The Experts below are selected from a list of 16185 Experts worldwide ranked by ideXlab platform
Leo M L Stolk - One of the best experts on this subject based on the ideXlab platform.
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therapeutic drug monitoring of everolimus using the Dried Blood Spot method in combination with liquid chromatography mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2009Co-Authors: J Van Der Heijden, Karin Hoogtanders, M H L Christiaans, Y M De Beer, G J De Jong, Cees Neef, Leo M L StolkAbstract:An assay of everolimus based on finger prick sampling and consecutive application as a Blood Spot on sampling paper has been developed. We explored several methods [K. Hoogtanders, J. van der Heijden, M. Christiaans, P. Edelbroek, J. van Hooff, L. Stolk, J. Pharm. Biomed. Anal. 44 (2006) 658-664; A. Allanson, M. Cotton, J. Tettey, et al., J. Pharm. Biomed. Anal. 44 (2007) 963-969] and developed a new method, namely the impregnation of sampling paper with a solution of plasma-protein, formic acid and ammonium acetate, in combination with the extraction of the Blood Spot by filter filtration. This kind of sample preparation provides new possibilities for Blood Spot sampling especially if analytes are adsorbed to the paper. The Dried Blood Spot was analysed using the HPLC-electrospray-tandem mass spectrometry method, with 32-desmethoxyrapamycin as the internal standard. The working range of our study was 2-30 microg/l. Within this range, intra-and inter-assay variability for precision and accuracy was <15%. Everolimus Blood Spot samples proved stable for 3 days at 60 degrees C and for 32 days at 4 degrees C. Everolimus concentrations of one stable out-patient were compared after both Blood Spot sampling and conventional venous sampling on various occasions. Results indicate that this new method is promising for therapeutic drug monitoring in stable renal transplant patients.
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Dried Blood Spot methods in therapeutic drug monitoring methods assays and pitfalls
Therapeutic Drug Monitoring, 2009Co-Authors: P Edelbroek, Jacques Van Der Heijden, Leo M L StolkAbstract:This article reviews Dried Blood Spot (DBS) sampling in therapeutic drug monitoring. The DBS method involves applying whole Blood obtained via a fingerprick to a sampling paper. After drying and transportation, the Blood Spot is extracted and analyzed in the laboratory. Assays of many medicines in DBS have already been reported in the literature and are reviewed here. The technique involved in and factors that may influence the accuracy and reproducibility of DBS methods are also discussed. DBS sampling ultimately seems to be a useful technique for therapeutic drug monitoring that could have many advantages in comparison with conventional venous sampling. However, its benefits must be weighed against the degree of potential errors introduced via the sampling method; there is evidently a need for more standardization, quality assurance, basic research, and assay development.
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therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method
Journal of Pharmaceutical and Biomedical Analysis, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was <7.5% and 15%, respectively. Tacrolimus concentrations of 24 stable out patients were compared after both Blood Spot sampling and conventional venous sampling. Method agreement was investigated with the methods of Passing and Bablok and Bland Altman and proved suitable for clinical use. The Dried Blood Spot method for tacrolimus seems promising for patient monitoring.
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Dried Blood Spot measurement of tacrolimus is promising for patient monitoring
Transplantation, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, J P Van Hooff, Afke Van De Plas, Leo M L StolkAbstract:The usefulness of Dried Blood Spot (DBS) sampling for therapeutic drug monitoring of tacrolimus was investigated with renal transplant patients. There was no significant difference between the concentrations (ranging 3.33-53.9 mug/l) of 34 samples of 26 stable renal transplant outpatients, measured both after venous and DBS sampling. DBS sampling is easy to perform because concentrations with and without nurse assistance did not significantly differ. No significant difference was found between tacrolimus concentrations in 20 duplicate DBS samples before and after postal transport. DBS seems promising for routine patient monitoring.
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Therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method.
Journal of pharmaceutical and biomedical analysis, 2006Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was
Jan-willem C. Alffenaar - One of the best experts on this subject based on the ideXlab platform.
