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Tilanus A, Drusano G. Inoculum-Based Dosing: A Novel Concept for Combining Time with Concentration-Dependent Antibiotics to Optimize Clinical and Microbiological Outcomes in Severe Gram Negative Sepsis. Antibiotics (Basel) 2023; 12:1581. [PMID: 37998783 PMCID: PMC10668771 DOI: 10.3390/antibiotics12111581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023] Open
Abstract
Certain classes of antibiotics show "concentration dependent" antimicrobial activity; higher concentrations result in increased bacterial killing rates, in contrast to "time dependent antibiotics", which show antimicrobial activity that depends on the time that antibiotic concentrations remain above the MIC. Aminoglycosides and fluoroquinolones are still widely used concentration-dependent antibiotics. These antibiotics are not hydrolyzed by beta-lactamases and are less sensitive to the inoculum effect, which can be defined as an increased MIC for the antibiotic in the presence of a relatively higher bacterial load (inoculum). In addition, they possess a relatively long Post-Antibiotic Effect (PAE), which can be defined as the absence of bacterial growth when antibiotic concentrations fall below the MIC. These characteristics make them interesting complementary antibiotics in the management of Multi-Drug Resistant (MDR) bacteria and/or (neutropenic) patients with severe sepsis. Global surveillance studies have shown that up to 90% of MDR Gram-negative bacteria still remain susceptible to aminoglycosides, depending on the susceptibility breakpoint (e.g., CLSI or EUCAST) being applied. This percentage is notably lower for fluoroquinolones but depends on the region, type of organism, and mechanism of resistance involved. Daily (high-dose) dosing of aminoglycosides for less than one week has been associated with significantly less nephro/oto toxicity and improved target attainment. Furthermore, higher-than-conventional dosing of fluoroquinolones has been linked to improved clinical outcomes. Beta-lactam antibiotics are the recommended backbone of therapy for severe sepsis. Since these antibiotics are time-dependent, the addition of a second concentration-dependent antibiotic could serve to quickly lower the bacterial inoculum, create PAE, and reduce Penicillin-Binding Protein (PBP) expression. Inadequate antibiotic levels at the site of infection, especially in the presence of high inoculum infections, have been shown to be important risk factors for inadequate resistance suppression and therapeutic failure. Therefore, in the early phase of severe sepsis, effort should be made to optimize the dose and quickly lower the inoculum. In this article, the authors propose a novel concept of "Inoculum Based Dosing" in which the decision for antibiotic dosing regimens and/or combination therapy is not only based on the PK parameters of the patient, but also on the presumed inoculum size. Once the inoculum has been lowered, indirectly reflected by clinical improvement, treatment simplification should be considered to further treat the infection.
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Affiliation(s)
- Alwin Tilanus
- Department of Infectious Diseases, Clinica Los Nogales, Calle 95 # 23-61, Bogota 110221, Colombia
| | - George Drusano
- Institute for Therapeutic Innovation, University of Florida, 6550 Sanger Road, Orlando, FL 32827, USA;
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2
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Chang Y, Sun W, Murchie AIH, Chen D. Genome-wide identification of Kanamycin B binding RNA in Escherichia coli. BMC Genomics 2023; 24:120. [PMID: 36927548 PMCID: PMC10018874 DOI: 10.1186/s12864-023-09234-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND The aminoglycosides are established antibiotics that inhibit bacterial protein synthesis by binding to ribosomal RNA. Additional non-antibiotic aminoglycoside cellular functions have also been identified through aminoglycoside interactions with cellular RNAs. The full extent, however, of genome-wide aminoglycoside RNA interactions in Escherichia coli has not been determined. Here, we report genome-wide identification and verification of the aminoglycoside Kanamycin B binding to Escherichia coli RNAs. Immobilized Kanamycin B beads in pull-down assays were used for transcriptome-profiling analysis (RNA-seq). RESULTS Over two hundred Kanamycin B binding RNAs were identified. Functional classification analysis of the RNA sequence related genes revealed a wide range of cellular functions. Small RNA fragments (ncRNA, tRNA and rRNA) or small mRNA was used to verify the binding with Kanamycin B in vitro. Kanamycin B and ibsC mRNA was analysed by chemical probing. CONCLUSIONS The results will provide biochemical evidence and understanding of potential extra-antibiotic cellular functions of aminoglycosides in Escherichia coli.
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Affiliation(s)
- Yaowen Chang
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Wenxia Sun
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Alastair I H Murchie
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China. .,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
| | - Dongrong Chen
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China. .,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
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3
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Butler DA, Rana AP, Krapp F, Patel SR, Huang Y, Ozer EA, Hauser AR, Bulman ZP. Optimizing aminoglycoside selection for KPC-producing Klebsiella pneumoniae with the aminoglycoside-modifying enzyme (AME) gene aac(6')-Ib. J Antimicrob Chemother 2021; 76:671-679. [PMID: 33326561 DOI: 10.1093/jac/dkaa480] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/22/2020] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES KPC-producing Klebsiella pneumoniae (KPC-Kp) isolates commonly co-harbour the aminoglycoside-modifying enzyme (AME) gene aac(6')-Ib, which encodes an AME that can confer resistance to some of the commercially available aminoglycosides. We sought to determine the influence of AAC(6')-Ib in KPC-Kp on the pharmacodynamic activity of aminoglycosides. METHODS Six KPC-Kp clinical isolates, three with and three without aac(6')-Ib, were analysed. Using these isolates, the bacterial killing of amikacin, gentamicin and tobramycin was assessed in static time-kill experiments. The pharmacodynamic activity of the aminoglycosides was then assessed in a dynamic one-compartment infection model over 72 h using simulated human pharmacokinetics of once-daily dosing with amikacin (15 mg/kg), gentamicin (5 mg/kg) and tobramycin (5 mg/kg). RESULTS At clinically relevant aminoglycoside concentrations in time-kill experiments and the dynamic one-compartment model, gentamicin was more active than amikacin or tobramycin against the isolates harbouring aac(6')-Ib. Amikacin, gentamicin and tobramycin all showed progressively reduced bacterial killing with exposure to repeated doses against most isolates in the dynamic one-compartment model. MIC values were generally not a good predictor of gentamicin pharmacodynamic activity against KPC-Kp, but were more reliable for amikacin and tobramycin. CONCLUSIONS Gentamicin may be preferred over amikacin or tobramycin for treatment of KPC-Kp infections. However, gentamicin MICs are not a consistent predictor of its pharmacodynamic activity and unexpected treatment failures are possible.
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Affiliation(s)
- David A Butler
- University of Illinois at Chicago College of Pharmacy, Chicago, IL, USA
| | - Amisha P Rana
- University of Illinois at Chicago College of Pharmacy, Chicago, IL, USA
| | - Fiorella Krapp
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano, Lima, Peru
| | - Shitalben R Patel
- University of Illinois at Chicago College of Pharmacy, Chicago, IL, USA
| | - Yanqin Huang
- University of Illinois at Chicago College of Pharmacy, Chicago, IL, USA
| | - Egon A Ozer
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Alan R Hauser
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Zackery P Bulman
- University of Illinois at Chicago College of Pharmacy, Chicago, IL, USA
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4
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Bystritskaya E, Chernysheva N, Stenkova A, Guzev K, Rakin A, Isaeva M. Differential Expression of Yersinia pseudotuberculosis General Porin Genes during Short- and Long-Term Antibiotic Stresses. Molecules 2021; 26:3956. [PMID: 34203552 PMCID: PMC8272246 DOI: 10.3390/molecules26133956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 11/25/2022] Open
Abstract
Here, we investigated general porin regulation in Yersinia pseudotuberculosis 488, the causative agent of Far Eastern scarlet-like fever, in response to sublethal concentrations of antibiotics. We chose four antibiotics of different classes and measured gene expression using qRT-PCR and GFP reporter systems. Our data showed temporal regulation of the general porin genes ompF and ompC caused by antibiotic stress. The porin transcription initially decreased, providing early defensive response of the bacterium, while it returned to that of the untreated cells on prolonged antibiotic exposure. Unlike the major porin genes, the transcription of the alternative porin genes ompX and lamB was increased. Moreover, a short-term ompR- and marA-mediated porin regulation was observed. The main finding was a phenotypic heterogeneity of Y. pseudotuberculosis population manifested in variable porin gene expression under carbenicillin exposure. This may offer adaptive fitness advantages for a particular bacterial subpopulation.
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Affiliation(s)
- Evgeniya Bystritskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Nadezhda Chernysheva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Anna Stenkova
- School of Biomedicine, Far Eastern Federal University, 8 Sukhanova St., 690090 Vladivostok, Russia;
| | - Konstantin Guzev
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Alexander Rakin
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute for Bacterial Infections and Zoonoses, Naumburger Str. 96a, D-07743 Jena, Germany;
| | - Marina Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
- School of Biomedicine, Far Eastern Federal University, 8 Sukhanova St., 690090 Vladivostok, Russia;
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5
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Sou T, Hansen J, Liepinsh E, Backlund M, Ercan O, Grinberga S, Cao S, Giachou P, Petersson A, Tomczak M, Urbas M, Zabicka D, Vingsbo Lundberg C, Hughes D, Hobbie SN, Friberg LE. Model-Informed Drug Development for Antimicrobials: Translational PK and PK/PD Modeling to Predict an Efficacious Human Dose for Apramycin. Clin Pharmacol Ther 2020; 109:1063-1073. [PMID: 33150591 PMCID: PMC8048880 DOI: 10.1002/cpt.2104] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/18/2020] [Indexed: 12/12/2022]
Abstract
Apramycin represents a subclass of aminoglycoside antibiotics that has been shown to evade almost all mechanisms of clinically relevant aminoglycoside resistance. Model-informed drug development may facilitate its transition from preclinical to clinical phase. This study explored the potential of pharmacokinetic/pharmacodynamic (PK/PD) modeling to maximize the use of in vitro time-kill and in vivo preclinical data for prediction of a human efficacious dose (HED) for apramycin. PK model parameters of apramycin from four different species (mouse, rat, guinea pig, and dog) were allometrically scaled to humans. A semimechanistic PK/PD model was developed from the rich in vitro data on four Escherichia coli strains and subsequently the sparse in vivo efficacy data on the same strains were integrated. An efficacious human dose was predicted from the PK/PD model and compared with the classical PK/PD index methodology and the aminoglycoside dose similarity. One-compartment models described the PK data and human values for clearance and volume of distribution were predicted to 7.07 L/hour and 26.8 L, respectively. The required fAUC/MIC (area under the unbound drug concentration-time curve over MIC ratio) targets for stasis and 1-log kill in the thigh model were 34.5 and 76.2, respectively. The developed PK/PD model predicted the efficacy data well with strain-specific differences in susceptibility, maximum bacterial load, and resistance development. All three dose prediction approaches supported an apramycin daily dose of 30 mg/kg for a typical adult patient. The results indicate that the mechanistic PK/PD modeling approach can be suitable for HED prediction and serves to efficiently integrate all available efficacy data with potential to improve predictive capacity.
