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Busse D, Schaeftlein A, Solms A, Ilia L, Michelet R, Zeitlinger M, Huisinga W, Kloft C. Which Analysis Approach Is Adequate to Leverage Clinical Microdialysis Data? A Quantitative Comparison to Investigate Exposure and Reponse Exemplified by Levofloxacin. Pharm Res 2021; 38:381-395. [PMID: 33723793 PMCID: PMC7994214 DOI: 10.1007/s11095-021-02994-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/05/2020] [Indexed: 01/22/2023]
Abstract
Purpose Systematic comparison of analysis methods of clinical microdialysis data for impact on target-site drug exposure and response. Methods 39 individuals received a 500 mg levofloxacin short-term infusion followed by 24-h dense sampling in plasma and microdialysate collection in interstitial space fluid (ISF). ISF concentrations were leveraged using non-compartmental (NCA) and compartmental analysis (CA) via (ii) relative recovery correction at midpoint of the collection interval (midpoint-NCA, midpoint-CA) and (ii) dialysate-based integrals of time (integral-CA). Exposure and adequacy of community-acquired pneumonia (CAP) therapy via pharmacokinetic/pharmacodynamic target-attainment (PTA) analysis were compared between approaches. Results Individual AUCISF estimates strongly varied for midpoint-NCA and midpoint-CA (≥52.3%CV) versus integral-CA (≤32.9%CV) owing to separation of variability in PK parameters (midpoint-CA = 46.5%–143%CVPK, integral-CA = 26.4%–72.6%CVPK) from recovery-related variability only in integral-CA (41.0%–50.3%CVrecovery). This also led to increased variability of AUCplasma for midpoint-CA (56.0%CV) versus midpoint-NCA and integral-CA (≤33.0%CV), and inaccuracy of predictive model performance of midpoint-CA in plasma (visual predictive check). PTA analysis translated into 33% of evaluated patient cases being at risk of incorrectly rejecting recommended dosing regimens at CAP-related epidemiological cut-off values. Conclusions Integral-CA proved most appropriate to characterise clinical pharmacokinetics- and microdialysis-related variability. Employing this knowledge will improve the understanding of drug target-site PK for therapeutic decision-making. Supplementary Information The online version contains supplementary material available at 10.1007/s11095-021-02994-1.
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Affiliation(s)
- David Busse
- Institute of Pharmacy, Department of Clinical Pharmacy and Biochemistry, Freie Universitaet Berlin, Berlin, Germany.,Graduate Research Training program PharMetrX, Berlin/Potsdam, Germany
| | | | - Alexander Solms
- Institute of Mathematics, University of Potsdam, Potsdam, Germany.,Clinical Pharmacometrics, Bayer AG, Berlin, Germany
| | - Luis Ilia
- Institute of Pharmacy, Department of Clinical Pharmacy and Biochemistry, Freie Universitaet Berlin, Berlin, Germany
| | - Robin Michelet
- Institute of Pharmacy, Department of Clinical Pharmacy and Biochemistry, Freie Universitaet Berlin, Berlin, Germany
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Wilhelm Huisinga
- Institute of Mathematics, University of Potsdam, Potsdam, Germany
| | - Charlotte Kloft
- Institute of Pharmacy, Department of Clinical Pharmacy and Biochemistry, Freie Universitaet Berlin, Berlin, Germany.
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2
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Sartini I, Łebkowska-Wieruszewska B, Sitovs A, Lisowski A, Poapolathep A, Giorgi M. Levofloxacin pharmacokinetics and tissue residue concentrations after oral administration in Bilgorajska geese. Br Poult Sci 2020; 62:193-198. [PMID: 33121260 DOI: 10.1080/00071668.2020.1842855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
1. The aim of this study was to assess the pharmacokinetics of levofloxacin, a third-generation fluoro-quinolone antimicrobial drug, in geese (n = 26) after either single intravenous or oral administration, and to evaluate the depletion profile in goose muscle, heart, liver, kidney and lung after a single oral dose.2. The pharmacokinetic study involved 16 geese which were randomly divided into two groups (n = 8/group), the first received levofloxacin (2 mg/kg) intravenously while the second was treated with orally (5 mg/kg). The tissue depletion study involved 10 geese which were dosed orally (5 mg/kg) and two animals were killed at different time-points in order to collect the selected tissues. Levofloxacin was quantified in all the matrices tested by a validated high-performance liquid chromatography (HPLC) method, using a spectrofluorimetric detector. The pharmacokinetics were analysed using a non-compartmental model.3. Plasma concentrations were quantified after up to 24 h in animals administered intravenously and up to 48 h after oral treatment. Levofloxacin was rapidly absorbed after oral administration (Tmax = 0.38 h) showing high bioavailability (95.57 ± 20.61%). The drug showed a moderate volume of distribution (1.40 ± 0.28 ml/g) and rapid clearance (0.28 ± 0.06 ml/g/h). No statistical differences in estimates were found between the two different administration methods (P > 0.05). Drug residues were highest at 6 h and decreased constantly up to 48 h in all the selected tissues. Liver and kidney had the highest levofloxacin concentrations.4. According to the pharmacokinetic/pharmacodynamic surrogate index (AUC/MIC) the levofloxacin dose regimen (after oral administration) used in the present study could be active against bacteria at a minimum inhibitory concentration (MIC) > 0.24 μg/ml in geese. In addition, drug accumulation in the liver might be controlled using an estimated preliminary withdrawal time of 90 h.
