scholarly journals Intrapulmonary Distribution of Intravenous Telavancin in Healthy Subjects and Effect of Pulmonary Surfactant on In Vitro Activities of Telavancin and Other Antibiotics

2007 ◽  
Vol 52 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Mark H. Gotfried ◽  
Jeng-Pyng Shaw ◽  
Bret M. Benton ◽  
Kevin M. Krause ◽  
Michael R. Goldberg ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Pulmonary Surfactant ◽  
Respiratory Infections ◽  
Time Profile ◽  
Epithelial Lining Fluid ◽  
Plasma Ratio ◽  
The Third ◽  
Concentration Time ◽  
In Vitro Antibacterial Activity

ABSTRACT Steady-state concentrations of telavancin, a novel, bactericidal lipoglycopeptide, were determined in the plasma, pulmonary epithelial lining fluid (ELF), and alveolar macrophages (AMs) of 20 healthy subjects. Telavancin at 10 mg of drug/kg of body weight/day was administered as a 1-h intravenous infusion on three successive days, with bronchoalveolar lavage performed on five subjects, each at 4, 8, 12, and 24 h after the last dose. Plasma samples were collected before the first and third infusions and at 1, 2, 3, 4, 8, 12, and 24 h after the third infusion. The plasma telavancin concentration-time profile was as reported previously. Telavancin (mean ± standard deviation) penetrated well into ELF (3.73 ± 1.28 μg/ml at 8 h and 0.89 ± 1.03 μg/ml at 24 h) and extensively into AMs (19.0 ± 16.8 μg/ml at 8 h, 45.0 ± 22.4 μg/ml at 12 h, and 42.0 ± 31.4 μg/ml at 24 h). Mean concentrations in AMs and plasma at 12 h were 45.0 μg/ml and 22.9 μg/ml (mean AM/plasma ratio, 1.93), respectively, and at 24 h were 42.0 μg/ml and 7.28 μg/ml (mean AM/plasma ratio, 6.67), respectively. Over the entire dosing interval, telavancin was present in ELF and AMs at concentrations up to 8-fold and 85-fold, respectively, above its MIC90 for methicillin-resistant Staphylococcus aureus (0.5 μg/ml). Pulmonary surfactant did not affect telavancin's in vitro antibacterial activity. Telavancin was well tolerated. These results support the proposal for further clinical evaluation of telavancin for treating gram-positive respiratory infections.

scholarly journals Development of a Physiologically Based Pharmacokinetic Model for Prediction of Ethanol Concentration-Time Profile in Different Organs

2020 ◽  
Author(s):  
Armin Sadighi ◽  
Lorenzo Leggio ◽  
Fatemeh Akhlaghi
Keyword(s):  
Pbpk Model ◽  
Organ Damage ◽  
Time Profile ◽  
Sensitivity Analyses ◽  
Pbpk Modeling ◽  
Time Curve ◽  
Physiologically Based Pharmacokinetic ◽  
Concentration Time ◽  
Physiologically Based

Abstract Aims A physiologically based pharmacokinetic (PBPK) modeling approach was used to simulate the concentration-time profile of ethanol (EtOH) in stomach, duodenum, plasma and other tissues upon consumption of beer and whiskey under fasted and fed conditions. Methods A full PBPK model was developed for EtOH using the advanced dissolution, absorption and metabolism (ADAM) model fully integrated into the Simcyp Simulator® 15 (Simcyp Ltd., Sheffield, UK). The prediction performance of the developed model was verified and the EtOH concentration-time profile in different organs was predicted. Results Simcyp simulation showed ≤ 2-fold difference in values of EtOH area under the concentration-time curve (AUC) in stomach and duodenum as compared to the observed values. Moreover, the simulated EtOH maximum concentration (Cmax), time to reach Cmax (Tmax) and AUC in plasma were comparable to the observed values. We showed that liver is exposed to the highest EtOH concentration, faster than other organs (Cmax = 839.50 mg/L and Tmax = 0.53 h), while brain exposure of EtOH (AUC = 1139.43 mg·h/L) is the highest among all other organs. Sensitivity analyses (SAs) showed direct proportion of EtOH rate and extent of absorption with administered EtOH dose and inverse relationship with gastric emptying time (GE) and steady-state volume of distribution (Vss). Conclusions The current PBPK model approach might help with designing in vitro experiments in the area of alcohol organ damage or alcohol-drug interaction studies.