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Affiliation(s)
- Tomás Sou
- Pharmacometrics, Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Jon Hansen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institute, Copenhagen, Denmark
| | | | - Maria Backlund
- Department of Pharmacy, Uppsala University Drug Optimization and Pharmaceutical Profiling, Uppsala University, Uppsala, Sweden
| | - Onur Ercan
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | | | - Sha Cao
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Paraskevi Giachou
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Anna Petersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Magdalena Tomczak
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland
| | - Malgorzata Urbas
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland
| | - Dorota Zabicka
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland
| | | | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Sven N Hobbie
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Lena E Friberg
- Pharmacometrics, Department of Pharmacy, Uppsala University, Uppsala, Sweden
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6
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Maiden MM, Waters CM. Triclosan depletes the membrane potential in Pseudomonas aeruginosa biofilms inhibiting aminoglycoside induced adaptive resistance. PLoS Pathog 2020; 16:e1008529. [PMID: 33125434 PMCID: PMC7657502 DOI: 10.1371/journal.ppat.1008529] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 11/11/2020] [Accepted: 09/15/2020] [Indexed: 12/18/2022] Open
Abstract
Biofilm-based infections are difficult to treat due to their inherent resistance to antibiotic treatment. Discovering new approaches to enhance antibiotic efficacy in biofilms would be highly significant in treating many chronic infections. Exposure to aminoglycosides induces adaptive resistance in Pseudomonas aeruginosa biofilms. Adaptive resistance is primarily the result of active antibiotic export by RND-type efflux pumps, which use the proton motive force as an energy source. We show that the protonophore uncoupler triclosan depletes the membrane potential of biofilm growing P. aeruginosa, leading to decreased activity of RND-type efflux pumps. This disruption results in increased intracellular accumulation of tobramycin and enhanced antimicrobial activity in vitro. In addition, we show that triclosan enhances tobramycin effectiveness in vivo using a mouse wound model. Combining triclosan with tobramycin is a new anti-biofilm strategy that targets bacterial energetics, increasing the susceptibility of P. aeruginosa biofilms to aminoglycosides.
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Affiliation(s)
- Michael M. Maiden
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- The BEACON Center for The Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Christopher M. Waters
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- The BEACON Center for The Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
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7
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Kuti JL, Kim A, Cloutier DJ, Nicolau DP. Evaluation of Plazomicin, Tigecycline, and Meropenem Pharmacodynamic Exposure against Carbapenem-Resistant Enterobacteriaceae in Patients with Bloodstream Infection or Hospital-Acquired/Ventilator-Associated Pneumonia from the CARE Study (ACHN-490-007). Infect Dis Ther 2019; 8:383-396. [PMID: 31254273 PMCID: PMC6702525 DOI: 10.1007/s40121-019-0251-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION CARE was a Phase 3, randomized study evaluating the efficacy and safety of plazomicin-based combination therapy compared with colistin-based combination therapy for the treatment of patients with bloodstream infections or hospital-acquired/ventilator-associated pneumonia due to carbapenem-resistant Enterobacteriaceae (CRE). Adjunctive therapies included either tigecycline or meropenem. We sought to understand the contribution of tigecycline and meropenem to plazomicin-treated-patient outcomes by determining their observed pharmacodynamic exposures against baseline pathogens. METHODS Blood samples collected for plazomicin therapeutic monitoring were assayed for tigecycline and meropenem concentrations. Population pharmacokinetic models were constructed for each antibiotic. Using the individual Bayesian posterior or a covariate-based model, concentration time profiles were simulated to estimate the pharmacodynamic exposures for each patient. Pharmacodynamic thresholds for plazomicin, tigecycline, and meropenem were a total area under the curve to minimum inhibitory concentration ratio (AUC/MIC) ≥ 85, free (f) AUC/MIC ≥ 0.9, and free time above the MIC (fT > MIC) of ≥ 40%, respectively. RESULTS Fifteen plazomicin-treated patients were included (12 received tigecycline, 4 received meropenem, 1 received both). Microbiological response was observed in 13 (86.7%) and clinical efficacy was achieved in 11 (73.3%). Plazomicin achieved its pharmacodynamic target in all 15 patients. Meropenem fT > MIC was 0% in all 4 patients, and tigecycline fAUC/MIC was ≥ 0.9 in 9 (75%) patients. Overall, 6 (40%) of 15 patients had a tigecycline or meropenem exposure below the requisite thresholds. Microbiological response and clinical efficacy were observed in 100% (6/6) and 83.3% (5/6) of patients with low threshold attainment by tigecycline and meropenem dosing regimens, respectively. CONCLUSIONS Plazomicin successfully achieved its requisite pharmacodynamic exposure, and these data suggest that optimization of tigecycline and meropenem therapy was not required for the combination to achieve microbiological response and clinical efficacy against serious CRE infections. TRIAL REGISTRATION ClinicalTrials.gov number, NCT01970371. FUNDING Achaogen, Inc.
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Affiliation(s)
- Joseph L Kuti
- Center for Anti-Infective Research and Development, Hartford Hospital, 80 Seymour Street, Hartford, CT, 06102, USA
| | - Aryun Kim
- Achaogen Inc., 1 Tower Place, Suite 300, South San Francisco, 94080, CA, USA
| | - Daniel J Cloutier
- Achaogen Inc., 1 Tower Place, Suite 300, South San Francisco, 94080, CA, USA
| | - David P Nicolau
- Center for Anti-Infective Research and Development, Hartford Hospital, 80 Seymour Street, Hartford, CT, 06102, USA.
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8
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Zhou S, Zhuang Y, Zhu X, Yao F, Li H, Li H, Zou X, Wu J, Zhou H, Nuer G, Huang Y, Li S, Peng Q. YhjX Regulates the Growth of Escherichia coli in the Presence of a Subinhibitory Concentration of Gentamicin and Mediates the Adaptive Resistance to Gentamicin. Front Microbiol 2019; 10:1180. [PMID: 31191496 PMCID: PMC6545925 DOI: 10.3389/fmicb.2019.01180] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 05/09/2019] [Indexed: 02/05/2023] Open
Abstract
The mechanisms of adaptive resistance of Escherichia coli to aminoglycosides remain unclear. Our RNA-Seq study found that expression of yhjX was markedly upregulated during initial exposure to subinhibitory concentrations of gentamicin. The expression of yhjX was then downregulated dramatically during a second exposure to gentamicin compared to the first exposure. YhjX encodes a putative transporter of the major facilitator superfamily, which is known to be the sole target of the YpdA/YpdB two-component system, the expression of which is highly and specifically induced by pyruvate. To investigate the effect of yhjX on the adaptive resistance of E. coli, in the present study, we constructed yhjX deletion and complemented strains of E. coli ATCC25922. Changes in extracellular pyruvate levels of wide-type and yhjX mutant were measured to determine whether YhjX functions as a pyruvate transporter. The results showed that yhjX deletion improved the growth of E. coli in medium containing subinhibitory concentrations of gentamicin. The yhjX deletion mutant did not exhibit adaptive resistance to subinhibitory concentrations of gentamicin. YhjX might not function as a pyruvate efflux pump in E. coli but was associated with the decrease following a sharp increase in the extracellular pyruvate level. Our findings indicate that yhjX regulates the growth of E. coli in the presence of a subinhibitory concentration of gentamicin and mediates the adaptive resistance to gentamicin.
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Affiliation(s)
- Shuqin Zhou
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yijing Zhuang
- Department of Science and Education, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Xiaojuan Zhu
- Department of Anesthesiology, First People’s Hospital of Kashi, Kashi, China
| | - Fen Yao
- Department of Pharmacology, Shantou University Medical College, Shantou, China
| | - Haiyan Li
- Department of Pharmacology, Shantou University Medical College, Shantou, China
| | - Huifang Li
- Department of Anesthesiology, First People’s Hospital of Kashi, Kashi, China
| | - Xiaoguang Zou
- Department of Pharmacy, First People’s Hospital of Kashi, Kashi, China
| | - Jianhua Wu
- Department of Science and Education, First People’s Hospital of Kashi, Kashi, China
| | - Huifang Zhou
- Department of Clinical Laboratory, First People’s Hospital of Kashi, Kashi, China
| | - Gulibaier Nuer
- Department of Anesthesiology, First People’s Hospital of Kashi, Kashi, China
| | - Yuanchun Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Shao Li
- Department of Hepatobiliary II, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Qing Peng
- Department of Hepatobiliary II, Zhujiang Hospital of Southern Medical University, Guangzhou, China
- *Correspondence: Qing Peng,
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Expression of Pseudomonas aeruginosa Antibiotic Resistance Genes Varies Greatly during Infections in Cystic Fibrosis Patients. Antimicrob Agents Chemother 2018; 62:AAC.01789-18. [PMID: 30201819 DOI: 10.1128/aac.01789-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 11/20/2022] Open
Abstract
The lungs of individuals with cystic fibrosis (CF) become chronically infected with Pseudomonas aeruginosa that is difficult to eradicate by antibiotic treatment. Two key P. aeruginosa antibiotic resistance mechanisms are the AmpC β-lactamase that degrades β-lactam antibiotics and MexXYOprM, a three-protein efflux pump that expels aminoglycoside antibiotics from the bacterial cells. Levels of antibiotic resistance gene expression are likely to be a key factor in antibiotic resistance but have not been determined during infection. The aims of this research were to investigate the expression of the ampC and mexX genes during infection in patients with CF and in bacteria isolated from the same patients and grown under laboratory conditions. P. aeruginosa isolates from 36 CF patients were grown in laboratory culture and gene expression measured by reverse transcription-quantitative PCR (RT-qPCR). The expression of ampC varied over 20,000-fold and that of mexX over 2,000-fold between isolates. The median expression levels of both genes were increased by the presence of subinhibitory concentrations of antibiotics. To measure P. aeruginosa gene expression during infection, we carried out RT-qPCR using RNA extracted from fresh sputum samples obtained from 31 patients. The expression of ampC varied over 4,000-fold, while mexX expression varied over 100-fold, between patients. Despite these wide variations, median levels of expression of ampC in bacteria in sputum were similar to those in laboratory-grown bacteria. The expression of mexX was higher in sputum than in laboratory-grown bacteria. Overall, our data demonstrate that genes that contribute to antibiotic resistance can be highly expressed in patients, but there is extensive isolate-to-isolate and patient-to-patient variation.
