Isavuconazole: Case Report and Pharmacokinetic Considerations

Chemotherapy ◽  
2018 ◽  
Vol 63 (5) ◽  
pp. 253-256 ◽  
Author(s):  
Francesco Marchesi ◽  
Corrado Girmenia ◽  
Bianca Maria Goffredo ◽  
Emanuela Salvatorelli ◽  
Atelda Romano ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Plasma Concentrations ◽  
Real Life ◽  
Concomitant Administration ◽  
Invasive Fungal Disease ◽  
High Plasma ◽  
Adult Patients ◽  
Therapeutic Drug ◽  
Hepatic Toxicity ◽  
Maintenance Chemotherapy

Invasive fungal disease (IFD) is one of the major causes of morbidity and mortality in immunocompromised patients. Voriconazole (VCZ) and posaconazole (PCZ) remain the most widely used antifungals for the prophylaxis and treatment of IFD. However, VCZ and PCZ are liable for drug-drug interactions and show a pharmacokinetic variability that requires therapeutic drug monitoring (TDM). Isavuconazole (IVZ) is a newest generation triazole antifungal approved for the treatment of invasive aspergillosis (IA) in adult patients and for the treatment of invasive mucormycosis in adult patients for whom treatment with amphotericin B is inappropriate. In clinical trials, IVZ showed linear pharmacokinetics and little or no evidence for interactions with other drugs. There is only modest evidence on IVZ pharmacokinetics and TDM in real-life settings. Here, we report on IVZ pharmacokinetics in a young adult with Ph chromosome-negative acute lymphoblastic leukemia (ALL) who developed a “probable” IA during induction chemotherapy. The patient was initially treated with VCZ, but she developed a severe hepatic toxicity that was associated to the high plasma levels of VCZ. Therefore, VCZ was discontinued and the patient was switched to IVZ. After a loading dose of IVZ, the patient remained on IVZ for 5 months while also receiving standard maintenance chemotherapy for ALL. At day 65 after the start of IVZ, the patient experienced a significant hepatic toxicity; however, no change in IVZ plasma concentrations was observed in the face of a concomitant administration of many other drugs (cancer drugs, antiemetics, other anti-infectives). Hepatic toxicity resolved after discontinuing maintenance chemotherapy but not IVZ. These results show that (i) IVZ plasma concentrations remained stable throughout and were not affected by concomitant ALL therapy, and (ii) there was no relation between IVZ plasma concentration and hepatic toxicity. Thus, in clinical practice IVZ may not require TDM.

scholarly journals Validation of an HPLC–MS/MS Method for the Determination of Plasma Ticagrelor and Its Active Metabolite Useful for Research and Clinical Practice

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 278
Author(s):  
Jennifer Lagoutte-Renosi ◽  
Bernard Royer ◽  
Vahideh Rabani ◽  
Siamak Davani
Keyword(s):  
Active Metabolite ◽  
Plasma Concentrations ◽  
Antiplatelet Agent ◽  
High Plasma ◽  
Therapeutic Drug ◽  
Routine Practice ◽  
Daily Routine ◽  
Limit Of Quantification ◽  
Wide Range

Ticagrelor is an antiplatelet agent which is extensively metabolized in an active metabolite: AR-C124910XX. Ticagrelor antagonizes P2Y12 receptors, but recently, this effect on the central nervous system has been linked to the development of dyspnea. Ticagrelor-related dyspnea has been linked to persistently high plasma concentrations of ticagrelor. Therefore, there is a need to develop a simple, rapid, and sensitive method for simultaneous determination of ticagrelor and its active metabolite in human plasma to further investigate the link between concentrations of ticagrelor, its active metabolite, and side effects in routine practice. We present here a new method of quantifying both molecules, suitable for routine practice, validated according to the latest Food and Drug Administration (FDA) guidelines, with a good accuracy and precision (<15% respectively), except for the lower limit of quantification (<20%). We further describe its successful application to plasma samples for a population pharmacokinetics study. The simplicity and rapidity, the wide range of the calibration curve (2–5000 µg/L for ticagrelor and its metabolite), and high throughput make a broad spectrum of applications possible for our method, which can easily be implemented for research, or in daily routine practice such as therapeutic drug monitoring to prevent overdosage and occurrence of adverse events in patients.

scholarly journals Pregnancy-Related Effects on Nelfinavir-M8 Pharmacokinetics: a Population Study with 133 Women

