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Jager NGL, Van Ewijk-Beneken Kolmer E, Aarnoutse R, Te Brake LHM. Influence of ultrafiltration conditions on the measurement of unbound drug concentrations: flucloxacillin as an example. J Antimicrob Chemother 2024; 79:1187-1190. [PMID: 38569058 PMCID: PMC11062936 DOI: 10.1093/jac/dkae092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/09/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND When performing therapeutic drug monitoring (TDM) for flucloxacillin, it is advised to measure the unbound, not the total, flucloxacillin concentration. To be able to accurately quantify unbound flucloxacillin concentrations, a reliable analytical method is indispensable. OBJECTIVE To determine the influence of temperature and pH of the sample during ultrafiltration on the measured unbound fraction of flucloxacillin. MATERIALS AND METHODS We performed three different experiments. In a single laboratory experiment, we investigated the influence of ultrafiltration temperature (10°C, room temperature and 37°C) on the measured unbound fraction of flucloxacillin for three concentration levels. In a multiple laboratory experiment, the results of eight laboratories participating in an international quality control programme measuring unbound flucloxacillin concentrations were analysed. In the third experiment, patient samples were ultrafiltrated using four different conditions: (i) physiological pH and room temperature; (ii) unadjusted pH (pH 9 after freezing) and room temperature; (iii) physiological pH and 37°C and (iv) unadjusted pH and 37°C. RESULTS For all experiments, measurement of samples that were ultrafiltrated at room temperature resulted in a substantially lower unbound fraction compared to samples that were ultrafiltrated at 37°C. Adjusting the pH to physiological pH only had a minimal impact on the measured unbound fraction. CONCLUSIONS On the basis of these findings and considering the need for fast, simple and reproducible sample pretreatment for TDM purposes, we conclude that ultrafiltration of flucloxacillin should be performed at physiological temperature (37°C), but adjustment of pH does not seem to be necessary.
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Affiliation(s)
- Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Rob Aarnoutse
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lindsey H M Te Brake
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
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Mekking XM, Velthoven-Graafland K, Teulen MJA, Brüggemann RJM, te Brake LHM, Jager NGL. Development and validation of an UPLC-MS/MS assay for the simultaneous quantification of seven commonly used antibiotics in human plasma and its application in therapeutic drug monitoring. J Antimicrob Chemother 2024; 79:883-890. [PMID: 38416407 PMCID: PMC10984926 DOI: 10.1093/jac/dkae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/02/2024] [Indexed: 02/29/2024] Open
Abstract
OBJECTIVE To develop and validate an UPLC-MS/MS assay for simultaneous determination of the total concentration of ceftazidime, ciprofloxacin, flucloxacillin, piperacillin, tazobactam, sulfamethoxazole, N-acetyl sulfamethoxazole and trimethoprim, and the protein-unbound concentration of flucloxacillin, in human plasma to be used for research and clinical practice. METHODS Sample pretreatment included protein precipitation with methanol. For the measurement of protein-unbound flucloxacillin, ultrafiltration was performed at physiological temperature. For all compounds, a stable isotopically labelled internal standard was used. Reliability of the results was assessed by participation in an international quality control programme. RESULTS The assay was successfully validated according to the EMA guidelines over a concentration range of 0.5-100 mg/L for ceftazidime, 0.05-10 mg/L for ciprofloxacin, 0.4-125 mg/L for flucloxacillin, 0.2-60 mg/L for piperacillin, 0.15-30 mg/L for tazobactam, 1-200 mg/L for sulfamethoxazole and N-acetyl sulfamethoxazole, 0.05-10 mg/L for trimethoprim and 0.10-50 mg/L for unbound flucloxacillin. For measurement of total concentrations, the within- and between-day accuracy ranged from 90.0% to 109%, and 93.4% to 108%, respectively. Within- and between-day precision (variation coefficients, CVs) ranged from 1.70% to 11.2%, and 0.290% to 5.30%, respectively. For unbound flucloxacillin, within-day accuracy ranged from 103% to 106% and between-day accuracy from 102% to 105%. The within- and between-day CVs ranged from 1.92% to 7.11%. Results of the international quality control programme showed that the assay is reliable. CONCLUSIONS The method provided reliable, precise and accurate measurement of seven commonly prescribed antibiotics, including the unbound concentration of flucloxacillin. This method is now routinely applied in research and clinical practice.
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Affiliation(s)
- Xin Meng Mekking
- School of Pharmacy, Utrecht University, Leuvenlaan 4, 3584 CE, Utrecht, The Netherlands
| | - Kirsten Velthoven-Graafland
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Marga J A Teulen
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Lindsey H M te Brake
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
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Derijks-Engwegen JYMN, Jager NGL. Dosing and Exposure of Vancomycin With Continuous Infusion: A Retrospective Study. Clin Pharmacol Ther 2024. [PMID: 38409960 DOI: 10.1002/cpt.3221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 02/09/2024] [Indexed: 02/28/2024]
Abstract
Vancomycin continuous infusion (CI) has suggested benefits over intermittent infusion: reduced nephrotoxicity, higher target attainment, and simpler therapeutic drug monitoring (TDM). Empiric dosing regimens range from 30-60 mg/kg/day and it is unclear which regimen results in optimal exposure. This study evaluates whether a dosing regimen of 45 mg/kg/day after a 20 mg/kg loading dose for patients with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min results in adequate exposure. We retrospectively analyzed plasma concentrations from patients treated with vancomycin CI as routine clinical care between February and October 2021. Patients under 18 years old, with renal replacement therapy, reduced creatinine clearance (Chronic Kidney Disease Epidemiology Collaboration < 50 mL min/1.73 m2 ) or outpatient antibiotic therapy were excluded. Dose, renal function, and blood draw procedures were assessed for each measured vancomycin sample. Initially, 121 samples were included. Subsequently, 7 samples, 6 of which with concentrations ≥ 40 mg/L, were verified to be incorrectly drawn and excluded. With doses of 40-50 mg/kg/day concentrations ranged from 18.4-61.0 mg/L. Only 25% were within the target window of 17-25 mg/L and 15% were ≥ 40 mg/L. Supratherapeutic concentrations were observed in 89% of samples from patients dosed 40-60 mg/kg/day with eGFR 50-80 mL/min. Concluding, an empiric dosing regimen of 45 mg/kg results in too high vancomycin exposure and thus we recommend lower doses and differentiation according to renal function. Additionally, when measuring concentrations over 40 mg/L incorrect sampling must be excluded before dose adjustment and the large variability in exposure between patients, warrants the need for swift TDM.