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Dried Blood Spot validation of five immunosuppressants without hematocrit correction on two lc ms ms systems
Bioanalysis, 2017Co-Authors: Remco A. Koster, Jan-willem C. Alffenaar, Herman Veenhof, Rixt Botma, Alle Tjipke Hoekstra, Stefan P Berger, Stephan J L Bakker, Daan J TouwAbstract:Aim: Hematocrit (Ht) effects remain a challenge in Dried Blood Spot (DBS) sampling. The aim was to develop an immunosuppressant DBS assay on two LC–MS/MS systems covering a clinically relevant Ht range without Ht correction. Results: The method was partially validated for tacrolimus, sirolimus, everolimus, cyclosporin A and fully validated for mycophenolic acid on an Agilent and Thermo LC–MS/MS system. Bias caused by Ht effects were within 15% for all immunosuppressants between Ht levels of 0.23 and 0.48 l/l. Clinical validation of DBS versus whole Blood samples for tacrolimus and cyclosporin A showed no differences between the two matrices. Conclusion: A multiple immunosuppressant DBS method without Ht correction, has been validated, including a clinical validation for tacrolimus and cyclosporin A, making this procedure suitable for home sampling.
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what is the right Blood hematocrit preparation procedure for standards and quality control samples for Dried Blood Spot analysis
Bioanalysis, 2015Co-Authors: Remco A. Koster, Jan-willem C. Alffenaar, Rixt Botma, Daan J Touw, Ben Greijdanus, Donald R A Uges, Jos G W KosterinkAbstract:Remco Koster is a research analyst and PhD candidate at the University Medical Center Groningen and University of Groningen. He has been working in the field of bioanalysis for over 13 years, where he has developed numerous analytical methods using LC-MS/MS. His main research focus is the influence of various matrices on the development and performance of analytical methods using LC-MS/MS. The development of high-speed extraction and analysis methods for drugs and drugs of abuse in human matrices like Blood, plasma, hair, saliva and Dried Blood Spots often leads to improved procedures for preparation of standards and quality control samples, sample handling and validation. Two hematocrit preparation procedures for standards and quality control samples were evaluated in order to improve the quality of procedures for Dried Blood Spot validation and analysis.
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Role of therapeutic drug monitoring in pulmonary infections: use and potential for expanded use of Dried Blood Spot samples
Bioanalysis, 2015Co-Authors: Susan Hofman, Mathieu S. Bolhuis, Remco A. Koster, Onno W. Akkerman, Sander Van Assen, Christophe P. Stove, Jan-willem C. AlffenaarAbstract:Respiratory tract infections are among the most common infections in men. We reviewed literature to document their pharmacological treatments, and the extent to which therapeutic drug monitoring (TDM) is needed during treatment. We subsequently examined potential use of Dried Blood Spots as sample procedure for TDM. TDM was found to be an important component of clinical care for many (but not all) pulmonary infections. For gentamicin, linezolid, voriconazole and posaconazole Dried Blood Spot methods and their use in TDM were already evident in literature. For glycopeptides, β-lactam antibiotics and fluoroquinolones it was determined that development of a Dried Blood Spot (DBS) method could be useful. This review identifies specific antibiotics for which development of DBS methods could support the optimization of treatment of pulmonary infections.
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Dried Blood Spot analysis suitable for therapeutic drug monitoring of voriconazole fluconazole and posaconazole
Antimicrobial Agents and Chemotherapy, 2013Co-Authors: Kim C M Van Der Elst, Ben Greijdanus, Jos G W Kosterink, Lambert F R Span, Kai Van Hateren, Karin M Vermeulen, Tjip S Van Der Werf, D R A Uges, Jan-willem C. AlffenaarAbstract:Invasive aspergillosis and candidemia are important causes of morbidity and mortality in immunocompromised and critically ill patients. The triazoles voriconazole, fluconazole, and posaconazole are widely used for the treatment and prophylaxis of these fungal infections. Due to the variability of the pharmacokinetics of the triazoles among and within individual patients, therapeutic drug monitoring is important for optimizing the efficacy and safety of antifungal treatment. A Dried Blood Spot (DBS) analysis was developed and was clinically validated for voriconazole, fluconazole, and posaconazole in 28 patients. Furthermore, a questionnaire was administered to evaluate the patients' opinions of the sampling method. The DBS analytical method showed linearity over the concentration range measured for all triazoles. Results for accuracy and precision were within accepted ranges; samples were stable at room temperature for at least 12 days; and different hematocrit values and Blood Spot volumes had no significant influence. The ratio of the drug concentration in DBS samples to that in plasma was 1.0 for voriconazole and fluconazole and 0.9 for posaconazole. Sixty percent of the patients preferred DBS analysis as a sampling method; 15% preferred venous Blood sampling; and 25% had no preferred method. There was significantly less perception of pain with the DBS sampling method (P = 0.021). In conclusion, DBS analysis is a reliable alternative to venous Blood sampling and can be used for therapeutic drug monitoring of voriconazole, fluconazole, and posaconazole. Patients were satisfied with DBS sampling and had less pain than with venous sampling. Most patients preferred DBS sampling to venous Blood sampling.
