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Goutelle S, Jullien V, Bru JP, Cattoir V, Gauzit R, Lesprit P, Lina G, Schramm F, Canoui E, Lepeule R. Defining standard and high dosages for β-lactam agents administered by intermittent, prolonged or continuous infusion: a PK/PD simulation study. J Antimicrob Chemother 2023; 78:2762-2769. [PMID: 37796958 DOI: 10.1093/jac/dkad300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND The new definitions of antimicrobial susceptibility categories proposed by EUCAST in 2020 require the definition of standard and high dosages of antibiotic. For injectable β-lactams, standard and high dosages have been proposed for short-infusion regimens only. OBJECTIVES To evaluate dosages for β-lactams administered by prolonged infusion (PI) and continuous infusion (CI). METHODS Monte Carlo simulations were performed for seven injectable β-lactams: aztreonam, cefepime, cefotaxime, cefoxitin, ceftazidime, piperacillin and temocillin. Various dosage regimens based on short infusion, PI or CI were simulated in virtual patients. Pharmacokinetic (PK) profiles and PTAs were obtained based on reference population PK models, as well as PK/pharmacodynamic targets and MIC breakpoints proposed by EUCAST. Alternative dosage regimens associated with PTA values similar to those of recommended dosages up to the breakpoints were considered acceptable. RESULTS Adequate PTAs were confirmed for most EUCAST short-infusion dosage regimens. A total of 9 standard and 14 high dosages based on PI (3 to 4 h) or CI were identified as alternatives. For cefepime and aztreonam, only PI and CI regimens could achieve acceptable PTAs for infections caused by Pseudomonas spp.: 2 g q8h as PI of 4 h or 6 g/24 h CI for cefepime; 2 g q6h as PI of 3 h or 6 g/24 h CI for aztreonam. CONCLUSIONS These alternative standard and high dosage regimens are expected to provide antibiotic exposure compatible with new EUCAST definitions of susceptibility categories and associated MIC breakpoints. However, further clinical evaluation is necessary.
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Affiliation(s)
- Sylvain Goutelle
- Hospices Civils de Lyon, Groupement Hospitalier Nord, Service de Pharmacie, Lyon, France
- Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5558, Laboratoire de Biométrie et Biologie Évolutive, Villeurbanne, France
- Univ Lyon, Université Claude Bernard Lyon 1, ISPB-Faculté de Pharmacie de Lyon, Lyon, France
| | - Vincent Jullien
- Unité Fonctionnelle de Pharmacologie, AP-HP, Groupe Hospitalier Paris Seine Saint-Denis, Bondy, F-93140, France
- Département de Pharmacologie, Université Sorbonne Paris Nord, Bobigny, F-93000, France
| | - Jean-Pierre Bru
- Service des Maladies Infectieuses, Centre Hospitalier Annecy Genevois, Pringy Cedex 74374, France
| | - Vincent Cattoir
- Service de Bactériologie-Hygiène Hospitalière, CHU de Rennes, Rennes, F-35033, France
| | - Rémy Gauzit
- Infectiologie Transversale, CHU Cochin, AP-HP, Paris, 75014, France
| | - Philippe Lesprit
- Service des Maladies Infectieuses, CHU Grenoble Alpes, La Tronche, F-38700, France
| | - Gérard Lina
- Institut des Agents Infectieux, Hôpital de la Croix-Rousse, Hospices Civils de Lyon and Equipe Pathogénie des Staphylocoques, Centre International de Recherche en Infectiologie, INSERM U1111, CNRS, UMR 5308, ENS de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Frédéric Schramm
- Laboratory of Bacteriology, FMTS-CHRU Strasbourg, University of Strasbourg, Strasbourg, F67000, France
| | - Etienne Canoui
- Equipe mobile d'infectiologie, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpitaux Universitaires Paris Centre-Cochin, Paris, F75014, France
| | - Raphael Lepeule
- Unité Transversale de Traitement des Infections, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpitaux Universitaires Henri Mondor, Créteil, F-94010, France
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Population Pharmacokinetics and Probability of Target Attainment of Different Dosing Regimens of Ceftazidime in Critically Ill Patients with a Proven or Suspected Pseudomonas aeruginosa Infection. Antibiotics (Basel) 2021; 10:antibiotics10060612. [PMID: 34063815 PMCID: PMC8224000 DOI: 10.3390/antibiotics10060612] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022] Open
Abstract
Altered pharmacokinetics (PK) of hydrophilic antibiotics in critically ill patients is common, with possible consequences for efficacy and resistance. We aimed to describe ceftazidime population PK in critically ill patients with a proven or suspected Pseudomonas aeruginosa infection and to establish optimal dosing. Blood samples were collected for ceftazidime concentration measurement. A population PK model was constructed, and probability of target attainment (PTA) was assessed for targets 100% T > MIC and 100% T > 4 × MIC in the first 24 h. Ninety-six patients yielded 368 ceftazidime concentrations. In a one-compartment model, variability in ceftazidime clearance (CL) showed association with CVVH. For patients not receiving CVVH, variability in ceftazidime CL was 103.4% and showed positive associations with creatinine clearance and with the comorbidities hematologic malignancy, trauma or head injury, explaining 65.2% of variability. For patients treated for at least 24 h and assuming a worst-case MIC of 8 mg/L, PTA was 77% for 100% T > MIC and 14% for 100% T > 4 × MIC. Patients receiving loading doses before continuous infusion demonstrated higher PTA than patients who did not (100% T > MIC: 95% (n = 65) vs. 13% (n = 15); p < 0.001 and 100% T > 4 × MIC: 20% vs. 0%; p = 0.058). The considerable IIV in ceftazidime PK in ICU patients could largely be explained by renal function, CVVH use and several comorbidities. Critically ill patients are at risk for underexposure to ceftazidime when empirically aiming for the breakpoint MIC for P. aeruginosa. A loading dose is recommended.
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Population Pharmacokinetics and Dose Optimization of Ceftazidime and Imipenem in Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease. Pharmaceutics 2021; 13:pharmaceutics13040456. [PMID: 33801657 PMCID: PMC8066993 DOI: 10.3390/pharmaceutics13040456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 11/26/2022] Open
Abstract
Background: Ceftazidime and imipenem have been increasingly used to treat Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD) due to their extended-spectrum covering Pseudomonas aeruginosa. This study aims to describe the population pharmacokinetic (PK) and pharmacodynamic (PD) target attainment for ceftazidime and imipenem in patients with AECOPD. Methods: We conducted a prospective PK study at Bach Mai Hospital (Viet Nam). A total of 50 (ceftazidime) and 44 (imipenem) patients with AECOPD were enrolled. Population PK analysis was performed using Monolix 2019R1 and Monte Carlo simulations were conducted to determine the optimal dose regimen with respect to the attainment of 60% and 40% fT>MIC for ceftazidime and imipenem, respectively. A dosing algorithm was developed to identify optimal treatment doses. Results: Ceftazidime and imipenem PK was best described by a one-compartment population model with a volume of distribution and clearance of 23.7 L and 8.74 L/h for ceftazidime and 15.1 L and 7.88 L/h for imipenem, respectively. Cockcroft–Gault creatinine clearance represented a significant covariate affecting the clearance of both drugs. Increased doses with prolonged infusion were found to cover pathogens with reduced susceptibility. Conclusions: This study describes a novel and versatile three-level dosing algorithm based on patients’ renal function and characteristic of the infective pathogen to explore ceftazidime and imipenem optimal regimen for AECOPD.
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Pharmacokinetic and Pharmacodynamic Optimization of Antibiotic Therapy in Cystic Fibrosis Patients: Current Evidences, Gaps in Knowledge and Future Directions. Clin Pharmacokinet 2021; 60:409-445. [PMID: 33486720 DOI: 10.1007/s40262-020-00981-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 10/22/2022]
Abstract
Antibiotic therapy is one of the main treatments for cystic fibrosis (CF). It aims to eradicate bacteria during early infection, calms down the inflammatory process, and leads to symptom resolution of pulmonary exacerbations. CF can modify both the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of antibiotics, therefore specific PK/PD endpoints should be determined in the context of CF. Currently available data suggest that optimal PK/PD targets cannot be attained in sputum with intravenous aminoglycosides. Continuous infusion appears preferable for β-lactam antibiotics, but optimal concentrations in sputum are unlikely to be reached, with some possible exceptions such as meropenem and ceftolozane. Usual doses are likely suboptimal for fluoroquinolones and linezolid, whereas daily doses of 45-60 mg/kg and 200 mg could be convenient for vancomycin and doxycycline, respectively. Weekly azithromycin doses of 22-30 mg/kg could also be appropriate for its anti-inflammatory effect. The difficulty with achieving optimal concentrations supports the use of combined treatments and the inhaled administration route, as very high local concentrations, concomitantly with low systemic exposure, can be obtained with the inhaled route for aminoglycosides, colistin, and fluoroquinolones, thus minimizing the risk of toxicity.
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Antibiotics in Adult Cystic Fibrosis Patients: A Review of Population Pharmacokinetic Analyses. Clin Pharmacokinet 2021; 60:447-470. [PMID: 33447944 DOI: 10.1007/s40262-020-00970-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND Lower respiratory tract infections are common in adult patients with cystic fibrosis (CF) and are frequently caused by Pseudomonas aeruginosa, resulting in chronic lung inflammation and fibrosis. The progression of multidrug-resistant strains of P. aeruginosa and alterations in the pharmacokinetics of many antibiotics in CF make optimal antimicrobial therapy a challenge, as reflected by high between- and inter-individual variability (IIV). OBJECTIVES This review provides a synthesis of population pharmacokinetic models for various antibiotics prescribed in adult CF patients, and aims at identifying the most reported structural models, covariates and sources of variability influencing the dose-concentration relationship. METHODS A literature search was conducted using the PubMed database, from inception to August 2020, and articles were retained if they met the inclusion/exclusion criteria. RESULTS A total of 19 articles were included in this review. One-, two- and three-compartment models were reported to best describe the pharmacokinetics of various antibiotics. The most common covariates were lean body mass and creatinine clearance. After covariate inclusion, the IIV (range) in total body clearance was 27.2% (10.40-59.7%) and 25.9% (18.0-33.9%) for β-lactams and aminoglycosides, respectively. IIV in total body clearance was estimated at 36.3% for linezolid and 22.4% for telavancin. The IIV (range) in volume of distribution was 29.4% (8.8-45.9%) and 15.2 (11.6-18.0%) for β-lactams and aminoglycosides, respectively, and 26.9% for telavancin. The median (range) of residual variability for all studies, using a combined (proportional and additive) model, was 12.7% (0.384-30.80%) and 0.126 mg/L (0.007-1.88 mg/L), respectively. CONCLUSION This is the first review that highlights key aspects of different population pharmacokinetic models of antibiotics prescribed in adult CF patients, effectively proposing relevant information for clinicians and researchers to optimize antibiotic therapy in CF.