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Affiliation(s)
| | - Nynke G L Jager
- Department of Pharmacy, Radboudumc, Nijmegen, The Netherlands
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Mouton JWA, Raaijmakers J, Botterblom M, Toonen M, ter Heine R, Smeets RL, Brüggemann RJM, te Brake L, Jager NGL. Development and validation of a bioanalytical assay for the measurement of total and unbound teicoplanin in human serum. J Antimicrob Chemother 2023; 78:2723-2730. [PMID: 37757461 PMCID: PMC10631822 DOI: 10.1093/jac/dkad290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND The glycopeptide teicoplanin is considered first-line treatment for severe infections caused by Gram-positive bacteria. Individualized treatment of teicoplanin is gaining interest. As only protein-unbound drug is pharmacologically active, a sensitive assay measuring unbound and total teicoplanin is indispensable for pharmacological research and dose optimization. OBJECTIVES To develop and validate a UPLC-MS/MS method to quantify unbound and total teicoplanin in human serum. METHODS The developed assay was validated according to the ICH guideline M10 on Bioanalytical Method Validation and study sample analysis. Unbound teicoplanin was obtained by ultrafiltration. The assay was cross-validated with a quantitative microsphere (QMS) immunoassay in a side-by-side comparison using 40 patient samples. RESULTS With the developed and validated method, all main teicoplanin components (A2-1, A2-2/A2-3, A2-4/A2-5 and A3-1) can be quantified. Total run time was 5.5 min. Concentration range was 2.5-150 mg/L for total and 0.1-25 mg/L for unbound teicoplanin. Precision (coefficient of variation) and accuracy (bias) of total teicoplanin were 5.97% and 107%, respectively, and 7.17% and 108%, respectively, for unbound teicoplanin.Bland-Altman analysis showed total concentrations measured with the UPLC-MS/MS method were equivalent to the results of the QMS immunoassay. A total of 188 samples from 30 patients admitted to the ICU and haematology department were measured; total concentrations ranged between 2.92 and 98.5 mg/L, and unbound concentrations ranged between 0.37 and 30.7 mg/L. CONCLUSIONS The developed method provided rapid, precise and accurate measurement of unbound and total teicoplanin. The developed method is now routinely applied in pharmacological research and clinical practice.
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Affiliation(s)
- J W A Mouton
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - J Raaijmakers
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M Botterblom
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M Toonen
- Department of Laboratory Medicine, Radboudumc Laboratory for Diagnostics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - R ter Heine
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - R L Smeets
- Department of Laboratory Medicine, Radboudumc Laboratory for Diagnostics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - R J M Brüggemann
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - L te Brake
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
| | - N G L Jager
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands
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Patanwala AE, Jager NGL, Radosevich JJ, Brüggemann R. An update on drug-drug interactions for care of the acutely ill in the era of COVID-19. Am J Health Syst Pharm 2023; 80:1301-1308. [PMID: 37368815 PMCID: PMC10516707 DOI: 10.1093/ajhp/zxad152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Indexed: 06/29/2023] Open
Abstract
PURPOSE To provide key pharmacological concepts underlying drug-drug interactions (DDIs), a decision-making framework, and a list of DDIs that should be considered in the context of contemporary acutely ill patients with COVID-19. SUMMARY DDIs are frequently encountered in the acutely ill. The implications of DDIs include either increased risk of drug toxicity or decreased effectiveness, which may have severe consequences in the acutely ill due to lower physiological and neurocognitive reserves in these patients. In addition, an array of additional therapies and drug classes have been used for COVID-19 that were not typically used in the acute care setting. In this update on DDIs in the acutely ill, we provide key pharmacological concepts underlying DDIs, including a discussion of the gastric environment, the cytochrome P-450 (CYP) isozyme system, transporters, and pharmacodynamics in relation to DDIs. We also provide a decision-making framework that elucidates the identification of DDIs, risk assessment, selection of alternative therapies, and monitoring. Finally, important DDIs pertaining to contemporary acute care clinical practice related to COVID-19 are discussed. CONCLUSION Interpreting and managing DDIs should follow a pharmacologically based approach and a systematic decision-making process to optimize patient outcomes.
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Affiliation(s)
- Asad E Patanwala
- Faculty of Medicine and Health, School of Pharmacy, The University of Sydney, Camperdown, New South Wales, and Department of Pharmacy, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
| | - Nynke G L Jager
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, and Radboudumc Institute for Health Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - John J Radosevich
- Department of Pharmacy Services, Dignity Health–St. Joseph’s Hospital & Medical Center, Phoenix, AZ, USA
| | - Roger Brüggemann
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, and Radboudumc Institute for Health Sciences Center of Expertise in Mycology Radboudumc/CWZ, Radboud University Medical Center, Nijmegen, the Netherlands
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Korzilius JW, Gompelman M, Wezendonk GTJ, Jager NGL, Rovers CP, Brüggemann RJM, Wanten GJA. Oral antimicrobial agents in patients with short bowel syndrome: worth a try! J Antimicrob Chemother 2023:dkad198. [PMID: 37390353 PMCID: PMC10393866 DOI: 10.1093/jac/dkad198] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023] Open
Abstract
BACKGROUND The use of oral antimicrobial agents in patients with short bowel syndrome (SBS) is challenging due to the changes in gastrointestinal anatomy that may result in diminished absorption and altered drug bioavailability. Prospective studies evaluating bioavailability of antimicrobial agents after oral administration in SBS patients are lacking. OBJECTIVES To determine the bioavailability of orally administered antimicrobial agents commonly used for treatment in SBS patients to guide clinical decision making when faced with infections. METHODS We performed an explorative, clinical study investigating the pharmacokinetics (PK) of clindamycin, ciprofloxacin, flucloxacillin and fluconazole in SBS patients with intestinal failure. Participants received a combination of two antimicrobial agents simultaneously. To determine the oral bioavailability, participants received a single oral and IV dose of both agents on two occasions, after which they underwent intensive PK sampling on six predefined time points up to 12 hours after administration. Primary outcome was the oral bioavailability of these antimicrobial agents. Secondary outcomes were intravenous PK characteristics following non-compartmental analysis. RESULTS Eighteen SBS patients were included: the mean (SD) age was 59 (17) years and 61% of participants were female. The median observed (IQR) bioavailability of ciprofloxacin, clindamycin, flucloxacillin and fluconazole were 36% (24-50), 93% (56-106), 50% (32-76) and 98% (61-107), respectively. CONCLUSION The bioavailability of selected antimicrobial agents in certain patients with SBS appeared to be better than expected, providing a feasible treatment option. Due to the large observed differences between patients, therapeutic drug monitoring should be part of the treatment to safeguard adequate exposure in all patients. TRIAL REGISTRATION Registered in the Dutch Trial Register (NL7796) and EudraCT number 2019-002587-28.