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Dried Blood Spot analysis for therapeutic drug monitoring of linezolid in patients with multidrug resistant tuberculosis
Antimicrobial Agents and Chemotherapy, 2012Co-Authors: Mathieu S. Bolhuis, Remco A. Koster, Ben Greijdanus, D R A Uges, W C M De Lange, R Van Altena, Jacobus Brouwers, Jan-willem C. AlffenaarAbstract:Linezolid is a promising antimicrobial agent for the treatment of multidrug-resistant tuberculosis (MDR-TB), but its use is limited by toxicity. Therapeutic drug monitoring (TDM) may help to minimize toxicity while adequate drug exposure is maintained. Conventional plasma sampling and monitoring might be hindered in many parts of the world by logistical problems that may be solved by Dried Blood Spot (DBS) sampling. The aim of this study was to develop and validate a novel method for TDM of linezolid in MDR-TB patients using DBS sampling. Plasma, venous DBS, and capillary DBS specimens were obtained simultaneously from eight patients receiving linezolid. A DBS sampling method was developed and clinically validated by comparing DBS with plasma results using Passing-Bablok regression and Bland-Altman analysis. This study showed that DBS analysis was reproducible and robust. Accuracy and between- and within-day precision values from three validations presented as bias and coefficient of variation (CV) were less than 17.2% for the lower limit of quantification and less than 7.8% for other levels. The method showed a high recovery of approximately 95% and a low matrix effect of less than 8.7%. DBS specimens were stable at 37°C for 2 months and at 50°C for 1 week. The ratio of the concentration of linezolid in DBS samples to that in plasma was 1.2 (95% confidence interval [CI], 1.12 to 1.27). Linezolid exposure calculated from concentrations DBS samples and plasma showed good agreement. In conclusion, DBS analysis of linezolid is a promising tool to optimize linezolid treatment in MDR-TB patients. An easy sampling procedure and high sample stability may facilitate TDM, even in underdeveloped countries with limited resources and where conventional plasma sampling is not feasible.
Karin Hoogtanders - One of the best experts on this subject based on the ideXlab platform.
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therapeutic drug monitoring of everolimus using the Dried Blood Spot method in combination with liquid chromatography mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2009Co-Authors: J Van Der Heijden, Karin Hoogtanders, M H L Christiaans, Y M De Beer, G J De Jong, Cees Neef, Leo M L StolkAbstract:An assay of everolimus based on finger prick sampling and consecutive application as a Blood Spot on sampling paper has been developed. We explored several methods [K. Hoogtanders, J. van der Heijden, M. Christiaans, P. Edelbroek, J. van Hooff, L. Stolk, J. Pharm. Biomed. Anal. 44 (2006) 658-664; A. Allanson, M. Cotton, J. Tettey, et al., J. Pharm. Biomed. Anal. 44 (2007) 963-969] and developed a new method, namely the impregnation of sampling paper with a solution of plasma-protein, formic acid and ammonium acetate, in combination with the extraction of the Blood Spot by filter filtration. This kind of sample preparation provides new possibilities for Blood Spot sampling especially if analytes are adsorbed to the paper. The Dried Blood Spot was analysed using the HPLC-electrospray-tandem mass spectrometry method, with 32-desmethoxyrapamycin as the internal standard. The working range of our study was 2-30 microg/l. Within this range, intra-and inter-assay variability for precision and accuracy was <15%. Everolimus Blood Spot samples proved stable for 3 days at 60 degrees C and for 32 days at 4 degrees C. Everolimus concentrations of one stable out-patient were compared after both Blood Spot sampling and conventional venous sampling on various occasions. Results indicate that this new method is promising for therapeutic drug monitoring in stable renal transplant patients.