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Bui S, Facchin A, Ha P, Bouchet S, Leroux S, Nacka F, Fayon M, Jacqz-Aigrain E. Population pharmacokinetics of ceftazidime in critically ill children: impact of cystic fibrosis. J Antimicrob Chemother 2020; 75:2232-2239. [PMID: 32457995 DOI: 10.1093/jac/dkaa170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/30/2020] [Accepted: 04/02/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Pharmacokinetics data on ceftazidime are sparse for the paediatric population, particularly for children with cystic fibrosis (CF) or severe infections. OBJECTIVES To characterize the population pharmacokinetics of ceftazidime in critically ill children, identify covariates that affect drug disposition and evaluate the current dosing regimens. METHODS The study was registered with Clinicaltrials.gov (NCT01344512). Children receiving ceftazidime were selected in 13 French hospitals. Plasma concentrations were determined by UPLC-MS/MS. Population pharmacokinetic analyses were performed using NONMEN software. RESULTS One hundred and eight patients, aged 28 days to 12 years, with CF (n = 32), haematology and/or oncology disorders (n = 47) or severe infection (n = 29) were included. Ceftazidime was administered by continuous or intermittent infusions; 271 samples were available for analysis. A two-compartment model with first-order elimination and allometric scaling was developed and covariate analysis showed that ceftazidime pharmacokinetics were also significantly affected by CLCR and CF. Ceftazidime clearance was 82% higher in CF than in non-CF patients. Monte Carlo simulations showed that the percentage of target attainment (PTA) for the target of T>MIC = 65% was (i) lower in CF than in non-CF children with intermittent infusions and (ii) higher with continuous than intermittent infusion in all children. CONCLUSIONS The population pharmacokinetics model for ceftazidime in children was influenced by body weight, CLCR and CF. A higher PTA was obtained with continuous versus intermittent infusions. Further studies should explore the benefits of continuous versus intermittent infusion of ceftazidime, including current versus increased doses in CF children.
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Affiliation(s)
- S Bui
- Centre d'Investigation Clinique (CIC1401), Centre de Ressources et de Compétences de la Mucoviscidose (CRCM), Centre de Recherche Cardio-thoracique de Bordeaux (U1045), Université de Bordeaux, Centre Hospitalier Universitaire de Bordeaux Groupe hospitalier Pellegrin, Bordeaux, France
| | - A Facchin
- Département de Pharmacologie Pédiatrique et Pharmacogénétique, Centre Hospitalier Universitaire Robert Debré APHP, Paris, France.,Service de Pharmacie, Centre hospitalier Intercommunal Robert Ballanger, Aulnay-sous-Bois, France.,Université de Paris, Paris, France
| | - P Ha
- Département de Pharmacologie Pédiatrique et Pharmacogénétique, Centre Hospitalier Universitaire Robert Debré APHP, Paris, France
| | - S Bouchet
- Département de Pharmacologie et de toxicologie, Centre Hospitalier Universitaire de Bordeaux, Groupe hospitalier Pellegrin, Bordeaux, France
| | - S Leroux
- Département de Pharmacologie Pédiatrique et Pharmacogénétique, Centre Hospitalier Universitaire Robert Debré APHP, Paris, France
| | - F Nacka
- Centre d'Investigation Clinique (CIC1401), Centre de Ressources et de Compétences de la Mucoviscidose (CRCM), Centre de Recherche Cardio-thoracique de Bordeaux (U1045), Université de Bordeaux, Centre Hospitalier Universitaire de Bordeaux Groupe hospitalier Pellegrin, Bordeaux, France
| | - M Fayon
- Centre d'Investigation Clinique (CIC1401), Centre de Ressources et de Compétences de la Mucoviscidose (CRCM), Centre de Recherche Cardio-thoracique de Bordeaux (U1045), Université de Bordeaux, Centre Hospitalier Universitaire de Bordeaux Groupe hospitalier Pellegrin, Bordeaux, France
| | - E Jacqz-Aigrain
- Département de Pharmacologie Pédiatrique et Pharmacogénétique, Centre Hospitalier Universitaire Robert Debré APHP, Paris, France.,Université de Paris, Paris, France.,Centre d'Investigation Clinique (CIC1426), Centre Hospitalier Universitaire Robert Debré APHP, Paris, France
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7
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Muller AE, Huttner B, Huttner A. Therapeutic Drug Monitoring of Beta-Lactams and Other Antibiotics in the Intensive Care Unit: Which Agents, Which Patients and Which Infections? Drugs 2019; 78:439-451. [PMID: 29476349 DOI: 10.1007/s40265-018-0880-z] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antibiotics are among the medications most frequently administered to the critically ill, a population with high levels of intra- and inter-individual pharmacokinetic variability. Our knowledge of the relationships among antibiotic dosing, exposure and clinical effect in this population has increased in recent decades. Therapeutic drug monitoring (TDM) of serum antibiotic concentrations is the most practical means of assessing adequate antibiotic exposure, though until recently, it has been underutilised for this end. Now TDM is becoming more widespread, particularly for the beta-lactam antibiotics, a class historically thought to have a wide therapeutic range. We review the basic requirements, indications, and targets for effective TDM of the glycopeptides, aminoglycosides, quinolones and beta-lactam antibiotics in the adult intensive-care setting, with a special focus on TDM of the beta-lactam antibiotics, the most widely used antibiotic class.
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Affiliation(s)
- Anouk E Muller
- Department of Medical Microbiology, Haaglanden Medisch Centrum, The Hague, The Netherlands.,Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Benedikt Huttner
- Division of Infectious Diseases, University Hospitals of Geneva, Rue Gabrielle-Gentil-Perret 4, 1205, Geneva, Switzerland
| | - Angela Huttner
- Division of Infectious Diseases, University Hospitals of Geneva, Rue Gabrielle-Gentil-Perret 4, 1205, Geneva, Switzerland.
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Stein GE, Smith CL, Scharmen A, Kidd JM, Cooper C, Kuti J, Mitra S, Nicolau DP, Havlichek DH. Pharmacokinetic and Pharmacodynamic Analysis of Ceftazidime/Avibactam in Critically Ill Patients. Surg Infect (Larchmt) 2018; 20:55-61. [PMID: 30351195 DOI: 10.1089/sur.2018.141] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The pharmacokinetics, especially the volume of distribution (Vd), of ß-lactam antibiotics can be altered in critically ill patients. This can lead to decreased serum concentrations and a reduction in clinical cures. Ceftazidime/avibactam (CZA) is a new antimicrobial agent utilized in critically ill patients although its pharmacokinetics has not been well defined in these patients. PATIENTS AND METHODS In this study, the serum concentrations of CZA from adult patients treated in an intensive care unit (ICU) with standard dosing regimens were measured and both pharmacokinetic and pharmacodynamic parameters were computed. The pharmacodynamic analyses included Monte Carlo simulations to determine the probability of target attainment (PTA: free ceftazidime concentrations exceed the minimum inhibitory concentration [MIC] for 50% of the dosing interval; free avibactam concentrations exceed 1 mg/L over the dosing interval) and serum time-kill curves against multi-drug-resistant Enterobacteriaceae susceptible to CZA. Serum concentrations were measured in 10 critically ill patients at two, four, six, and eight hours after multiple doses (infused over two hours) of CZA. RESULTS A significant linear relation between creatinine clearance and total body clearance was identified for both ceftazidime (R = 0.91) and avibactam (R = 0.88). The mean clearance, volume of distribution, and half-life for ceftazidime were 6.1 ± 3.8 L/h, 35 ± 10.5 L, and 4.8 ± 2.15 h, respectively. For avibactam, these values were 11.1 ± 6.8 L/h, 50.8 ± 14.3 L, and 4.1 ± 2.1 h, respectively. Ceftazidime/avibactam achieved optimal PTA for bacteria with MICs of 16 mg/L or less. Furthermore, time-kill experiments revealed that serum concentrations of CZA, at each collection time, exhibited bactericidal (≥ 3 log10 CFU/mL reduction) activity against each of the study isolates. CONCLUSION In conclusion, our study results suggest that the current dosing regimens of CZA can provide effective antimicrobial activity in ICU patients against CZA-susceptible (MIC ≤8 mg/L) isolates.