2006 ◽  
Vol 50 (6) ◽  
pp. 2079-2086 ◽  
Author(s):  
Déborah Hirt ◽  
Jean-Marc Treluyer ◽  
Vincent Jullien ◽  
Ghislaine Firtion ◽  
Hélène Chappuy ◽  
...  
Keyword(s):  
Population Study ◽  
Time Course ◽  
Plasma Concentrations ◽  
Elimination Rate ◽  
Concomitant Administration ◽  
Individual Characteristics ◽  
Individual Treatment ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Linear Absorption

ABSTRACT A relationship between nelfinavir antiretroviral efficacy and plasma concentrations has been previously established. As physiological changes associated with pregnancy have a large impact on the pharmacokinetics of many drugs, a nelfinavir population study with women was developed, and the large intersubject variability was analyzed in order to optimize individual treatment schedules for this drug during pregnancy. A population pharmacokinetic model was developed in order to describe the concentration time course of nelfinavir and its metabolite M8 in pregnant and nonpregnant women. Individual characteristics, such as age, body weight, and weeks of gestation or delivery, which may influence nelfinavir-M8 pharmacokinetics were investigated. Data from therapeutic drug monitoring in 133 women treated with nelfinavir were retrospectively analyzed with NONMEM. Nelfinavir pharmacokinetics was described by a one-compartment model with linear absorption and elimination and M8 produced from the nelfinavir central compartment. Mean pharmacokinetic estimates and the corresponding intersubject percent variabilities for a nonpregnant woman were the following: absorption rate, 0.83 h−1; absorption lag time, 0.85 h; apparent nelfinavir elimination clearance (CL10/F), 35.5 liters/h (50%); apparent volume of distribution (V/F), 596 liters (118%); apparent formation clearance to M8 (CL1M/F), 0.65 liters/h (69%); and M8 elimination rate constant (k M0), 3.3 h−1 (59%). During pregnancy, we observed significant increases in nelfinavir (44.4 liters/h) and M8 (5 h−1) elimination but unchanged nelfinavir transformation clearance to M8, suggesting an induction of CYP3A4 but no effect on CYP2C19. Apparent nelfinavir clearance and volume showed a twofold increase on the day of delivery, suggesting a decrease in bioavailability on this day. The M8 elimination rate was increased by concomitant administration of nonnucleoside reverse transcriptase inhibitors. A trough nelfinavir plasma concentration above 1 mg/liter was previously shown to improve the antiretroviral response. The Bayesian individual pharmacokinetic estimates suggested that the dosage should not be changed in pregnant women but may be doubled on the day of delivery.

scholarly journals A limited sampling schedule to estimate individual pharmacokinetics of pemetrexed in patients with varying renal functions

2019 ◽  
Vol 85 (1) ◽  
pp. 231-235
Author(s):  
Nikki de Rouw ◽  
Sabine Visser ◽  
Stijn L. W. Koolen ◽  
Joachim G. J. V. Aerts ◽  
Michel M. van den Heuvel ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Plasma Concentrations ◽  
Real Life ◽  
Accurate Estimation ◽  
Therapeutic Drug ◽  
Limited Sampling ◽  
Exposure Response ◽  
Squared Error ◽  
Precise Prediction ◽  
Sampling Schedule

Abstract Purpose Pemetrexed is a widely used cytostatic agent with an established exposure–response relationship. Although dosing is based on body surface area (BSA), large interindividual variability in pemetrexed plasma concentrations is observed. Therapeutic drug monitoring (TDM) can be a feasible strategy to reduce variability in specific cases leading to potentially optimized pemetrexed treatment. The aim of this study was to develop a limited sampling schedule (LSS) for the assessment of pemetrexed pharmacokinetics. Methods Based on two real-life datasets, several limited sampling designs were evaluated on predicting clearance, using NONMEM, based on mean prediction error (MPE %) and normalized root mean squared error (NRMSE %). The predefined criteria for an acceptable LSS were: a maximum of four sampling time points within 8 h with an MPE and NRMSE ≤ 20%. Results For an accurate estimation of clearance, only four samples in a convenient window of 8 h were required for accurate and precise prediction (MPE and NRMSE of 3.6% and 5.7% for dataset 1 and of 15.5% and 16.5% for dataset 2). A single sample at t = 24 h performed also within the criteria with MPE and NRMSE of 5.8% and 8.7% for dataset 1 and of 11.5% and 16.4% for dataset 2. Bias increased when patients had lower creatinine clearance. Conclusions We presented two limited sampling designs for estimation of pemetrexed pharmacokinetics. Either one can be used based on preference and feasibility.

scholarly journals Antifungal Prophylaxis with Posaconazole Delayed-Release Tablet and Oral Suspension in a Real-Life Setting: Plasma Levels, Efficacy, and Tolerability

