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- Bulman, Zackery P., et al.
(author)
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Research priorities towards precision antibiotic therapy to improve patient care
- 2022
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In: LANCET MICROBE. - : Elsevier. - 2666-5247. ; 3:10, s. e795-e802
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Journal article (peer-reviewed)abstract
- Antibiotic resistance presents an incessant threat to our drug armamentarium that necessitates novel approaches to therapy. Over the past several decades, investigation of pharmacokinetic and pharmacodynamic (PKPD) principles has substantially improved our understanding of the relationships between the antibiotic, pathogen, and infected patient. However, crucial gaps in our understanding of the pharmacology of antibacterials and their optimal use in the care of patients continue to exist; simply attaining antibiotic exposures that are considered adequate based on traditional targets can still result in treatment being unsuccessful and resistance proliferation for some infections. It is this salient paradox that points to key future directions for research in antibiotic therapeutics. This Personal View discusses six priority areas for antibiotic pharmacology research: (1) antibiotic-pathogen interactions, (2) antibiotic targets for combination therapy, (3) mechanistic models that describe the time-course of treatment response, (4) understanding and modelling of host response to infection, (5) personalised medicine through therapeutic drug management, and (6) application of these principles to support development of novel therapies. Innovative approaches that enhance our understanding of antibiotic pharmacology and facilitate more accurate predictions of treatment success, coupled with traditional pharmacology research, can be applied at the population level and to individual patients to improve outcomes.
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- Chaurasia, Chandra S., et al.
(author)
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AAPS-FDA workshop white paper : microdialysis principles, application and regulatory perspectives
- 2007
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In: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 24:5, s. 1014-1025
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Journal article (peer-reviewed)abstract
- Many decisions in drug development and medical practice are based on measuring blood concentrations of endogenous and exogenous molecules. Yet most biochemical and pharmacological events take place in the tissues. Also, most drugs with few notable exceptions exert their effects not within the bloodstream, but in defined target tissues into which drugs have to distribute from the central compartment. Assessing tissue drug chemistry has, thus, for long been viewed as a more rational way to provide clinically meaningful data rather than gaining information from blood samples. More specifically, it is often the extracellular (interstitial) tissue space that is most closely related to the site of action (biophase) of the drug. Currently microdialysis (microD) is the only tool available that explicitly provides data on the extracellular space. Although microD as a preclinical and clinical tool has been available for two decades, there is still uncertainty about the use of microD in drug research and development, both from a methodological and a regulatory point of view. In an attempt to reduce this uncertainty and to provide an overview of the principles and applications of microD in preclinical and clinical settings, an AAPS-FDA workshop took place in November 2005 in Nashville, TN, USA. Stakeholders from academia, industry and regulatory agencies presented their views on microD as a tool in drug research and development.
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4. |
- Chaurasia, Chandra S., et al.
(author)
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AAPS-FDA Workshop White Paper : microdialysis principles, application, and regulatory perspectives
- 2007
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In: Journal of clinical pharmacology. - : Wiley. - 0091-2700 .- 1552-4604. ; 47:5, s. 589-603
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Journal article (peer-reviewed)abstract
- Many decisions in drug development and medical practice are based on measuring blood concentrations of endogenous and exogenous molecules. Yet most biochemical and pharmacological events take place in the tissues. Also, most drugs with few notable exceptions exert their effects not within the bloodstream, but in defined target tissues into which drugs have to distribute from the central compartment. Assessing tissue drug chemistry has, thus, for long been viewed as a more rational way to provide clinically meaningful data rather than gaining information from blood samples. More specifically, it is often the extracellular (interstitial) tissue space that is most closely related to the site of action (biophase) of the drug. Currently microdialysis (μD) is the only tool available that explicitly provides data on the extracellular space. Although μD as a preclinical and clinical tool has been available for two decades, there is still uncertainty about the use of μD in drug research and development, both from a methodological and a regulatory point of view. In an attempt to reduce this uncertainty and to provide an overview of the principles and applications of μD in preclinical and clinical settings, an AAPS-FDA workshop took place in November 2005 in Nashville, TN, USA. Stakeholders from academia, industry and regulatory agencies presented their views on μD as a tool in drug research and development.
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5. |
- Dubbelboer, Ilse R
(author)
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Biopharmaceutical investigations of doxorubicin formulations used in liver cancer treatment : Studies in healthy pigs and liver cancer patients, combined with pharmacokinetic and biopharmaceutical modelling
- 2017
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Doctoral thesis (other academic/artistic)abstract
- There are currently two types of drug formulation in clinical use in the locoregional treatment of intermediate hepatocellular carcinoma (HCC). In the emulsion LIPDOX, the cytostatic agent doxorubicin (DOX) is dissolved in the aqueous phase, which is emulsified with the oily contrast agent Lipiodol® (LIP). In the microparticular system DEBDOX, DOX is loaded into the drug-eluting entity DC Bead™.The overall aim of the thesis was to improve pharmaceutical understanding of the LIPDOX and DEBDOX formulations, in order to facilitate the future development of novel drug delivery systems. In vivo release of DOX from the formulations and the disposition of DOX and its active metabolite doxorubicinol (DOXol) were assessed in an advanced multisampling-site acute healthy pig model and in patients with HCC. The release of DOX and disposition of DOX and DOXol where further analysed using physiologically based pharmacokinetic (PBPK) and biopharmaceutical (PBBP) modelling. The combination of in vivo investigations and in silico modelling could provide unique insight into the mechanisms behind drug release and disposition.The in vivo release of DOX from LIPDOX is not extended and controlled, as it is from DEBDOX. With both formulations, DOX is released as a burst during the early phase of administration. The in vivo release of DOX from LIPDOX was faster than from DEBDOX in both pigs and patients. The release from DEBDOX was slow and possibly incomplete. The in vivo release of DOX from LIPDOX and DEBDOX could be described by using the PBBP model in combination with in vitro release profiles.The disposition of DOX and DOXol was modelled using a semi-PBPK model containing intracellular binding sites. The contrast agent Lipiodol® did not affect the hepatobiliary disposition of DOX in the pig model. The control substance used in this study, cyclosporine A, inhibited the biliary excretion of DOX and DOXol but did not alter metabolism in healthy pigs. The disposition of DOX is similar in healthy pigs and humans, which was shown by the ease of translation of the semi-PBPK pig model to the human PBBP model.
