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Miller RP, Berlouis ME, Hall AG, Simpson AHR, Smith IDM, Hall AC. Effects of Antibiotics on α-Toxin Levels during Staphylococcus aureus Culture: Implications for the Protection of Chondrocytes in a Model of Septic Arthritis. Cartilage 2021; 12:362-376. [PMID: 30762428 PMCID: PMC8236659 DOI: 10.1177/1947603519828433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Septic arthritis results from joint infection by Staphylococcus aureus, which produces potent α-toxin causing cell death, potentially leading to permanent cartilage damage. Treatment is by joint irrigation and antibiotics, although it is unclear if, following treatment with antibiotics which cause bacterial lysis, there is release of additional stored α-toxin. DESIGN A rabbit erythrocyte hemolysis assay was optimised to assess biologically-active α-toxin from cultured S. aureus α-toxin strain DU5946. Hemoglobin release was measured spectrophotometrically following addition of a bacteriostatic antibiotic (linezolid) or a bacteriolytic antibiotic (penicillin). A bovine cartilage model of septic arthritis was used to test the protective effects of antibiotics against S. aureus infection. RESULTS During S. aureus culture, α-toxin levels increased rapidly but the rate of rise was quickly (within 20 minutes) suppressed by linezolid (25 μg/mL). Penicillin also reduced the increase in α-toxin levels; however, the time course was relatively slow compared to linezolid even at high concentrations (50,000 U/mL). The efficacy of penicillin (250,000 U/mL) at reducing the rise in α-toxin was approximately 8% less than that of linezolid (P < 0.05) suggesting the presence of additional toxin. This could be due to a delayed action of penicillin, and/or release of a small pool of stored α-toxin from dying bacteria. In a bovine cartilage model, however, there was no difference between the protection of in situ chondrocytes against S. aureus by penicillin or linezolid (P > 0.05). CONCLUSION The results suggested that equally effective protection of chondrocytes against S. aureus septic arthritis may be obtained by the bacteriostatic or bacteriolytic antibiotics tested.
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Affiliation(s)
- Robbie P. Miller
- Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Marie E. Berlouis
- Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Alan G. Hall
- Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - A. Hamish R.W. Simpson
- Musculoskeletal Research Unit, Department of Orthopaedic Surgery, University of Edinburgh, Edinburgh, Scotland, UK
| | - Innes D. M. Smith
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, Scotland, UK
| | - Andrew C. Hall
- Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK,Andrew C. Hall, Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9AG, Scotland, UK
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Brown E, Gould FK. Oral antibiotics for infective endocarditis: a clinical review. J Antimicrob Chemother 2021; 75:2021-2027. [PMID: 32240296 DOI: 10.1093/jac/dkaa106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Current guidelines for management of infective endocarditis (IE) advise 4-6 weeks of IV antibiotics. This is based on historical data from animal models, which set a precedent for high peak serum antimicrobial levels, thought to be only achievable with IV therapy. However, there has been increasing recent interest in oral antibiotics as an alternative to prolonged parenteral therapy, not limited to treatment of IE. This review examines the theory behind parenteral antibiotic administration with reference to the MICs of relevant pathogens. By comparing published serum antimicrobial levels after oral and IV administration we suggest that safe levels of commonly used antibiotics can be achieved orally. We have then reviewed the literature to date on oral antibiotics for IE. The largest randomized controlled trial (RCT) in this area, the POET trial, concluded that oral therapy was non-inferior to prolonged IV therapy in stable patients with left-sided IE. Additionally, there have been two smaller RCTs published, as well as a number of observational studies over the last 50 years, utilizing a variety of different patient groups, methods and treatment strategies. This body of evidence gives weight to a potential shift in practice towards oral therapy, primarily as a step-down treatment. We conclude that pharmacological data offer theoretical reassurance for the safety of oral therapy. This is coupled with a growing evidence base for non-inferiority of oral antimicrobials compared with prolonged parenteral therapy in practice.
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Affiliation(s)
- Evelyn Brown
- Microbiology Department, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK
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Wilbaux M, Fuchs A, Samardzic J, Rodieux F, Csajka C, Allegaert K, van den Anker JN, Pfister M. Pharmacometric Approaches to Personalize Use of Primarily Renally Eliminated Antibiotics in Preterm and Term Neonates. J Clin Pharmacol 2016; 56:909-35. [PMID: 26766774 DOI: 10.1002/jcph.705] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/13/2022]
Abstract
Sepsis remains a major cause of mortality and morbidity in neonates, and, as a consequence, antibiotics are the most frequently prescribed drugs in this vulnerable patient population. Growth and dynamic maturation processes during the first weeks of life result in large inter- and intrasubject variability in the pharmacokinetics (PK) and pharmacodynamics (PD) of antibiotics. In this review we (1) summarize the available population PK data and models for primarily renally eliminated antibiotics, (2) discuss quantitative approaches to account for effects of growth and maturation processes on drug exposure and response, (3) evaluate current dose recommendations, and (4) identify opportunities to further optimize and personalize dosing strategies of these antibiotics in preterm and term neonates. Although population PK models have been developed for several of these drugs, exposure-response relationships of primarily renally eliminated antibiotics in these fragile infants are not well understood, monitoring strategies remain inconsistent, and consensus on optimal, personalized dosing of these drugs in these patients is absent. Tailored PK/PD studies and models are useful to better understand relationships between drug exposures and microbiological or clinical outcomes. Pharmacometric modeling and simulation approaches facilitate quantitative evaluation and optimization of treatment strategies. National and international collaborations and platforms are essential to standardize and harmonize not only studies and models but also monitoring and dosing strategies. Simple bedside decision tools assist clinical pharmacologists and neonatologists in their efforts to fine-tune and personalize the use of primarily renally eliminated antibiotics in term and preterm neonates.