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Dried Blood Spot measurement application in tacrolimus monitoring using limited sampling strategy and abbreviated auc estimation
Transplant International, 2007Co-Authors: Chi Yuen Cheung, Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, Afke Van De Plas, Yan Lun Liu, Yiu Han Chan, Koon Shing Choi, Chi Chung Shek, Ka Foon ChauAbstract:Dried Blood Spot (DBS) sampling and high-performance liquid chromatography tandem-mass spectrometry have been developed in monitoring tacrolimus levels. Our center favors the use of limited sampling strategy and abbreviated formula to estimate the area under concentration-time curve (AUC(0-12)). However, it is inconvenient for patients because they have to wait in the center for Blood sampling. We investigated the application of DBS method in tacrolimus level monitoring using limited sampling strategy and abbreviated AUC estimation approach. Duplicate venous samples were obtained at each time point (C(0), C(2), and C(4)). To determine the stability of Blood samples, one venous sample was sent to our laboratory immediately. The other duplicate venous samples, together with simultaneous fingerprick Blood samples, were sent to the University of Maastricht in the Netherlands. Thirty six patients were recruited and 108 sets of Blood samples were collected. There was a highly significant relationship between AUC(0-12), estimated from venous Blood samples, and fingerprick Blood samples (r(2) = 0.96, P < 0.0001). Moreover, there was an excellent correlation between whole Blood venous tacrolimus levels in the two centers (r(2) = 0.97; P < 0.0001). The Blood samples were stable after long-distance transport. DBS sampling can be used in centers using limited sampling and abbreviated AUC(0-12) strategy as drug monitoring.
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therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method
Journal of Pharmaceutical and Biomedical Analysis, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was <7.5% and 15%, respectively. Tacrolimus concentrations of 24 stable out patients were compared after both Blood Spot sampling and conventional venous sampling. Method agreement was investigated with the methods of Passing and Bablok and Bland Altman and proved suitable for clinical use. The Dried Blood Spot method for tacrolimus seems promising for patient monitoring.
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Dried Blood Spot measurement of tacrolimus is promising for patient monitoring
Transplantation, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, J P Van Hooff, Afke Van De Plas, Leo M L StolkAbstract:The usefulness of Dried Blood Spot (DBS) sampling for therapeutic drug monitoring of tacrolimus was investigated with renal transplant patients. There was no significant difference between the concentrations (ranging 3.33-53.9 mug/l) of 34 samples of 26 stable renal transplant outpatients, measured both after venous and DBS sampling. DBS sampling is easy to perform because concentrations with and without nurse assistance did not significantly differ. No significant difference was found between tacrolimus concentrations in 20 duplicate DBS samples before and after postal transport. DBS seems promising for routine patient monitoring.
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Therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method.
Journal of pharmaceutical and biomedical analysis, 2006Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was
J Van Der Heijden - One of the best experts on this subject based on the ideXlab platform.
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therapeutic drug monitoring of everolimus using the Dried Blood Spot method in combination with liquid chromatography mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2009Co-Authors: J Van Der Heijden, Karin Hoogtanders, M H L Christiaans, Y M De Beer, G J De Jong, Cees Neef, Leo M L StolkAbstract:An assay of everolimus based on finger prick sampling and consecutive application as a Blood Spot on sampling paper has been developed. We explored several methods [K. Hoogtanders, J. van der Heijden, M. Christiaans, P. Edelbroek, J. van Hooff, L. Stolk, J. Pharm. Biomed. Anal. 44 (2006) 658-664; A. Allanson, M. Cotton, J. Tettey, et al., J. Pharm. Biomed. Anal. 44 (2007) 963-969] and developed a new method, namely the impregnation of sampling paper with a solution of plasma-protein, formic acid and ammonium acetate, in combination with the extraction of the Blood Spot by filter filtration. This kind of sample preparation provides new possibilities for Blood Spot sampling especially if analytes are adsorbed to the paper. The Dried Blood Spot was analysed using the HPLC-electrospray-tandem mass spectrometry method, with 32-desmethoxyrapamycin as the internal standard. The working range of our study was 2-30 microg/l. Within this range, intra-and inter-assay variability for precision and accuracy was <15%. Everolimus Blood Spot samples proved stable for 3 days at 60 degrees C and for 32 days at 4 degrees C. Everolimus concentrations of one stable out-patient were compared after both Blood Spot sampling and conventional venous sampling on various occasions. Results indicate that this new method is promising for therapeutic drug monitoring in stable renal transplant patients.