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10
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de With K, Allerberger F, Amann S, Apfalter P, Brodt HR, Eckmanns T, Fellhauer M, Geiss HK, Janata O, Krause R, Lemmen S, Meyer E, Mittermayer H, Porsche U, Presterl E, Reuter S, Sinha B, Strauß R, Wechsler-Fördös A, Wenisch C, Kern WV. Strategies to enhance rational use of antibiotics in hospital: a guideline by the German Society for Infectious Diseases. Infection 2017; 44:395-439. [PMID: 27066980 PMCID: PMC4889644 DOI: 10.1007/s15010-016-0885-z] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Introduction In the time of increasing resistance and paucity of new drug development there is a growing need for strategies to enhance rational use of antibiotics in German and Austrian hospitals. An evidence-based guideline on recommendations for implementation of antibiotic stewardship (ABS) programmes was developed by the German Society for Infectious Diseases in association with the following societies, associations and institutions: German Society of Hospital Pharmacists, German Society for Hygiene and Microbiology, Paul Ehrlich Society for Chemotherapy, The Austrian Association of Hospital Pharmacists, Austrian Society for Infectious Diseases and Tropical Medicine, Austrian Society for Antimicrobial Chemotherapy, Robert Koch Institute. Materials and methods A structured literature research was performed in the databases EMBASE, BIOSIS, MEDLINE and The Cochrane Library from January 2006 to November 2010 with an update to April 2012 (MEDLINE and The Cochrane Library). The grading of recommendations in relation to their evidence is according to the AWMF Guidance Manual and Rules for Guideline Development. Conclusion The guideline provides the grounds for rational use of antibiotics in hospital to counteract antimicrobial resistance and to improve the quality of care of patients with infections by maximising clinical outcomes while minimising toxicity. Requirements for a successful implementation of ABS programmes as well as core and supplemental ABS strategies are outlined. The German version of the guideline was published by the German Association of the Scientific Medical Societies (AWMF) in December 2013.
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Affiliation(s)
- K de With
- Division of Infectious Diseases, University Hospital Carl Gustav Carus at the TU Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - F Allerberger
- Division Public Health, Austrian Agency for Health and Food Safety (AGES), Vienna, Austria
| | - S Amann
- Hospital Pharmacy, Munich Municipal Hospital, Munich, Germany
| | - P Apfalter
- Institute for Hygiene, Microbiology and Tropical Medicine (IHMT), National Reference Centre for Nosocomial Infections and Antimicrobial Resistance, Elisabethinen Hospital Linz, Linz, Austria
| | - H-R Brodt
- Department of Infectious Disease Medical Clinic II, Goethe-University Frankfurt, Frankfurt, Germany
| | - T Eckmanns
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - M Fellhauer
- Hospital Pharmacy, Schwarzwald-Baar Hospital, Villingen-Schwenningen, Germany
| | - H K Geiss
- Department of Hospital Epidemiology and Infectiology, Sana Kliniken AG, Ismaning, Germany
| | - O Janata
- Department for Hygiene and Infection Control, Danube Hospital, Vienna, Austria
| | - R Krause
- Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Graz, Austria
| | - S Lemmen
- Division of Infection Control and Infectious Diseases, University Hospital RWTH Aachen, Aachen, Germany
| | - E Meyer
- Institute of Hygiene and Environmental Medicine, Charité, University Medicine Berlin, Berlin, Germany
| | - H Mittermayer
- Institute for Hygiene, Microbiology and Tropical Medicine (IHMT), National Reference Centre for Nosocomial Infections and Antimicrobial Resistance, Elisabethinen Hospital Linz, Linz, Austria
| | - U Porsche
- Department for Clinical Pharmacy and Drug Information, Landesapotheke, Landeskliniken Salzburg (SALK), Salzburg, Austria
| | - E Presterl
- Department of Infection Control and Hospital Epidemiology, Medical University of Vienna, Vienna, Austria
| | - S Reuter
- Clinic for General Internal Medicine, Infectious Diseases, Pneumology and Osteology, Klinikum Leverkusen, Leverkusen, Germany
| | - B Sinha
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - R Strauß
- Department of Medicine 1, Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Erlangen, Germany
| | - A Wechsler-Fördös
- Department of Antibiotics and Infection Control, Krankenanstalt Rudolfstiftung, Vienna, Austria
| | - C Wenisch
- Medical Department of Infection and Tropical Medicine, Kaiser Franz Josef Hospital, Vienna, Austria
| | - W V Kern
- Division of Infectious Diseases, Department of Medicine, Freiburg University Medical Center, Freiburg, Germany
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Abstract
Although aminoglycosides remain an essential part of therapy of severe gram-negative infections in critically ill patients, the use of extended-interval aminoglycoside dosing (EIAD) in this population is highly controversial. The rationale for EIAD is based on major pharmacodynamic characteristics of the aminoglycosides, which include concentration-dependent bactericidal effects, postantibiotic effect, and adaptive resistance. Alterations in the pharmacokinetics of aminoglycosides in the critically ill have been well documented, including changes in both drug distribution and elimination. These pharmacokinetic alterations may prevent critically ill patients from realizing the potential benefits of EIAD by reducing serum concentrations achieved by recommended EIAD regimens and may perhaps place patients at risk of therapeutic failure. Although numerous studies of EIAD have been conducted, there is a lack of data specifically concerning the efficacy and safety of EIAD in the critically ill. The most appropriate methods for monitoring EIAD in this population are also not clearly established. There are thus many questions regarding the suitability of EIAD in the critically ill. This article briefly reviews the rationale for EIAD and data related to the pharmacokinetics, efficacy, safety, and clinical monitoring of EIAD in critically ill patients. Considerations and recommendations for use of EIAD in the critically ill are provided.
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Affiliation(s)
- Douglas N. Fish
- Department of Pharmacy Practice, University of Colorado School of Pharmacy, Department of Pharmacy, University of Colorado Hospital, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Campus Box C- 238, Denver, CO 80262,
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12
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Rees VE, Bulitta JB, Oliver A, Tsuji BT, Rayner CR, Nation RL, Landersdorfer CB. Resistance suppression by high-intensity, short-duration aminoglycoside exposure against hypermutable and non-hypermutable Pseudomonas aeruginosa. J Antimicrob Chemother 2016; 71:3157-3167. [PMID: 27521357 DOI: 10.1093/jac/dkw297] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES Hypermutable bacteria are causing a drastic problem via their enhanced ability to become resistant. Our objectives were to compare bacterial killing and resistance emergence between differently shaped tobramycin concentration-time profiles at a given fAUC/MIC, and determine the tobramycin exposure durations that prevent resistance. METHODS Static concentration time-kill studies over 24 h used Pseudomonas aeruginosa WT strains (ATCC 27853 and PAO1) and hypermutable PAOΔmutS. fAUC/MIC values of 36, 72 and 168 were assessed at initial inocula of 106 and 104 cfu/mL (all strains) and 101.2 cfu/mL (PAOΔmutS only) in duplicate. Tobramycin was added at 0 h and removed at 1, 4, 10 or 24 h. Proportions of resistant bacteria and MICs were determined at 24 h. Mechanism-based modelling was conducted. RESULTS For all strains, high tobramycin concentrations over 1 and 4 h resulted in more rapid and extensive initial killing compared with 10 and 24 h exposures at a given fAUC/MIC. No resistance emerged for 1 and 4 h durations of exposure, although extensive regrowth of susceptible bacteria occurred. The 24 h duration of exposure revealed less regrowth, but tobramycin-resistant populations had completely replaced susceptible bacteria by 24 h for the 106 cfu/mL inoculum. The hypermutable PAOΔmutS showed the highest numbers of resistant bacteria. Total and resistant bacterial counts were described well by novel mechanism-based modelling. CONCLUSIONS Extensive resistance emerged for 10 and 24 h durations of exposure, but not for shorter durations. The tobramycin concentration-time profile shape is vital for resistance prevention and should aid the introduction of optimized combination regimens.
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Affiliation(s)
- Vanessa E Rees
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia
| | - Jürgen B Bulitta
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain
| | - Brian T Tsuji
- School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Craig R Rayner
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia.,d3 medicine LLC, Parsippany, NJ, USA
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia
| | - Cornelia B Landersdorfer
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia .,School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
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13
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Kim A, Kutschke A, Ehmann DE, Patey SA, Crandon JL, Gorseth E, Miller AA, McLaughlin RE, Blinn CM, Chen A, Nayar AS, Dangel B, Tsai AS, Rooney MT, Murphy-Benenato KE, Eakin AE, Nicolau DP. Pharmacodynamic Profiling of a Siderophore-Conjugated Monocarbam in Pseudomonas aeruginosa: Assessing the Risk for Resistance and Attenuated Efficacy. Antimicrob Agents Chemother 2015; 59:7743-52. [PMID: 26438502 PMCID: PMC4649189 DOI: 10.1128/aac.00831-15] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/29/2015] [Indexed: 01/05/2023] Open
Abstract
The objective of this study was to investigate the risk of attenuated efficacy due to adaptive resistance for the siderophore-conjugated monocarbam SMC-3176 in Pseudomonas aeruginosa by using a pharmacokinetic/pharmacodynamic (PK/PD) approach. MICs were determined in cation-adjusted Mueller-Hinton broth (MHB) and in Chelex-treated, dialyzed MHB (CDMHB). Spontaneous resistance was assessed at 2× to 16× the MIC and the resulting mutants sequenced. Efficacy was evaluated in a neutropenic mouse thigh model at 3.13 to 400 mg/kg of body weight every 3 h for 24 h and analyzed for association with free time above the MIC (fT>MIC). To closer emulate the conditions of the in vivo model, we developed a novel assay testing activity mouse whole blood (WB). All mutations were found in genes related to iron uptake: piuA, piuC, pirR, fecI, and pvdS. Against four P. aeruginosa isolates, SMC-3176 displayed predictable efficacy corresponding to the fT>MIC using the MIC in CDMHB (R(2) = 0.968 to 0.985), with stasis to 2-log kill achieved at 59.4 to 81.1%. Efficacy did not translate for P. aeruginosa isolate JJ 4-36, as the in vivo responses were inconsistent with fT>MIC exposures and implied a threshold concentration that was greater than the MIC. The results of the mouse WB assay indicated that efficacy was not predictable using the MIC for JJ 4-36 and four additional isolates, against which in vivo failures of another siderophore-conjugated β-lactam were previously reported. SMC-3176 carries a risk of attenuated efficacy in P. aeruginosa due to rapid adaptive resistance preventing entry via the siderophore-mediated iron uptake systems. Substantial in vivo testing is warranted for compounds using the siderophore approach to thoroughly screen for this in vitro-in vivo disconnect in P. aeruginosa.