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Affiliation(s)
- I Sartini
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - B Łebkowska-Wieruszewska
- Department of Pharmacology, Toxicology and Environmental Protection, University of Life Sciences, Lublin, Poland
| | - A Sitovs
- Department of Pharmacology, Riga Stradins University, Riga, Latvia
| | - A Lisowski
- Institute of Animal Breeding and Biodiversity Conservation, University of Life Sciences, Lublin, Poland
| | - A Poapolathep
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - M Giorgi
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
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3
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Quantification of microdialysis related variability in humans: Clinical trial design recommendations. Eur J Pharm Sci 2020; 157:105607. [PMID: 33141034 DOI: 10.1016/j.ejps.2020.105607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Target-site concentrations obtained via the catheter-based minimally invasive microdialysis technique often exhibit high variability. Catheter calibration is commonly performed via retrodialysis, in which a transformation factor, termed relative recovery (RR), is determined. Leveraging RR values from a rich data set of a very large clinical microdialysis study, promised to contribute critical insight into the origin of the reportedly high target-site variability. The present work aimed (i) to quantify and explain variability in RR associated with the patient (including non-obese vs. obese) and the catheter, and (ii) to derive recommendations on the design of future clinical microdialysis studies. METHODS A prospective, age- and sex-matched parallel group, single-centre trial in non-obese and obese patients (BMI=18.7-86.9 kg/m2) was performed. 1-3 RR values were obtained in the interstitial fluid of the subcutaneous fat tissue in one catheter per upper arm of 120 patients via the retrodialysis method (nRR=1008) for a panel of drugs (linezolid, meropenem, tigecycline, cefazolin, fosfomycin, piperacillin and acetaminophen). A linear mixed-effects model was developed to quantify the different types of variability in RR and to explore the association between RR and patient body size descriptors. RESULTS Estimated RR was highest for acetaminophen (69.7%, 95%CI=65.0% to 74.3%) and lowest for piperacillin (40.4%, 95%CI=34.6% to 46.0%). The linear mixed-effects modelling analysis showed that variability associated with the patient (σ=15.9%) was the largest contributor (46.7%) to overall variability, whereas the contribution of variability linked to the catheter (σ=5.55%) was ~1/6 (16.8%). The relative contribution of residual unexplained variability (σ=12.0%, including intracatheter variability) was ~1/3 (36.4%). The limits of agreement of repeated RR determinations in a single catheter ranged from 0.694-1.64-fold (linezolid) to 0.510-3.02-fold (cefazolin). Calculated fat mass affected RR, explaining the observed lower RR in obese (ΔRRmean= -29.7% relative reduction) versus non-obese patients (p<0.001); yet only 15.8% of interindividual variability was explained by this effect. No difference in RR was found between catheters implanted into the left or right arm (p=0.732). CONCLUSIONS Three recommendations for clinical microdialysis trial design were derived: 1) High interindividual variability underscored the necessity of measuring individual RR per patient. 2) The low relative contribution of intercatheter variability to overall variability indicated that measuring RR with a single catheter per patient is sufficient for reliable catheter calibration. 3) The wide limits of agreement from multiple RR in the same catheter implied an uncertainty of a factor of two in target-site drug concentration estimation necessitating to perform catheter calibration (retrodialysis sampling) multiple times per patient. To allow routine clinical use of microdialysis, research efforts should aim at further understanding and minimising the method-related variability. Optimised study designs in clinical trials will ultimately yield more informative microdialysis data and increase our understanding of this valuable sampling technique to derive target-site drug exposure.
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Sartini I, Łebkowska-Wieruszewska B, Kim TW, Lisowski A, Poapolathep A, Giorgi M. Pharmacokinetic and tissue analyses of levofloxacin in sheep (Ovis aries Linnaeus) after multiple-dose administration. Res Vet Sci 2019; 128:124-128. [PMID: 31778853 DOI: 10.1016/j.rvsc.2019.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 10/25/2022]
Abstract
The aim of this study was to assess the pharmacokinetic profile of LFX in sheep after intravenous (IV) and oral (PO) administration of 2 mg/kg LFX once a day for 5 days and to evaluate its tissue depletion in the muscles, heart, liver, lungs, and kidneys. Twenty healthy female sheep were randomly divided into two equal groups. Each group was further randomly subdivided into two equal subgroups (n = 5). Group 1 was used for blood collection and underwent a crossover design (2 × 2 Latin square). Group 2 was randomly subdivided into two equal subgroups (n = 5) for IV and PO route respectively, and used for tissue collection. A single sheep was sacrificed at each time point and the organs were harvested. Samples were analyzed using a validated HPLC method with fluorescence detection. LFX administered orally was rapidly absorbed with a peak plasma concentration of 2866 ± 239 ng/mL and an absolute oral bioavailability of 114 ± 27.7%. The pharmacokinetic estimates were comparable between PO and IV administration. According to the pharmacokinetic/pharmacodynamic surrogate index (area under the curve / minimum inhibitory concentration) of 100-125, LFX has the potential to be an effective treatment for infections caused by bacteria with a MIC of 0.049-0.061 μg/mL. LFX was detected for up to 48 h in all the tissues samples. The kidney had the highest LFX concentration after IV and PO administration. The AUCtissue/plasma ratio was lower than 1 in all tissues indicating absence of LFX tissue accumulation.
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Affiliation(s)
- Irene Sartini
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - Beata Łebkowska-Wieruszewska
- Department of Pharmacology, Toxicology and Environmental Protection, University of Life Sciences, Lublin, Poland
| | - Tae Won Kim
- College of Veterinary Medicine, Chungnam National University, Daejeon, South Korea
| | - Andrzej Lisowski
- Institute of Animal Breeding and Biodiversity Conservation, University of Life Sciences, Lublin, Poland
| | - Amnart Poapolathep
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Mario Giorgi
- Department of Veterinary Sciences, University of Pisa, Via Livornese (lato monte), San Piero a Grado, 56122 Pisa, Italy.