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Dried Blood Spot measurement application in tacrolimus monitoring using limited sampling strategy and abbreviated auc estimation
Transplant International, 2007Co-Authors: Chi Yuen Cheung, Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, Afke Van De Plas, Yan Lun Liu, Yiu Han Chan, Koon Shing Choi, Chi Chung Shek, Ka Foon ChauAbstract:Dried Blood Spot (DBS) sampling and high-performance liquid chromatography tandem-mass spectrometry have been developed in monitoring tacrolimus levels. Our center favors the use of limited sampling strategy and abbreviated formula to estimate the area under concentration-time curve (AUC(0-12)). However, it is inconvenient for patients because they have to wait in the center for Blood sampling. We investigated the application of DBS method in tacrolimus level monitoring using limited sampling strategy and abbreviated AUC estimation approach. Duplicate venous samples were obtained at each time point (C(0), C(2), and C(4)). To determine the stability of Blood samples, one venous sample was sent to our laboratory immediately. The other duplicate venous samples, together with simultaneous fingerprick Blood samples, were sent to the University of Maastricht in the Netherlands. Thirty six patients were recruited and 108 sets of Blood samples were collected. There was a highly significant relationship between AUC(0-12), estimated from venous Blood samples, and fingerprick Blood samples (r(2) = 0.96, P < 0.0001). Moreover, there was an excellent correlation between whole Blood venous tacrolimus levels in the two centers (r(2) = 0.97; P < 0.0001). The Blood samples were stable after long-distance transport. DBS sampling can be used in centers using limited sampling and abbreviated AUC(0-12) strategy as drug monitoring.
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therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method
Journal of Pharmaceutical and Biomedical Analysis, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was <7.5% and 15%, respectively. Tacrolimus concentrations of 24 stable out patients were compared after both Blood Spot sampling and conventional venous sampling. Method agreement was investigated with the methods of Passing and Bablok and Bland Altman and proved suitable for clinical use. The Dried Blood Spot method for tacrolimus seems promising for patient monitoring.
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Dried Blood Spot measurement of tacrolimus is promising for patient monitoring
Transplantation, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, J P Van Hooff, Afke Van De Plas, Leo M L StolkAbstract:The usefulness of Dried Blood Spot (DBS) sampling for therapeutic drug monitoring of tacrolimus was investigated with renal transplant patients. There was no significant difference between the concentrations (ranging 3.33-53.9 mug/l) of 34 samples of 26 stable renal transplant outpatients, measured both after venous and DBS sampling. DBS sampling is easy to perform because concentrations with and without nurse assistance did not significantly differ. No significant difference was found between tacrolimus concentrations in 20 duplicate DBS samples before and after postal transport. DBS seems promising for routine patient monitoring.
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Therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method.
Journal of pharmaceutical and biomedical analysis, 2006Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was
M H L Christiaans - One of the best experts on this subject based on the ideXlab platform.