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Affiliation(s)
- Aryun Kim
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Amy Kutschke
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - David E Ehmann
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Sara A Patey
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Jared L Crandon
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, Connecticut, USA
| | - Elise Gorseth
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Alita A Miller
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Robert E McLaughlin
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Christina M Blinn
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - April Chen
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Asha S Nayar
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Brian Dangel
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Andy S Tsai
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - Michael T Rooney
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | | | - Ann E Eakin
- Infection Innovative Medicines, AstraZeneca Pharmaceuticals LP, Waltham, Massachusetts, USA
| | - David P Nicolau
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, Connecticut, USA
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14
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Erickson KE, Otoupal PB, Chatterjee A. Gene Expression Variability Underlies Adaptive Resistance in Phenotypically Heterogeneous Bacterial Populations. ACS Infect Dis 2015; 1:555-67. [PMID: 27623410 DOI: 10.1021/acsinfecdis.5b00095] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The root cause of the antibiotic resistance crisis is the ability of bacteria to evolve resistance to a multitude of antibiotics and other environmental toxins. The regulation of adaptation is difficult to pinpoint due to extensive phenotypic heterogeneity arising during evolution. Here, we investigate the mechanisms underlying general bacterial adaptation by evolving wild-type Escherichia coli populations to dissimilar chemical toxins. We demonstrate the presence of extensive inter- and intrapopulation phenotypic heterogeneity across adapted populations in multiple traits, including minimum inhibitory concentration, growth rate, and lag time. To search for a common response across the heterogeneous adapted populations, we measured gene expression in three stress-response networks: the mar regulon, the general stress response, and the SOS response. While few genes were differentially expressed, clustering revealed that interpopulation gene expression variability in adapted populations was distinct from that of unadapted populations. Notably, we observed both increases and decreases in gene expression variability upon adaptation. Sequencing select genes revealed that the observed gene expression trends are not necessarily attributable to genetic changes. To further explore the connection between gene expression variability and adaptation, we propagated single-gene knockout and CRISPR (clustered regularly interspaced short palindromic repeats) interference strains and quantified impact on adaptation to antibiotics. We identified significant correlations that suggest genes with low expression variability have greater impact on adaptation. This study provides evidence that gene expression variability can be used as an indicator of bacterial adaptive resistance, even in the face of the pervasive phenotypic heterogeneity underlying adaptation.
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Affiliation(s)
- Keesha E. Erickson
- Department of Chemical and Biological Engineering and ‡BioFrontiers
Institute, University of Colorado, 596 UCB, Boulder, Colorado 80303, United States
| | - Peter B. Otoupal
- Department of Chemical and Biological Engineering and ‡BioFrontiers
Institute, University of Colorado, 596 UCB, Boulder, Colorado 80303, United States
| | - Anushree Chatterjee
- Department of Chemical and Biological Engineering and ‡BioFrontiers
Institute, University of Colorado, 596 UCB, Boulder, Colorado 80303, United States
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15
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Abstract
Aminoglycosides are among the oldest antibiotics available to treat serious infections caused by primarily, Gram-negative bacteria. The most commonly utilized parenteral agents in this class include gentamicin, tobramycin and amikacin. Aminoglycosides are concentration-dependent, bactericidal agents that undergo active transport into the cell where they inhibit protein synthesis on the 30S subunit of the bacterial ribosome. As the use of aminoglycosides became more widespread, the toxic effects of these agents, most notably ototoxicity and nephrotoxicity, became more apparent. When other, safer, antimicrobial agents became available, the use of aminoglycosides sharply declined. The development of multi-drug resistance among bacteria has now lead clinicians to reexamine the role of the aminoglycosides in the treatment of serious infections. This review will revisit the mechanism and risk factors for the development of aminoglycoside-induced nephrotoxicity, as well as strategies to prevent patients from developing nephrotoxicity.
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Affiliation(s)
- Kurt A Wargo
- Division of Internal Medicine, Auburn University Harrison School of Pharmacy, Huntsville, AL, USA
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16
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Sherwin CMT, Wead S, Stockmann C, Healy D, Spigarelli MG, Neely A, Kagan R. Amikacin population pharmacokinetics among paediatric burn patients. Burns 2013; 40:311-8. [PMID: 23876785 DOI: 10.1016/j.burns.2013.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The objectives of this study were to (1) determine the pharmacokinetics of amikacin among children with severe burn and (2) identify influential covariates. METHODS Population-based pharmacokinetic modelling was performed in NONMEM 7.2 for hospitalized children who received amikacin at 10-20mg/kg divided two, three, or four times per day as part of early empiric treatment of presumed burn-related sepsis. RESULTS The analysis included data from 70 patients (6 months to 17 years) with 282 amikacin serum concentrations. Amikacin's mean Cmax was 33.2±9.4μg/mL and the mean Cmin was 3.8±4.6μg/mL. The final covariate model estimated clearance as 5.98L/h/70kg (4.97-6.99, 95% CI), the volume of distribution in the central compartment as 16.7L/70kg (14.0-19.4, 95% CI), the volume of distribution in the peripheral compartment as 40.1L/70kg (15.0-80.4, 95% CI), and the inter-compartmental clearance as 3.38L/h/70kg (2.44-4.32, 95% CI). In multivariate analyses, current weight (P<0.001) was a significant covariate, while age, sex, height, serum creatinine, C-reactive protein, platelet count, the extent and type of burn, and concomitant vancomycin administration did not influence amikacin pharmacokinetics. DISCUSSION Children with burn featured elevated amikacin clearance when compared to healthy adult volunteers. However, peak amikacin concentrations are comparable to those attained in other critically-ill children, suggesting that elevated amikacin clearance may not result in sub-therapeutic antibacterial effects. In this study, we found that amikacin displays two-compartment pharmacokinetics, with weight exerting a strong effect upon amikacin clearance. Further pharmacodynamic studies are needed to establish the optimal dosing regimen for amikacin in paediatric burn patients.
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Affiliation(s)
- Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Paediatrics, University of Utah School of Medicine, Salt Lake City, Utah, United States.
| | - Stephanie Wead
- James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio, United States
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Paediatrics, University of Utah School of Medicine, Salt Lake City, Utah, United States
| | - Daniel Healy
- James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio, United States; The Shriners Hospitals for Children(®), Cincinnati, Ohio, United States
| | - Michael G Spigarelli
- Division of Clinical Pharmacology, Department of Paediatrics, University of Utah School of Medicine, Salt Lake City, Utah, United States
| | - Alice Neely
- Department of Surgery, University of Cincinnati, Cincinnati, Ohio, United States; The Shriners Hospitals for Children(®), Cincinnati, Ohio, United States
| | - Richard Kagan
- Department of Surgery, University of Cincinnati, Cincinnati, Ohio, United States; The Shriners Hospitals for Children(®), Cincinnati, Ohio, United States
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17
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Abstract
The adequate management of central nervous system (CNS) infections requires that antimicrobial agents penetrate the blood-brain barrier (BBB) and achieve concentrations in the CNS adequate for eradication of the infecting pathogen. This review details the currently available literature on the pharmacokinetics (PK) of antibacterials in the CNS of children. Clinical trials affirm that the physicochemical properties of a drug remain one of the most important factors dictating penetration of antimicrobial agents into the CNS, irrespective of the population being treated (i.e. small, lipophilic drugs with low protein binding exhibit the best translocation across the BBB). These same physicochemical characteristics determine the primary disposition pathways of the drug, and by extension the magnitude and duration of circulating drug concentrations in the plasma, a second major driving force behind achievable CNS drug concentrations. Notably, these disposition pathways can be expected to change during the normal process of growth and development. Finally, CNS drug penetration is influenced by the nature and extent of the infection (i.e. the presence of meningeal inflammation). Aminoglycosides have poor CNS penetration when administered intravenously. Intrathecal gentamicin has been studied in children with more promising results, often exceeding the minimum inhibitory concentration. There are very limited data with intrathecal tobramycin in children. However, in the few patients that have been studied, the CSF concentrations were highly variable. Penicillins generally have good CNS penetration. Aqueous penicillin G reaches greater concentrations than procaine or benzathine penicillin. Concentrations remain detectable for ≥ 12 h. Of the aminopenicillins, both ampicillin and parenteral amoxicillin reach adequate CNS concentrations; however, orally administered amoxicillin resulted in much lower concentrations. Nafcillin and piperacillin are the final two penicillins with pediatric data: their penetration is erratic at best. Cephalosporins vary greatly in regard to their CSF penetration. Few first- and second-generation cephalosporins are able to reach higher CSF concentrations. Cefuroxime is the only exception and is usually avoided due to its adverse effects and slower sterilization of the CSF than third-generation agents. Ceftriaxone, cefotaxime, ceftazidime, cefixime and cefepime have been studied in children and are all able to adequately penetrate the CSF. As with penicillins, concentrations are greatest in the presence of meningeal inflammation. Meropenem and imipenem are the only carbapenems with pediatric data. Imipenem reaches higher CSF concentrations; however, meropenem is preferred due to its lower incidence of seizures. Aztreonam has also demonstrated favorable penetration but only one study has been completed in children. Both chloramphenicol and sulfamethoxazole/trimethoprim (cotrimoxazole) penetrate into the CNS well; however, significant toxicities limit their use. The small size and minimal protein binding of fosfomycin contribute to its favorable CNS PK. Although rarely used, it achieves higher concentrations in the presence of inflammation and accumulation is possible. Linezolid reaches high CSF concentrations; however, more frequent dosing might be required in infants due to their increased elimination. Metronidazole also has very limited information but it demonstrated favorable results similar to adult data; CSF concentrations even exceeded plasma concentrations at certain time points. Rifampin (rifampicin) demonstrated good CNS penetration after oral administration. Vancomycin demonstrates poor CNS penetration after intravenous administration. When combined with intraventricular therapy, CNS concentrations are much greater. Of the antituberculosis agents, isoniazid, pyrazinamide and streptomycin have been studied in children. Isoniazid and pyrazinamide have favorable CSF penetration. Streptomycin appears to produce unpredictable CSF levels. No pediatric-specific data are available for clindamycin, daptomycin, macrolides, tetracyclines, and fluoroquinolones. Daptomycin, fluoroquinolones, and tetracyclines have demonstrated favorable CNS penetration in adults; however, data are limited due to their potential pediatric-specific toxicities and newness within the marketplace. Macrolides and clindamycin have demonstrated poor CNS penetration in adults and thus have not been studied in pediatrics.