scholarly journals Pharmacodynamics of Isavuconazole in a DynamicIn VitroModel of Invasive Pulmonary Aspergillosis

2015 ◽  
Vol 60 (1) ◽  
pp. 278-287 ◽  
Author(s):  
Helen Box ◽  
Joanne Livermore ◽  
Adam Johnson ◽  
Laura McEntee ◽  
Timothy W. Felton ◽  
...  
Keyword(s):  
Invasive Pulmonary Aspergillosis ◽  
Pathogenic Fungi ◽  
Time Profile ◽  
Wild Type ◽  
Time Curve ◽  
Content Type ◽  
Concentration Time ◽  
Target Values ◽  
Maximal Suppression

ABSTRACTIsavuconazonium sulfate is a novel triazole prodrug that has been recently approved for the treatment of invasive aspergillosis by the FDA. The active moiety (isavuconazole) has a broad spectrum of activity against many pathogenic fungi. This study utilized a dynamicin vitromodel of the human alveolus to describe the pharmacodynamics of isavuconazole against two wild-type and two previously defined azole-resistant isolates ofAspergillus fumigatus. A human-like concentration-time profile for isavuconazole was generated. MICs were determined using CLSI and EUCAST methodologies. Galactomannan was used as a measure of fungal burden. Target values for the area under the concentration-time curve (AUC)/MIC were calculated using a population pharmacokinetics-pharmacodynamics (PK-PD) mathematical model. Isolates with higher MICs required higher AUCs in order to achieve maximal suppression of galactomannan. The AUC/MIC targets necessary to achieve 90% probability of galactomannan suppression of <1 were 11.40 and 11.20 for EUCAST and CLSI, respectively.

scholarly journals 692. In Vitro Antibacterial Activity of Cefiderocol Against a Multi-national Collection of Carbapenem-Nonsusceptible Gram-Negative Bacteria From Respiratory Infections: SIDERO-WT-2014–2017

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S313-S314
Author(s):  
Sonia N Rao ◽  
Sean T Nguyen ◽  
Melinda M Soriano ◽  
Jennifer M Hayes ◽  
Meredith M Hackel ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Respiratory Infections ◽  
Active Agent ◽  
Vitro Activity ◽  
Surveillance Program ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Mueller Hinton ◽  
In Vitro Antibacterial Activity

Abstract Background Cefiderocol (CFDC) is a new siderophore cephalosporin with potent in vitro activity against a broad range of Gram-negative (GN) pathogens, including carbapenem-nonsusceptible (Carb-NS) strains. We evaluated the in vitro activity of CFDC and comparator agents against recent clinical Carb-NS GN respiratory isolates collected from North America and Europe as part of the multi-national SIDERO-WT surveillance program. Methods A total of 2831 Carb-NS GN respiratory isolates collected from 2014 to 2017 were tested centrally (IHMA, Inc., Schaumburg, IL). Minimum inhibitory concentrations (MIC) were determined for CFDC, cefepime (FEP), ceftazidime–avibactam (CZA), ceftolozane-tazobactam (C/T), ciprofloxacin (CIP), colistin (CST), and meropenem (MEM) by broth microdilution and interpreted according to the 2018 CLSI guidelines. CFDC MICs were tested in iron-depleted cation-adjusted Mueller–Hinton broth, and interpreted according to the 2018 CLSI provisional breakpoints. Carb-NS strains were defined as MEM MIC of ≥2 µg/mL for Enterobacteriaceae (ENB) and of ≥4 µg/mL for nonfermenters (NF). Results CFDC exhibited predictable in vitro activity against 2807 clinically relevant Carb-NS GN isolates (214 ENB, 1086 A. baumannii complex, 693 P. aeruginosa, 794 S. maltophilia, and 20 Burkholderia cepacia) isolated from respiratory infections. CFDC was the most active agent against Carb-NS ENB with 97.7% susceptibility followed by 78.0% CZA, 59.4% CST, and 16.4% CIP. Against Carb-NS A. baumannii complex, CFDC demonstrated 94% susceptibility vs. 83.7% for CST. CFDC was the most active agent against Carb-NS P. aeruginosa with 99.9% susceptibility followed by 97.8% CST, 77.6% C/T, and 77.5% CZA. 99.7% of S. maltophilia and 100% of B. cepacia isolates had CFDC MICs of ≤4 µg/mL. The MIC90s of tested compounds for clinically relevant pathogens are shown in the table. Conclusion In a multinational collection of Carb-NS GN respiratory isolates, CFDC demonstrated potent in vitro activity with MIC90 of ≤4 µg/mL for all clinically relevant ENB and NF. These findings suggest that CFDC can be a potential option for the treatment of respiratory infections caused by Carb-NS ENB, A. baumannii complex, P. aeruginosa, S. maltophilia, and B. cepacia. Disclosures All authors: No reported disclosures.