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therapeutic drug monitoring of everolimus using the Dried Blood Spot method in combination with liquid chromatography mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2009Co-Authors: J Van Der Heijden, Karin Hoogtanders, M H L Christiaans, Y M De Beer, G J De Jong, Cees Neef, Leo M L StolkAbstract:An assay of everolimus based on finger prick sampling and consecutive application as a Blood Spot on sampling paper has been developed. We explored several methods [K. Hoogtanders, J. van der Heijden, M. Christiaans, P. Edelbroek, J. van Hooff, L. Stolk, J. Pharm. Biomed. Anal. 44 (2006) 658-664; A. Allanson, M. Cotton, J. Tettey, et al., J. Pharm. Biomed. Anal. 44 (2007) 963-969] and developed a new method, namely the impregnation of sampling paper with a solution of plasma-protein, formic acid and ammonium acetate, in combination with the extraction of the Blood Spot by filter filtration. This kind of sample preparation provides new possibilities for Blood Spot sampling especially if analytes are adsorbed to the paper. The Dried Blood Spot was analysed using the HPLC-electrospray-tandem mass spectrometry method, with 32-desmethoxyrapamycin as the internal standard. The working range of our study was 2-30 microg/l. Within this range, intra-and inter-assay variability for precision and accuracy was <15%. Everolimus Blood Spot samples proved stable for 3 days at 60 degrees C and for 32 days at 4 degrees C. Everolimus concentrations of one stable out-patient were compared after both Blood Spot sampling and conventional venous sampling on various occasions. Results indicate that this new method is promising for therapeutic drug monitoring in stable renal transplant patients.
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Dried Blood Spot measurement application in tacrolimus monitoring using limited sampling strategy and abbreviated auc estimation
Transplant International, 2007Co-Authors: Chi Yuen Cheung, Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, Afke Van De Plas, Yan Lun Liu, Yiu Han Chan, Koon Shing Choi, Chi Chung Shek, Ka Foon ChauAbstract:Dried Blood Spot (DBS) sampling and high-performance liquid chromatography tandem-mass spectrometry have been developed in monitoring tacrolimus levels. Our center favors the use of limited sampling strategy and abbreviated formula to estimate the area under concentration-time curve (AUC(0-12)). However, it is inconvenient for patients because they have to wait in the center for Blood sampling. We investigated the application of DBS method in tacrolimus level monitoring using limited sampling strategy and abbreviated AUC estimation approach. Duplicate venous samples were obtained at each time point (C(0), C(2), and C(4)). To determine the stability of Blood samples, one venous sample was sent to our laboratory immediately. The other duplicate venous samples, together with simultaneous fingerprick Blood samples, were sent to the University of Maastricht in the Netherlands. Thirty six patients were recruited and 108 sets of Blood samples were collected. There was a highly significant relationship between AUC(0-12), estimated from venous Blood samples, and fingerprick Blood samples (r(2) = 0.96, P < 0.0001). Moreover, there was an excellent correlation between whole Blood venous tacrolimus levels in the two centers (r(2) = 0.97; P < 0.0001). The Blood samples were stable after long-distance transport. DBS sampling can be used in centers using limited sampling and abbreviated AUC(0-12) strategy as drug monitoring.
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therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method
Journal of Pharmaceutical and Biomedical Analysis, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was <7.5% and 15%, respectively. Tacrolimus concentrations of 24 stable out patients were compared after both Blood Spot sampling and conventional venous sampling. Method agreement was investigated with the methods of Passing and Bablok and Bland Altman and proved suitable for clinical use. The Dried Blood Spot method for tacrolimus seems promising for patient monitoring.
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Dried Blood Spot measurement of tacrolimus is promising for patient monitoring
Transplantation, 2007Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, J P Van Hooff, Afke Van De Plas, Leo M L StolkAbstract:The usefulness of Dried Blood Spot (DBS) sampling for therapeutic drug monitoring of tacrolimus was investigated with renal transplant patients. There was no significant difference between the concentrations (ranging 3.33-53.9 mug/l) of 34 samples of 26 stable renal transplant outpatients, measured both after venous and DBS sampling. DBS sampling is easy to perform because concentrations with and without nurse assistance did not significantly differ. No significant difference was found between tacrolimus concentrations in 20 duplicate DBS samples before and after postal transport. DBS seems promising for routine patient monitoring.
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Therapeutic drug monitoring of tacrolimus with the Dried Blood Spot method.
Journal of pharmaceutical and biomedical analysis, 2006Co-Authors: Karin Hoogtanders, J Van Der Heijden, M H L Christiaans, P Edelbroek, J P Van Hooff, Leo M L StolkAbstract:In a preliminary investigation an assay for tacrolimus based on fingerprick sampling and consecutive application as a Blood Spot on sampling paper has been developed. The Dried Blood Spot was analysed by HPLC-tandem mass spectrometry. The validated range was 1-30 microg/l. Intra- and inter-assay variability for precision and accuracy was
