plasma concentration and the systemic exposure of tizoxanide (T) after oral administration of O-carbamoyl tizoxanide prodrugs were much greater than that produced by equimolar dosage of nitazoxanide. It was also found that the plasma concentration and the systemic exposure of tizoxanide glucuronide (TG) were much lower than that produced by nitazoxanide. Conclusion: Further analysis showed that the suitable plasma stability of O-carbamoyl tizoxanide prodrugs is the key factor in maximizing the plasma concentration and the systemic exposure of the active ingredient tizoxanide.

Pharmacokinetic Evaluation of Voriconazole Treatment in Critically Ill Patients Undergoing Continuous Venovenous Hemofiltration

2011 ◽  
Vol 33 (4) ◽  
pp. 393-397 ◽  
Author(s):  
Jaroslav Radej ◽  
Ales Krouzecky ◽  
Pavel Stehlik ◽  
Roman Sykora ◽  
Jiri Chvojka ◽  
...  
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Continuous Venovenous Hemofiltration ◽  
Pharmacokinetic Evaluation

scholarly journals Benefits of a Pharmacology Antimalarial Reference Standard and Proficiency Testing Program Provided by the Worldwide Antimalarial Resistance Network (WWARN)

2014 ◽  
Vol 58 (7) ◽  
pp. 3889-3894 ◽  
Author(s):  
Chris Lourens ◽  
Niklas Lindegardh ◽  
Karen I. Barnes ◽  
Philippe J. Guerin ◽  
Carol H. Sibley ◽  
...  
Keyword(s):  
Proficiency Testing ◽  
Antimalarial Drug ◽  
Drug Exposure ◽  
Plasma Concentrations ◽  
Quality Of Data ◽  
Internal Standards ◽  
Resistance Network ◽  
Antimalarial Resistance ◽  
Different Populations

ABSTRACTComprehensive assessment of antimalarial drug resistance should include measurements of antimalarial blood or plasma concentrations in clinical trials and in individual assessments of treatment failure so that true resistance can be differentiated from inadequate drug exposure. Pharmacometric modeling is necessary to assess pharmacokinetic-pharmacodynamic relationships in different populations to optimize dosing. To accomplish both effectively and to allow comparison of data from different laboratories, it is essential that drug concentration measurement is accurate. Proficiency testing (PT) of laboratory procedures is necessary for verification of assay results. Within the Worldwide Antimalarial Resistance Network (WWARN), the goal of the quality assurance/quality control (QA/QC) program is to facilitate and sustain high-quality antimalarial assays. The QA/QC program consists of an international PT program for pharmacology laboratories and a reference material (RM) program for the provision of antimalarial drug standards, metabolites, and internal standards for laboratory use. The RM program currently distributes accurately weighed quantities of antimalarial drug standards, metabolites, and internal standards to 44 pharmacology,in vitro, and drug quality testing laboratories. The pharmacology PT program has sent samples to eight laboratories in four rounds of testing. WWARN technical experts have provided advice for correcting identified problems to improve performance of subsequent analysis and ultimately improved the quality of data. Many participants have demonstrated substantial improvements over subsequent rounds of PT. The WWARN QA/QC program has improved the quality and value of antimalarial drug measurement in laboratories globally. It is a model that has potential to be applied to strengthening laboratories more widely and improving the therapeutics of other infectious diseases.

Evaluation of plasma levels of meropenem in septic patients during extracorporeal blood purification

2021 ◽  
Vol 20 (4) ◽  
pp. 81-94
Author(s):  
Artem V. Marukhov ◽  
Elena V. Murzina ◽  
Mikhail V. Zakharov ◽  
Genrikh A. Sofronov ◽  
Lyudmila V. Buryakova ◽  
...  
Keyword(s):  
Septic Shock ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Selective Adsorption ◽  
Plasma Concentrations ◽  
Blood Purification ◽  
Continuous Hemodiafiltration ◽  
Extracorporeal Blood ◽  
Extracorporeal Blood Purification ◽  
Extracorporeal Support

The relevance. Meropenem is a broad-spectrum carbapenem antibiotic widely used to treat patients with sepsis / septic shock. Critically ill patients are usually supported with one of the forms extracorporeal blood purification. However, data on the effect of various extracorporeal support techniques on the pharmacokinetics and pharmacodynamics of meropenem are insufficient or contradictory. Aim: To evaluate the effectiveness of meropenem dosage regimens in the treatment of septic patients during extracorporeal blood purification. Materials and methods. Plasma concentrations of meropenem were monitored in three critically ill patients with sepsis or septic shock. Patients were treated using various extracorporeal support techniques. Meropenem was used as empirical antibacterial mono- or complex therapy (1 g every 8 or 12 hours). Meropenem concentrations in plasma were determined by validated assay methods on Acquity ultraefficient liquid chromatography (UPLC) H-Class system. Results. It is shown that the meropenem plasma concentration in critically ill patients changes significantly. It was found that the standard meropenem dosing regimens in patients with sepsis / septic shock during continuous hemodiafiltration do not ensure the achievement of the PK/PD target of 100% TMIC for sensitive strains (MIC2 mg/L) and for intermediate resistance pathogens (2MIC8 mg/L). Continuous hemofiltration and selective adsorption of lipopolysaccharide have a less pronounced effect on the clearance of meropenem. Conclusion. To increase the effectiveness of antibacterial therapy, it is necessary to conduct research aimed at developing protocols for dosing antibacterial drugs for the treatment of sepsis during extracorporeal blood purification.

Hydrocortisone vs Tocilizumab Effects on Cytokine Storm in Critically Ill Patients with COVID-19.

2020 ◽  
Author(s):  
Maria Vargas ◽  
Pasquale Buonanno ◽  
Carmine Iacovazzo ◽  
Gaetano Di Spigna ◽  
Daniela Spalletti ◽  
...  
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Statistical Significance ◽  
Plasma Concentrations ◽  
Severe Pneumonia ◽  
Cytokine Storm ◽  
Tnf Α ◽  
Speed Up ◽  
The Impact ◽  
Late Stages

Abstract Introduction: Patients with severe pneumonia due COVID-19 are reported to have substantially lower lymphocyte counts and higher plasma concentrations of a number of inflammatory cytokines. In the late stages of COVID-19, cytokine storms are the mainly cause of disease progression and death. We performed a prospective observational study to evaluate the impact of tocilizumab and hydrocortisone on cytokine storm in critically ill patients with COVID-19.Methods: We included all adult patients with laboratory-confirmed COVID-19 infection and severe respiratory failure admitted to our ICU from March 10 to April 30. As therapeutic options, patients received tocilizumab od hydrocortisone. The primary end point was the evaluation of cytokine storm in terms of variation of the IL-6 and IL-6R, sgp130 and TNF-α concentrations during time to different treatment.Results: Eight patients received tocilizumab while 15 patients received hydrocortisone. IL-6 levels were lower in the hydrocortisone group with statistical significance was found at the days 2, 3, 8 and 9. The levels of IL-6R were lower during the days in the hydrocortisone group with statistical significance at days 1, 2, 3, 4, 5, 6, 8 and 10. Hydrocortisone group had higher levels of TNF-α at days 2, 3 and 4. The levels of sgo130 between tocilizumab and hydrocortisone groups were not statistically different during the days.Conclusions: In critically ill patients with severe COVID-19, the use of hydrocortisone allowed a better control of the cytokine storms, was further associated to less days of curarization, pronation and length of stay in ICU, and speed up the time to get negative RT-PCR swab.

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