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Affiliation(s)
- Gary E Stein
- 1 Department of Medicine, Michigan State University , East Lansing, Michigan
| | - Curtis L Smith
- 2 Ferris State University , College of Pharmacy, Lansing, Michigan
| | - Amy Scharmen
- 1 Department of Medicine, Michigan State University , East Lansing, Michigan
| | - James M Kidd
- 3 Center for Anti-Infective Research and Development, Hartford Hospital , Hartford, Conecticut
| | - Christopher Cooper
- 1 Department of Medicine, Michigan State University , East Lansing, Michigan
| | - Joseph Kuti
- 3 Center for Anti-Infective Research and Development, Hartford Hospital , Hartford, Conecticut
| | - Subhashis Mitra
- 1 Department of Medicine, Michigan State University , East Lansing, Michigan
| | - David P Nicolau
- 3 Center for Anti-Infective Research and Development, Hartford Hospital , Hartford, Conecticut
| | - Daniel H Havlichek
- 1 Department of Medicine, Michigan State University , East Lansing, Michigan
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Pharmacokinetic-Pharmacodynamic Target Attainment Analyses To Determine Optimal Dosing of Ceftazidime-Avibactam for the Treatment of Acute Pulmonary Exacerbations in Patients with Cystic Fibrosis. Antimicrob Agents Chemother 2017; 61:AAC.00988-17. [PMID: 28784670 DOI: 10.1128/aac.00988-17] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/24/2017] [Indexed: 11/20/2022] Open
Abstract
Acute pulmonary exacerbations (APE) involving Pseudomonas aeruginosa are associated with increased morbidity and mortality in cystic fibrosis (CF) patients. Drug resistance is a significant challenge to treatment. Ceftazidime-avibactam (CZA) demonstrates excellent in vitro activity against isolates recovered from CF patients, including drug-resistant strains. Altered pharmacokinetics (PK) of several beta-lactam antibiotics have been reported in CF patients. Therefore, this study sought to characterize the PK of CZA and perform target attainment analyses to determine the optimal treatment regimen. The PK of CZA in 12 adult CF patients administered 3 intravenous doses of 2.5 g every 8 h infused over 2 h were determined. Population modeling utilized the maximum likelihood expectation method. Monte Carlo simulations determined the probability of target attainment (PTA). An exposure target consisting of the cumulative percentage of a 24-h period that the free drug concentration exceeds the MIC under steady-state pharmacokinetic conditions (fT>MIC) was evaluated for ceftazidime (CAZ), and an exposure target consisting of the cumulative percentage of a 24-h period that the free drug concentration exceeds a 1-mg/liter threshold concentration (fT>1 mg/liter) was evaluated for avibactam (AVI). Published CAZ and CZA MIC distributions were incorporated to evaluate cumulative response probabilities. CAZ and AVI were best described by one-compartment models. The values of total body clearance (CL; CAZ CL, 7.53 ± 1.28 liters/h; AVI CL, 12.30 ± 1.96 liters/h) and volume of distribution (V; CAZ V, 18.80 ± 6.54 liters; AVI V, 25.30 ± 4.43 liters) were broadly similar to published values for healthy adults. CZA achieved a PTA (fT>MIC, 50%) of >0.9 for MICs of ≤16 mg/liter. The overall likelihood of a treatment response was 0.82 for CZA, whereas it was 0.42 for CAZ. These data demonstrate improved pharmacodynamics of CZA in comparison with those of CAZ and provide guidance on the optimal dosing of CZA for future studies. (This study has been registered at ClinicalTrials.gov under registration no. NCT02504827.).
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Delattre IK, Taccone FS, Jacobs F, Hites M, Dugernier T, Spapen H, Laterre PF, Wallemacq PE, Van Bambeke F, Tulkens PM. Optimizing β-lactams treatment in critically-ill patients using pharmacokinetics/pharmacodynamics targets: are first conventional doses effective? Expert Rev Anti Infect Ther 2017; 15:677-688. [PMID: 28571493 DOI: 10.1080/14787210.2017.1338139] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION The pharmacokinetic/pharmacodynamic index determining β-lactam activity is the percentage of the dosing interval (%T) during which their free serum concentration remains above a critical threshold over the minimum inhibitory concentration (MIC). Regrettably, neither the value of %T nor that of the threshold are clearly defined for critically-ill patients. Areas covered: We review and assess the targets proposed for β-lactams in critical illness by screening the literature since 1997. Depending on the study intention (clinical cure vs. suppression of resistance), targets proposed range from 20%T > 1xMIC to 100%T > 5xMIC. Assessment and comparative analysis of their respective clinical efficacy suggest that a value of 100%T > 4xMIC may be needed. Simulation studies, however, show that this target will not be reached at first dose for the majority of critically-ill patients if using the most commonly recommended doses. Expert commentary: Considering that critically-ill patients are highly vulnerable and likely to experience antibiotic underexposure, and because effective initial treatment is a key determinant of clinical outcome, we support the use of a target of 100%T > 4xMIC, which could not only maximize efficacy but also minimize emergence of resistance. Clinical and microbiological studies are needed to test for the feasibility and effectiveness of reaching such a demanding target.
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Affiliation(s)
- Isabelle K Delattre
- a Louvain Drug Research Institute , Université catholique de Louvain , Brussels , Belgium.,b Department of Clinical Chemistry , Cliniques Universitaires St-Luc , Brussels , Belgium
| | - Fabio S Taccone
- c Department of Intensive Care , Hôpital Erasme , Brussels , Belgium
| | - Frédérique Jacobs
- d Department of Infectious Diseases , Hôpital Erasme , Brussels , Belgium
| | - Maya Hites
- d Department of Infectious Diseases , Hôpital Erasme , Brussels , Belgium
| | - Thierry Dugernier
- e Department of Intensive Care , Clinique St-Pierre , Ottignies , Belgium
| | - Herbert Spapen
- f Department of Intensive Care , Universitair Ziekenhuis Brussel , Brussels , Belgium
| | | | - Pierre E Wallemacq
- b Department of Clinical Chemistry , Cliniques Universitaires St-Luc , Brussels , Belgium
| | - Françoise Van Bambeke
- a Louvain Drug Research Institute , Université catholique de Louvain , Brussels , Belgium
| | - Paul M Tulkens
- a Louvain Drug Research Institute , Université catholique de Louvain , Brussels , Belgium
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Monogue ML, Kuti JL, Nicolau DP. Optimizing Antibiotic Dosing Strategies for the Treatment of Gram-negative Infections in the Era of Resistance. Expert Rev Clin Pharmacol 2016; 9:459-76. [DOI: 10.1586/17512433.2016.1133286] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Zhuang L, Sy SK, Xia H, Singh RP, Mulder MB, Liu C, Derendorf H. Evaluation of in vitro synergy between vertilmicin and ceftazidime against Pseudomonas aeruginosa using a semi-mechanistic pharmacokinetic/pharmacodynamic model. Int J Antimicrob Agents 2015; 45:151-60. [DOI: 10.1016/j.ijantimicag.2014.09.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 09/13/2014] [Indexed: 10/24/2022]
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Abstract
Objectives: Obesity may alter the pharmacokinetics of β-lactams. The goal of this study was to evaluate if and why serum concentrations are inadequate when standard β-lactam regimens are administered to obese, non-critically ill patients. Subjects and methods: During first year, we consecutively included infected, obese patients (body mass index (BMI) ⩾30 kg m−2) who received meropenem (MEM), piperacillin-tazobactam (TZP) or cefepime/ceftazidime (CEF). Patients with severe sepsis or septic shock, or those hospitalized in the intensive care unit were excluded. Serum drug concentrations were measured twice during the elimination phase by high-performance liquid chromatography. We evaluated whether free or total drug concentrations were >1 time (fT>minimal inhibition concentration (MIC)) or >4 times (T>4MIC) the clinical breakpoints for Pseudomonas aeruginosa during optimal periods of time: ⩾40% for MEM, ⩾50% for TZP and ⩾70% for CEF. Results: We included 56 patients (median BMI: 36 kg m−2): 14 received MEM, 31 TZP and 11 CEF. The percentage of patients who attained target fT>MIC and T>4MIC were 93% and 21% for MEM, 68% and 19% for TZP, and 73% and 18% for CEF, respectively. High creatinine clearance (107 (range: 6–398) ml min−1) was the only risk factor in univariate and multivariate analyses to predict insufficient serum concentrations. Conclusions: In obese, non-critically ill patients, standard drug regimens of TZP and CEF resulted in insufficient drug concentrations to treat infections due to less susceptible bacteria. Augmented renal clearance was responsible for these low serum concentrations. New dosage regimens need to be explored in this patient population (EUDRA-CT: 2011-004239-29).
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Cuenca-Estrella M, Rodriguez-Tudela JL. The current role of the reference procedures by CLSI and EUCAST in the detection of resistance to antifungal agentsin vitro. Expert Rev Anti Infect Ther 2014; 8:267-76. [DOI: 10.1586/eri.10.2] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Clinical pharmacodynamics of antipseudomonal cephalosporins in patients with ventilator-associated pneumonia. Antimicrob Agents Chemother 2013; 58:1359-64. [PMID: 24342637 DOI: 10.1128/aac.01463-13] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Advanced-generation cephalosporins are frequently used for empirical coverage of ventilator-associated pneumonia (VAP) due to their activity against a broad spectrum of Gram-positive and Gram-negative aerobic bacteria, including Pseudomonas aeruginosa and Enterobacteriaceae. Providing optimal antibiotic exposure is essential to achieving successful response in patients with VAP. We evaluated exposures of two antipseudomonal cephalosporins, ceftazidime and cefepime, in patients with VAP due to Gram-negative bacilli to identify the pharmacodynamic parameter predictive of microbiological success. Population pharmacokinetic models were used to estimate individual free drug exposures. Pharmacodynamic indices were determined for each patient using the baseline Gram-negative bacilli with the highest drug MIC. Classification and regression tree analysis was utilized to partition exposure breakpoints, and multivariate logistic regression was conducted to identify predictors of microbiological success. A total of 73 patients (18 receiving ceftazidime therapy and 55 receiving cefepime therapy) were included. MICs ranged widely from 0.047 to 96 μg/ml. The microbiological success rate was 58.9%. Predictive breakpoints were identified for all pharmacodynamic parameters, including a serum fT>MIC greater than 53% (P=0.02). When controlling for APACHE II (odds ratio [OR], 1.01; 95% confidence interval, 0.93 to 1.09; P=0.85) and combination therapy (OR, 0.74; 95% confidence interval, 0.25 to 2.19; P=0.59), achieving a greater than 53% fT>MIC remained a significant predictor of success (OR, 10.3; 95% confidence interval, 1.1 to 92.3; P=0.04). In patients with VAP due to Gram-negative bacilli, serum exposure of greater than 53% fT>MIC was found to be a significant predictor of favorable microbiological response for antipseudomonal cephalosporins. These data are useful when determining dosing regimens for cephalosporin agents under development for pneumonia.