scholarly journals Preclinical Pharmacokinetics of MI-219, a Novel Human Double Minute 2 (HDM2) Inhibitor and Prediction of Human Pharmacokinetics

2012 ◽  
Vol 15 (2) ◽  
pp. 265 ◽  
Author(s):  
Peng Zou ◽  
Nan Zheng ◽  
Yanke Yu ◽  
Shanghai Yu ◽  
Wei Sun ◽  
...  
Keyword(s):  
Allometric Scaling ◽  
Human Study ◽  
Volume Of Distribution ◽  
Time Profile ◽  
In Vitro Assays ◽  
Pharmacokinetic Studies ◽  
Human Pharmacokinetics ◽  
Preclinical Pharmacokinetics ◽  
Concentration Time

Purpose. The two purposes of this study were evaluating preclinical pharmacokinetics of MI-219 and predicting clearance (CL) and volume of distribution at steady-state (Vdss) of MI-219 in humans. Methods. Pharmacokinetic studies were conducted on mice, rats, dogs, and monkeys. Human CL of MI-219 was predicted using allometric scaling (SA), multi-exponential allometric scaling (ME), rule of exponents (RoE), single species scaling, two-term power equation (TTPE), physiologically based in vitro-in vivo extrapolation (IVIVE), and fu corrected intercept method (FCIM). In vitro assays were conducted to determine in vitro intrinsic CL, protein binding, and blood-plasma partition coefficients. To estimate half-life of MI-219, plasma concentration–time profile in humans was predicted using kallynochron and apolysichron time transformation (Dedrick plots) and normalization with MRT and Vdss (Wajima’s method). In addition, simultaneous interspecies scaling of CL, Vdss and concentration–time profile were performed by using Nonlinear Mixed Effects Modeling (NONMEM). Results. Preclinical studies showed that the elimination of MI-219 was mainly through metabolism. The validation using observed monkey CL and Vdss showed that MA, IVIVE and Oie-Tozer methods were accurately than the other methods. Human CL of MI-219 predicted by ME and IVIVE was between 0.237-0.342 L*h-1*kg-1. Human Vdss predicted by Oie-Tozer method and allometric scaling of unbound volume of distribution of tissues (VT/fuT) method was between 0.93-1.40 L*kg-1. Superimposition of rat, monkey and dog data was observed in Dedrick plots and Wajima’s transformations. Conclusions. The predicted human pharmacokinetics is useful for the design of first-in-human study. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Penetration of GSK1322322 into Epithelial Lining Fluid and Alveolar Macrophages as Determined by Bronchoalveolar Lavage

2013 ◽  
Vol 58 (1) ◽  
pp. 419-423 ◽  
Author(s):  
Odin J. Naderer ◽  
Keith A. Rodvold ◽  
Lori S. Jones ◽  
John Z. Zhu ◽  
Chester L. Bowen ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Alveolar Macrophages ◽  
Bacterial Infections ◽  
Time Course ◽  
Respiratory Pathogens ◽  
Epithelial Lining ◽  
Time Curve ◽  
Epithelial Lining Fluid ◽  
Concentration Time

ABSTRACTGSK1322322 is a potent peptide deformylase inhibitor within vitroandin vivoactivity against multidrug-resistant skin and respiratory pathogens. This report provides plasma and intrapulmonary pharmacokinetics, safety, and tolerability of GSK1322322 after repeat (twice daily intravenous dosing for 4 days) dosing at 1,500 mg. Plasma samples were collected over the last 12-hour dosing interval of repeat dosing following the day 4 morning dose (the last dose). Bronchoalveolar lavage samples were collected once in each subject, either before or at 2 or 6 h after the last intravenous dose. Plasma area under the concentration-time curve (AUC0–τ) was 66.7 μg · h/ml, and maximum concentration of drug in serum (Cmax) was 25.4 μg/ml following repeat doses of intravenous GSK1322322. The time course of epithelial lining fluid (ELF) and alveolar macrophages (AM) mirrored the plasma concentration-time profile. The AUC0–τfor ELF and AM were 78.9 μg · h/ml and 169 μg · h/ml, respectively. The AUC0–τratios of ELF and AM to total plasma were 1.2 and 2.5, respectively. These ratios increased to 3.5 and 7.4, respectively, when unbound plasma was considered. These results are supportive of GSK1322322 as a potential antimicrobial agent for the treatment of lower respiratory tract bacterial infections caused by susceptible pathogens. (This study has been registered atClinicalTrials.govunder registration number NCT01610388.)