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- Khan, David D.
(author)
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Pharmacokinetic-Pharmacodynamic modeling and prediction of antibiotic effects
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Problems of emerging antibiotic resistance are becoming a serious threat worldwide, and at the same time, the interest to develop new antimicrobials has declined. There is consequently a need for efficient methods to develop new treatments that minimize the risk of resistance development and that are effective on infections caused by resistant strains. Based on in silico mathematical models, describing the time course of exposure (Pharmacokinetics, PK) and effect (Pharmacodynamics, PD) of a drug, information can be collected and the outcome of various exposures may be predicted. A general model structure, that characterizes the most important features of the system, has advantages as it can be used for different situations. The aim of this thesis was to develop Pharmacokinetic-Pharmacodynamic (PKPD) models describing the bacterial growth and killing after mono- and combination exposures to antibiotics and to explore the predictive ability of PKPD-models across preclinical experimental systems. Models were evaluated on data from other experimental settings, including prediction into animals. A PKPD model characterizing the growth and killing for a range of E. coli bacteria strains, with different MICs, as well as emergence of resistance, was developed. The PKPD model was able to predict results from different experimental conditions including high start inoculum experiments, a range of laboratory and clinical strains as well as experiments where wild-type and mutant bacteria are competing at different drug concentrations. A PKPD model, developed based on in vitro data, was also illustrated to have the capability to replicate the data from an in vivo study. This thesis illustrates the potential of PKPD models to characterize in vitro data and their usage for predictions of different types of experiments. The thesis supports the use of PKPD models to facilitate development of new drugs and to improve the use of existing antibiotics.
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- Mouton, Johan W., et al.
(author)
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Tissue concentrations : do we ever learn?
- 2008
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In: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 61:2, s. 235-237
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Journal article (peer-reviewed)abstract
- Over the last decades, numerous papers have appeared--and still are appearing--that describe concentrations in tissues in an effort to predict the efficacy of an antimicrobial agent based on these concentrations and MICs for microorganisms. A common method is to use measurements of concentrations in tissue homogenates, comparing these with values derived from the corresponding blood samples and on that basis draw conclusions with respect to the potential clinical use of the drug. This approach is not justifiable for a number of reasons that includes both pharmacokinetic as well as pharmacodynamic causes. This way of presenting data with the derived conclusions is often misleading and may ultimately be harmful in patient care.
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10. |
- Rayner, Craig R., et al.
(author)
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Model-Informed Drug Development for Anti-Infectives : State of the Art and Future
- 2021
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In: Clinical Pharmacology and Therapeutics. - : John Wiley & Sons. - 0009-9236 .- 1532-6535. ; 109:4, s. 867-891
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Journal article (peer-reviewed)abstract
- Model-informed drug development (MIDD) has a long and rich history in infectious diseases. This review describes foundational principles of translational anti-infective pharmacology, including choice of appropriate measures of exposure and pharmacodynamic (PD) measures, patient subpopulations, and drug-drug interactions. Examples are presented for state-of-the-art, empiric, mechanistic, interdisciplinary, and real-world evidence MIDD applications in the development of antibacterials (review of minimum inhibitory concentration-based models, mechanism-based pharmacokinetic/PD (PK/PD) models, PK/PD models of resistance, and immune response), antifungals, antivirals, drugs for the treatment of global health infectious diseases, and medical countermeasures. The degree of adoption of MIDD practices across the infectious diseases field is also summarized. The future application of MIDD in infectious diseases will progress along two planes; "depth" and "breadth" of MIDD methods. "MIDD depth" refers to deeper incorporation of the specific pathogen biology and intrinsic and acquired-resistance mechanisms; host factors, such as immunologic response and infection site, to enable deeper interrogation of pharmacological impact on pathogen clearance; clinical outcome and emergence of resistance from a pathogen; and patient and population perspective. In particular, improved early assessment of the emergence of resistance potential will become a greater focus in MIDD, as this is poorly mitigated by current development approaches. "MIDD breadth" refers to greater adoption of model-centered approaches to anti-infective development. Specifically, this means how various MIDD approaches and translational tools can be integrated or connected in a systematic way that supports decision making by key stakeholders (sponsors, regulators, and payers) across the entire development pathway.
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