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Affiliation(s)
- Mélanie Wilbaux
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Aline Fuchs
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Janko Samardzic
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Institute of Pharmacology, Clinical Pharmacology and Toxicology, Medical Faculty, University of Belgrade, Belgrade, Serbia
| | - Frédérique Rodieux
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Chantal Csajka
- Division of Clinical Pharmacology, Service of Biomedicine, Department of Laboratory, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,Department of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Belgium.,Intensive Care and Department of Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Johannes N van den Anker
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Intensive Care and Department of Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.,Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
| | - Marc Pfister
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Quantitative Solutions LP, Menlo Park, CA, USA
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Landersdorfer CB, Kirkpatrick CMJ, Kinzig-Schippers M, Bulitta JB, Holzgrabe U, Drusano GL, Sörgel F. Population pharmacokinetics at two dose levels and pharmacodynamic profiling of flucloxacillin. Antimicrob Agents Chemother 2007; 51:3290-7. [PMID: 17576847 PMCID: PMC2043233 DOI: 10.1128/aac.01410-06] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Flucloxacillin is often used for the treatment of serious infections due to sensitive staphylococci. The pharmacokinetic (PK)-pharmacodynamic (PD) breakpoint of flucloxacillin has not been determined by the use of population PK. Targets based on the duration of non-protein-bound concentrations above the MIC (fT(>MIC)) best correlate with clinical cure rates for beta-lactams. We compared the breakpoints for flucloxacillin between several dosage regimens. In a randomized, two-way crossover study, 10 healthy volunteers received 500 mg and 1,000 mg flucloxacillin as 5-min intravenous infusions. Drug concentrations were determined by high-pressure liquid chromatography. We used the programs WinNonlin for noncompartmental analysis and statistics and NONMEM for population PK and Monte Carlo simulation. We compared the probability of target attainment (PTA) for intermittent- and continuous-dosage regimens based on the targets of fT(>MIC)s of > or =50% and > or =30% of the dosing interval. The clearance and the volume of distribution were very similar after the administration of 500 mg and 1,000 mg flucloxacillin. We estimated renal and nonrenal clearances of 5.37 liters/h (coefficient of variation, 19%) and 2.73 liters/h (33%). For near maximal killing (target, fT(>MIC) of > or =50%) flucloxacillin showed a robust (> or =90%) PTA up to MICs of 0.75 to 1 mg/liter (PTA of 86% at 1 mg/liter) for a continuous or a prolonged infusion of 6 g/day. Short-term infusions of 6 g/day had a lower breakpoint of 0.25 to 0.375 mg/liter. The flucloxacillin PK was linear for doses of 500 mg and 1,000 mg. Prolonged and continuous infusion at a 66% lower daily dose achieved the same PK-PD breakpoints as short-term infusions. Prolonged infusion and continuous infusion are appealing options for the treatment of serious infections caused by sensitive staphylococci.
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Bergeron MG, Desaulniers D, Lessard C, Lemieux M, Després JP, Métras J, Raymond G, Brochu G. Concentrations of fusidic acid, cloxacillin, and cefamandole in sera and atrial appendages of patients undergoing cardiac surgery. Antimicrob Agents Chemother 1985; 27:928-32. [PMID: 4026265 PMCID: PMC180189 DOI: 10.1128/aac.27.6.928] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The concentrations of cefamandole, cloxacillin and fusicid acid were measured in the serum and heart tissue of 100 recipients of these drugs before cardiac surgery. During cardiopulmonary bypass, mean (+/- standard deviation) peak concentrations in serum of all patients were 63.0 +/- 34.0 micrograms of cefamandole per ml, 30.8 +/- 17.7 micrograms of cloxacillin per ml, and 32.4 +/- 10.8 micrograms of fusidic acid per ml. Mean (+/- standard deviation) concentrations in atrial appendages taken 1 h (+/- 15 min) after infusion were 21.3 +/- 11.0 micrograms of cefamandole per g, 23.8 +/- 17.3 micrograms of cloxacillin per g, and 10.7 +/- 4.2 micrograms of fusidic acid per g. No cloxacillin could be detected in 5 of 39 heart specimens. Mean tissue-to-serum ratios at 1 h for cefamandole, cloxacillin, and fusidic acid were respectively 0.35, 0.73, and 0.33. Fusidic acid, a drug which is highly effective in vitro against both methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, was detectable in heart tissue in concentrations which were 12 times higher than the MICs of this agent against these resistant microorganisms.
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MARTIN IANCA, LOVE DARIAN, ROSE REUBENJ. Levels of the isoxazolyl penicillins, cloxacillin and flucloxacillin, in serum and synovia of horses. J Vet Pharmacol Ther 1980. [DOI: 10.1111/j.1365-2885.1980.tb00475.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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