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Adaptive and mutational resistance: role of porins and efflux pumps in drug resistance. Clin Microbiol Rev 2013; 25:661-81. [PMID: 23034325 DOI: 10.1128/cmr.00043-12] [Citation(s) in RCA: 540] [Impact Index Per Article: 49.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The substantial use of antibiotics in the clinic, combined with a dearth of new antibiotic classes, has led to a gradual increase in the resistance of bacterial pathogens to these compounds. Among the various mechanisms by which bacteria endure the action of antibiotics, those affecting influx and efflux are of particular importance, as they limit the interaction of the drug with its intracellular targets and, consequently, its deleterious effects on the cell. This review evaluates the impact of porins and efflux pumps on two major types of resistance, namely, mutational and adaptive types of resistance, both of which are regarded as key phenomena in the global rise of antibiotic resistance among pathogenic microorganisms. In particular, we explain how adaptive and mutational events can dramatically influence the outcome of antibiotic therapy by altering the mechanisms of influx and efflux of antibiotics. The identification of porins and pumps as major resistance markers has opened new possibilities for the development of novel therapeutic strategies directed specifically against these mechanisms.
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Fischer MO, Parienti JJ, Daurel C, Debruyne D, Verdon R, Gérard JL, Hanouz JL, Fellahi JL. An information campaign on aminoglycosides use during septic shock failed to improve the quality of care. ACTA ACUST UNITED AC 2011; 31:e1-5. [PMID: 22154443 DOI: 10.1016/j.annfar.2011.08.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 08/16/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Septic shock remains a major cause of death in intensive care units (ICU) and an inappropriate antibiotic regimen worsens the prognosis. The aim of the study was to assess the impact of an information campaign on modalities of prescription of aminoglycosides in septic shock. STUDY DESIGN A prospective observational study. METHODS Consecutive septic shock patients admitted to the surgical ICU over a 2-year period were included. An information campaign allowed to differentiate between a pre- (P1) and a post- (P2) interventional period. The campaign clarified the rules and requirements for pharmacological monitoring of aminoglycosides. The main objective was to increase the rate of prescription of peak serum aminoglycoside following the first intravenous injection. RESULTS One hundred and forty-eight patients (P1=76 and P2=72) were finally included into the study. Similar clinical characteristics were observed during both periods. The rate of prescription of peak serum aminoglycoside following the first injection was performed in 49% (P1) versus 65% (P2), P=0.09. The length of stay in ICU was 16 days [extremes: 1-74] (P1) versus 17 days [extremes: 1-133] (P2) (P=0.84). Inhospital mortality was 28% (P1) versus 26% (P2), P=0.86. CONCLUSIONS An information campaign describing the modalities of prescription of aminoglycosides in septic shock failed to improve medical practices and patient outcomes. A mobile team of antibiotics could be useful in daily practice.
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Affiliation(s)
- M-O Fischer
- Pôle anesthésie-réanimation-Samu-Smur-coordination hospitalière-hémovigilance, CHU de Caen, France.
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20
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Pagkalis S, Mantadakis E, Mavros MN, Ammari C, Falagas ME. Pharmacological Considerations for the Proper Clinical Use of Aminoglycosides. Drugs 2011; 71:2277-94. [DOI: 10.2165/11597020-000000000-00000] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Pharmacokinetic-pharmacodynamic model for gentamicin and its adaptive resistance with predictions of dosing schedules in newborn infants. Antimicrob Agents Chemother 2011; 56:179-88. [PMID: 22037853 DOI: 10.1128/aac.00694-11] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gentamicin is commonly used in the management of neonatal infections. Development of adaptive resistance is typical for aminoglycosides and reduces the antibacterial effect. There is, however, a lack of understanding of how this phenomenon influences the effect of different dosing schedules. The aim was to develop a pharmacokinetic-pharmacodynamic (PKPD) model that describes the time course of the bactericidal activity of gentamicin and its adaptive resistance and to investigate different dosing schedules in preterm and term newborn infants based on the developed model. In vitro time-kill curve experiments were conducted on a strain of Escherichia coli (MIC of 2 mg/liter). The gentamicin exposure was either constant (0.125 to 16 mg/liter) or dynamic (simulated concentration-time profiles in a kinetic system with peak concentrations of 2.0, 3.9, 7.8, and 16 mg/liter given as single doses or as repeated doses every 6, 12, or 24 h). Semimechanistic PKPD models were fitted to the bacterial counts in the NONMEM (nonlinear mixed effects modeling) program. A model with compartments for growing and resting bacteria, with a function allowing the maximal bacterial killing of gentamicin to reduce with exposure, characterized both the fast bactericidal effect and the adaptive resistance. Despite a lower peak concentration, preterm neonates were predicted to have a higher bacterial killing effect than term neonates for the same per-kg dose because of gentamicin's longer half-life. The model supported an extended dosing interval of gentamicin in preterm neonates, and for all neonates, dosing intervals of 36 to 48 h were as effective as a 24-h dosing interval for the same total dose.
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Pharmacokinetic/pharmacodynamic (PK/PD) indices of antibiotics predicted by a semimechanistic PKPD model: a step toward model-based dose optimization. Antimicrob Agents Chemother 2011; 55:4619-30. [PMID: 21807983 DOI: 10.1128/aac.00182-11] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A pharmacokinetic-pharmacodynamic (PKPD) model that characterizes the full time course of in vitro time-kill curve experiments of antibacterial drugs was here evaluated in its capacity to predict the previously determined PK/PD indices. Six drugs (benzylpenicillin, cefuroxime, erythromycin, gentamicin, moxifloxacin, and vancomycin), representing a broad selection of mechanisms of action and PK and PD characteristics, were investigated. For each drug, a dose fractionation study was simulated, using a wide range of total daily doses given as intermittent doses (dosing intervals of 4, 8, 12, or 24 h) or as a constant drug exposure. The time course of the drug concentration (PK model) as well as the bacterial response to drug exposure (in vitro PKPD model) was predicted. Nonlinear least-squares regression analyses determined the PK/PD index (the maximal unbound drug concentration [fC(max)]/MIC, the area under the unbound drug concentration-time curve [fAUC]/MIC, or the percentage of a 24-h time period that the unbound drug concentration exceeds the MIC [fT(>MIC)]) that was most predictive of the effect. The in silico predictions based on the in vitro PKPD model identified the previously determined PK/PD indices, with fT(>MIC) being the best predictor of the effect for β-lactams and fAUC/MIC being the best predictor for the four remaining evaluated drugs. The selection and magnitude of the PK/PD index were, however, shown to be sensitive to differences in PK in subpopulations, uncertainty in MICs, and investigated dosing intervals. In comparison with the use of the PK/PD indices, a model-based approach, where the full time course of effect can be predicted, has a lower sensitivity to study design and allows for PK differences in subpopulations to be considered directly. This study supports the use of PKPD models built from in vitro time-kill curves in the development of optimal dosing regimens for antibacterial drugs.
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Adaptive resistance to cationic compounds in Pseudomonas aeruginosa. Int J Antimicrob Agents 2011; 37:187-93. [PMID: 21295448 DOI: 10.1016/j.ijantimicag.2010.11.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 11/11/2010] [Indexed: 11/20/2022]
Abstract
Adaptive resistance is an autoregulated phenomenon characterised by induction of resistance in the presence of drug and reversal to the sensitive phenotype in its absence. This type of resistance is well documented for polycationic antibiotics, including aminoglycosides and polymyxins, in Pseudomonas aeruginosa and other aerobic Gram-negative bacilli. It is not caused by selection of resistant mutants but rather by phenotypic alterations in order to survive the lethal drug effect. Adaptive resistance to aminoglycosides is mainly mediated by the MexXY-OprM efflux pump that is rapidly upregulated in bacteria surviving the first exposure to aminoglycosides and is downregulated when bacteria are no longer in contact with the drug. A two-component regulatory system designated ParR-ParS plays a major role in adaptive resistance induced by cationic peptides. In the presence of cationic peptides, ParR-ParS activates the lipopolysaccharide modification operon (arnBCADTEF) leading to increased resistance in polymyxins and aminoglycosides. The bactericidal kinetics related to adaptive resistance have important clinical implications and provide a rationale for administering cationic antibiotics in larger initial and longer interval bolus dosing. A better understanding of this phenomenon and the molecular mechanisms responsible will be essential not only for optimum use of cationic antibiotics but also for developing new agents with ability to counteract the detrimental effects of adaptive resistance and thus enhance the therapeutic efficacy of polycationic compounds.
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Fernández L, Breidenstein EBM, Hancock REW. Creeping baselines and adaptive resistance to antibiotics. Drug Resist Updat 2011; 14:1-21. [PMID: 21288762 DOI: 10.1016/j.drup.2011.01.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 01/22/2023]
Abstract
The introduction of antimicrobial drugs in medicine gave hope for a future in which all infectious diseases could be controlled. Decades later it appears certain this will not be the case, because antibiotic resistance is growing relentlessly. Bacteria possess an extraordinary ability to adapt to environmental challenges like antimicrobials by both genetic and phenotypic means, which contributes to their evolutionary success. It is becoming increasingly appreciated that adaptation is a major mechanism behind the acquisition and evolution of antibiotic resistance. Adaptive resistance is a specific class of non-mutational resistance that is characterized by its transient nature. It occurs in response to certain environmental conditions or due to epigenetic phenomena like persistence. We propose that this type of resistance could be the key to understanding the failure of some antibiotic therapy programs, although adaptive resistance mechanisms are still somewhat unexplored. Similarly, hard wiring of some of the changes involved in adaptive resistance might explain the phenomenon of "baseline creep" whereby the average minimal inhibitory concentration (MIC) of a given medically important bacterial species increases steadily but inexorably over time, making the likelihood of breakthrough resistance greater. This review summarizes the available information on adaptive resistance.