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Chant C, Leung A, Friedrich JO. Optimal dosing of antibiotics in critically ill patients by using continuous/extended infusions: a systematic review and meta-analysis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R279. [PMID: 24289230 PMCID: PMC4056781 DOI: 10.1186/cc13134] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 11/13/2013] [Indexed: 01/07/2023]
Abstract
Introduction The aim of this study was to determine whether using pharmacodynamic-based dosing of antimicrobials, such as extended/continuous infusions, in critically ill patients is associated with improved outcomes as compared with traditional dosing methods. Methods We searched Medline, HealthStar, EMBASE, Cochrane Clinical Trial Registry, and CINAHL from inception to September 2013 without language restrictions for studies comparing the use of extended/continuous infusions with traditional dosing. Two authors independently selected studies, extracted data on methodology and outcomes, and performed quality assessment. Meta-analyses were performed by using random-effects models. Results Of 1,319 citations, 13 randomized controlled trials (RCTs) (n = 782 patients) and 13 cohort studies (n = 2,117 patients) met the inclusion criteria. Compared with traditional non-pharmacodynamic-based dosing, RCTs of continuous/extended infusions significantly reduced clinical failure rates (relative risk (RR) 0.68; 95% confidence interval (CI) 0.49 to 0.94, P = 0.02) and intensive care unit length of stay (mean difference, −1.5; 95% CI, −2.8 to −0.2 days, P = 0.02), but not mortality (RR, 0.87; 95% CI, 0.64 to 1.19; P = 0.38). No significant between-trial heterogeneity was found for these analyses (I2 = 0). Reduced mortality rates almost achieved statistical significance when the results of all included studies (RCTs and cohort studies) were pooled (RR, 0.83; 95% CI, 0.69 to 1.00; P = 0.054). Conclusions Pooled results from small RCTs suggest reduced clinical failure rates and intensive care unit length-of-stay when using continuous/extended infusions of antibiotics in critically ill patients. Reduced mortality rates almost achieved statistical significance when the results of RCTs were combined with cohort studies. These results support the conduct of adequately powered RCTs to define better the utility of continuous/extended infusions in the era of antibiotic resistance.
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MacVane SH, Kuti JL, Nicolau DP. Prolonging β-lactam infusion: a review of the rationale and evidence, and guidance for implementation. Int J Antimicrob Agents 2013; 43:105-13. [PMID: 24359838 DOI: 10.1016/j.ijantimicag.2013.10.021] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
Abstract
Given the sparse antibiotic pipeline and the increasing prevalence of resistant organisms, efforts should be made to optimise the pharmacodynamic exposure of currently available agents. Prolonging the infusion duration is a strategy used to increase the percentage of the dosing interval that free drug concentrations remain above the minimum inhibitory concentration (fT>MIC), the pharmacodynamic efficacy driver for time-dependent antibiotics such as β-lactams. β-Lactams, the most commonly prescribed class of antibiotics owing to their efficacy and safety profile, have been the mainstay of therapy since the discovery of penicillin over 60 years ago. Mounting evidence, including the use of population pharmacokinetic modelling and Monte Carlo simulation, suggests that prolonging the infusion time of β-lactam antibiotics may have advantages over standard infusion techniques, including an enhanced probability of achieving requisite fT>MIC exposures, lower mortality and potentially reductions in infection/antibiotic-related costs. As a result of these favourable attributes, clinical practice guidelines support the use of prolonged-infusion β-lactams in the treatment of many severe infections. This article discusses the rationale and evidence for prolonging the infusion of β-lactam antibiotics and provides guidance for the implementation of a prolonged-infusion programme.
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Affiliation(s)
- Shawn H MacVane
- Center for Anti-Infective Research and Development, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102, USA
| | - Joseph L Kuti
- Center for Anti-Infective Research and Development, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102, USA
| | - David P Nicolau
- Center for Anti-Infective Research and Development, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102, USA; Division of Infectious Diseases, Hartford Hospital, Hartford, CT, USA.
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del Mar Fernández de Gatta M, Martin-Suarez A, Lanao JM. Approaches for dosage individualisation in critically ill patients. Expert Opin Drug Metab Toxicol 2013; 9:1481-93. [PMID: 23898816 DOI: 10.1517/17425255.2013.822486] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Pharmacokinetic variability in critically ill patients is the result of the overlapping of multiple pathophysiological and clinical factors. Unpredictable exposure from standard dosage regimens may influence the outcome of treatment. Therefore, strategies for dosage individualisation are recommended in this setting. AREAS COVERED The authors focus on several approaches for dosage individualisation that have been developed, ranging from the well-established therapeutic drug monitoring (TDM) up to the innovative application of pharmacogenomics criteria. Furthermore, the authors summarise the specific population pharmacokinetic models for different drugs developed for critically ill patients to improve the initial dosage selection and the Bayesian forecasting of serum concentrations. The authors also consider the use of Monte Carlo simulation for the selection of dosage strategies. EXPERT OPINION Pharmacokinetic/pharmacodynamics (PK/PD) modelling and dosage individualisation methods based on mathematical and statistical criteria will contribute in improving pharmacologic treatment in critically ill patients. Moreover, substantial effort will be necessary to integrate pharmacogenomics criteria into critical care practice. The lack of availability of target biomarkers for dosage adjustment emphasizes the value of TDM which allows a large part of treatment outcome variability to be controlled.
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Affiliation(s)
- M del Mar Fernández de Gatta
- University of Salamanca, Institute of Biomedical Research of Salamanca (IBSAL), Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy , Avda. Licenciado Méndez Núñez, 37007 Salamanca , Spain +0034 923 294 536 ; +0034 923 294 515 ;
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Evaluation of initial and steady-state gatifloxacin pharmacokinetics and dose in pulmonary tuberculosis patients by using monte carlo simulations. Antimicrob Agents Chemother 2013; 57:4164-71. [PMID: 23774436 DOI: 10.1128/aac.00479-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A 4-month regimen of gatifloxacin with rifampin, isoniazid, and pyrazinamide is being evaluated for the treatment of tuberculosis in a phase 3 randomized controlled trial (OFLOTUB). A prior single-dose study found that gatifloxacin exposure increased by 14% in the combination. The aims of the study are to evaluate the initial and steady-state pharmacokinetics of gatifloxacin when daily doses are given to patients with newly diagnosed drug-sensitive pulmonary tuberculosis as part of a combination regimen and to evaluate the gatifloxacin dose with respect to the probability of attaining a pharmacokinetic/pharmacodynamic target. We describe the population pharmacokinetics of gatifloxacin from the first dose to a median of 28 days in 169 adults enrolled in the OFLOTUB trial in Benin, Guinea, Senegal, and South Africa. The probability of achieving a ratio of ≥125 for the area under the concentration time curve to infinity (AUC0-∞) for the free fraction of gatifloxacin over the MIC (fAUC/MIC) was investigated using Monte Carlo simulations. The median AUC0-∞ of 41.2 μg · h/ml decreased on average by 14.3% (90% confidence interval [CI], -90.5% to +61.5%) following multiple 400-mg daily doses. At steady state, 90% of patients achieved an fAUC/MIC of ≥125 only when the MIC was <0.125 μg/ml. We conclude that systemic exposure to gatifloxacin declines with repeated daily 400-mg doses when used together with rifampin, isoniazid, and pyrazinamide, thus compensating for any initial increase in gatifloxacin levels due to a drug interaction. (The OFLOTUB study has been registered at ClinicalTrials.gov under registration no. NCT00216385.).
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Monte Carlo simulations based on phase 1 studies predict target attainment of ceftobiprole in nosocomial pneumonia patients: a validation study. Antimicrob Agents Chemother 2013; 57:2047-53. [PMID: 23403430 DOI: 10.1128/aac.02292-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Monte Carlo simulation (MCS) of antimicrobial dosage regimens during drug development to derive predicted target attainment values is frequently used to choose the optimal dose for the treatment of patients in phase 2 and 3 studies. A criticism is that pharmacokinetic (PK) parameter estimates and variability in healthy volunteers are smaller than those in patients. In this study, the initial estimates of exposure from MCS were compared with actual exposure data in patients treated with ceftobiprole in a phase 3 nosocomial-pneumonia (NP) study (NTC00210964). Results of MCS using population PK data from ceftobiprole derived from 12 healthy volunteers were used (J. W. Mouton, A. Schmitt-Hoffmann, S. Shapiro, N. Nashed, N. C. Punt, Antimicrob. Agents Chemother. 48:1713-1718, 2004). Actual individual exposures in patients were derived after building a population pharmacokinetic model and were used to calculate the individual exposure to ceftobiprole (the percentage of time the unbound concentration exceeds the MIC [percent fT > MIC]) for a range of MIC values. For the ranges of percent fT > MIC used to determine the dosage schedule in the phase 3 NP study, the MCS using data from a single phase 1 study in healthy volunteers accurately predicted the actual clinical exposure to ceftobiprole. The difference at 50% fT > MIC at an MIC of 4 mg/liter was 3.5% for PK-sampled patients. For higher values of percent fT > MIC and MICs, the MCS slightly underestimated the target attainment, probably due to extreme values in the PK profile distribution used in the simulations. The probability of target attainment based on MCS in healthy volunteers adequately predicted the actual exposures in a patient population, including severely ill patients.