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5
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Oesterreicher Z, Lackner E, Jäger W, Höferl M, Zeitlinger M. Lack of dermal penetration of topically applied gentamicin as pharmacokinetic evidence indicating insufficient efficacy. J Antimicrob Chemother 2019; 73:2823-2829. [PMID: 30113678 DOI: 10.1093/jac/dky274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/15/2018] [Indexed: 12/19/2022] Open
Abstract
Background Treatment of skin and superficial soft tissue infections with topically applied antibiotics is a controversial topic, because only few clinical studies exist and target site concentrations after topical treatment are widely unknown. Objectives This study aimed to investigate the target site concentration of topically applied gentamicin as a potential cause of therapeutic failure and to explore if microporation by laser might be used to improve penetration of gentamicin through the skin barrier. Methods Six healthy volunteers were included in this cross-over Phase 1 study. On two study days, separated by a washout period, microdialysate and plasma sampling was performed for 6 h after administration of 500 mg of gentamicin cream on a predefined area. On one of the study days the skin was microporated before drug application using the P.L.E.A.S.E. Professional laser system. Results In intact skin, Cmax and AUC values were 3.3 ± 5.64 ng/mL and 5.4 ± 10.4 ng·h/mL, respectively; thereby far under the threshold needed to treat common pathogens. With a Cmax of 474.2 ± 555.3 ng/mL laser application showed a significant increase in tissue penetration and decrease in pharmacokinetic variability; however, even after microporation no therapeutically active concentrations were achieved as indicated by Cmax/epidemiological cut-off ratios of 0.237 and 0.059 for Staphylococcus aureus and Pseudomonas aeruginosa, respectively. Solely after administration on microporated skin, plasma concentrations of gentamicin were quantifiable (lower limit of quantification 10 pg/mL). Conclusions This study confirmed that after topical administration gentamicin penetration through the dermal barrier is insufficient, providing pharmacokinetic evidence that topical gentamicin in its current form might be inappropriate to treat skin infections.
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Affiliation(s)
- Zoe Oesterreicher
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria
| | - Edith Lackner
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria
| | - Walter Jäger
- Department of Pharmaceutical Chemistry, University of Vienna, Althanstrasse 14, Vienna, Austria
| | - Martina Höferl
- Department of Pharmaceutical Chemistry, University of Vienna, Althanstrasse 14, Vienna, Austria
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria
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Farghaly Aly U, Abou-Taleb HA, Abdellatif AA, Sameh Tolba N. Formulation and evaluation of simvastatin polymeric nanoparticles loaded in hydrogel for optimum wound healing purpose. DRUG DESIGN DEVELOPMENT AND THERAPY 2019; 13:1567-1580. [PMID: 31190737 PMCID: PMC6512793 DOI: 10.2147/dddt.s198413] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Purpose The aim of this study was to formulate a hydrogel loaded with polymeric nanoparticles (PoNPs) of simvastatin (SIM) for topical wound healing application. Materials and methods The SIM PoNPs were prepared by using the nanoprecipitation method to improve the drug solubility and skin permeation. Furthermore, drug content, solubility, particle size, surface charge, and transmission electron microscopy of the prepared PoNPs were evaluated. Then, the PoNPs were loaded on hydrogel, and physical characteristics, in vitro release, and ex vivo permeation of the hydrogel were evaluated. Finally, the prepared gel was applied on rat wounds, and a histopathological study was performed. Results The results showed that the drug content in the PoNPs was 86.4%. The PoNPs were spherical in shape with a smooth surface and a uniform size distribution. The particle size was 268.4±2.6, polydispersity index was ≤0.302, and zeta potential was −33±1.67 mV. The hydrogel loaded with SIM PoNPs was homogenous, and the pH was accepted and compatible with the skin. Moreover, the viscosity and spreadability assured its ease of application. The drug content was 97.25±0.02%. Furthermore, about 81% of SIM was released within 24 hours, while in the ex vivo permeation study 69.19% of SIM passed through the skin after 24 hours. Finally, the histopathological studies confirmed the efficacy of the SIM PoNPs-loaded hydrogel in wound healing due to the formation of the normal epithelial layer on day 11 after wound creation. Conclusion The hydrogel loaded with SIM PoNPs showed a good efficacy in accelerating the healing of the rat wound with complete epithelialization and minimal inflammatory cell infiltration.
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Affiliation(s)
- Usama Farghaly Aly
- Department of Pharmaceutics, Faculty of Pharmacy, Minia University, El-Minia, Egypt,
| | - Heba A Abou-Taleb
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Nahda University (NUB), Beni-Suef, Egypt
| | - Ahmed Ah Abdellatif
- Department of Pharmaceutics, College of Pharmacy, Qassim University, Al Qassim, Kingdom of Saudi Arabia.,Department of Pharmaceutics and Industrial Pharmacy, Al-Azhar University, Assiut, Egypt
| | - Nahla Sameh Tolba
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Nahda University (NUB), Beni-Suef, Egypt
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Tomas A, Stilinović N, Sabo A, Tomić Z. Use of microdialysis for the assessment of fluoroquinolone pharmacokinetics in the clinical practice. Eur J Pharm Sci 2019; 131:230-242. [PMID: 30811969 DOI: 10.1016/j.ejps.2019.02.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/22/2019] [Accepted: 02/22/2019] [Indexed: 12/12/2022]
Abstract
Antibacterial drugs, including fluoroquinolones, can exert their therapeutic action only with adequate penetration at the infection site. Multiple factors, such as rate of protein binding, drug liposolubility and organ blood-flow all influence ability of antibiotics to penetrate target tissues. Microdialysis is an in vivo sampling technique that has been successfully applied to measure the distribution of fluoroquinolones in the interstitial fluid of different tissues both in animal studies and clinical setting. Tissue concentrations need to be interpreted within the context of the pathogenesis and causative agents implicated in infections. Integration of microdialysis -derived tissue pharmacokinetics with pharmacodynamic data offers crucial information for correlating exposure with antibacterial effect. This review explores these concepts and provides an overview of tissue concentrations of fluoroquinolones derived from microdialysis studies and explores the therapeutic implications of fluoroquinolone distribution at various target tissues.