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Affiliation(s)
- Julia W Korzilius
- Department of Gastroenterology and Hepatology, Radboud university medical center, Nijmegen, the Netherlands
| | - Michelle Gompelman
- Department of Gastroenterology and Hepatology, Radboud university medical center, Nijmegen, the Netherlands
| | - Guus T J Wezendonk
- Department of Gastroenterology and Hepatology, Radboud university medical center, Nijmegen, the Netherlands
| | - Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud university medical center, Nijmegen, the Netherlands
| | - Chantal P Rovers
- Department of Internal Medicine, Division of Infectious Diseases, Radboud university medical center, Nijmegen, the Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud university medical center, Nijmegen, the Netherlands
| | - Geert J A Wanten
- Department of Gastroenterology and Hepatology, Radboud university medical center, Nijmegen, the Netherlands
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de Vroom SL, Pistorius MCM, Bijleveld YA, Geerlings SE, Mathôt RAA, van Hest RM, Jager NGL. Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Assay for the Determination of Total and Unbound Ciprofloxacin Concentrations in Human Plasma. Ther Drug Monit 2022; 44:552-557. [PMID: 35094000 DOI: 10.1097/ftd.0000000000000969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 12/11/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although unbound ciprofloxacin is responsible for antibacterial effects, assays measuring the unbound drug plasma concentrations are scarce. This study aimed to develop and validate a rapid, reproducible, and sensitive liquid chromatography-tandem mass spectrometry assay for the determination of total and unbound ciprofloxacin plasma concentrations. METHODS The determination of total ciprofloxacin concentrations required a 10 μL sample, while for unbound ciprofloxacin concentrations, it was 100 μL. Unbound ciprofloxacin was separated from protein-bound ciprofloxacin through ultrafiltration. A deuterated internal standard was used, and the sample preparation involved protein precipitation. The method was fully validated over a concentration range of 0.02-5.0 mg/L, according to the US Food and Drug Administration guidelines. In addition, its clinical application was demonstrated. RESULTS The total run time was 1.5 minutes. For total ciprofloxacin plasma concentrations, the mean accuracy ranged from 94.5% to 105.0% across the validated range, the intraday imprecision was ≤7.6%, and the interday imprecision was ≤9.8%. For unbound ciprofloxacin plasma concentrations, the mean accuracy ranged from 92.8% to 102.1% across the validated range, the intraday imprecision was ≤7.0%, and the interday imprecision was ≤9.6%. Ciprofloxacin in plasma and ultrafiltrate remained stable for at least 96 hours at room temperature, at least 4 years at -80°C, and at least 3 freeze/thaw cycles (-80°C), with a minimum interval of 24 hours. CONCLUSIONS The presented method is precise and accurate. It has been implemented in clinical care and research projects at a university hospital, permitting rapid determination of total and unbound ciprofloxacin.
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Affiliation(s)
- Suzanne L de Vroom
- Department of Internal Medicine, Division of Infectious Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Infection and Immunity (AI&II)
| | - Marcel C M Pistorius
- Department of Hospital Pharmacy, Division of Clinical Pharmacology, Amsterdam UMC, University of Amsterdam; and
| | - Yuma A Bijleveld
- Department of Hospital Pharmacy, Division of Clinical Pharmacology, Amsterdam UMC, University of Amsterdam; and
| | - Suzanne E Geerlings
- Department of Internal Medicine, Division of Infectious Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Infection and Immunity (AI&II)
| | - Ron A A Mathôt
- Department of Hospital Pharmacy, Division of Clinical Pharmacology, Amsterdam UMC, University of Amsterdam; and
| | - Reinier M van Hest
- Department of Hospital Pharmacy, Division of Clinical Pharmacology, Amsterdam UMC, University of Amsterdam; and
| | - Nynke G L Jager
- Department of Hospital Pharmacy, Division of Clinical Pharmacology, Amsterdam UMC, University of Amsterdam; and
- Department of Pharmacy, Radboud University Medical Center and Radboud Institute for Health Sciences, Nijmegen, Netherlands
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Gompelman M, Jager NGL, Wallenburg E, Brüggemann RJM, Bleeker-Rovers CP, Wanten GJA. Oral Antibiotics in Patients with Short Bowel Syndrome: Do or Don't? Eur J Drug Metab Pharmacokinet 2021; 46:821-823. [PMID: 34491533 DOI: 10.1007/s13318-021-00715-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Michelle Gompelman
- Intestinal Failure Unit, Department of Gastroenterology and Hepatology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6500 HB, Nijmegen, The Netherlands.
| | - Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eveline Wallenburg
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Internal Medicine, Division of Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chantal P Bleeker-Rovers
- Department of Internal Medicine, Division of Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Geert J A Wanten
- Intestinal Failure Unit, Department of Gastroenterology and Hepatology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6500 HB, Nijmegen, The Netherlands
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Wallenburg E, Brüggemann RJM, Roberts JA, Jager NGL, Ulldemolins M, Wilkes S, Schouten J, Chin PKL, Ter Heine R. A meta-analysis of protein binding of flucloxacillin in healthy volunteers and hospitalized patients. Clin Microbiol Infect 2021; 28:446.e1-446.e7. [PMID: 34245903 DOI: 10.1016/j.cmi.2021.06.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/21/2021] [Accepted: 06/26/2021] [Indexed: 12/18/2022]
Abstract
OBJECTIVES The aim of this study was to develop a mechanistic protein-binding model to predict the unbound flucloxacillin concentrations in different patient populations. METHODS A mechanistic protein-binding model was fitted to the data using non-linear mixed-effects modelling. Data were obtained from four datasets, containing 710 paired total and unbound flucloxacillin concentrations from healthy volunteers, non-critically ill and critically ill patients. A fifth dataset with data from hospitalized patients was used for evaluation of our model. The predictive performance of the mechanistic model was evaluated and compared with the calculation of the unbound concentration with a fixed unbound fraction of 5%. Finally, we performed a fit-for-use evaluation, verifying whether the model-predicted unbound flucloxacillin concentrations would lead to clinically incorrect dose adjustments. RESULTS The mechanistic protein-binding model predicted the unbound flucloxacillin concentrations more accurately than assuming an unbound fraction of 5%. The mean prediction error varied between -26.2% to 27.8% for the mechanistic model and between -30.8% to 83% for calculation with a fixed factor of 5%. The normalized root mean squared error varied between 36.8% and 69% respectively between 57.1% and 134%. Predicting the unbound concentration with the use of the mechanistic model resulted in 6.1% incorrect dose adjustments versus 19.4% if calculated with a fixed unbound fraction of 5%. CONCLUSIONS Estimating the unbound concentration with a mechanistic protein-binding model outperforms the calculation with the use of a fixed protein binding factor of 5%, but neither demonstrates acceptable performance. When performing dose individualization of flucloxacillin, this should be done based on measured unbound concentrations rather than on estimated unbound concentrations from the measured total concentrations. In the absence of an assay for unbound concentrations, the mechanistic binding model should be preferred over assuming a fixed unbound fraction of 5%.
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Affiliation(s)
- Eveline Wallenburg
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands.
| | - Roger J M Brüggemann
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia; Departments of Pharmacy and Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Australia; Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Nynke G L Jager
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marta Ulldemolins
- Infectious Diseases-Internal Medicine Departments, Hospital Universitari de Bellvitge, l'Hospitalet de Llobregat, Barcelona, Spain
| | - Sarah Wilkes
- Erasmus MC, University Medical Centre Rotterdam, Department of Hospital Pharmacy, Rotterdam, the Netherlands; Department of Clinical Pharmacy, Deventer Hospital, Deventer, the Netherlands
| | - Jeroen Schouten
- Department of Intensive Care, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Paul K L Chin
- Univeristy of Otago, Department of Clinical Pharmacology, Canterbury District Health Board, Christchurch, New Zealand
| | - Rob Ter Heine
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
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10
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Jager NGL, van Hest RM, Xie J, Wong G, Ulldemolins M, Brüggemann RJM, Lipman J, Roberts JA. Optimization of flucloxacillin dosing regimens in critically ill patients using population pharmacokinetic modelling of total and unbound concentrations. J Antimicrob Chemother 2021; 75:2641-2649. [PMID: 32443147 PMCID: PMC7443729 DOI: 10.1093/jac/dkaa187] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/29/2022] Open
Abstract
Background Initial appropriate anti-infective therapy is associated with improved outcomes in patients with severe infections. In critically ill patients, altered pharmacokinetic (PK) behaviour is common and known to influence the achievement of PK/pharmacodynamic targets. Objectives To describe population PK and optimized dosing regimens for flucloxacillin in critically ill patients. Methods First, we developed a population PK model, estimated between-patient variability (BPV) and identified covariates that could explain BPV through non-linear mixed-effects analysis, using total and unbound concentrations obtained from 35 adult critically ill patients treated with intermittent flucloxacillin. Second, we validated the model using external datasets from two different countries. Finally, frequently prescribed dosing regimens were evaluated using Monte Carlo simulations. Results A two-compartment model with non-linear protein binding was developed and validated. BPV of the maximum binding capacity decreased from 42.2% to 30.4% and BPV of unbound clearance decreased from 88.1% to 71.6% upon inclusion of serum albumin concentrations and estimated glomerular filtration rate (eGFR; by CKD-EPI equation), respectively. PTA (target of 100%fT>MIC) was 91% for patients with eGFR of 33 mL/min and 1 g q6h, 87% for patients with eGFR of 96 mL/min and 2 g q4h and 71% for patients with eGFR of 153 mL/min and 2 g q4h. Conclusions For patients with high creatinine clearance who are infected with moderately susceptible pathogens, therapeutic drug monitoring is advised since there is a risk of underexposure to flucloxacillin. Due to the non-linear protein binding of flucloxacillin and the high prevalence of hypoalbuminaemia in critically ill patients, dose adjustments should be based on unbound concentrations.