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Zobell JT, Waters CD, Young DC, Stockmann C, Ampofo K, Sherwin CMT, Spigarelli MG. Optimization of anti-pseudomonal antibiotics for cystic fibrosis pulmonary exacerbations: II. cephalosporins and penicillins. Pediatr Pulmonol 2013; 48:107-22. [PMID: 22949297 DOI: 10.1002/ppul.22669] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 06/04/2012] [Indexed: 11/08/2022]
Abstract
Acute pulmonary exacerbations (APE) are well-described complications of cystic fibrosis (CF) and are associated with progressive morbidity and mortality. Despite aggressive management with two or more intravenous anti-pseudomonal agents, approximately 25% of exacerbations will result in a loss of lung function. The aim of this review is to provide an evidence-based summary of pharmacokinetic/pharmacodynamic (PK/PD), tolerability, and efficacy studies utilizing anti-pseudomonal cephalosporins (i.e., ceftazidime and cefepime) and penicillins (i.e., piperacillin-tazobactam and ticarcillin-clavulanate) in the treatment of APE and to identify areas where further study is warranted. The ceftazidime and cefepime dosing ranges from the literature are 200-400 mg/kg/day divided every 6-8 hr, maximum 8-12 g/day, and 150-200 mg/kg/day divided every 6-8 hr, up to 6-8 g/day, respectively. The literature supported dosing ranges for piperacillin and ticarcillin are 350-600 mg/kg/day divided every 4 hr, maximum 18-24 g/day of piperacillin component, and 400-750 mg/kg/day divided every 6 hr, up to 24-30 g/day of ticarcillin component, respectively. As a large portion of CF patients will not regain their lung function following an APE, we suggest the need to optimize antibiotic dosing and dosing regimens used to treat an APE in efforts to improve outcomes for CF patients infected with Pseudomonas aeruginosa. Future studies are needed to determine the clinical efficacy of higher than FDA-approved doses of ceftazidime, cefepime, and ticarcillin-clavulanate in APE. The usefulness of high dose piperacillin (>600 mg/kg/day) may be limited due to treatment-related adverse effects. Further understanding of these adverse effects in CF patients is needed.
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Affiliation(s)
- Jeffery T Zobell
- Pharmacy, Intermountain Primary Children's Medical Center, Salt Lake City, Utah 84113, USA.
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Georges B, Conil JM, Ruiz S, Seguin T, Cougot P, Fourcade O, Houin G, Saivin S. Ceftazidime dosage regimen in intensive care unit patients: from a population pharmacokinetic approach to clinical practice via Monte Carlo simulations. Br J Clin Pharmacol 2012; 73:588-96. [PMID: 21988468 DOI: 10.1111/j.1365-2125.2011.04117.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT The large variability in drug pharmacokinetic disposition has already been described in ICU patients leading to important variations in drugs concentrations. The usual recommended dosage of ceftazidime is not adapted for all ICU situations and ceftazidime should be monitored closely. New recommendations have to be given for some specific cases. WHAT THIS STUDY ADDS Our results propose individual therapeutic drug monitoring taking into account: For the patient: the reason of admission in the ICU, the mechanical ventilation status and the creatinine clearance calculated by the modified diet in renal disease (MDRD). • For the antibiotics: the lung distribution, the minimal inhibitory concentration (MIC) of the strain to eradicate and the potential toxicity. AIM To predict the ceftazidime dosage regimen as a function of the glomerular filtration rate expressed by the modification of the diet in renal disease (MDRD), reason for admission and mechanical ventilation in intensive care unit (ICU) patients to treat Pseudomonas aeruginosa pneumonia. METHOD A published and qualified population pharmacokinetic model was used to perform Monte Carlo simulations of ceftazidime concentrations. The serum target of 40-100 mg l(-1) was defined based on the minimal inhibitory concentration (MIC), the European break point (EBP), the pulmonary drug diffusion and toxicity. The recommended dosage regimens were based on the maximum percentile of the patients with simulated steady state concentrations reaching the target. RESULTS Steady-state was reached at 72 h whatever the MDRD. The simulations of serum concentrations generated higher percentiles of the population reaching the target after continuous administration. We recommend a 4 g continuous dose after the usual 2 g loading dose for patients with MDRD from 10 to 30 ml min(-1) , 6 g for MDRD between 40 and 80 ml min(-1) , 8 g for MDRD from 90 to 110 ml min(-1) , 10 g for MDRD from 120 to 190 ml min(-1) and 12 g day(-1) for patients with MDRD higher than 200 ml min(-1) . CONCLUSION Our study demonstrated that in ICU patients for a given MDRD, steady-state takes longer to reach in polytrauma patients than in patients with medical or post surgery reasons for admission. Continuous infusion ensures that a higher percentage of patients reaches the target than the same dose given by discontinuous administration and this only depends on MDRD.
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Affiliation(s)
- Bernard Georges
- Pôle d'Anesthésie Réanimation, CHU Rangueil, TSA 50032, Toulouse, France
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Zelenitsky SA, Ariano RE, McCrae ML, Vercaigne LM. Initial Vancomycin Dosing Protocol to Achieve Therapeutic Serum Concentrations in Patients Undergoing Hemodialysis. Clin Infect Dis 2012; 55:527-33. [DOI: 10.1093/cid/cis458] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Mouton J, Brown D, Apfalter P, Cantón R, Giske C, Ivanova M, MacGowan A, Rodloff A, Soussy CJ, Steinbakk M, Kahlmeter G. The role of pharmacokinetics/pharmacodynamics in setting clinical MIC breakpoints: the EUCAST approach. Clin Microbiol Infect 2012; 18:E37-45. [DOI: 10.1111/j.1469-0691.2011.03752.x] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zobell JT, Stockmann C, Young DC, Cash J, McDowell BJ, Korgenski K, Sherwin CMT, Spigarelli M, Chatfield BA, Ampofo K. Population pharmacokinetic and pharmacodynamic modeling of high-dose intermittent ticarcillin-clavulanate administration in pediatric cystic fibrosis patients. Clin Ther 2011; 33:1844-50. [PMID: 22018680 DOI: 10.1016/j.clinthera.2011.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2011] [Indexed: 11/18/2022]
Abstract
BACKGROUND The Intermountain Cystic Fibrosis Pediatric Center utilizes ticarcillin-clavulanate 400 mg/kg/d divided every 6 hours, (maximum 24 g/d). This dosing strategy is higher than the Food and Drug Administration (FDA)-approved package labeling. We evaluated the microbiologic efficacy of this dosing regimen. OBJECTIVES The primary study objective was to predict the pharmacokinetic (PK) and pharmacodynamic (PD) MIC breakpoints (the highest MIC with a probability of target attainment [PTA] of at least 90%) for the bacteriostatic and bactericidal targets of ticarcillin activity against Pseudomonas aeruginosa using the study dosing regimen. A secondary objective was to evaluate the tolerability profile of the higher ticarcillin-clavulanate dosing regimen in children with cystic fibrosis (CF). METHODS This was a population-based PK-PD modeling study of pediatric CF patients admitted from January 1, 2005 to December 31, 2009 who received the dosing regimen for at least 7 days. Population PK and PD models were used to estimate PK and PD parameters for 127 clinically evaluable patients. A 10,000-patient Monte Carlo simulation was performed to estimate the target time in which free drug concentrations exceeded the MIC of the infecting organism. The 2 PK-PD targets of microbiologic efficacy included ≥30% for bacteriostasis and ≥50% for bactericidal effects of ticarcillin-clavulanate at higher than FDA-approved doses. RESULTS A total of 127 patients (age, 0-19 years) met inclusion criteria. Serum concentration levels were modeled in this patient population using published PK parameters with intermittent ticarcillin peak concentrations reaching 288 (93.4) mg/L. The model predicted the PTA of the MICs for P. aeruginosa with a near-maximal bactericidal PK-PD MIC breakpoint of 16 μg/mL and a bacteriostasis PK-PD MIC breakpoint of 32 μg/mL. CONCLUSIONS The results of our simulation suggest that in this select pediatric population, higher than FDA-approved doses of ticarcillin-clavulanate were effective in achieving bactericidal effects among pseudomonal isolates with MICs <16 μg/mL. Bacteriostatic and bactericidal effects were not frequently achieved among P. aeruginosa isolates with MICs >32 μg/mL. Additional studies are warranted to determine the clinical effectiveness of this dosing regimen.
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Affiliation(s)
- Jeffery T Zobell
- Pharmacy, Intermountain Primary Children's Medical Center, Salt Lake City, Utah, USA
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Gonçalves-Pereira J, Póvoa P. Antibiotics in critically ill patients: a systematic review of the pharmacokinetics of β-lactams. Crit Care 2011; 15:R206. [PMID: 21914174 PMCID: PMC3334750 DOI: 10.1186/cc10441] [Citation(s) in RCA: 284] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 06/28/2011] [Accepted: 09/13/2011] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Several reports have shown marked heterogeneity of antibiotic pharmacokinetics (PK) in patients admitted to ICUs, which might potentially affect outcomes. Therefore, the pharmacodynamic (PD) parameter of the efficacy of β-lactam antibiotics, that is, the time that its concentration is above the bacteria minimal inhibitory concentration (T > MIC), cannot be safely extrapolated from data derived from the PK of healthy volunteers. METHODS We performed a full review of published studies addressing the PK of intravenous β-lactam antibiotics given to infected ICU patients. Study selection comprised a comprehensive bibliographic search of the PubMed database and bibliographic references in relevant reviews from January 1966 to December 2010. We selected only English-language articles reporting studies addressing β-lactam antibiotics that had been described in at least five previously published studies. Studies of the PK of patients undergoing renal replacement therapy were excluded. RESULTS A total of 57 studies addressing six different β-lactam antibiotics (meropenem, imipenem, piperacillin, cefpirome, cefepime and ceftazidime) were selected. Significant PK heterogeneity was noted, with a broad, more than twofold variation both of volume of distribution and of drug clearance (Cl). The correlation of antibiotic Cl with creatinine clearance was usually reported. Consequently, in ICU patients, β-lactam antibiotic half-life and T > MIC were virtually unpredictable, especially in those patients with normal renal function. A better PD profile was usually obtained by prolonged or even continuous infusion. Tissue penetration was also found to be compromised in critically ill patients with septic shock. CONCLUSIONS The PK of β-lactam antibiotics are heterogeneous and largely unpredictable in ICU patients. Consequently, the dosing of antibiotics should be supported by PK concepts, including data derived from studies of the PK of ICU patients and therapeutic drug monitoring.