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Affiliation(s)
- Ana Tomas
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Serbia.
| | - Nebojša Stilinović
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Serbia
| | - Ana Sabo
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Serbia
| | - Zdenko Tomić
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Serbia
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8
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Landoni MF, Albarellos GA. Pharmacokinetics of levofloxacin after single intravenous, oral and subcutaneous administration to dogs. J Vet Pharmacol Ther 2018; 42:171-178. [DOI: 10.1111/jvp.12726] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 09/04/2018] [Accepted: 09/16/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Maria Fabiana Landoni
- Cátedra de Farmacología; Facultad de Ciencias Veterinarias; CONICET; Universidad Nacional de La Plata; La Plata Buenos Aires Argentina
| | - Gabriela Alejandra Albarellos
- Cátedra de Farmacología; Facultad de Ciencias Veterinarias; Universidad de Buenos Aires; Buenos Aires Buenos Aires Argentina
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9
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Oesterreicher Z, Minichmayr I, Sauermann R, Marhofer D, Lackner E, Jäger W, Maier-Salamon A, Schwameis R, Kloft C, Zeitlinger M. Pharmacokinetics of doripenem in plasma and epithelial lining fluid (ELF): comparison of two dosage regimens. Eur J Clin Pharmacol 2017; 73:1609-1613. [PMID: 28920154 PMCID: PMC5684299 DOI: 10.1007/s00228-017-2327-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/22/2017] [Indexed: 11/30/2022]
Abstract
Purpose In 2014, FDA released a warning for prescription of doripenem for ventilator-associated bacterial pneumonia due to unsatisfactory clinical cure rates. The present study explores if the observed lack of efficacy might be explained by insufficient target site pharmacokinetics in intensive care patients after two different infusion schemes. Methods Plasma and bronchoalveolar lavage sampling was performed in 16 intubated patients with pneumonia receiving doripenem either as 1-h or as 4-h infusion. Doripenem concentrations were measured at steady state in plasma over 8 h, bronchoalvoelar lavage was performed in each patient once either after 0 h, 2 h, 4 h or 6 h. Results In plasma, mean values of Cmax, Tmax and AUC0–8 were 16.87 mg/L, 0.69 h and 52.98 mg/L×h after 1 h of infusion, and 12.94 mg/L, 3.21 h and 70.64 mg/L×h after 4 h of infusion, respectively. While the later tmax in plasma was with delay mirrored in the lung, for ELF, much lower concentrations were observed (Cmax, Tmax and AUC0–8 after 1-h infusion of 4.6 mg/L, 2 h and 15.3 mg/L×h and after 4-h infusion 6.9 mg/L, 4 h and 14.8 mg/L×h). Conclusion The difference in plasma pharmacokinetics after 1-h and 4-h infusion reflects in the concentration versus time profile in the lung, but concentration at the target site was not only considerably lower but also subject to high inter-individual variability. We hypothesise that insufficient concentrations at the target site might have contributed to the previously described lack of clinical efficacy and confirmed the demand for assessment of target site pharmacokinetics in larger patient collectives.
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Affiliation(s)
- Zoe Oesterreicher
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Iris Minichmayr
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, Berlin, Germany
| | - Robert Sauermann
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Daniela Marhofer
- Department of Anaesthesia and Intensive Care Medicine, Medical University of Vienna, Vienna, Austria
| | - Edith Lackner
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Walter Jäger
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | | | - Richard Schwameis
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Charlotte Kloft
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, Berlin, Germany
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
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10
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Mand'ák J, Pojar M, Maláková J, Lonsk V, Palicka V, Zivný P. Tissue and plasma concentrations of cephuroxime during cardiac surgery in cardiopulmonary bypass — a microdialysis study. Perfusion 2016; 22:129-36. [PMID: 17708162 DOI: 10.1177/0267659107080116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aim: Wound and mediastinal infections are still very serious complications of open-heart surgery, in spite of the use of prophylactic antibiotics. The use of cardiopulmonary bypass (CPB) is associated with profound physiological changes affecting the pharmacokinetic behaviour of antibiotics. The aim of this pilot study was to monitor the tissue concentrations of cephuroxime (prophylactic antibiotic) in skeletal muscle during cardiac surgery using CPB by interstitial microdialysis. These concentrations were compared with plasma concentrations of cephuroxime. Material and methods: Nine adult patients operated on using CPB were enrolled in this study. Cephuroxime was used as a prophylactic antibiotic (1st dose — 3 g of cefuroxime i.v. with anesthesia induction, 2nd dose — 1.5 g i.v. after CPB with protamine sulphate, 3rd dose — 1.5 g i.v. 8 hours after the surgery). Interstitial microdialysis was performed by probe CMA 60 (CMA Microdialysis AB, Sweden) inserted into the patient's deltoid muscle. Concentrations of cephuroxime in dialysates and in plasma were determined by the modified fluid chromatography method. The unbound cephuroxime fraction in plasma was obtained by using an ultrafiltration method. Samples of dialysates were collected at the following intervals: before CPB, each 30 minutes of CPB, at the end of CPB. Samples of blood were collected at these intervals: incision, start of CPB, each 30 minutes of CPB, at the end of CPB, at the end of surgery. Concentrations of cephuroxime in tissue were corrected by in vivo recoveries of the microdialysis probes. Results: Plasma concentrations of cephuroxime were 163.5 ± 40.1, 79.3 ± 17.4, 73.7 ± 16.8, 66.1 ± 18.3, 57.0 ± 10.9, 120.7 ± 29.9 (mg . L—1) and concentrations of free plasma fraction of cephuroxime were 119.5 ± 35.2, 67.8 ± 15.5, 66.0 ± 12.5, 54.8 ± 12.2, 49.6 ± 9.8, 102.6 ± 26.0 (mg . L—1). The concentrations of cephuroxime in dialysates were 44.3 ± 15.7, 36.1 ± 11.6, 31.9 ± 9.3, 34.6 ± 12.3, 27.6 ± 12.9, 56.7 ± 17.6 (mg . L—1). The mean in vivo recovery of cephuroxime in this study was 30%. Corrected concentrations (calculated by in vivo recovery) of cephuroxime in skeletal muscle were 148, 120, 106, 115, 92, 189 (mg . L—1). Conclusion: Our preliminary results show that CPB can modify the time course of cephuroxime plasma and tissue concentrations. A decrease in plasma drug concentrations occurred at the start of CPB and lasted until CPB ended. An increase in plasma concentrations corresponds to the second drug dose after CPB. The concentrations of cephuroxime in skeletal muscle (corrected by recovery) during CPB are higher than plasma concentrations. It is influenced by important changes during CPB; closely associated with hemodilution, a shift of intravascular volume, solutes and albumin to the extravascular space and inconstant protein binding of cephuroxime during operation. Perfusion (2007) 22, 129—136.