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Affiliation(s)
- Lucía Fernández
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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Gauzit R. Actualités en antibiothérapie — Aminosides toujours et encore: bon usage et suivi thérapeutique. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s13546-010-0106-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mavros MN, Polyzos KA, Rafailidis PI, Falagas ME. Once versus multiple daily dosing of aminoglycosides for patients with febrile neutropenia: a systematic review and meta-analysis. J Antimicrob Chemother 2010; 66:251-9. [DOI: 10.1093/jac/dkq451] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Barbour A, Scaglione F, Derendorf H. Class-dependent relevance of tissue distribution in the interpretation of anti-infective pharmacokinetic/pharmacodynamic indices. Int J Antimicrob Agents 2010; 35:431-8. [PMID: 20219329 DOI: 10.1016/j.ijantimicag.2010.01.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 10/19/2022]
Abstract
The pharmacokinetic/pharmacodynamic (PK/PD) indices useful for predicting antimicrobial clinical efficacy are well established. The most common indices include the time free drug concentration in plasma is above the minimum inhibitory concentration (MIC) (fT(>MIC)) expressed as a percent of the dosing interval, the ratio of maximum concentration to MIC (C(max)/MIC), and the ratio of the area under the 24-h concentration-time curve to MIC (AUC(0-24)/MIC). A single PK/PD index may correlate well with an entire antimicrobial class. For example, the beta-lactams correlate well with the fT(>MIC). However, other classes may be more complex and a single index cannot be generalised to the class, e.g. the macrolides. The rationale behind which PK/PD index best correlates with efficacy depends on several factors, including the mechanism of action, the microbial kill kinetics, the degree of protein binding and the degree of tissue distribution. Studies have traditionally emphasised the first two factors, whilst the significance of protein binding and tissue distribution is increasingly appreciated. In fact, the latter two factors may partially elucidate why the magnitude of reported target indices are not always as expected. For example, tigecycline and telithromycin are clinically efficacious with average serum concentrations below their MICs over a 24-h period. Therefore, to understand more fully the PK/PD relationship of antibiotics and to better predict the clinical efficacy of antibiotic dosing regimens, assessment of free drug concentrations at the site of action is warranted.
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Abstract
OBJECTIVES Once-daily gentamicin therapy is becoming increasingly common in pediatric practice; however, little is known about pharmacokinetics in critical illness. Gentamicin exhibits concentration dependant killing; thus, peak serum concentrations at least eight times higher than minimum inhibition concentration of the target organism have been recommended. We wanted to derive pharmacokinetic parameters for gentamicin in critical illness and to evaluate whether a dose of 8 mg/kg provides an adequate peak serum concentration (>16 mg/L). PATIENTS AND INTERVENTIONS Population-based pharmacokinetic analyses were undertaken using therapeutic drug monitoring data collected prospectively in an intensive care unit over 6 months (n = 50 children). Monte Carlo simulations were used to estimate the probability of achieving 1) peak concentrations >16 mg/L; and 2) trough concentrations <2 mg/L at 24 and 36 hrs. MEASUREMENTS AND MAIN RESULTS The optimal pharmacokinetic model was of two-compartment disposition with zero order input and additive residual error. Weight was associated nonlinearly with clearance and linearly with volume, and age was a significant covariate for clearance. An 8-mg/kg dose provided near 100% probability of achieving adequate peak concentrations at all ages. However this probability decreased rapidly at doses <7 mg/kg with neonates being the most susceptible. Approximately 50% of nonpremature neonates within the first week of life, 25% of infants, and 10% of children are likely to need a dose interval >24 hrs. CONCLUSIONS A gentamicin dose of 8 mg/kg is highly likely to achieve peak concentrations >16 mg/L in critically ill children. A considerable proportion will require dose intervals >24 hrs; thus, therapeutic drug monitoring is essential.
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Current use for old antibacterial agents: polymyxins, rifamycins, and aminoglycosides. Infect Dis Clin North Am 2010; 23:1053-75, x. [PMID: 19909897 DOI: 10.1016/j.idc.2009.06.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This article reviews three classes of antibacterial agents that are uncommonly used in bacterial infections and therefore can be thought of as special-use agents. The polymyxins are reserved for gram-negative bacilli that are resistant to virtually all other classes of drugs. Rifampin is used therapeutically, occasionally as a companion drug in treatment of refractory gram-positive coccal infections, especially those involving foreign bodies. Rifaximin is a new rifamycin that is a strict enteric antibiotic approved for treatment of traveler's diarrhea and is showing promise as a possible agent for refractory Clostridium difficile infections. The aminoglycosides are used mainly as companion drugs for the treatment of resistant gram-negative bacillary infections and for gram-positive coccal endocarditis.
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Mueller EW, Boucher BA. The Use of Extended-Interval Aminoglycoside Dosing Strategies for the Treatment of Moderate-to-Severe Infections Encountered in Critically Ill Surgical Patients. Surg Infect (Larchmt) 2009; 10:563-70. [DOI: 10.1089/sur.2007.080] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Eric W. Mueller
- Department of Pharmacy Services, The University Hospital, Cincinnati, Ohio
| | - Bradley A. Boucher
- Department of Clinical Pharmacy, The University of Tennessee Health Science Center, Memphis, Tennessee
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Touw DJ, Westerman EM, Sprij AJ. Therapeutic drug monitoring of aminoglycosides in neonates. Clin Pharmacokinet 2009; 48:71-88. [PMID: 19271781 DOI: 10.2165/00003088-200948020-00001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The efficacy and toxicity of aminoglycosides show a strong direct positive relationship with blood drug concentrations, therefore, therapy with aminoglycosides in adults is usually guided by therapeutic drug monitoring. Dosing regimens in adults have evolved from multiple daily dosing to extended-interval dosing. This evolution has also taken place in neonates. Neonates, however, display large interindividual differences in the pharmacokinetics of aminoglycosides due to developmental differences early in life. The volume of distribution of aminoglycosides shows a strong relationship with bodyweight, which tends to be larger (corrected for bodyweight) in more premature infants and those with sepsis. Renal clearance of aminoglycosides increases with gestational age and accelerates immediately after birth. Because of these developmental influences, there is great inter- and intraindividual variability in the volume of distribution and clearance of these drugs, and investigators have established aminoglycoside dosing regimens based on bodyweight and/or gestational age. Widely practised dosing regimens comprise 4-5 mg/kg bodyweight of gentamicin every 24-48 hours as a first dose, followed by dose adjustment based on therapeutic drug monitoring. Although formal toxicity studies are scarce, there is no evidence that aminoglycoside toxicity in neonates differs from that in adults. Monitoring of blood drug concentrations and intelligent reconstruction of individual pharmacokinetic behaviour using a population pharmacokinetic model, optimally chosen blood sampling times and appropriate pharmacokinetic software, help clinicians to quickly optimize aminoglycoside dosing regimens to maximize the clinical effect and minimize the toxicity of these drugs.
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O’Shea S, Duffull S, Johnson DW. Aminoglycosides in Hemodialysis Patients: Is the Current Practice of Post Dialysis Dosing Appropriate? Semin Dial 2009; 22:225-30. [DOI: 10.1111/j.1525-139x.2008.00554.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Roberts JA, Lipman J. Pharmacokinetic issues for antibiotics in the critically ill patient. Crit Care Med 2009; 37:840-51; quiz 859. [PMID: 19237886 DOI: 10.1097/ccm.0b013e3181961bff] [Citation(s) in RCA: 582] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To discuss the altered pharmacokinetic properties of selected antibiotics in critically ill patients and to develop basic dose adjustment principles for this patient population. DATA SOURCES PubMed, EMBASE, and the Cochrane-Controlled Trial Register. STUDY SELECTION Relevant papers that reported pharmacokinetics of selected antibiotic classes in critically ill patients and antibiotic pharmacodynamic properties were reviewed. Antibiotics and/or antibiotic classes reviewed included aminoglycosides, beta-lactams (including carbapenems), glycopeptides, fluoroquinolones, tigecycline, linezolid, lincosamides, and colistin. DATA SYNTHESIS Antibiotics can be broadly categorized according to their solubility characteristics which can, in turn, help describe possible altered pharmacokinetics that can be caused by the pathophysiological changes common to critical illness. Hydrophilic antibiotics (e.g., aminoglycosides, beta-lactams, glycopeptides, and colistin) are mostly affected with the pathphysiological changes observed in critically ill patients with increased volumes of distribution and altered drug clearance (related to changes in creatinine clearance). Lipophilic antibiotics (e.g., fluoroquinolones, macrolides, tigecycline, and lincosamides) have lesser volume of distribution alterations, but may develop altered drug clearances. Using antibiotic pharmacodynamic bacterial kill characteristics, altered dosing regimens can be devised that also account for such pharmacokinetic changes. CONCLUSIONS Knowledge of antibiotic pharmacodynamic properties and the potential altered antibiotic pharmacokinetics in critically ill patients can allow the intensivist to develop individualized dosing regimens. Specifically, for renally cleared drugs, measured creatinine clearance can be used to drive many dose adjustments. Maximizing clinical outcomes and minimizing antibiotic resistance using individualized doses may be best achieved with therapeutic drug monitoring.
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Affiliation(s)
- Jason A Roberts
- University of Queensland, Pharmacy Department, Royal Brisbane and Women's Hospital, Herston, Australia
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Beaulac C, Sachetelli S, Lagace J. In Vitro Bactericidal Evaluation of a Low Phase Transition Temperature Liposomal Tobramycin Formulation as a Dry Powder Preparation Against Gram Negative and Gram Positive Bacteria. J Liposome Res 2008. [DOI: 10.3109/08982109909018652] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Roberts JA, Kruger P, Paterson DL, Lipman J. Antibiotic resistance--what's dosing got to do with it? Crit Care Med 2008; 36:2433-40. [PMID: 18596628 DOI: 10.1097/ccm.0b013e318180fe62] [Citation(s) in RCA: 232] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE This review seeks to identify original research articles that link antibiotic dosing and the development of antibiotic resistance for different antibiotic classes. Using this data, we seek to apply pharmacodynamic principles to assist clinical practice for suppressing the emergence of resistance. Concepts such as mutant selection window and mutant prevention concentration will be discussed. DATA SOURCES PubMed, EMBASE, and the Cochrane Controlled Trial Register. STUDY SELECTION All articles that related antibiotic doses and exposure to the formation of antibiotic resistance were reviewed. DATA SYNTHESIS The escalation of antibiotic resistance continues worldwide, most prominently in patients in intensive care units. Data are emerging from in vitro and in vivo studies that suggest that inappropriately low antibiotic dosing may be contributing to the increasing rate of antibiotic resistance. Fluoroquinolones have widely been researched and publications on other antibiotic classes are emerging. Developing dosing regimens that adhere to pharmacodynamic principles and maximize antibiotic exposure is essential to reduce the increasing rate of antibiotic resistance. CONCLUSIONS Antibiotic dosing must aim to address not only the bacteria isolated, but also the most resistant subpopulation in the colony, to prevent the advent of further resistant infections because of the inadvertent selection pressure of current dosing regimens. This may be achieved by maximizing antibiotic exposure by administering the highest recommended dose to the patient.
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Affiliation(s)
- Jason A Roberts
- Burns Trauma and Critical Care Research Centre, University of Queensland, Herston, Australia.
