scholarly journals Multicenter Study of Posaconazole Therapeutic Drug Monitoring: Exposure-Response Relationship and Factors Affecting Concentration

2012 ◽  
Vol 56 (11) ◽  
pp. 5503-5510 ◽  
Author(s):  
Michael J. Dolton ◽  
John E. Ray ◽  
Sharon C.-A. Chen ◽  
Kingsley Ng ◽  
Lisa Pont ◽  
...  

ABSTRACTPosaconazole has an important role in the prophylaxis and salvage treatment of invasive fungal infections (IFIs), although poor and variable bioavailability remains an important clinical concern. Therapeutic drug monitoring of posaconazole concentrations has remained contentious, with the use of relatively small patient cohorts in previous studies hindering the assessment of exposure-response relationships. This multicenter retrospective study aimed to investigate relationships between posaconazole concentration and clinical outcomes and adverse events and to assess clinical factors and drug interactions that may affect posaconazole concentrations. Medical records were reviewed for patients who received posaconazole and had ≥1 concentration measured at six hospitals in Australia. Data from 86 patients with 541 posaconazole concentrations were included in the study. Among 72 patients taking posaconazole for prophylaxis against IFIs, 12 patients (17%) developed a breakthrough fungal infection; median posaconazole concentrations were significantly lower than in those who did not develop fungal infection (median [range], 289 [50 to 471] ng/ml versus 485 [0 to 2,035] ng/ml;P< 0.01). The median posaconazole concentration was a significant predictor of breakthrough fungal infection via binary logistic regression (P< 0.05). A multiple linear regression analysis identified a number of significant drug interactions associated with reduced posaconazole exposure, including coadministration with proton pump inhibitors, metoclopramide, phenytoin or rifampin, and the H2antagonist ranitidine (P< 0.01). Clinical factors such as mucositis, diarrhea, and the early posttransplant period in hematopoietic stem cell transplant recipients were also associated with reduced posaconazole exposure (P< 0.01). Low posaconazole concentrations are common and are associated with breakthrough fungal infection, supporting the utility of monitoring posaconazole concentrations to ensure optimal systemic exposure.

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 ◽  
...  

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.


2021 ◽  
Author(s):  
Tingting Chen ◽  
Zhiqiang Lin ◽  
Huatang Zhang ◽  
Qingquan Zhang ◽  
Limian Hong ◽  
...  

Abstract Background The safety and efficacy of Voriconazole in Acquired Immune Deficiency Syndrome (AIDS) patients is difficult to guarantee. In this study, Therapeutic Drug Monitoring (TDM) of Voriconazole in AIDS patients was investigated with the aim to further verify the significance of voriconazole TDM in AIDS patients and to explore more strategies to improve individualized medication. Methods The data of AIDS patients who underwent voriconazole TDM in our hospital from May 2018 to August 2021 were collected. The basic information of patients, the results of voriconazole TDM, the individualized intervention, the affecting factors of voriconazole concentration were analyzed, as well as the relationship between voriconazole trough concentration and safety. Results A total of 46 tests of voriconazole TDM were performed in 28 AIDS patients. Only 57.14% patients reached the therapeutic range at first TDM, and 87.50% patients reached the therapeutic range after intervention based on first TDM. 21.43% patients develop voriconazole-related Adverse Drug Reactions (ADRs), and ADRs were mostly occurred when voriconazole concentration is above 5.0 µg/mL. Spearman correlation coefficient rs was calculated to be 0.729 for voriconazole trough concentration and the incidence of ADRs, exhibiting a significant, positive linear correlation (P=0. 017). 50% patients had polypharmacy and drug interactions are common. For example, rifampicin can significantly reduce the plasma concentration of voriconazole. Multiple linear regression analysis showed Hypoproteinemia was a significant factor affecting voriconazole trough concentration(P=0.006). Conclusion AIDS patients usually have a low attainment rate of voriconazole trough concentration after initiation of standard dosing regimen. The affecting factors seem multifactorial and complex, of which hypoproteinemia is of great significance. Meanwhile, we need to be alert to the effects of drug interactions. The incidence of voriconazole related ADRs is high, mostly occurring when voriconazole concentration is above 5.0 µg/mL. Therefore, TDM can provide meaningful guidance for dosage optimization of voriconazole, and the dosage adjustment method in Chinese Guideline is applicable for the population of AIDS patients.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S635-S635
Author(s):  
Giorgos Hadjivassiliou ◽  
Claire Rummage ◽  
Craig Hoesley ◽  
Matthew L Brown

Abstract Background Patients who undergo allogeneic hematopoietic stem cell transplantation (alloHSCT) are at increased risk for invasive fungal infections with associated high morbidity and mortality that necessitates the use of prophylactic antifungals. Voriconazole is commonly used for prophylaxis, but there are no recommendations for therapeutic drug monitoring. The purpose of this study was to characterize voriconazole therapeutic drug monitoring and associated outcomes in this patient population. Methods AlloHSCT patients receiving voriconazole prophylaxis at the University of Alabama at Birmingham Hospital between March 2015 and March 2018 were included in the analysis. Serum voriconazole levels (SVL) were evaluated to determine what percentage of patients achieved prophylactic or therapeutic concentrations. Incidence of invasive fungal infections (IFI) and voriconazole discontinuation was also assessed. Results Voriconazole prophylaxis was used in 151 of 162 alloHSCT patients, and 120 patients (79%) had SVL drawn correctly (≥4 days after initiation of course). We found that 35 (29%) patients achieved a subtherapeutic level (<0.5 μg/mL), 17 (14%) prophylactic level (0.5 to 1 μg/mL), 68 (57%) therapeutic level (1 to 5.5 μg/mL), and no patients achieved a supratherapeutic level (level ≥5.5 μg/mL). Voriconazole prophylaxis was discontinued early in 60 of 151 patients. Most common etiologies for discontinuation included liver function test abnormalities (44%) and encephalopathy (21%). The average SVL was 1.2 μg/mL in those requiring discontinuation. Four patients (3%) developed an IFI while receiving prophylactic voriconazole, of which only 1 had subtherapeutic level. Conclusion Even though approximately one-third of patients achieved a subtherapeutic SVL, there was no correlation with breakthrough IFI. There was also no linear correlation between SVL and risk of adverse effects requiring discontinuation. Our observational data do not support a need for therapeutic drug monitoring in alloHSCT patients receiving prophylactic voriconazole. Disclosures All authors: No reported disclosures.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1991
Author(s):  
Matylda Resztak ◽  
Joanna Sobiak ◽  
Andrzej Czyrski

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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