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Affiliation(s)
- J Mand'ák
- Department of Cardiac Surgery, Charles University, Faculty of Medicine and University Hospital, Hradec Kralove, Czech Republic.
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11
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Practical concept of pharmacokinetics/pharmacodynamics in the management of skin and soft tissue infections. Curr Opin Infect Dis 2016; 29:153-9. [DOI: 10.1097/qco.0000000000000256] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Kiang TKL, Häfeli UO, Ensom MHH. A comprehensive review on the pharmacokinetics of antibiotics in interstitial fluid spaces in humans: implications on dosing and clinical pharmacokinetic monitoring. Clin Pharmacokinet 2015; 53:695-730. [PMID: 24972859 DOI: 10.1007/s40262-014-0152-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The objective of the current review was to provide an updated and comprehensive summary on pharmacokinetic data describing the distribution of antimicrobials into interstitial fluid (ISF) by comparing drug concentration versus time profiles between ISF and blood/plasma in healthy individuals and/or diseased populations. An extensive literature search identified 55 studies detailing 87 individual comparisons. For each antibiotic (antibacterial) (or antibiotic class), we comment on dosing implications based on tissue ISF distribution characteristics and determine the suitability of conducting clinical pharmacokinetic monitoring (CPM) using a previously published scoring algorithm. Using piperacillin as an example, there is evidence supporting different degrees of drug penetration into the ISF of different tissues. A higher dose of piperacillin may be required to achieve an adequate ISF concentration in soft tissue infections. To achieve these higher doses, alternative administration regimens such as intravenous infusions may be utilized. Data also suggest that piperacillin can be categorized as a 'likely suitable' agent for CPM in ISF. Regression analyses of data from the published studies, including protein binding, molecular weight, and predicted partition coefficient (using XlogP3) as dependent variables, indicated that protein binding was the only significant predictor for the extent of drug distribution as determined by ratios of the area under the concentration-time curve between muscle ISF/total plasma (R (2) = 0.65, p < 0.001) and adipose ISF/total plasma (R (2) = 0.48, p < 0.004). Although recurrent limitations (i.e., small sample size, lack of statistical comparisons, lack of steady-state conditions, high individual variability) were identified in many studies, these data are still valuable and allowed us to generate general dosing guidelines and assess the suitability of using ISF for CPM.
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Affiliation(s)
- Tony K L Kiang
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada
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13
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Wicha SG, Haak T, Zink K, Kees F, Kloft C, Kees MG. Population pharmacokinetics and target attainment analysis of moxifloxacin in patients with diabetic foot infections. J Clin Pharmacol 2015; 55:639-46. [DOI: 10.1002/jcph.464] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/15/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Sebastian G. Wicha
- Department of Clinical Pharmacy and Biochemistry; Institute of Pharmacy; Freie Universitaet Berlin; Berlin Germany
| | - Thomas Haak
- Diabetes Center Mergentheim; Bad Mergentheim Germany
| | - Karl Zink
- Diabetes Center Mergentheim; Bad Mergentheim Germany
| | - Frieder Kees
- Department of Pharmacology; University of Regensburg; Regensburg Germany
| | - Charlotte Kloft
- Department of Clinical Pharmacy and Biochemistry; Institute of Pharmacy; Freie Universitaet Berlin; Berlin Germany
| | - Martin G. Kees
- Department of Clinical Pharmacy and Biochemistry; Institute of Pharmacy; Freie Universitaet Berlin; Berlin Germany
- Department of Anesthesiology and Intensive Care; Charité Universitätsmedizin Berlin; Berlin Germany
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14
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Liu D, Xu S, Xiao H, Wang Z, Mao N, Zhou J, Liu R, Huang Y. Quantitative determination of unbound levofloxacin by simultaneous microdialysis in rat pancreas after intravenous and oral doses. ACTA ACUST UNITED AC 2014; 66:1215-21. [PMID: 24961375 DOI: 10.1111/jphp.12252] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 03/02/2014] [Indexed: 12/01/2022]
Abstract
OBJECTIVE We compared the pharmacokinetic profile of unbound levofloxacin in rat pancreas after an oral dose with that after an intravenous dose to determine if oral administration of levofloxacin could potentially be used. METHOD Levofloxacin was administered either intravenously or orally into male Sprague-Dawley rats at the concentration of 42 mg/kg per day, mimicking the human dose of 400 mg/day. The concentrations of levofloxacin in extracellular fluid (ECF) of rat pancreatic tissues were determined using microdialysis coupled with high-performance liquid chromatography (HPLC). Levofloxacin was equally distributed into ECF of rat pancreatic tissues with either intravenous route (AUCpancreas /AUCblood , 0.97 ± 0.02) or oral route (AUCpancreas /AUCblood , 0.96 ± 0.03). KEY FINDINGS The penetration rates (PR) of pancreas-to-blood on the same target site between the two routes were the same. The intravenous antibiotic AUC/MIC ratios of common Gram-positive pancreatic bacteria ranged from 83.43 to 667.44; meanwhile, the ratio of common Gram-negative pancreatic bacteria ranged from 41.71 to 2669.74. The oral antibiotic AUC/MIC ratios for common gram-positive and Gram-negative pancreatic bacteria were from 78.54 to 628.31, and 39.27 to 2513.22, respectively (P > 0.05). CONCLUSIONS Intravenous administration had similar penetration efficacy to oral administration at an equivalent dose. Furthermore, levofloxacin had a good penetration through the blood-pancreas barrier.
