scholarly journals Sensitive and Rapid Quantification of Busulfan in Small Plasma Volumes by Liquid Chromatography–Electrospray Mass Spectrometry

2001 ◽  
Vol 47 (8) ◽  
pp. 1437-1442 ◽  
Author(s):  
Thomas E Mürdter ◽  
Janet Coller ◽  
Alexander Claviez ◽  
Frank Schönberger ◽  
Ute Hofmann ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Internal Standard ◽  
Therapeutic Drug ◽  
High Dose ◽  
Selected Ion Monitoring ◽  
Hematopoietic Stem ◽  
Adults And Children ◽  
Liquid Chromatographic

Abstract Background: High-dose busulfan is widely used in conditioning regimens before hematopoietic stem cell transplantation in both adults and children. Large interindividual variability in pharmacokinetics after oral administration has been reported; therefore, therapeutic drug monitoring of busulfan may decrease the incidence of drug-related toxicity (for example, hepatic venoocclusive disease) and may also improve therapeutic efficacy. Methods: Busulfan concentrations were quantified using 200 μL of plasma and liquid–liquid extraction with diethyl ether after the addition of [2H8]busulfan as the internal standard. Separation and detection of busulfan and [2H8]busulfan were achieved with a LUNA C8 column (5 μm; 150 × 2 mm i.d.) at 30 °C, a HP 1100 liquid chromatography system, and a HP 1100 single-quadrupole mass spectrometer. Busulfan and [2H8]busulfan were detected as ammonium adducts in selected-ion monitoring mode at m/z 264.2 and 272.2, respectively. Results: The calibration curve was linear at 5–2000 μg/L busulfan. Intra- and interassay imprecision (CV) and bias were both <11%. The limits of detection and quantification were 2 and 5 μg/L, respectively. Extraction recovery of busulfan was >87%. Analysis of pharmacokinetics in four patients receiving high-dose busulfan indicated that minimum busulfan concentrations before the next dose were 405–603 μg/L, with no interference observed. Conclusions: The new rapid and sensitive liquid chromatographic–mass spectrometric assay is an appropriate method for quantification of busulfan in human plasma, making therapeutic drug monitoring of busulfan faster and easier in clinical practice.

scholarly journals Software for Dosage Individualization of Voriconazole for Immunocompromised Patients

2013 ◽  
Vol 57 (4) ◽  
pp. 1888-1894 ◽  
Author(s):  
William W. Hope ◽  
Michael VanGuilder ◽  
J. Peter Donnelly ◽  
Nicole M. A. Blijlevens ◽  
Roger J. M. Brüggemann ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Fungal Infections ◽  
Plasma Concentrations ◽  
Therapeutic Drug ◽  
Cell Transplant ◽  
Multiple Model ◽  
Pharmacokinetic Variability ◽  
Hematopoietic Stem ◽  
Wide Range

ABSTRACTThe efficacy of voriconazole is potentially compromised by considerable pharmacokinetic variability. There are increasing insights into voriconazole concentrations that are safe and effective for treatment of invasive fungal infections. Therapeutic drug monitoring is increasingly advocated. Software to aid in the individualization of dosing would be an extremely useful clinical tool. We developed software to enable the individualization of voriconazole dosing to attain predefined serum concentration targets. The process of individualized voriconazole therapy was based on concepts of Bayesian stochastic adaptive control. Multiple-model dosage design with feedback control was used to calculate dosages that achieved desired concentration targets with maximum precision. The performance of the software program was assessed using the data from 10 recipients of an allogeneic hematopoietic stem cell transplant (HSCT) receiving intravenous (i.v.) voriconazole. The program was able to model the plasma concentrations with a high level of precision, despite the wide range of concentration trajectories and interindividual pharmacokinetic variability. The voriconazole concentrations predicted after the last dosages were largely concordant with those actually measured. Simulations provided an illustration of the way in which the software can be used to adjust dosages of patients falling outside desired concentration targets. This software appears to be an extremely useful tool to further optimize voriconazole therapy and aid in therapeutic drug monitoring. Further prospective studies are now required to define the utility of the controller in daily clinical practice.

scholarly journals A Novel, Rapid, and Low-Volume Assay for Therapeutic Drug Monitoring of Posaconazole and Other Long-Chain Azole-Class Antifungal Drugs

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Gregory R. Wiedman ◽  
Yanan Zhao ◽  
David S. Perlin
Keyword(s):  
Liquid Chromatography ◽  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Therapeutic Drug ◽  
Serum Samples ◽  
Human Serum Samples ◽  
Long Chain