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Affiliation(s)
- Nynke G L Jager
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia.,Department of Pharmacy, Radboud University Medical Center and Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Reinier M van Hest
- Department of Hospital Pharmacy - Clinical Pharmacology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jiao Xie
- Department of Pharmacy, The Second Affiliated Hospital of Xi'an Jiaotong University, Shaanxi, China
| | - Gloria Wong
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia
| | - Marta Ulldemolins
- Internal Medicine - Infectious Diseases Departments, Hospital Universitari de Bellvitge, l'Hospitalet de Llobregat, Spain
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud University Medical Center and Radboud Institute for Health Sciences, Nijmegen, The Netherlands
| | - Jeffrey Lipman
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia.,Departments of Pharmacy (J.A.R.) and Intensive Care (J.L.), Royal Brisbane and Women's Hospital, Brisbane, Australia.,Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia.,Departments of Pharmacy (J.A.R.) and Intensive Care (J.L.), Royal Brisbane and Women's Hospital, Brisbane, Australia.,Nîmes University Hospital, University of Montpellier, Nîmes, France.,Centre for Translational Anti-infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, Australia
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de Vroom SL, van Hest RM, van Daalen FV, Kuil SD, Mathôt RAA, Geerlings SE, Jager NGL. Pharmacokinetic/pharmacodynamic target attainment of ciprofloxacin in adult patients on general wards with adequate and impaired renal function. Int J Antimicrob Agents 2020; 56:106166. [PMID: 32941947 DOI: 10.1016/j.ijantimicag.2020.106166] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/05/2020] [Accepted: 09/10/2020] [Indexed: 01/01/2023]
Abstract
Limited prospective data on pharmacokinetic/pharmacodynamic (PK/PD) target attainment of ciprofloxacin in patients with adequate and impaired renal function (eGFR <30 mL/min/1.73m2) are available in the literature. We aimed to investigate whether the PK/PD target (AUC/MIC ≥125) is attained in patients with adequate and impaired renal function receiving regular and reduced ciprofloxacin doses. This prospective observational cohort study included adult patients on general wards treated with ciprofloxacin. Three blood samples per patient were obtained for ciprofloxacin concentration measurement. Individual AUCs were calculated using a population PK model developed by non-linear mixed-effects modelling. Forty patients were included, of whom eight had impaired renal function and were treated with a guideline-recommended reduced dose. Using the clinical breakpoint MIC of the most isolated bacteria (Escherichia coli, 0.25 mg/L), AUC0-24/MIC ≥125 was attained in 13/32 (41%) patients with adequate renal function receiving regular doses and in 1/8 (13%) patients with impaired renal function receiving reduced doses. Median drug exposure (AUC0-24) for patients with impaired renal function was 19.0 [interquartile range (IQR) 14.2-23.3] mg/L•h, which was statistically significantly lower than that for patients with adequate renal function [29.3 (IQR 25.0-36.0) mg/L•h] (P < 0.01). AUC0-24/MIC ≥125 is not attained in the majority of adult patients on general wards for clinically relevant bacteria with MICs at or just below the clinical breakpoint. The risk of not attaining the target appears to be highest in patients with impaired renal function receiving guideline-recommended reduced doses, as drug exposure is significantly lower in these patients.
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Affiliation(s)
- Suzanne L de Vroom
- Amsterdam UMC, University of Amsterdam, Department of Internal Medicine, Division of Infectious Diseases, Amsterdam Infection and Immunity (AI&II), Meibergdreef 9, Amsterdam, Netherlands.
| | - Reinier M van Hest
- Amsterdam UMC, University of Amsterdam, Department of Hospital Pharmacy, Division of Clinical Pharmacology, Meibergdreef 9, Amsterdam, Netherlands.
| | - Frederike V van Daalen
- Amsterdam UMC, University of Amsterdam, Department of Internal Medicine, Division of Infectious Diseases, Amsterdam Infection and Immunity (AI&II), Meibergdreef 9, Amsterdam, Netherlands
| | - Sacha D Kuil
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Ron A A Mathôt
- Amsterdam UMC, University of Amsterdam, Department of Hospital Pharmacy, Division of Clinical Pharmacology, Meibergdreef 9, Amsterdam, Netherlands
| | - Suzanne E Geerlings
- Amsterdam UMC, University of Amsterdam, Department of Internal Medicine, Division of Infectious Diseases, Amsterdam Infection and Immunity (AI&II), Meibergdreef 9, Amsterdam, Netherlands
| | - Nynke G L Jager
- Amsterdam UMC, University of Amsterdam, Department of Hospital Pharmacy, Division of Clinical Pharmacology, Meibergdreef 9, Amsterdam, Netherlands; Radboud University Medical Center, Department of Hospital Pharmacy, Geert Grooteplein 10, Nijmegen, the Netherlands
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12
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Lubout CMA, Goorden SMI, van den Hurk K, Jaeger B, Jager NGL, van Koningsbruggen S, Chegary M, van Karnebeek CDM. Successful Treatment of Hereditary Folate Malabsorption With Intramuscular Folinic Acid. Pediatr Neurol 2020; 102:62-66. [PMID: 31371121 DOI: 10.1016/j.pediatrneurol.2019.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/08/2019] [Accepted: 06/12/2019] [Indexed: 01/28/2023]
Abstract
BACKGROUND Hereditary folate malabsorption is a multisystem disease owing to biallelic variants in the gene encoding the proton-coupled folate transporter. Hereditary folate malabsorption is treated with folinic acid, aimed to restore blood and cerebrospinal fluid folate levels. Little is known as to whether oral or intramuscular supplementation of folinic acid is most effective. METHODS Here we describe a one-year-old boy with hereditary folate malabsorption presenting with the typical features including failure to thrive, aphthous stomatitis, macrocytic anemia along with severe developmental impairment and epilepsy, as well as a magnetic resonance imaging of the brain showing bilateral occipital, cortical calcifications characteristic of hereditary folate malabsorption. We compared the effect of treatment with oral folinic acid versus intramuscular folinic acid supplementation by measuring plasma and cerebrospinal fluid folate levels. RESULTS Compared with oral administration, intramuscular treatment resulted in higher folate levels in blood and, most importantly, normalization of folate levels in cerebrospinal fluid. Clinically, nearly all systemic and neurological symptoms resolved. CONCLUSION Normal cerebrospinal fluid folate levels can be achieved in individuals with hereditary folate malabsorption with intramuscular (but not with oral) administration of folinic acid.
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Affiliation(s)
- Charlotte M A Lubout
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital, Amsterdam Gastro-Enterology & Metabolism Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Susanna M I Goorden
- Department of Clinical Chemistry, Laboratory of Genetic Metabolic Diseases, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Karin van den Hurk
- Department of Clinical Chemistry, OLVG Lab BV, Amsterdam, The Netherlands
| | - Bregje Jaeger
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Nynke G L Jager
- Department of Clinical Pharmacology and Pharmacy, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | | | - Malika Chegary
- Department of Pediatrics, OLVG, Amsterdam, The Netherlands
| | - Clara D M van Karnebeek
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital, Amsterdam Gastro-Enterology & Metabolism Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands; Department of Clinical Genetics, Amsterdam University Medical Centres, Amsterdam, The Netherlands.