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Scheetz MH, Hurt KM, Noskin GA, Oliphant CM. Applying antimicrobial pharmacodynamics to resistant gram-negative pathogens. Am J Health Syst Pharm 2006; 63:1346-60. [PMID: 16809756 DOI: 10.2146/ajhp050403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Guided antibiotic adjustment for the treatment of multidrug-resistant, gram-negative pathogens is explored. SUMMARY Multidrug-resistant pathogens are being isolated with increasing frequency, while the production of novel agents to circumvent resistance has slowed to a near halt. Hence, antimicrobial adjustment based on drug pharmacokinetic and pharmacodynamic properties has moved to the forefront of treatment. Pharmacodynamic principles for major classes of antimicrobials are reviewed, and the use of susceptibility reports to optimize pharmacodynamics to treat gram-negative infections is described. The need for the application of antimicrobial pharmacodynamics continues to grow as resistance to the agents becomes more common. Susceptibility reports, including antibiograms, and their limitations are briefly discussed. The resistance profiles of the beta-lactams (including carbapenems), aminoglycosides, fluoroquinolones, tetracyclines and glycylcyclines, and the polymyxins are reviewed, and the pharmacodynamic optimization of these profiles is explored. CONCLUSION Various mechanisms account for resistance of bacteria to antibiotics. The appropriate use of pharmacokinetics and pharmacodynamics can guide antibiotic therapy and enhance the likelihood of success.
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Affiliation(s)
- Marc H Scheetz
- Department of Pharmacy, Northwestern Memorial Hospital, Chicago, IL 60611, USA.
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Lister PD. The role of pharmacodynamic research in the assessment and development of new antibacterial drugs. Biochem Pharmacol 2006; 71:1057-65. [PMID: 16316633 DOI: 10.1016/j.bcp.2005.10.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/18/2005] [Accepted: 10/24/2005] [Indexed: 10/25/2022]
Abstract
Antibacterial resistance continues to increase world wide, with some bacterial pathogens exhibiting resistance to virtually all available drugs. As the plague of antibacterial resistance continues to grow and create serious therapeutic problems, it is essential that the development of new antibacterial agents continue. Pharmacodynamic research plays an important role in the development of new antibacterial agents, as pharmacodynamic data can help define the clinical potential of a new drug and identify the strengths and weaknesses in comparison to other drugs already on the market. Furthermore, pharmacodynamic experiments can help focus the clinical phases of drug development by providing key information on the pharmacodynamic parameters that influence efficacy and the pharmacodynamic targets that should be achieved to optimize clinical success. Characterization of these pharmacodynamic properties for a new drug in development can help direct the design of the best dose and dosing strategy for clinical trials. This review will focus on the tools, methods, and strategies used to characterize the pharmacodynamics of antibacterial agents and aide in their development for clinical use.
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Affiliation(s)
- Philip D Lister
- Center for Research in Anti-Infectives and Biotechnology, Department of Medical Microbiology and Immunology, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.
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Wiuff C, Zappala RM, Regoes RR, Garner KN, Baquero F, Levin BR. Phenotypic tolerance: antibiotic enrichment of noninherited resistance in bacterial populations. Antimicrob Agents Chemother 2005; 49:1483-94. [PMID: 15793130 PMCID: PMC1068602 DOI: 10.1128/aac.49.4.1483-1494.2005] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When growing bacteria are exposed to bactericidal concentrations of antibiotics, the sensitivity of the bacteria to the antibiotic commonly decreases with time, and substantial fractions of the bacteria survive. Using Escherichia coli CAB1 and antibiotics of five different classes (ampicillin, ciprofloxacin, rifampin, streptomycin, and tetracycline), we examine the details of this phenomenon and, with the aid of mathematical models, develop and explore the properties and predictions of three hypotheses that can account for this phenomenon: (i) antibiotic decay, (ii) inherited resistance, and (iii) phenotypic tolerance. Our experiments cause us to reject the first two hypotheses and provide evidence that this phenomenon can be accounted for by the antibiotic-mediated enrichment of subpopulations physiologically tolerant to but genetically susceptible to these antibiotics, phenotypic tolerance. We demonstrate that tolerant subpopulations generated by exposure to one concentration of an antibiotic are also tolerant to higher concentrations of the same antibiotic and can be tolerant to antibiotics of the other four types. Using a mathematical model, we explore the effects of phenotypic tolerance to the microbiological outcome of antibiotic treatment and demonstrate, a priori, that it can have a profound effect on the rate of clearance of the bacteria and under some conditions can prevent clearance that would be achieved in the absence of tolerance.
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Affiliation(s)
- C Wiuff
- Department of Biology, Emory University, 1510 Clifton Rd., Atlanta, Georgia 30322, USA.
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Locksmith GJ, Chin A, Vu T, Shattuck KE, Hankins GDV. High compared with standard gentamicin dosing for chorioamnionitis: a comparison of maternal and fetal serum drug levels. Obstet Gynecol 2005; 105:473-9. [PMID: 15738010 DOI: 10.1097/01.aog.0000151106.87930.1a] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To compare umbilical cord and maternal serum peak gentamicin concentration, gentamicin elimination, and clinical outcomes between women who received once-daily compared with standard, thrice-daily dosing for clinical chorioamnionitis. METHODS We randomly assigned 38 laboring women, at least 34 weeks gestation, with clinical chorioamnionitis, into 1 of 2 gentamicin dosing groups: 5.1 mg/kg every 24 hours (once-daily; n = 18), or 120 mg followed by 80 mg every 8 hours (standard; n = 20). We measured maternal serum peak and delivery gentamicin concentrations and cord serum levels at delivery. Polynomial curve fitting was used to summarize gentamicin elimination. We also compared maternal and neonatal outcomes. RESULTS Demographic characteristics of the 2 groups were similar. Median maternal peak gentamicin levels were higher with once-daily (18.2 microg/mL) compared with standard dosing (7.1 microg/mL) (P < .001). Maternal serum levels decreased below 2 microg/mL by 10 hours in the once-daily group and by 5 hours in the standard dosing group. Extrapolated peak cord serum levels were 6.9 microg/mL in the once-daily and 2.9 microg/mL in the standard dosing arm. Cord levels decreased below 2 microg/mL by 10 hours in the once-daily and by 5 hours in the standard dosing group. We found no differences in maternal or neonatal outcomes. CONCLUSION Peak maternal serum gentamicin levels ranged from 13 to 25 microg/mL after a dose of 5.1 mg/kg. Single-dose gentamicin resulted in fetal serum peak levels that were closer to optimal neonatal values. Gentamicin clearance in the term fetus was similar to published values for the newborn infant. No adverse effects of high-dose therapy were noted.
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Affiliation(s)
- Gregory J Locksmith
- Department of Obstetrics & Gynecology, Division of Maternal-Fetal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.
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Affiliation(s)
- Keith Poole
- Department of Microbiology & Immunology, Rm. 737 Botterell Hall, Queen's University, Kingston, ON K7L 3N6, Canada.
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Kaye D. Current use for old antibacterial agents: polymyxins, rifampin, and aminoglycosides. Infect Dis Clin North Am 2004; 18:669-89, x. [PMID: 15308281 DOI: 10.1016/j.idc.2004.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This article discusses three classes of antibacterial agents that are uncommonly used in bacterial infections (other than mycobacterial infections) and can be thought of as special-use agents. These are the polymyxins, rifampin, and the aminoglycosides.
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Affiliation(s)
- Donald Kaye
- Department of Medicine, Drexel University, College of Medicine, 3300 Henry Avenue, Philadelphia, PA 19129, USA.
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Markantonis SL, Kostopanagiotou G, Panidis D, Smirniotis V, Voros D. Effects of blood loss and fluid volume replacement on serum and tissue gentamicin concentrations during colorectal surgery. Clin Ther 2004; 26:271-81. [PMID: 15038949 DOI: 10.1016/s0149-2918(04)90025-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2003] [Indexed: 10/26/2022]
Abstract
BACKGROUND The prophylactic administration of antimicrobial agents to surgical patients has become standard practice to minimize the risk for postsurgical infection. During surgery, factors such as renal clearance, fluid administration, and blood loss contribute to drug concentrations achieved in the blood and tissues. The aminoglycoside gentamicin was chosen to investigate these factors because it is used for standard antimicrobial prophylaxis in colorectal surgery. OBJECTIVE The aim of this study was to investigate the effects of surgical blood loss and fluid volume replacement on gentamicin concentrations in serum and in 3 tissue types (subcutaneous fat, epiploic fat, and colonic wall) in patients undergoing colorectal surgery. METHODS This uncontrolled, open-label study was conducted at the Aretaieion Hospital (Athens, Greece) between November 2002 and March 2003. Patients selected for this study were scheduled to undergo elective colorectal surgery of ? 2-hour duration with general and epidural anesthesia and to receive gentamicin as major antimicrobial prophylaxis. Blood and tissue samples were obtained concurrently at specific times throughout each procedure. The effect of intraoperative blood loss on gentamicin concentrations and its pharmacokinetic properties was determined. RESULTS Sixteen patients completed the study (11 men, 5 women; white race, 16 patients [100%]; mean [SD] age, 61 [3] years [range, 39-80 years]). Mean (SEM) serum gentamicin concentration was found to be insufficient; the maximum plasma drug concentration/minimum inhibitory concentration (MIC) ratio was <8:1 for pathogens commonly isolated in the surgical unit of the hospital (MIC: 1-4 microg/mL). The mean (SEM) concentration at first surgical incision was 7.83 (0.82) microg/mL and decreased to 2.60 (0.28) microg/mL at skin closure, resulting in borderline effectiveness even for susceptible gram-positive microorganisms (MIC approximately 1.0). Initially, mean (SEM) tissue gentamicin concentrations in subcutaneous fat, epiploic fat, and colonic wall were low (2.02 [0.34] microg/mL, 2.41 [0.42] microg/mL, and 1.93 [0.38] microg/mL, respectively) and decreased approximately 1.0 microg/mL ( approximately 50%) by skin closure. Statistically significant positive correlations were found between gentamicin concentrations in serum and tissues (P </= 0.03). A strong negative correlation was found between the intravenously administered fluids and gentamicin concentrations in serum and tissues (P </= 0.04). CONCLUSIONS In this study, the administration of a 2-mg/kg dose of gentamicin as antimicrobial prophylaxis during colorectal surgery associated with significant intraoperative blood loss and therefore requiring significant fluid replacement did not achieve concentrations of the drug above MICs for gram-negative microorganisms throughout the procedures in either serum or tissue samples.
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Affiliation(s)
- Sophia L Markantonis
- Laboratory of Biopharmaceutics and Pharmacokinetics, School of Pharmacy, University of Athens, Panepistimiopolis, Athens, Greece.