scholarly journals Pharmacodynamics of Levofloxacin in a Murine Pneumonia Model of Pseudomonas aeruginosa Infection: Determination of Epithelial Lining Fluid Targets

2009 ◽  
Vol 53 (8) ◽  
pp. 3325-3330 ◽  
Author(s):  
Arnold Louie ◽  
Christine Fregeau ◽  
Weiguo Liu ◽  
Robert Kulawy ◽  
G. L. Drusano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Single Agent ◽  
Time Profile ◽  
Epithelial Lining ◽  
Time Data ◽  
Time Curve ◽  
Epithelial Lining Fluid ◽  
Mutational Frequency ◽  
Concentration Time ◽  
Low Exposure

ABSTRACT The dose choice for Pseudomonas aeruginosa remains a matter of debate. The actual exposure targets required for multilog killing of organisms at the primary infection site have not been delineated. We studied Pseudomonas aeruginosa PAO1 using a murine model of pneumonia. We employed a large mathematical model to fit all the concentration-time data in plasma and epithelial lining fluid (ELF) as well as colony counts in lung simultaneously for all drug doses. Penetration into ELF was calculated to be approximately 77.7%, as indexed to the ratio of the area under the concentration-time curve for ELF (AUCELF) to the AUCplasma. We determined the ELF concentration-time profile required to drive a stasis response as well as 1-, 2-, or 3-log10(CFU/g) kill. AUC/MIC ratios of 12.4, 31.2, 62.8, and 127.6 were required to drive these bacterial responses. Emergence of resistance was seen only at the two lowest doses (three of five animals at 50 mg/kg [body weight] and one of five animals at 100 mg/kg). The low exposure targets were likely driven by a low mutational frequency to resistance. Bridging to humans was performed using Monte Carlo simulation. With a 750-mg levofloxacin dose, target attainment rates fell below 90% at 4 mg/liter, 1 mg/liter, and 0.5 mg/liter for 1-, 2-, and 3-log kills, respectively. Given the low exposure targets seen with this strain, we conclude that levofloxacin at a 750-mg dose is not adequate for serious Pseudomonas aeruginosa pneumonia as a single agent. More isolates need to be studied to make these observations more robust.

scholarly journals Cephalosporin clinical concentration–time profile modelling and in-vitro bactericidal effects on Escherichia coli

1999 ◽  
Vol 44 (4) ◽  
pp. 471-476 ◽  
Author(s):  
Kate A. Cholewka ◽  
Lisa L. Ioannides-Demos ◽  
Lisa Liolios ◽  
Phillip Paull ◽  
W. John Spicer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Time Profile ◽  
Concentration Time ◽  
Bactericidal Effects

scholarly journals Improvement of the Bioavailability and Glycaemic Metabolism of Cinnamon Oil in Rats by Liquid Loadable Tablets

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chunchao Han ◽  
Bo Cui
Keyword(s):  
Insulin Secretion ◽  
Blood Glucose ◽  
Plasma Concentration ◽  
Time Profile ◽  
Release Profile ◽  
In Vitro Dissolution ◽  
Pharmacokinetic Parameters ◽  
Cinnamon Oil ◽  
Concentration Time

The purpose of this study is to investigate the bioavailability and glycaemic metabolism of cinnamon oil (CIO) carried by liquid-loadable tablets (CIO-LLTs), the carrier of a CIO self-emulsifying formulation (CIO-LS). The results of tests performed to evaluate the physical properties of the CIO-LLT complied with Chinese Pharmacopeia (2010). The release profile suggested that the CIO-LLT preserved the enhancement of in vitro dissolution of cio. After orally administration, the plasma concentration-time profile and pharmacokinetic parameters suggested that a significant increase (P<0.0001) in theCmax, AUC andFwere observed in the CIO-LLT. The blood glucose and the HbA1c were significantly decreased in alloxan-induced hyperglycemic rats (P<0.05,P<0.01, resp.), while the level of insulin secretion was markedly elevated in alloxan-induced hyperglycemic rats (P<0.05). The alloxan-damaged pancreaticβ-cells of the rats were partly recovered gradually after the rats were administered with CIO-LLT 45 days later. CIO-LLT could improve the bioavailability and glycaemic metabolism of CIO.