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Affiliation(s)
- Deding Liu
- Department of Orthopedics, 153 Central Hospital of PLA, Zhengzhou, China
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15
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Lode HM. Preserving the efficacy of front-line fluoroquinolones through selective use to optimise clinical outcomes. Int J Antimicrob Agents 2014; 43:497-507. [DOI: 10.1016/j.ijantimicag.2014.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 02/18/2014] [Accepted: 02/20/2014] [Indexed: 01/06/2023]
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16
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Validation of an efficient LC-microdialysis method for gemifloxacin quantitation in lung, kidney and liver of rats. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 919-920:62-6. [DOI: 10.1016/j.jchromb.2013.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 01/05/2013] [Accepted: 01/08/2013] [Indexed: 11/23/2022]
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17
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Pham L, Christensen JM, Rodriguez-Proteau R. Pharmacokinetic Prediction of Levofloxacin Accumulation in Tissue and Its Association to Tendinopathy. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/pp.2013.41018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Tasso L, de Andrade C, Dalla Costa T. Pharmacokinetic/pharmacodynamic modelling of the bactericidal activity of free lung concentrations of levofloxacin and gatifloxacin against Streptococcus pneumoniae. Int J Antimicrob Agents 2011; 38:307-13. [DOI: 10.1016/j.ijantimicag.2011.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 11/30/2022]
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19
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Blakeley J, Portnow J. Microdialysis for assessing intratumoral drug disposition in brain cancers: a tool for rational drug development. Expert Opin Drug Metab Toxicol 2010; 6:1477-91. [PMID: 20969450 DOI: 10.1517/17425255.2010.523420] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
IMPORTANCE OF THE FIELD many promising targeted agents and combination therapies are being investigated for brain cancer. However, the results from recent clinical trials have been disappointing. A better understanding of the disposition of drug in the brain early in drug development would facilitate appropriate channeling of new drugs into brain cancer clinical trials. AREAS COVERED IN THIS REVIEW barriers to successful drug activity against brain cancer and issues affecting intratumoral drug concentrations are reviewed. The use of the microdialysis technique for extracellular fluid (ECF) sampling and its application to drug distribution studies in brain are reviewed using published literature from 1995 to the present. The benefits and limitations of microdialysis for performing neuorpharmacokinetic (nPK) and neuropharmacodynamic (nPD) studies are discussed. WHAT THE READER WILL GAIN the reader will gain an appreciation of the challenges involved in identifying agents likely to have efficacy in brain cancer, an understanding of the general principles of microdialysis, and the power and limitations of using this technique in early drug development for brain cancer therapies. TAKE HOME MESSAGE a major factor preventing efficacy of anti-brain cancer drugs is limited access to tumor. Intracerebral microdialysis allows sampling of drug in the brain ECF. The resulting nPK/nPD data can aid in the rational selection of drugs for investigation in brain tumor clinical trials.
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Affiliation(s)
- Jaishri Blakeley
- Johns Hopkins University, Neurosurgery and Oncology, Baltimore, MD 21231, USA.
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20
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Edginton AN, Ahr G, Willmann S, Stass H. Defining the role of macrophages in local moxifloxacin tissue concentrations using biopsy data and whole-body physiologically based pharmacokinetic modelling. Clin Pharmacokinet 2009; 48:181-7. [PMID: 19385711 DOI: 10.2165/00003088-200948030-00004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVES This study used a whole-body physiologically based pharmacokinetic (WB-PBPK) model for moxifloxacin, plus in vitro and in vivo literature data on its interaction with macrophages, to interpret biopsy results generated from patients undergoing primarily colorectal surgery. METHODS A WB-PBPK model was developed using PK-Sim(R) software and refined using observed plasma profiles. The model was assessed by comparing predictions of unbound interstitial concentrations with in vivo data from a microdialysis study. RESULTS Incorporating in vitro data on the percentage volume of macrophages in a colorectal resection (8.1%) plus the in vivo kinetic and accumulation potential of moxifloxacin in macrophages into the WB-PBPK model, biopsy concentrations and kinetics were predicted and compared with observed data. The WB-PBPK model accurately described adipose and muscle interstitial unbound concentrations. The predicted biopsy concentrations (including interstitial, intracellular, vascular space and macrophages) were slightly greater than the observed values, although the kinetic (i.e. observed biopsy half-life = 21 hours) was similar to that of moxifloxacin in macrophages (20.8 hours) and thus similar to the predicted biopsy half-life. A reduction in the predicted biopsy concentrations to match the observed data required a decrease in the volume fraction of macrophages from 8.1% to 3.6%. CONCLUSION When plasma concentrations are known, WB-PBPK is a method to determine interstitial and intracellular concentrations. In this study, integration of biopsy data with WB-PBPK allowed for generation and testing of hypotheses to determine the reason for the observed biopsy kinetics. This type of translational modelling may lead to a better understanding of the anti-infective pharmacokinetic/pharmacodynamic relationship.