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Affiliation(s)
- Joao Gonçalves-Pereira
- Polyvalent Intensive Care Unit, São Francisco Xavier Hospital, Estrada do Forte do Alto do Duque, 1449-005 Lisboa, Portugal
- CEDOC, Faculty of Medical Sciences, New University of Lisbon, Campo dos Mártires da Pátria, 130, 1169-056 Lisboa, Portugal
| | - Pedro Póvoa
- Polyvalent Intensive Care Unit, São Francisco Xavier Hospital, Estrada do Forte do Alto do Duque, 1449-005 Lisboa, Portugal
- CEDOC, Faculty of Medical Sciences, New University of Lisbon, Campo dos Mártires da Pátria, 130, 1169-056 Lisboa, Portugal
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Chisholm SA, Mouton JW, Lewis DA, Nichols T, Ison CA, Livermore DM. Cephalosporin MIC creep among gonococci: time for a pharmacodynamic rethink? J Antimicrob Chemother 2010; 65:2141-8. [DOI: 10.1093/jac/dkq289] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pharmacokinetics of clindamycin in pregnant women in the peripartum period. Antimicrob Agents Chemother 2010; 54:2175-81. [PMID: 20176904 DOI: 10.1128/aac.01017-09] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The study presented here was performed to determine the pharmacokinetics of intravenously administered clindamycin in pregnant women. Seven pregnant women treated with clindamycin were recruited. Maternal blood and arterial and venous umbilical cord blood samples were obtained. Maternal clindamycin concentrations were analyzed by nonlinear mixed-effects modeling with the NONMEM program. The data were best described by a linear three-compartment model. The clearance and the volume of distribution at steady state were 10.0 liters/h and 6.32 x 10(3) liters, respectively. Monte Carlo simulations were performed to determine the area under the concentration curve (AUC) for the free (unbound) drug (f) in maternal serum for 24 h divided by the MIC (fAUC(0-24)/MIC). At a MIC of 0.5 mg/liter, which is the EUCAST breakpoint, the attainment at the lower 95% confidence interval (CI) was 24.6 if the level of protein binding was 65%, and this value concurred well with the target value of 27. However, for higher degrees of protein binding, as has been described in the literature, the attainment was lower, down to 10.2 for a protein binding level of 85% (lower 95% CI). The concentrations in umbilical cord blood were lower than those in maternal blood. The concentration-time profiles in maternal serum indicate that the level of exposure to clindamycin may be too low in these patients. Together with the lower concentrations in umbilical cord blood, this finding suggests that the current dosing regimen may not be adequate to protect all neonates from group B streptococcal disease.
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Population pharmacokinetic comparison and pharmacodynamic breakpoints of ceftazidime in cystic fibrosis patients and healthy volunteers. Antimicrob Agents Chemother 2010; 54:1275-82. [PMID: 20065059 DOI: 10.1128/aac.00936-09] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite the promising activity of ceftazidime against Pseudomonas aeruginosa and Burkholderia cepacia, there has not yet been a study that directly compared the pharmacokinetics (PK) of ceftazidime in cystic fibrosis (CF) patients and healthy volunteers by population PK methodology. We assessed the population PK and PK/pharmacodynamic (PD) breakpoints of ceftazidime in CF patients and healthy volunteers. Eight CF patients (total body weight [WT] [average +/- standard deviation] = 42.9 +/- 18.4 kg) and seven healthy volunteers (WT = 66.2 +/- 4.9 kg) received 2 g ceftazidime as a 5-min intravenous infusion. High-performance liquid chromatography (HPLC) was used for drug analysis, and NONMEM (results reported), S-ADAPT, and NPAG were used for parametric and nonparametric population PK modeling. We considered linear and allometric body size models to scale clearance and volume of distribution. Monte Carlo simulations were based on a target time of non-protein-bound plasma concentration of ceftazidime above MIC of > or =65%, which represents near-maximal killing. Unscaled total clearance was 19% lower in CF patients, and volume of distribution was 36% lower. Total clearance was 7.82 liters/h for CF patients and 6.68 liters/h for healthy volunteers with 53 kg fat-free mass. Allometric scaling by fat-free mass reduced the between-subject variability by 32% for clearance and by 18 to 26% for volume of both peripheral compartments compared to linear scaling by WT. A 30-min ceftazidime infusion of 2 g/70 kg WT every 8 h (q8h) achieved robust (> or =90%) probabilities of target attainment (PTAs) for MICs of < or =1 mg/liter in CF patients and < or =3 mg/liter in healthy volunteers. Alternative modes of administration achieved robust PTAs up to markedly higher MICs of < or =8 to 12 mg/liter in CF patients for 5-h infusions of 2 g/70 kg WT q8h and < or =12 mg/liter for continuous infusion of 6 g/70 kg WT daily.
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Population pharmacokinetics of ceftazidime in intensive care unit patients: influence of glomerular filtration rate, mechanical ventilation, and reason for admission. Antimicrob Agents Chemother 2009; 53:4483-9. [PMID: 19635962 DOI: 10.1128/aac.00430-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to develop a population-pharmacokinetic model of ceftazidime in intensive care unit patients to include the influence of patients' characteristics on the pharmacokinetics. Forty-nine patients for model building and 23 patients for validation were included in a randomized study. They received ceftazidime at 2 g three times a day or as 6 g per day continuously. A NONMEM pharmacokinetic model was constructed, and the influences of covariates were studied. The model was validated by a comparison of the predicted and observed concentrations. A final model was elaborated from the whole population. Total clearance (CL) was significantly correlated with the glomerular filtration rate (GFR) calculated by modification of the diet in renal disease (MDRD), the central volume of distribution (V1) with intubation, and the peripheral volume of distribution (V2) with the reason for admission. The mean pharmacokinetic parameters were as follows: CL, 5.48 liters/h, 40%; V1, 10.48 liters, 34%; V2, 32.12 liters, 59%; total volume, 42.60 liters, 45%; and intercompartmental clearance, 16.19 liters/h, 42%. In the polytrauma population (mechanically ventilated), the time above the MIC at steady state never corresponds to 100% for discontinuous administration, and the target concentration of five times the MIC was reached with a 6-g/day dose only for patients with an MDRD of <150 ml/min. We showed that the GFR-MDRD, mechanical ventilation, and the reason for admission may influence the achieved concentrations of ceftazidime. Our model allows the a priori dosing to be adjusted to the individual patient.
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A Long Journey from Minimum Inhibitory Concentration Testing to Clinically Predictive Breakpoints: Deterministic and Probabilistic Approaches in Deriving Breakpoints. Infection 2009; 37:296-305. [DOI: 10.1007/s15010-009-7108-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 01/08/2009] [Indexed: 10/20/2022]
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Deal EN, Micek ST, Reichley RM, Ritchie DJ. Effects of an alternative cefepime dosing strategy in pulmonary and bloodstream infections caused by Enterobacter spp, Citrobacter freundii, and Pseudomonas aeruginosa: A single-center, open-label, prospective, observational study. Clin Ther 2009; 31:299-310. [DOI: 10.1016/j.clinthera.2009.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2008] [Indexed: 10/21/2022]
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Dufour G, Montravers P. Pharmacokinetics of antibiotics or antifungal drugs in intensive care units. Curr Infect Dis Rep 2008; 11:14-20. [DOI: 10.1007/s11908-009-0003-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Susceptibility of clinical isolates of Pseudomonas aeruginosa in the Northern Kyushu district of Japan to carbapenem antibiotics, determined by an integrated concentration method: evaluation of the method based on Monte Carlo simulation. J Infect Chemother 2008; 14:238-43. [PMID: 18574662 DOI: 10.1007/s10156-008-0609-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Accepted: 03/04/2008] [Indexed: 10/21/2022]
Abstract
In empirical antibacterial therapy, regional surveillance is expected to yield important information for the determination of the class and dosage regimen of antibacterial agents to be used when dealing with infections with organisms such as Pseudomonas aeruginosa, in which strains resistant to antibacterial agents have been increasing. The minimal inhibitory concentrations (MICs) of five carbapenem antibiotics against P. aeruginosa strains isolated in the Northern Kyushu district of Japan between 2005 and 2006 were measured, and 100 strains for which carbapenem MICs were < or =0.5-32 microg/ml were selected. In this study, MIC was measured by two methods, i.e., the common serial twofold dilution method and an integrated concentration method, in which the concentration was changed, in increments of 2 microg/ml, from 2 to 16 microg/ml. The MIC(50)/MIC(90) values for imipenem, meropenem, biapenem, doripenem, and panipenem, respectively, with the former method were 8/16, 4/16, 4/16, 2/8, and 16/16 microg/ml; and the values were 6/10, 4/12, 4/10, 2/6, and 10/16 microg/ml with the latter method. The MIC data obtained with both methods were subjected to pharmacokinetic/pharmacodynamic (PK/PD) analysis with Monte Carlo simulation to calculate the probability of achieving the target of time above MIC (T>MIC) with each carbapenem. The probability of achieving 25% time above the MIC (T>MIC; % of T>MIC for dosing intervals) and 40% T>MIC against P. aeruginosa with any dosage regimen was higher with doripenem than with any other carbapenem tested. When the two sets of MIC data were subjected to PK/PD analysis, the difference between the two methods in the probability of achieving each % T>MIC was small, thus endorsing the validity of the serial twofold dilution method.