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13
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Jager NGL, van Hest RM, Lipman J, Roberts JA, Cotta MO. Antibiotic exposure at the site of infection: principles and assessment of tissue penetration. Expert Rev Clin Pharmacol 2019; 12:623-634. [PMID: 31136211 DOI: 10.1080/17512433.2019.1621161] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: Since the majority of bacterial infections occur at sites outside the bloodstream, antibiotic tissue concentrations are of significant relevance to optimize treatment. The aim of this review is to aid the clinician in choosing optimal regimens for the treatment of extravascular infections. Areas covered: We discuss the principles of antibiotic tissue penetration and assess different approaches to obtain data on this subject. Finally, we present tissue penetration data for several relevant groups of antibiotic agents in a number of extravascular sites. Data were obtained from an extensive literature search in PubMed until February 2019. Expert opinion: There is still a long way to go before reliable information about tissue penetration of antibiotics is sufficiently available to serve as a basis for the design of optimal strategies for drug and dose selection. At this moment, there is a lack of robust data on tissue penetration, where both the sampling and measurement techniques as well as the relationship between tissue concentrations and clinical outcome of antibiotic treatment have to be better defined.
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Affiliation(s)
- Nynke G L Jager
- a University of Queensland Centre for Clinical Research, The University of Queensland , Brisbane , Australia.,b Department of Hospital Pharmacy - Clinical Pharmacology Unit, Amsterdam UMC , University of Amsterdam , Amsterdam , the Netherlands
| | - Reinier M van Hest
- b Department of Hospital Pharmacy - Clinical Pharmacology Unit, Amsterdam UMC , University of Amsterdam , Amsterdam , the Netherlands
| | - Jeffrey Lipman
- a University of Queensland Centre for Clinical Research, The University of Queensland , Brisbane , Australia.,c Departments of Pharmacy and Intensive Care , Royal Brisbane and Women's Hospital , Brisbane , Australia
| | - Jason A Roberts
- a University of Queensland Centre for Clinical Research, The University of Queensland , Brisbane , Australia.,c Departments of Pharmacy and Intensive Care , Royal Brisbane and Women's Hospital , Brisbane , Australia.,d Centre for Translational Anti-infective Pharmacodynamics, School of Pharmacy , The University of Queensland , Brisbane , Australia
| | - Menino O Cotta
- a University of Queensland Centre for Clinical Research, The University of Queensland , Brisbane , Australia.,d Centre for Translational Anti-infective Pharmacodynamics, School of Pharmacy , The University of Queensland , Brisbane , Australia
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Jager NGL, Zandvliet AS, Touw DJ, Penne EL. Optimization of anti-infective dosing regimens during online haemodiafiltration. Clin Kidney J 2017; 10:282-290. [PMID: 28396747 PMCID: PMC5381234 DOI: 10.1093/ckj/sfx009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 12/30/2016] [Indexed: 12/13/2022] Open
Abstract
Online haemodiafiltration (HDF) is increasingly used in clinical practice as a routine intermittent dialysis modality. It is well known that renal impairment and renal replacement therapy can substantially affect the pharmacokinetic behaviour of several drugs. However, surprisingly few data are available on the need for specific dose adjustments during HDF. Due to convection, drug clearance may be increased during HDF as compared with standard haemodialysis. This may be of particular interest in patients undergoing anti-infective therapy, since under-dosing may compromise patient outcomes and promote the emergence of bacterial resistance. Drug clearance during HDF is determined by (i) dialysis characteristics, (ii) drug characteristics and (iii) patient characteristics. In this review, we will discuss these different determinants of drug clearance during HDF and advise on how to adjust the dose of antibacterial, antimycotic and antiviral agents in patients undergoing HDF. In addition, the possible added value of therapeutic drug monitoring is discussed. The review provides guidance for optimization of anti-infective dosing regimens in HDF patients.
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Affiliation(s)
- Nynke G L Jager
- Department of Clinical Pharmacy, Northwest Clinics, Alkmaar, The Netherlands; Department of Clinical Pharmacology and Pharmacy, Academic Medical Centre, Amsterdam, The Netherlands
| | - Anthe S Zandvliet
- Department of Clinical Pharmacology and Pharmacy, VU Medical Centre, Amsterdam, The Netherlands
| | - Daniel J Touw
- Department of Clinical Pharmacy and Pharmacology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Erik L Penne
- Department of Internal Medicine, Northwest Clinics, Alkmaar, The Netherlands
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Jager NGL, van Hest RM, Lipman J, Taccone FS, Roberts JA. Therapeutic drug monitoring of anti-infective agents in critically ill patients. Expert Rev Clin Pharmacol 2016; 9:961-79. [PMID: 27018631 DOI: 10.1586/17512433.2016.1172209] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Initial adequate anti-infective therapy is associated with significantly improved clinical outcomes for patients with severe infections. However, in critically ill patients, several pathophysiological and/or iatrogenic factors may affect the pharmacokinetics of anti-infective agents leading to suboptimal drug exposure, in particular during the early phase of therapy. Therapeutic drug monitoring (TDM) may assist to overcome this problem. We discuss the available evidence on the use of TDM in critically ill patient populations for a number of anti-infective agents, including aminoglycosides, β-lactams, glycopeptides, antifungals and antivirals. Also, we present the available evidence on the practices of anti-infective TDM and describe the potential utility of TDM to improve treatment outcome in critically ill patients with severe infections. For aminoglycosides, glycopeptides and voriconazole, beneficial effects of TDM have been established on both drug effectiveness and potential side effects. However, for other drugs, therapeutic ranges need to be further defined to optimize treatment prescription in this setting.