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Affiliation(s)
- Andrea N Edginton
- Systems Biology, Bayer Technology Services GmbH, Leverkusen, Germany
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Stolle LB, plock N, Joukhadar C, Arpi M, Emmertsen KJ, Buerger C, Riegels-Nielsen P, Kloft C. Pharmacokinetics of linezolid in bone tissue investigated by in vivo microdialysis. ACTA ACUST UNITED AC 2009; 40:24-9. [DOI: 10.1080/00365540701509873] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Bello G, Alberto Pennisi M, Fragasso T, Mignani V, Antonelli M. Acute upper airway obstruction caused by Stenotrophomonas maltophilia soft tissue infection. ACTA ACUST UNITED AC 2009; 37:734-7. [PMID: 16191891 DOI: 10.1080/00365540510044436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A previously healthy 71-y-old male developed acute upper airway obstruction caused by a Stenotrophomonas maltophilia infection of the mucocutaneous and soft tissue of the neck. Ventilator support was provided via a small-calibre endotracheal tube. Stenotrophomonas was susceptible only to levofloxacin and cotrimoxazole. Antibiotic therapy rapidly improved the soft tissue oedema, allowing extubation and discharge from the intensive care unit.
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Affiliation(s)
- Giuseppe Bello
- Department of Anaesthesiology and Intensive Care Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
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23
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Pharmacokinetics and penetration of linezolid into inflamed soft tissue in diabetic foot infections. Eur J Clin Pharmacol 2008; 64:1093-100. [DOI: 10.1007/s00228-008-0531-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
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24
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Lung microdialysis study of levofloxacin in rats following intravenous infusion at steady state. Antimicrob Agents Chemother 2008; 52:3074-7. [PMID: 18591278 DOI: 10.1128/aac.00242-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lung microdialysis has been used with rats to investigate antibiotic distribution after single-dose administration. However, conducting such experiments after intravenous infusion at steady state would constitute a more convenient alternative, which was evaluated here, using levofloxacin (LVX) as a test compound. Microdialysis probes were inserted in blood and muscle, used as a comparator, between 9:00 a.m. and 11:00 a.m. Intravenous LVX infusion was started 6 h later and maintained until the end of the experiment at a rate of 1.0 mg.h(-1). Lung microdialysis probes were inserted on the morning of the next day. Rats were kept anesthetized during dialysate collection. In vivo probe recoveries were estimated by retrodialysis using a calibrator method, with ciprofloxacin (CIP) as the calibrator. LVX and CIP were analyzed in dialysates by high-performance liquid chromatography. The steady-state tissue-to-blood unbound-drug concentration ratios were 1.00 +/- 0.15 in muscle tissues and 1.06 +/- 0.40 in lungs, suggesting passive distribution of LVX in tissue. Although providing no information on rate of distribution, microdialysis investigations following drug infusion at steady state appear to be an interesting approach for characterization of antibiotic distribution in rat lungs.
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Park DJ, Phapale PB, Jang IJ, Cui S, Moon BJ, Kim JE, Kim W, Hwang SK, Yoon YR. An Improved UPLC Method for Rapid Analysis of Levofloxacin in Human Plasma. Chromatographia 2008. [DOI: 10.1365/s10337-008-0669-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Pojar M, Mandak J, Malakova J, Jokesova I. TISSUE AND PLASMA CONCENTRATIONS OF ANTIBIOTIC DURING CARDIAC SURGERY WITH CARDIOPULMONARY BYPASS - MICRODIALYSIS STUDY. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2008; 152:139-45. [DOI: 10.5507/bp.2008.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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27
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Tasso L, Bettoni CC, Oliveira LK, Costa TD. Evaluation of gatifloxacin penetration into skeletal muscle and lung by microdialysis in rats. Int J Pharm 2008; 358:96-101. [DOI: 10.1016/j.ijpharm.2008.02.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 02/19/2008] [Accepted: 02/20/2008] [Indexed: 11/25/2022]
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28
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Zhou ZL, Yang M, Yu XY, Peng HY, Shan ZX, Chen SZ, Lin QX, Liu XY, Chen TF, Zhou SF, Lin SG. A rapid and simple high-performance liquid chromatography method for the determination of human plasma levofloxacin concentration and its application to bioequivalence studies. Biomed Chromatogr 2007; 21:1045-51. [PMID: 17549677 DOI: 10.1002/bmc.851] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) for the determination of levofloxacin in human plasma is described. Neutralized with phosphate buffer (pH 7.0), the sample (0.1 mL) was extracted with dichlormethane (1 mL). After voltex-mixing and centrifuged at 3000g for 6 min at 4 degrees C, the upper aqueous layer was aspirated using a micro vacuum pump and the organic layer was directly transferred to a clean test tube without pipetting. The organic solvent was evaporated and the residues were reconstituted with the mobile phase. Levofloxacin and terazosin (internal standard, IS) were chromatographically separated on a C(18) column with a mobile phase containing phosphate buffer (pH 3.0, 10 mm), acetonitrile and triethylamine (76:24:0.076, v/v/v) at a flow rate of 1 mL/min. The analytes were detected using fluorescence detection at an excitation and emission wavelength of 295 and 440 nm, respectively. The linear range of the calibration curves was 0.0521-5.213 microg/mL for levofloxacin with a lower limit of quantitation (0.0521 microg/mL). The retention times of levofloxacin and terazosin were 2.5 and 3.1 min, respectively. Within- and between-run precision was less than 12 and 11%, respectively. Accuracy ranged from -6.3 to 4.5%. The recovery ranged from 86 to 89% at the concentrations of 0.0521, 0.5213 and 5.213 microg/mL. The present HPLC-FLD method is sensitive, efficient and reliable. The method described herein has been successfully used for the pharmacokinetic and bioequivalence studies of a levofloxacin formulation product after oral administration to healthy Chinese volunteers.