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De Jongh R, Hens R, Basma V, Mouton JW, Tulkens PM, Carryn S. Continuous versus intermittent infusion of temocillin, a directed spectrum penicillin for intensive care patients with nosocomial pneumonia: stability, compatibility, population pharmacokinetic studies and breakpoint selection. J Antimicrob Chemother 2007; 61:382-8. [PMID: 18070831 DOI: 10.1093/jac/dkm467] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND AND AIMS Temocillin, a 6alpha-methoxy-penicillin stable towards most beta-lactamases (including extended-spectrum beta-lactamase), is presented as an alternative to carbapenems for susceptible Enterobacteriaceae in microbiological surveys. We aimed at documenting its potential clinical usefulness in intensive care (IC) patients using pharmacokinetic/pharmacodynamic approaches applied to conventional (twice daily) and continuous infusion (CI) modes of administration. METHODS (i) In vitro evaluation of temocillin stability and compatibility with other drugs under conditions pertinent of CI in IC patients; (ii) pharmacokinetic study in patients treated by CI (4 g/day; n = 6) versus [twice daily (2 g every 12 h); n = 6]; (iii) population pharmacokinetic analysis of twice daily with Monte Carlo simulations to determine 95% probability of target attainment (PTA(95)) versus MIC (based on time above MIC > or = 40% for measured free drug). RESULTS Temocillin was stable at 37 degrees C in 8.34% solutions for 24 h and compatible with flucloxacillin and aminoglycosides, but not with several other antibiotic and non-antibiotic drugs. With CI, stable total serum concentrations were 73.5 +/- 3.0 mg/L (SEM) and free concentration 29.3 +/- 2.8 mg/L. With twice daily, Cmax (total drug) was 147 +/- 12.3 mg/L (SEM; free drug: 50.3 +/- 15.8 mg/L), lowest trough (total drug) 12.3 mg/L, and PTA(95) (free drug) obtained for MIC < or = 8 mg/L. CONCLUSIONS Temocillin (4 g/day) by CI yields stable free serum concentrations above the current breakpoint (16 mg/L), although individual variations may suggest lowering the breakpoint to 8 mg/L (as for twice daily) unless the daily dose or the frequency of administration is increased.
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Affiliation(s)
- Raf De Jongh
- Dienst Voor Intensieve Zorgen, Ziekenhuis Oost-Limburg, B-3600 Genk, Belgium
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Rodríguez-Tudela JL, Almirante B, Rodríguez-Pardo D, Laguna F, Donnelly JP, Mouton JW, Pahissa A, Cuenca-Estrella M. Correlation of the MIC and dose/MIC ratio of fluconazole to the therapeutic response of patients with mucosal candidiasis and candidemia. Antimicrob Agents Chemother 2007; 51:3599-604. [PMID: 17646421 PMCID: PMC2043257 DOI: 10.1128/aac.00296-07] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 04/14/2007] [Accepted: 07/12/2007] [Indexed: 11/20/2022] Open
Abstract
We report on the correlation of the outcomes for two cohorts of patients who had been treated for candidemia (126 episodes) or oropharyngeal candidiasis (110 episodes) with various doses of fluconazole and the MIC of fluconazole obtained by using the EUCAST standard for fermentative yeasts. Of 145 episodes caused by an isolate with a fluconazole MIC < or =2 mg/liter, 93.7% (136 of 145) responded to fluconazole treatment. The response for those infected with a strain with a MIC of 4 mg/liter was 66% but reached 100% when the dose was greater than 100 mg/day, whereas the response for those infected with strains with MICs > or =8 mg/liter was only 12%. Hence, a MIC of 2 mg/liter or 4 mg/liter was able to predict successful treatment. A cure rate of 93.9% (140 of 149) was achieved when the dose/MIC ratio was > or =100 but fell to 14.6% (16 of 109) when the ratio was less. The dose/MIC required to achieve a response rate of 50% (the 50% effective concentration) was 43.7 for the cohort of patients with oropharyngeal candidiasis. Classification and regression analysis indicated that a dose/MIC of 35.5 was the threshold for the prediction of cure or failure. However, an increase in exposure above this threshold further increased the probability of cure, and all patients were cured when the dose/MIC exceeded 100. Monte Carlo simulations showed a probability of target attainment of 99% at MICs < or =2 mg/liter and a pharmacodynamic target of a dose/MIC ratio of 100, which was equivalent to an unbound fraction of the fluconazole area under the curve versus the MIC of 79.
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Affiliation(s)
- Juan L Rodríguez-Tudela
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda Pozuelo km 2, 28220 Majadahonda, Spain.
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Muller AE, DeJongh J, Bult Y, Goessens WHF, Mouton JW, Danhof M, van den Anker JN. Pharmacokinetics of penicillin G in infants with a gestational age of less than 32 weeks. Antimicrob Agents Chemother 2007; 51:3720-5. [PMID: 17646418 PMCID: PMC2043294 DOI: 10.1128/aac.00318-07] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pharmacokinetics of penicillin G were studied in 20 preterm neonates with a gestational age of less than 32 weeks on day 3 of life by using a population approach performed with the nonlinear mixed effects modeling program NONMEM. The derived population estimates and the correlation matrix of these estimates were used to perform Monte Carlo simulations and obtain the probability of target attainment (PTA). The pharmacokinetics of penicillin G were best described by a two-compartment pharmacokinetic model. The population estimates of the central volume of distribution, the peripheral volume of distribution, the intercompartmental clearance, and the total body clearance were 0.359 +/- 0.06 liter, 0.152 +/- 0.03 liter, 0.774 +/- 0.28 liter/h, and 0.103 +/- 0.01 liter/h (mean +/- standard error), respectively. The terminal half-life was 3.9 h. Clearance increased significantly with increasing birth weight. Assuming the percentage of time that the concentration of unbound drug remained above the MIC of 50% for preterm neonates, the susceptibility breakpoint based on a 100% PTA was < or =4 mg/liter, simulating the current dosing regimen of 50,000 U/kg every 12 h. This regimen is therefore adequate for the treatment of common infections in neonates on the third day of life.
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Affiliation(s)
- Anouk E Muller
- Medical Centre Haaglanden (MCH), Department of Obstetrics and Gynecology, Lijnbaan 32, 2512 VA, The Hague, The Netherlands.
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Bulitta JB, Duffull SB, Kinzig-Schippers M, Holzgrabe U, Stephan U, Drusano GL, Sörgel F. Systematic comparison of the population pharmacokinetics and pharmacodynamics of piperacillin in cystic fibrosis patients and healthy volunteers. Antimicrob Agents Chemother 2007; 51:2497-507. [PMID: 17485505 PMCID: PMC1913222 DOI: 10.1128/aac.01477-06] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 02/11/2007] [Accepted: 04/27/2007] [Indexed: 11/20/2022] Open
Abstract
Respiratory tract infections cause 90% of premature mortality in patients with cystic fibrosis (CF). Treatment of Pseudomonas aeruginosa infection is often very problematic. Piperacillin-tazobactam has good activity against P. aeruginosa, but its pharmacokinetics (PK) in CF patients has not been compared to the PK in healthy volunteers in a controlled clinical study. Therefore, we compared the population PK and pharmacodynamics (PD) of piperacillin between CF patients and healthy volunteers. We studied 8 adult (median age, 20 years) CF patients (average total body weight [WT], 43.1 +/- 7.8 kg) and 26 healthy volunteers (WT, 71.1 +/- 11.8 kg) who each received 4 g piperacillin as a 5-min intravenous infusion. We determined piperacillin levels by high-performance liquid chromatography, and we used NONMEM for population PK and Monte Carlo simulation. We used a target time of nonprotein-bound concentration above the MIC of 50%, which represents near-maximal bacterial killing. Unscaled total clearance was 25% lower, and the volume of distribution was 31% lower in CF patients. Allometric scaling by lean body mass reduced the unexplained (random) between-subject variability in clearance by 26% compared to the variability of linear scaling by WT. A standard dosage regimen of 3 g/70 kg body WT every 4 h as a 30-min infusion (daily dose, 18 g) achieved a robust (> or =90%) probability-of-target attainment (PTA) for MICs of < or =12 mg/liter in CF patients and < or =16 mg/liter in healthy volunteers. Alternative modes of administration allowed a marked dose reduction to 9 g daily. Prolonged (4-h) infusions of 3 g/70 kg WT every 8 h and continuous infusion (daily dose, 9 g), achieved a robust PTA for MICs of < or =16 mg/liter in both groups. Piperacillin achieved PTA expectation values of 64% and 89% against P. aeruginosa infection in CF patients, based on susceptibility data from two German CF clinics.
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Affiliation(s)
- J B Bulitta
- Institute for Biomedical and Pharmaceutical Research, Nürnberg-Heroldsberg, Germany
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Vinks AA, van Rossem RN, Mathôt RAA, Heijerman HGM, Mouton JW. Pharmacokinetics of aztreonam in healthy subjects and patients with cystic fibrosis and evaluation of dose-exposure relationships using monte carlo simulation. Antimicrob Agents Chemother 2007; 51:3049-55. [PMID: 17576827 PMCID: PMC2043218 DOI: 10.1128/aac.01522-06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aztreonam (AZM) is a monobactam antibiotic with a high level of activity against gram-negative micro-organisms, including Pseudomonas aeruginosa. We evaluated AZM pharmacokinetics and pharmacokinetic-pharmacodynamic relationships in patients with cystic fibrosis (CF) and healthy subjects. Pharmacokinetic data in eight CF patients and healthy subjects that were matched for age, gender, weight, and height were obtained and analyzed by using the nonparametric adaptive grid algorithm. Probabilities of target attainment using percentages of time of unbound concentration above the MIC (fT>MIC) were obtained by using a Monte Carlo simulation. AZM total body clearance was significantly higher in CF patients (100.1 +/- 17.1 versus 76.2 +/- 7.4 ml/min in healthy subjects; P < 0.01). The pharmacokinetic parameter estimates for terminal half-life (1.54 +/- 0.17 h [mean +/- the standard deviation]) and volume of distribution (0.20 +/- 0.02 liters/kg in patients with CF patients were not different from those in healthy subjects. Monte Carlo simulations with a target of a fT>MIC of 50 to 60% at a dose of 1,000 mg every 8 h indicated a clinical breakpoint of 4 mg/liter and 1 to 2 mg/liter for healthy subjects and CF patients, respectively. This study using matched controls showed that AZM total body clearance and not the volume of distribution is higher in CF patients as a result of increased renal clearance. Pharmacokinetic parameter estimates in healthy subjects resulted in a clinical susceptibility breakpoint of < or =4 mg/liter for a dose of 1,000 mg every 8 h. Patients suspected of having high clearance rates, such as CF patients, should be monitored closely, with dosing regimens adjusted accordingly.