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Affiliation(s)
- Nynke G L Jager
- a Department of Pharmacy , Academic Medical Center , Amsterdam , The Netherlands
| | - Reinier M van Hest
- a Department of Pharmacy , Academic Medical Center , Amsterdam , The Netherlands
| | - Jeffrey Lipman
- b Burns Trauma and Critical Care Research Centre , The University of Queensland , Brisbane , Australia.,c Departments of Pharmacy and Intensive Care , Royal Brisbane and Women's Hospital , Brisbane , Australia
| | - Fabio S Taccone
- d Department of Intensive Care, Hopital Erasme , Université Libre de Bruxelles (ULB) , Brussels , Belgium
| | - Jason A Roberts
- b Burns Trauma and Critical Care Research Centre , The University of Queensland , Brisbane , Australia.,c Departments of Pharmacy and Intensive Care , Royal Brisbane and Women's Hospital , Brisbane , Australia.,e School of Pharmacy , The University of Queensland , Brisbane , Australia
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Jager NGL, Linn SC, Schellens JHM, Beijnen JH. Tailored Tamoxifen Treatment for Breast Cancer Patients: A Perspective. Clin Breast Cancer 2015; 15:241-4. [PMID: 25997856 DOI: 10.1016/j.clbc.2015.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/01/2015] [Accepted: 04/16/2015] [Indexed: 11/20/2022]
Abstract
Tamoxifen, an endocrine agent, is widely used in the treatment of estrogen receptor-positive breast cancer. It has greatly reduced disease recurrence and mortality rates of breast cancer patients, however, not all patients benefit from tamoxifen treatment because in approximately 25% to 30% of the patients the disease recurs. Many researchers have sought to find factors associated with endocrine treatment outcome in the past years, however, this quest has not been finished. In this article, we focus on a factor that might influence outcome of tamoxifen treatment: interpatient variability in tamoxifen pharmacokinetics. In recent years it has become clear that tamoxifen undergoes extensive metabolism and that some of the formed metabolites are much more pharmacologically active than tamoxifen itself. Despite the wide interpatient variability in tamoxifen pharmacokinetics and pharmacodynamics, all patients receive a standard dose of 20 mg tamoxifen per day. Different approaches can be pursued to individualize tamoxifen dosing: genotyping, phenotyping, and therapeutic drug monitoring. Therapeutic drug monitoring seems to be the most direct and promising approach, however, further clinical research is warranted to establish the added value of individual dosing in tamoxifen treatment optimization.
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Affiliation(s)
- Nynke G L Jager
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, The Netherlands.
| | - Sabine C Linn
- Department of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jan H M Schellens
- Department of Clinical Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Faculty of Science, Utrecht Institute of Pharmaceutical Sciences (UIPS), Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands
| | - Jos H Beijnen
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, The Netherlands; Department of Clinical Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Faculty of Science, Utrecht Institute of Pharmaceutical Sciences (UIPS), Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands
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Jager NGL, Stuurman FE, Baars JW, Opdam FL. Cerebrovascular events during nilotinib treatment. Neth J Med 2014; 72:113-114. [PMID: 24659599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- N G L Jager
- Department of Clinical Pharmacology, Antoni van Leeuwenhoek, Amsterdam, the Netherlands
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18
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Jager NGL, Rosing H, Schellens JHM, Linn SC, Beijnen JH. Tamoxifen dose and serum concentrations of tamoxifen and six of its metabolites in routine clinical outpatient care. Breast Cancer Res Treat 2014; 143:477-83. [PMID: 24390246 DOI: 10.1007/s10549-013-2826-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 12/23/2013] [Indexed: 12/01/2022]
Abstract
A sensitive and selective HPLC-MS/MS assay was used to analyze steady-state serum concentrations of tamoxifen, N-desmethyltamoxifen (E)-endoxifen, (Z)-endoxifen, N-desmethyl-4'-hydroxytamoxifen, 4-hydroxytamoxifen, and 4'-hydroxytamoxifen to support therapeutic drug monitoring (TDM) in patients treated with tamoxifen according to standard of care. When the (Z)-endoxifen serum concentration was below the predefined therapeutic threshold concentration of 5.9 ng/mL, the clinician was advised to increase the tamoxifen dose and to collect another serum sample. Paired serum samples from patients at one dose level at different time points during the tamoxifen treatment were used to assess the intra-patient variability. A total of 251 serum samples were analyzed, obtained from 205 patients. Of these patients, 197 used 20 mg tamoxifen per day and 8 patients used 10 mg/day. There was wide variability in tamoxifen and metabolite concentrations within the dosing groups. The threshold concentration for (Z)-endoxifen was reached in one patient (12 %) in the 10 mg group, in 153 patients (78 %) in the 20 mg group, and in 26 (96 %) of the patients who received a dose increase to 30 or 40 mg/day. Dose increase from 20 to 30 or 40 mg per day resulted in a significant increase in the mean serum concentrations of all analytes (p < 0.001). The mean intra-patient variability was between 10 and 20 % for all analytes. These results support the suitability of TDM for optimizing the tamoxifen treatment. It is shown that tamoxifen dose is related to (Z)-endoxifen exposure and increasing this dose leads to a higher serum concentration of tamoxifen and its metabolites. The low intra-patient variability suggests that only one serum sample is needed for TDM, making this a relatively noninvasive way to optimize the patient's treatment.