ABSTRACT Clinicians need a better way to accurately monitor the concentration of antimicrobials in patient samples. In this report, we describe a novel, low-sample-volume method to monitor the azole-class antifungal drug posaconazole, as well as certain other long-chain azole-class antifungal drugs in human serum samples. Posaconazole represents an important target for therapeutic drug monitoring (TDM) due to its widespread use in treating invasive fungal infections and well-recognized variability of pharmacokinetics. The current “gold standard” requires trough and peak monitoring through high-pressure liquid chromatography (HPLC) or liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Other methods include bioassays that use highly susceptible strains of fungi in culture plates or 96-well formats to monitor concentrations. Currently, no method exists that is both highly accurate in detecting free drug concentrations and is also rapid. Herein, we describe a new method using reduced graphene oxide (rGO) and a fluorescently labeled aptamer, which can accurately assess clinically relevant concentrations of posaconazole and other long-chain azole-class drugs in little more than 1 h in a total volume of 100 µl. IMPORTANCE This work describes an effective assay for TDM of long-chain azole-class antifungal drugs that can be used in diluted human serum samples. This assay will provide a quick, cost-effective method for monitoring concentrations of drugs such as posaconazole that exhibit well-documented pharmacokinetic variability. Our rGO-aptamer assay has the potential to improve health care for those struggling to treat fungal infections in rural or resource-limited setting.

scholarly journals Successful and safe long‐term treatment of cerebral aspergillosis with high‐dose voriconazole guided by therapeutic drug monitoring

2018 ◽  
Vol 85 (1) ◽  
pp. 266-269 ◽  
Author(s):  
Pier Giorgio Cojutti ◽  
Maria Merelli ◽  
Lorenzo Allegri ◽  
Giuseppe Damante ◽  
Matteo Bassetti ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Term Treatment ◽  
Therapeutic Drug ◽  
High Dose ◽  
Long Term Treatment

scholarly journals Recent Advances in Therapeutic Drug Monitoring of Voriconazole, Mycophenolic Acid, and Vancomycin: A Literature Review of Pediatric Studies

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1991
Author(s):  
Matylda Resztak ◽  
Joanna Sobiak ◽  
Andrzej Czyrski
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Mycophenolic Acid ◽  
Drug Monitoring ◽  
Pediatric Patients ◽  
Fungal Infections ◽  
Cord Blood Transplantation ◽  
Active Form ◽  
Therapeutic Drug ◽  
Hematopoietic Stem ◽  
Acute Kidney Disease

The review includes studies dated 2011–2021 presenting the newest information on voriconazole (VCZ), mycophenolic acid (MPA), and vancomycin (VAN) therapeutic drug monitoring (TDM) in children. The need of TDM in pediatric patients has been emphasized by providing the information on the differences in the drugs pharmacokinetics. TDM of VCZ should be mandatory for all pediatric patients with invasive fungal infections (IFIs). Wide inter- and intrapatient variability in VCZ pharmacokinetics cause achieving and maintaining therapeutic concentration during therapy challenging in this population. Demonstrated studies showed, in most cases, VCZ plasma concentrations to be subtherapeutic, despite the updated dosages recommendations. Only repeated TDM can predict drug exposure and individualizing dosing in antifungal therapy in children. In children treated with mycophenolate mofetil (MMF), similarly as in adult patients, the role of TDM for MMF active form, MPA, has not been well established and is undergoing continued debate. Studies on the MPA TDM have been carried out in children after renal transplantation, other organ transplantation such as heart, liver, or intestine, in children after hematopoietic stem cell transplantation or cord blood transplantation, and in children with lupus, nephrotic syndrome, Henoch-Schönlein purpura, and other autoimmune diseases. MPA TDM is based on the area under the concentration–time curve; however, the proposed values differ according to the treatment indication, and other approaches such as pharmacodynamic and pharmacogenetic biomarkers have been proposed. VAN is a bactericidal agent that requires TDM to prevent an acute kidney disease. The particular group of patients is the pediatric one. For this group, the general recommendations of the dosing may not be valid due to the change of the elimination rate and volume of distribution between the subjects. The other factor is the variability among patients that concerns the free fraction of the drug. It may be caused by both the patients’ population and sample preconditioning. Although VCZ, MMF, and VAN have been applied in pediatric patients for many years, there are still few issues to be solve regarding TDM of these drugs to ensure safe and effective treatment. Except for pharmacokinetic approach, pharmacodynamics and pharmacogenetics have been more often proposed for TDM.

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