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Affiliation(s)
- Alexander A Vinks
- Pediatric Pharmacology Research Unit, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 6018, Cincinnati, OH 45229-3039, USA.
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Eagye KJ, Kuti JL, Nicolau DP. Evaluating Empiric Treatment Options for Secondary Peritonitis Using Pharmacodynamic Profiling. Surg Infect (Larchmt) 2007; 8:215-26. [PMID: 17437367 DOI: 10.1089/sur.2006.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Selecting an appropriate agent for empiric antibiotic therapy for secondary peritonitis is challenging. The pathogens responsible, aerobic gram-negative bacilli in particular, are becoming more resistant to antibiotics. The purpose of this study was to predict the ability of common antimicrobial regimens to achieve optimal pharmacodynamic exposure against aerobic bacteria implicated in secondary peritonitis, while considering current national resistance trends. METHODS Monte Carlo simulation was used to model pharmacodynamic endpoints and compare the cumulative fraction of response (CFR) for imipenem-cilastatin, meropenem, ertapenem, piperacillin/tazobactam, ceftazidime, ceftriaxone, ciprofloxacin, and levofloxacin against isolates of species associated with secondary peritonitis. Minimum inhibitory concentration (MIC) distributions for isolates collected in North America were obtained from the 2004 MYSTIC database. Pharmacokinetic parameters were derived from the literature; the endpoints evaluated included free drug time above the MIC (fT(>MIC)) and the area under the concentration-time curve to MIC ratio (AUC:MIC). RESULTS The simulation predicted that several compounds would have a superior probability of providing appropriate coverage of aerobic bacteria: Imipenem-cilastatin (98.6% CFR at 1 g q8h), meropenem (98.2% CFR at 1 g q8h), ertapenem (91.7% CFR at 1 g q24h), piperacillin/ tazobactam (93.7% CFR at 3.375 g q6h), ceftazidime (91.1% CFR at 2 g q8h), and cefepime (92.9% CFR at 1 g q12h and 95.8% CFR at 2 g q12h). Ceftriaxone, ciprofloxacin, and levofloxacin exhibited CFRs < 82%. CONCLUSIONS Considering contemporary susceptibility data for aerobic bacteria, monotherapy with any of the three carbapenems or piperacillin/tazobactam 3.375 g q6h would provide optimal exposure for the pathogens commonly encountered in secondary peritonitis. Cefepime (in combination with metronidazole to provide anti-anaerobic coverage) also would be an acceptable choice, as would ceftazidime given at 2 g q8h (again in combination with metronidazole). Despite the popularity of combination therapy based on ciprofloxacin, levofloxacin, or ceftriaxone with metronidazole, these choices appear to be inferior to the other options because of emerging antibiotic resistance, particularly in E. coli.
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Affiliation(s)
- Kathryn J Eagye
- Center for Anti-Infective Research Development, Hartford Hospital, Hartford, CT 06102, USA
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Ludwig E, Konkoly-Thege M, Kuti JL, Nicolau DP. Optimising antibiotic dosing regimens based on pharmacodynamic target attainment against Pseudomonas aeruginosa collected in Hungarian hospitals. Int J Antimicrob Agents 2007; 28:433-8. [PMID: 17046212 DOI: 10.1016/j.ijantimicag.2006.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 07/03/2006] [Accepted: 07/04/2006] [Indexed: 11/30/2022]
Abstract
Owing to increasing resistance rates in Europe, pharmacodynamic analyses were proposed to determine optimal empirical antibiotic therapy against Pseudomonas aeruginosa isolated in Hungary. Minimum inhibitory concentrations for 180 non-duplicate P. aeruginosa collected from 14 hospitals in Hungary were determined by Etest methodology. A 5000-subject Monte Carlo simulation was performed to calculate the bactericidal cumulative fraction of response (CFR) for standard dosing regimens of cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem and piperacillin/tazobactam. In the case of poor CFR, alternative dosage regimens were simulated for selected agents by increasing the infusion time, dose and frequency. Owing to high resistance rates in Hungary, no regimen achieved >90% CFR. CFRs for standard dosing regimens were: meropenem 1g every 8h (q8h), 77.1%; ceftazidime 2g q8h, 75.3%; imipenem 0.5 g every 6h (q6h), 71.7%; and piperacillin/tazobactam 4.5 g and 3.375 g q6h, 72.4% and 71.0%, respectively. Ciprofloxacin achieved significantly lower bactericidal CFRs than any beta-lactam. Prolonged infusion regimens improved the CFR for cefepime, imipenem, meropenem and piperacillin/tazobactam. Overall, the highest CFR (88.1%) was achieved by a 3-h infusion of meropenem 2g q8h. Given the poor CFR predicted with standard dosage regimens against these isolates, it seems prudent to consider alternative dosage strategies such as increasing doses, frequencies or infusion times as well as combination therapy when empirically treating infections caused by P. aeruginosa in Hungary.
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Affiliation(s)
- Endre Ludwig
- Szent László Hospital, Department of Clinical Microbiology and Infectiology, Budapest, Hungary.
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Soy D, Torres A. Antibacterial dosage in intensive-care-unit patients based on pharmacokinetic/pharmacodynamic principles. Curr Opin Crit Care 2007; 12:477-82. [PMID: 16943729 DOI: 10.1097/01.ccx.0000244130.77365.c2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Selection of the best antibiotic dosage regimen in intensive-care-unit patients is a critical factor for decreasing morbidity and mortality rates. The integration of pharmacokinetics and pharmacodynamics is essential to establishing an adequate therapy. Many studies on this issue have been published in recent years due to its relevance, some of which are commented upon in this review. RECENT FINDINGS Several studies have shown that it is feasible to theoretically forecast pharmacodynamic outcomes and select the most adequate antibiotic therapy with Monte Carlo simulations. Moreover, new strategies such as the use of continuous or extended intravenous beta-lactam infusions may considerably improve therapeutic efficacy. SUMMARY Future studies are needed in patients to assess the influence of selecting antibiotic therapy based on the impact of pharmacokinetic/pharmacodynamic on mortality, morbidity, cost, etc. It would be of special interest to evaluate this impact on patients with infections caused by multiresistant pathogens, whose mortality rates are even higher. Moreover, although studies such as this would not be easy, mainly due to the large number of patients required to obtain statistically significant results, they should be strongly encouraged because of the possible clinical and economic benefits.
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Affiliation(s)
- Dolors Soy
- Pharmacy Service (UASP), Hospital Clinic Barcelona, IDIBAPS, Universitat de Barcelona, Spain.
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Bakker-Woudenberg IAJM, ten Kate MT, Goessens WHF, Mouton JW. Effect of treatment duration on pharmacokinetic/pharmacodynamic indices correlating with therapeutic efficacy of ceftazidime in experimental Klebsiella pneumoniae lung infection. Antimicrob Agents Chemother 2006; 50:2919-25. [PMID: 16940082 PMCID: PMC1563558 DOI: 10.1128/aac.00859-05] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 10/31/2005] [Accepted: 06/18/2006] [Indexed: 11/20/2022] Open
Abstract
The pharmacokinetic/pharmacodynamic (PK/PD) indices that define the therapeutic effect of the beta-lactam ceftazidime in a rat model of Klebsiella pneumoniae lung infection were investigated in relation to treatment duration and treatment endpoint. Treatment was started 24 h after infection with dosing regimens of 3.1 up to 1,600 mg/kg of body weight/day and dosing every 6, 12, or 24 h. When animals were treated for a relatively short period of 48 h, the duration of time that unbound plasma ceftazidime levels exceeded the MIC of the antibiotic for the infecting strain was the index that best correlated with therapeutic efficacy in terms of significant bacterial killing in the infected lung (microbiological effect). The maximum effect was reached when plasma ceftazidime levels were above the MIC for 60 to 70% of the dosing interval. However, when the treatment duration was extended to a relatively long period of 18 days instead of 48 h and animal survival rate instead of microbiological efficacy was taken as the endpoint, the fAUC/MIC ratio (where AUC is the area under the concentration-time curve) was the PK/PD index that best correlated with therapeutic efficacy. The PK/PD indices that effect 50% survival of rats for the fAUC/MIC ratios were 18.0 (95% confidence interval [95% CI], 16.3 to 19.9), 20.2 (95% CI, 13.8 to 29.4), and 27.9 (95% CI, 21.3 to 36.5) for the schedules of administration of every 6, 12, and 24 h, respectively. The fAUC/MIC needed for 100% survival was >100. We conclude that the PK/PD index that best correlates with outcome is dependent on the duration of treatment and/or the parameter of outcome. The effect of long-term treatment should be studied more extensively in other models of infection.
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Affiliation(s)
- Irma A J M Bakker-Woudenberg
- Department of Medical Microbiology & Infectious Diseases, Erasmus University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
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Kuti JL, Nicolau DP. Making the most of surveillance studies: summary of the OPTAMA Program. Diagn Microbiol Infect Dis 2005; 53:281-7. [PMID: 16360552 DOI: 10.1016/j.diagmicrobio.2005.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Accepted: 10/16/2005] [Indexed: 11/29/2022]
Abstract
Antibiotic surveillance studies lack consideration of pharmacodynamics and provide little information about optimal dosing. By using minimum inhibitory concentration (MIC) data derived from a global surveillance study and Monte Carlo simulation, the Optimizing Pharmacodynamic Target Attainment using the MYSTIC Antibiogram (OPTAMA) Program was established to impart greater understanding of the ability to attain pharmacodynamic exposure for specific dosing regimens and their relationship with percent susceptibility. Early OPTAMA studies focused on determining the cumulative fraction of response (CFR) for various antibiotics against Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa regionally in Europe and the Americas. Later reports considered the prevalence of specific bacteria causing infections to estimate the CFR for empiric therapy of pneumonia, bloodstream, complicated skin/skin structure, and intra-abdominal infections. Collectively, the approach of the OPTAMA Program provides a novel tool that complements susceptibility data to help in the selection of appropriate empirical antibiotic therapy at the national, regional, and institutional level.
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Affiliation(s)
- Joseph L Kuti
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT 06102, USA
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