scholarly journals Randomized, Double-Blind, Placebo-Controlled Studies of the Safety and Pharmacokinetics of Single and Multiple Ascending Doses of Eravacycline

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Joseph V. Newman ◽  
Jian Zhou ◽  
Sergey Izmailyan ◽  
Larry Tsai
Keyword(s):  
Healthy Subjects ◽  
Plasma Concentrations ◽  
Multidrug Resistant ◽  
Maximum Plasma ◽  
Double Blind ◽  
Time Curve ◽  
Concentration Time ◽  
Dosing Regimens ◽  
Aerobic And Anaerobic

ABSTRACT Eravacycline is a novel, fully synthetic fluorocycline antibiotic with in vitro activity against aerobic and anaerobic Gram-positive and Gram-negative pathogens, including multidrug-resistant (MDR) bacteria. The pharmacokinetics (PK), urinary excretion, and safety/tolerability of intravenous (i.v.) eravacycline were evaluated in single- and multiple-ascending-dose studies. Healthy subjects received single i.v. doses of 0.1 to 3 mg/kg of body weight or 10 days of treatment with 0.5 or 1.5 mg/kg every 24 h (q24h) over 30 min, 1.5 mg/kg q24h over 60 min, or 1 mg/kg q12h over 60 min. After single doses, total exposure (the area under the plasma concentration-time curve [AUC]) and the maximum plasma concentrations (Cmax) of eravacycline increased in an approximately dose-proportional manner. After multiple doses, steady state was achieved within 5 to 7 days. Accumulation ranged from approximately 7% to 38% with the q24h dosing regimens and was 45% with 1 mg/kg q12h. Eravacycline was generally well tolerated, with dose-related nausea, infusion site effects, and superficial phlebitis that were mild or moderate occurring. These results provide support for the 1-mg/kg q12h regimen used in clinical studies of eravacycline.

scholarly journals Use of an In Vitro Pharmacodynamic Model To Derive a Linezolid Regimen That Optimizes Bacterial Kill and Prevents Emergence of Resistance in Bacillus anthracis

2008 ◽  
Vol 52 (7) ◽  
pp. 2486-2496 ◽  
Author(s):  
A. Louie ◽  
H. S. Heine ◽  
K. Kim ◽  
D. L. Brown ◽  
B. VanScoy ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Drug Concentration ◽  
Human Subjects ◽  
Time Profile ◽  
Pharmacodynamic Model ◽  
Dose Fractionation ◽  
Serum Drug Concentration ◽  
Maximum Serum ◽  
Concentration Time

ABSTRACT Simulating the average non-protein-bound (free) human serum drug concentration-time profiles for linezolid in an in vitro pharmacodynamic model, we characterized the pharmacodynamic parameter(s) of linezolid predictive of kill and for prevention of resistance in Bacillus anthracis. In 10-day dose-ranging studies, the average exposure for ≥700 mg of linezolid given once daily (QD) resulted in >3-log CFU/ml declines in B. anthracis without resistance selection. Linezolid at ≤600 mg QD amplified for resistance. With twice-daily (q12h) dosing, linezolid at ≥500 mg q12 h was required for resistance prevention. In dose fractionation studies, killing of B. anthracis was predicted by the area under the time-concentration curve (AUC)/MIC ratio. However, resistance prevention was linked to the maximum serum drug concentration (C max)/MIC ratio. Monte Carlo simulations predicted that linezolid at 1,100 mg QD would produce in 96.7% of human subjects a free 24-h AUC that would match or exceed the average 24-h AUC of 78.5 mg·h/liter generated by linezolid at 700 mg QD while reproducing the shape of the concentration-time profile for this pharmacodynamically optimized regimen. However, linezolid at 700 mg q12h (cumulative daily dose of 1,400 mg) would produce an exposure that would equal or exceed the average free 24-h AUC of 90 mg·h/liter generated by linezolid at 500 mg q12h in 93.8% of human subjects. In conclusion, in our in vitro studies, the QD-administered, pharmacodynamically optimized regimen for linezolid killed drug-susceptible B. anthracis and prevented resistance emergence at lower dosages than q12h regimens. The lower dosage for the pharmacodynamically optimized regimen may decrease drug toxicity. Also, the QD administration schedule may improve patient compliance.

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