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Affiliation(s)
- N G L Jager
- Department of Pharmacy and Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Louwesweg 6, 1066 EC, Amsterdam, The Netherlands,
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Jager NGL, Koornstra RHT, Vincent AD, van Schaik RHN, Huitema ADR, Korse TM, Schellens JHM, Linn SC, Beijnen JH. Hot flashes are not predictive for serum concentrations of tamoxifen and its metabolites. BMC Cancer 2013; 13:612. [PMID: 24373320 PMCID: PMC3880169 DOI: 10.1186/1471-2407-13-612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 12/16/2013] [Indexed: 01/01/2023] Open
Abstract
Background Tamoxifen has dramatically reduced the recurrence and mortality rate of estrogen receptor positive breast cancer. However, the efficacy of tamoxifen varies between individuals and 40% of patients will have a recurrence despite adjuvant tamoxifen treatment. Factors that predict tamoxifen efficacy would be helpful for optimizing treatment. Serum concentrations of the active metabolite, endoxifen, may be positively related to treatment outcome. In addition, hot flashes are suggested to be positively associated with tamoxifen treatment outcome. Methods We investigated in a series of 109 patients whether the frequency and severity of hot flashes were related to concentrations of tamoxifen and its metabolites. A serum sample of all patients was analyzed for the concentration of tamoxifen, N-desmethyltamoxifen, endoxifen and 4-hydroxytamoxifen, as well as for estradiol concentrations and several single nucleotide polymorphisms in CYP2D6. Additionally, these patients completed a questionnaire concerning biometric data and treatment side effects. Results We found no evidence supporting an association between concentrations of tamoxifen or metabolites and either the frequency or severity of hot flashes in the covariate unadjusted analyses. However, including interactions with menopausal status and pre-treatment hot flash (PTHF) history indicated that post-menopausal women with PTHF experienced an increasing frequency of hot flashes with increasing serum concentrations of tamoxifen and its metabolites. This finding was not altered when adjusting for potential confounding factors (duration of tamoxifen treatment, CYP2D6 phenotype, estradiol serum concentration, age and body mass index). In addition we observed a positive association between body mass index and both hot flash frequency (p = 0.04) and severity (p < 0.0001). We also observed that patients with lower estradiol levels reported more severe hot flashes (p = 0.02). Conclusions No univariate associations were observed between concentrations of active tamoxifen metabolites and either the frequency or severity of hot flashes during treatment. However, the frequency of hot flashes may be exacerbated by higher serum concentrations of tamoxifen and its metabolites in post-menopausal women with a history of hot flashes prior to tamoxifen treatment.
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Affiliation(s)
- Nynke G L Jager
- Department of Pharmacy & Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Louwesweg 6, 1066 EC Amsterdam, The Netherlands.
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Dorlo TPC, Jager NGL, Beijnen JH, Schellens JHM. [Concomitant use of proton pump inhibitors and systemic corticosteroids]. Ned Tijdschr Geneeskd 2013; 157:A5540. [PMID: 23657097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVE To provide an overview of the incidence of peptic ulcer in patients who use systemic corticosteroids and of the underlying mechanism of action, in order to determine whether there is a need for gastric protection using proton pump inhibitors in these patients. DESIGN Systematic literature review of published meta-analyses and case-control studies, supported by relevant literature on the effects of corticosteroids in relation to the development of ulcers. METHOD Analysis of literature was performed using the PubMed database with the search terms 'adrenal cortex hormones', 'peptic ulcer' and their synonyms. Meta-analyses and case-control studies with more than 1000 patients were included. RESULTS The literature search resulted in 970 articles, of which 3 were classified as relevant meta-analyses and 3 as relevant case-control studies. All meta-analyses indicated that peptic ulcer is, at the most, a rare complication of systemic corticosteroid therapy occurring in less than 0.4-1.8% of patients. As the incidence is low, there is no indication for routine prophylaxis with proton pump inhibitors in combination with systemic corticosteroids. There is convincing evidence showing an increased risk of ulcers and a poorer recovery from these when NSAIDs and systemic corticosteroids are used concomitantly; this is a combination for which a proton pump inhibitor should be prescribed. CONCLUSION Systemic corticosteroid therapy only rarely causes a peptic ulcer. Routine prophylaxis with proton pump inhibitors is therefore not indicated for short-term systemic corticosteroid use.
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Affiliation(s)
- Thomas P C Dorlo
- Nederlands Kanker Instituut-Antoni van Leeuwenhoek Ziekenhuis en Slotervaartziekenhuis, Afd. Apotheek, Amsterdam, the Netherlands
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Teunissen SF, Jager NGL, Rosing H, Schinkel AH, Schellens JHM, Beijnen JH. Development and validation of a quantitative assay for the determination of tamoxifen and its five main phase I metabolites in human serum using liquid chromatography coupled with tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:1677-85. [PMID: 21543272 DOI: 10.1016/j.jchromb.2011.04.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 03/28/2011] [Accepted: 04/03/2011] [Indexed: 11/26/2022]
Abstract
A sensitive bioanalytical assay for the quantitative determination of tamoxifen and five of its phase I metabolites (N-desmethyltamoxifen, N-desmethyl-4-hydroxytamoxifen, N-desmethyl-4'-hydroxytamoxifen, 4-hydroxytamoxifen and 4'-hydroxytamoxifen) in serum is described. The method has been fully validated at ranges covering steady-state serum concentrations in patients receiving therapeutic dosages of tamoxifen. The bioanalytical assay is based on reversed phase liquid chromatography coupled with tandem mass spectrometry in the positive ion mode using multiple reaction monitoring for drug (-metabolite) quantification. The sample pretreatment consists of protein precipitation with acetonitrile using only 50 μL of serum. In the past, numerous assays have been developed by other groups for the quantification of tamoxifen and its phase I metabolites. However, the number of metabolites included in these studies is very limited and only very few of these assays have been fully validated. A liquid chromatography tandem mass spectrometry assay for the quantification of tamoxifen and four phase I metabolites in human serum that was previously developed by our group is now explicitly improved and described herein. Time of analysis has been reduced by 50% and sensitivity was increased by a reduction of the lower limit of quantification from 1.0 to 0.2 ng/mL for 4-hydroxytamoxifen and 4'-hydroxytamoxifen. Additionally, two phase I metabolites that have never been quantified in human serum hitherto, namely 4'-hydroxytamoxifen and N-desmethyl-4'-hydroxytamoxifen, were included in this assay. Validation results demonstrate an accurate and precise quantification of tamoxifen, N-desmethyltamoxifen, N-desmethyl-4-hydroxytamoxifen, N-desmethyl-4'-hydroxytamoxifen, 4-hydroxytamoxifen and 4'-hydroxytamoxifen in human serum. The applicability of the assay was demonstrated and it is now successfully used to support clinical studies in which patient-specific dose optimization is performed based on serum concentrations of tamoxifen metabolites.
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Affiliation(s)
- S F Teunissen
- Department of Pharmacy & Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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