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Affiliation(s)
- Zhi-Ling Zhou
- Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou 510080, People's Republic of China
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Noreddin AM, Haynes V. Use of Pharmacodynamic Principles to Optimise Dosage Regimens for Antibacterial Agents in the Elderly. Drugs Aging 2007; 24:275-92. [PMID: 17432923 DOI: 10.2165/00002512-200724040-00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Throughout most of the world we are witnessing an ever increasing number of aged people as a percentage of the general population. In the coming years, the unique spectrum of infections presented by an elderly population, particularly those in long-term care facilities, will challenge our ability to maintain an effective battery of antibacterials. The pharmacokinetic parameters of most antibacterial agents are altered when assessed in the elderly due in part to non-pathological physiological changes. The inability to clear a drug from the body due to declining lung, kidney/bladder, gastrointestinal and circulatory efficiency can cause accumulation in the body of drugs given in standard dosages. While this may have the potential benefit of achieving therapeutic concentrations at a lower dose, there is also a heightened risk of attaining toxic drug concentrations and an increased chance of unfavourable interactions with other medications. Pharmacodynamic issues in the elderly are related to problems that arise from treating elderly patients who may have a history of previous antibacterial treatment and exposure to resistant organisms from multiple hospitalisations. Furthermore, the elderly often acquire infections in tandem with other common disease states such as diabetes mellitus and heart disease. Thus, it is essential that optimised dosage strategies be designed specifically for this population using pharmacodynamic principles that take into account the unique circumstances of the elderly. Rational and effective dosage and administration strategies based on pharmacodynamic breakpoints and detailed understanding of the pharmacokinetics of antibacterials in the elderly increase the chances of achieving complete eradication of an infection in a timely manner. In addition, this strategy helps prevent selection of drug-resistant bacteria and minimises the toxic effects of antibacterial therapy in the elderly patient.
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Affiliation(s)
- Ayman M Noreddin
- College of Pharmacy, University of Minnesota, Duluth, Minnesota 55812, USA.
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Desruisseaux MS, Trujillo ME, Tanowitz HB, Scherer PE. Adipocyte, adipose tissue, and infectious disease. Infect Immun 2006; 75:1066-78. [PMID: 17118983 PMCID: PMC1828569 DOI: 10.1128/iai.01455-06] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Mahalia S Desruisseaux
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA
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Traunmüller F, Gattringer R, Zeitlinger MA, Graninger W, Müller M, Joukhadar C. Determination of telithromycin in human plasma and microdialysates by high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 822:133-6. [PMID: 15990374 DOI: 10.1016/j.jchromb.2005.05.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Revised: 05/03/2005] [Accepted: 05/26/2005] [Indexed: 10/25/2022]
Abstract
A high-performance liquid chromatography method for the quantitative determination of telithromycin in biological fluids is described. The method is suitable for plasma and microdialysates from the interstitial space fluid of skeletal muscle and subcutaneous adipose tissue. Plasma samples were deproteinised with trichloroacetic acid and neutralised with sodium hydroxide. Microdialysates were analysed without further preparation step. Telithromycin was separated isocratically on a reverse-phase column using acetonitrile-0.03 M ammonium acetate, pH 5.2 (43:57, v/v) at a flow rate of 0.8 mlmin(-1), and fluorescence detection (excitation 263 nm, emission 460 nm). The calibration curve was linear from 0.01 to 5 microgml(-1). Within- and between-day imprecision and inaccuracy was < or =10%. The limits of quantification were 0.02 and 0.015 microgml(-1) for plasma and microdialysates, respectively. Since telithromycin is decomposed in aqueous solution at ambient temperature, it is strongly recommended to store samples frozen at -80 degrees C, to maintain the temperature at 4 degrees C during all preparation steps, and to analyse samples within 120 min after thawing.
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Affiliation(s)
- Friederike Traunmüller
- Division of Clinical Pharmacokinetics, Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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Albarellos GA, Ambros LA, Landoni MF. Pharmacokinetics of levofloxacin after single intravenous and repeat oral administration to cats. J Vet Pharmacol Ther 2005; 28:363-9. [PMID: 16050816 DOI: 10.1111/j.1365-2885.2005.00669.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pharmacokinetic properties of the fluoroquinolone levofloxacin, were investigated in five cats after single intravenous and repeat oral administration at a daily dose of 10 mg/kg. Levofloxacin serum concentration was analyzed by microbiological assay using Klebsiella pneumoniae ATCC 10031 as test microorganism. Serum levofloxacin disposition after intravenous and oral dosing was best fitted to a bicompartmental and a monocompartmental open models with first-order elimination, respectively. After intravenous administration, distribution was rapid (t(1/2(d)) 0.26 +/- 0.18 h) and wide as reflected by the steady-state volume of distribution of 1.75 +/- 0.42 L/kg. Drug elimination was slow with a total body clearance of 0.14 +/- 0.04 L/h.kg and a t(1/2) for this process of 9.31 +/- 1.63 h. The mean residence time was of 12.99 +/- 2.12 h. After repeat oral administration, absorption half-life was of 0.18 +/- 0.12 h and Tmax of 1.62 +/- 0.84 h. The bioavailability was high (86.27 +/- 43.73%) with a peak plasma concentration at the steady state of 4.70 +/- 0.91 microg/mL. Drug accumulation was not significant after four oral administrations. Estimated efficacy predictors for levofloxacin after either intravenous or oral administration indicate a good profile against bacteria with a MIC value below of 0.5 microg/mL. However, for microorganisms with MIC values of 1 microg/mL it would be efficacious only when administered intravenously.
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Affiliation(s)
- G A Albarellos
- Departamento de Fisiopatología y Etiopatogenia, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina.
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