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Hocquet D, El Garch F, Vogne C, Plésiat P. Mécanisme de la résistance adaptative de Pseudomonas aeruginosa aux aminosides. ACTA ACUST UNITED AC 2003; 51:443-8. [PMID: 14568587 DOI: 10.1016/s0369-8114(03)00167-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Exposure of Pseudomonas aeruginosa to aminoglycosides frequently selects for recalcitrant subpopulations exhibiting an unstable, << adaptive >> resistance to these antibiotics. In this study, we investigated the implication in the phenomenon of MexXY-OprM, an active efflux system known to export aminoglycosides in P. aeruginosa. Immunoblotting experiments demonstrated that the transporter MexY, but not the outer membrane pore OprM, was overproduced during the post-drug exposure adaptation period in wild-type strain PAO1. Furthermore, MexY production was dependent upon the degree of bacterial exposure to gentamicin (drug concentration). In contrast to parental strain PAO1, mutants defective in MexXY or in OprM were unable to develop adaptive resistance. Altogether, these results indicate that the resistance process requires the rapid production of MexXY and the interaction of these proteins with the constitutively produced component OprM.
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Affiliation(s)
- D Hocquet
- Laboratoire de bactériologie, hôpital Jean-Minjoz, 25030 Besançon cedex, France.
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Hocquet D, Vogne C, El Garch F, Vejux A, Gotoh N, Lee A, Lomovskaya O, Plésiat P. MexXY-OprM efflux pump is necessary for a adaptive resistance of Pseudomonas aeruginosa to aminoglycosides. Antimicrob Agents Chemother 2003; 47:1371-5. [PMID: 12654672 PMCID: PMC152483 DOI: 10.1128/aac.47.4.1371-1375.2003] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Exposure of Pseudomonas aeruginosa to aminoglycosides frequently selects for recalcitrant subpopulations exhibiting an unstable, "adaptive" resistance to these antibiotics. In this study, we investigated the implication in the phenomenon of MexXY-OprM, an active efflux system known to export aminoglycosides in P. aeruginosa. Immunoblotting experiments demonstrated that the transporter MexY, but not the outer membrane pore OprM, was overproduced during the post-drug exposure adaptation period in wild-type strain PAO1. Furthermore, MexY production was dependent upon the degree of bacterial exposure to gentamicin (drug concentration). In contrast to parental strain PAO1, mutants defective in MexXY or in OprM were unable to develop adaptive resistance. Altogether, these results indicate that the resistance process requires the rapid production of MexXY and the interaction of these proteins with the constitutively produced component OprM.
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Affiliation(s)
- Didier Hocquet
- Laboratoire de Bactériologie, Hôpital Jean Minjoz, Besançon, France
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Affiliation(s)
- G Miflin
- Department of Paediatric Haematology, Children's Day Hospital, St. James University Hospital, Beckett Street, Leeds LS9 7TF, UK
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Bartal C, Danon A, Schlaeffer F, Reisenberg K, Alkan M, Smoliakov R, Sidi A, Almog Y. Pharmacokinetic dosing of aminoglycosides: a controlled trial. Am J Med 2003; 114:194-8. [PMID: 12637133 DOI: 10.1016/s0002-9343(02)01476-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate whether individualized pharmacokinetic dosing of aminoglycosides can reduce nephrotoxicity and improve the outcome of patients with gram-negative sepsis. METHODS We conducted a prospective controlled trial at a tertiary care university hospital. Eighty-one patients with suspected or documented gram-negative infections were enrolled. All were treated with either gentamicin or amikacin, according to clinical judgement. Patients were allocated to one of two groups based on the last digit (odd/even) of their identification number. In the study group (pharmacokinetic dosing) of 43 patients, plasma aminoglycoside levels were determined 1 hour after initiation of drug infusion and 8 to 16 hours later to estimate the elimination half-life and volume of distribution, from which the subsequent dosage schedule was calculated. Target peak plasma levels were 20 microg/mL for gentamicin and 60 microg/mL for amikacin. Target trough levels were <1 microg/mL for both drugs. The control group (fixed once-daily dosing) consisted of 38 patients who were prescribed single daily doses of gentamicin or amikacin. The primary endpoints were renal toxicity (> or = 25% increase in serum creatinine level or a serum creatinine level > or = 1.4 mg/dL) and 28-day mortality. RESULTS The two study groups were similar in age, sex, indications for therapy, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and clinical assessment at baseline. Although the pharmacokinetic group received significantly greater doses of aminoglycosides than did the once-daily group, the incidence of nephrotoxicity was significantly lower in the pharmacokinetic group (5% [2/43] vs. 21% [8/38], P = 0.03). There was no statistically significant difference in 28-day mortality (27% [12/43] vs. 22% [8/38], P = 0.3). CONCLUSION These results suggest that individualized pharmacokinetic dosing of aminoglycosides reduces the incidence of nephrotoxicity and allows the use of greater doses of aminoglycosides.
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Affiliation(s)
- Carmi Bartal
- Medical Intensive Care Unit, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Knoderer CA, Everett JA, Buss WF. Clinical issues surrounding once-daily aminoglycoside dosing in children. Pharmacotherapy 2003; 23:44-56. [PMID: 12523459 DOI: 10.1592/phco.23.1.44.31924] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Aminoglycoside antibiotics are first-line treatment for many infectious diseases in the pediatric population and are effective in adults. The traditional dosing interval in children is every 8-12 hours. Studies in adults reported equivalent efficacy and equal or less toxicity with once-daily regimens. Despite many studies in the adult population, this approach has yet to become standard practice in most pediatric hospitals. Reasons for lack of acceptance of this strategy in children include rapid aminoglycoside clearance, unknown duration of postantibiotic effect, safety concerns, and limited clinical and efficacy data.
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Affiliation(s)
- Chad A Knoderer
- Department of Pharmacy Services, James Whitcomb Riley Hospital for Children, Indianapolis, Indiana 46202, USA.
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Kraus DM, Pai MP, Rodvold KA. Efficacy and tolerability of extended-interval aminoglycoside administration in pediatric patients. Paediatr Drugs 2003; 4:469-84. [PMID: 12083974 DOI: 10.2165/00128072-200204070-00005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Aminoglycosides are commonly used to treat serious Gram-negative infections in pediatric patients. An effort to improve the efficacy and tolerability of this antibiotic class has led to evaluation of extended-interval aminoglycoside administration (EIAA). EIAA is designed to achieve higher peak plasma aminoglycoside concentrations, with relatively undetectable trough concentrations, when compared with conventional aminoglycoside administration (CAA), and is therefore expected to be markedly effective and to reduce drug accumulation and prevent nephrotoxicity and ototoxicity. Clinical trials evaluating EIAA in neonates included patients with suspected Gram-negative infections requiring short courses of aminoglycoside therapy. Consequently, comparative efficacy of EIAA versus CAA could not be assessed. In addition, ototoxicity was often not assessed, and nephrotoxicity was virtually undetectable. Similarly, trials evaluating EIAA versus CAA in infants and children have not demonstrated a difference in outcomes. The use of EIAA in children with febrile neutropenia has been evaluated primarily with amikacin. The incidences of nephrotoxicity and ototoxicity were low, and were similar between EIAA and CAA. No deaths were reported in any of these studies; however, this could be related to the inclusion of patients with undocumented bacteremia. Further investigation of EIAA is necessary in patients with documented bacteremia, since plasma aminoglycoside concentrations were undetectable for most of the dosage interval in children with febrile neutropenia who were treated once daily. Overall, clinical studies suggest that EIAA has similar efficacy to, and no higher risk of toxicity than, CAA in neonates, infants, and children. A few evaluations have also demonstrated that EIAA is cost-effective in neonates and in children with febrile neutropenia. Future studies evaluating the efficacy and tolerability of EIAA in pediatric patients with documented systemic infections should be prospective, randomized, controlled trials with sample sizes sufficient to detect differences between administration methods. Further evaluations should also address the optimal dosage and cost-effectiveness of EIAA in infants and children.
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Affiliation(s)
- Donna M Kraus
- College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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Toutain PL, del Castillo JRE, Bousquet-Mélou A. The pharmacokinetic-pharmacodynamic approach to a rational dosage regimen for antibiotics. Res Vet Sci 2002; 73:105-14. [PMID: 12204627 DOI: 10.1016/s0034-5288(02)00039-5] [Citation(s) in RCA: 280] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Pharmacokinetic-pharmacodynamic (PK/PD) surrogate indices (AUIC, AUC/MIC, C(max)/MIC, T>MIC) for measuring antibiotic efficacy are presented and reviewed. As clinical trials are not sufficiently sensitive to establish a dosage regimen which guarantees total bacteriological cure (Pollyanna phenomenon), PK/PD indexes have been proposed from in vitro, ex vivo, and in vivo infection models and subsequently validated in retrospective or prospective human clinical trials. The target value for time-dependent antibiotics (beta-lactams, macrolides) is a time above the MIC (T>MIC) of 50-80% of the dosage interval, while for concentration-dependent antibiotics (quinolones and aminoglycosides), the area under the inhibitory curve (AUIC, or more simply AUC/MIC of about 125h) is the best surrogate indicator of activity. Using the latter drugs, high concentrations achieved early during therapy are desirable to prevent the development of resistance. A C(max)/MIC ratio greater than 10-12 seems to be an appropriate target for aminoglycosides.
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Affiliation(s)
- P L Toutain
- UMR INRA de Physiopathologie et Toxicologie Expérimentales, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse cedex 03, France.
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Lister PD. Pharmacodynamics of 750 mg and 500 mg doses of levofloxacin against ciprofloxacin-resistant strains of Streptococcus pneumoniae. Diagn Microbiol Infect Dis 2002; 44:43-9. [PMID: 12376030 DOI: 10.1016/s0732-8893(02)00417-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An in vitro pharmacokinetic model (IVPM) was used to evaluate the pharmacodynamics of the 750 mg and 500 mg doses of levofloxacin against 4 ciprofloxacin-nonsusceptible Streptococcus pneumoniae. Levofloxacin MICs ranged from 1.4 to 3.2 micro g/ml. Log-phase cultures (5 x 10(7) cfu/ml) were inoculated into the IVPM and exposed to the peak free-drug concentrations of levofloxacin achieved in human serum with each dose. Levofloxacin was dosed at 0 and 24 h, elimination pharmacokinetics were simulated, and viable counts were measured over 30 h. The 750 mg dose was rapidly bactericidal against all 4 strains, achieving eradication within 30 h. Against strains with levofloxacin MICs of 1.4 and 1.8 micro g/ml, the 500 mg dose exhibited pharmacodynamics similar to the 750 mg dose. In contrast, against strains with levofloxacin MICs of 2.6 and 3.2 micro g/ml, viable counts never fell below 10(4) cfu/ml. The rapid killing and eradication of these pneumococci by the 750 mg dose warrant the clinical evaluation of this new dose in the treatment of pneumococcal infections.
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Affiliation(s)
- Philip D Lister
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, 2500 California Plaza, Omaha, Nebraska 68178, USA.
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