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
David Lenczuk ◽  
Wilma Zinke-Cerwenka ◽  
Hildegard Greinix ◽  
Albert Wölfler ◽  
Jürgen Prattes ◽  
...  
Keyword(s):  
Median Duration ◽  
Plasma Concentrations ◽  
Real Life ◽  
Antifungal Prophylaxis ◽  
Oral Solution ◽  
Therapeutic Drug ◽  
Graft Versus Host ◽  
Delayed Release ◽  
Real Life Setting ◽  
The Mean

ABSTRACT We continuously determined posaconazole plasma concentrations (PPCs) in 61 patients with hematological malignancies receiving posaconazole (PCZ) delayed-release tablets (DRT; 48 patients; median duration of intake, 92 days) and PCZ oral solution (OS; 13 patients; median duration of intake, 124 days). PCZ DRT and OS antifungal prophylaxis was efficient and well tolerated. Thirty-four of 48 patients (71%) receiving DRT always had PPCs of >0.7 mg/liter, while 14 of 48 patients (29%) had at least one PPC of ≤0.7 mg/liter. In patients receiving OS, 4 of 13 patients (31%) always had PPCs of >0.7 mg/liter, 6 of 13 patients (46%) had at least one PPC of ≤0.7 mg/liter, and 3 (23%) patients never reached a PPC of 0.7 mg/liter. In patients with at least one determined PPC, the mean proportion of all PPCs of >0.7 mg/liter was 91% for PCZ DRT, whereas it was 52% for PCZ OS ( P = 0.001). In the per sample analysis, PPCs were significantly more likely to be >0.7 mg/liter in patients receiving DRT than in patients receiving OS (PPCs were >0.7 mg/liter in 91.4% [297/325] of patients receiving DRT versus 70.3% [85/121] of patients receiving OS; P < 0.001). Patients receiving PCZ DRT had higher proportions of PPCs of >0.7 mg/liter than patients receiving OS both in the per patient and in the per sample analyses. Two patients (3%) had side effects during PCZ prophylaxis, and one (2%) had fungal breakthrough infection. Therapeutic drug monitoring enables detection of extended periods of PPCs of ≤0.7 mg/liter (e.g., due to nonadherence or graft-versus-host disease), which may also be associated with the loss of protective intracellular PCZ concentrations, regardless of the PCZ formulation.

scholarly journals Population pharmacokinetics of dolutegravir: influence of drug–drug interactions in a real-life setting

2019 ◽  
Vol 74 (9) ◽  
pp. 2690-2697 ◽  
Author(s):  
Catalina Barcelo ◽  
Manel Aouri ◽  
Perrine Courlet ◽  
Monia Guidi ◽  
Dominique L Braun ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Plasma Concentrations ◽  
Real Life ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Genetic Barrier ◽  
Good Tolerability ◽  
Standard Dosage ◽  
Real Life Setting ◽  
Trough Concentrations

Abstract Objectives Dolutegravir is widely prescribed owing to its potent antiviral activity, high genetic barrier and good tolerability. The aim of this study was to characterize dolutegravir’s pharmacokinetic profile and variability in a real-life setting and to identify individual factors and co-medications affecting dolutegravir disposition. Methods A population pharmacokinetic model was developed using NONMEM®. Relevant demographic factors, clinical factors and co-medications were tested as potential covariates. Simulations based on the final model served to compare expected dolutegravir concentrations under standard and alternative dosage regimens in the case of drug–drug interactions. Results A total of 620 dolutegravir plasma concentrations were collected from 521 HIV-infected individuals under steady-state conditions. A one-compartment model with first-order absorption and elimination best characterized dolutegravir pharmacokinetics. Typical dolutegravir apparent clearance (CL/F) was 0.93 L/h with 32% between-subject variability, the apparent volume of distribution was 20.2 L and the absorption rate constant was fixed to 2.24 h−1. Older age, higher body weight and current smoking were associated with higher CL/F. Atazanavir co-administration decreased dolutegravir CL/F by 38%, while darunavir modestly increased CL/F by 14%. Rifampicin co-administration showed the largest impact on CL/F. Simulations suggest that average dolutegravir trough concentrations are 63% lower after 50 mg/12h with rifampicin compared with a standard dosage of 50 mg/24h without rifampicin. Average trough concentrations after 100 mg/24h and 100 mg/12h with rifampicin are 92% and 25% lower than the standard dosage without rifampicin, respectively. Conclusions Patients co-treated with dolutegravir and rifampicin might benefit from therapeutic drug monitoring and individualized dosage increase, up to 100 mg/12 h in some cases.

scholarly journals Real-life isoniazid and rifampicin plasma concentrations in children: a tool for therapeutic drug monitoring of tuberculosis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chiara Tersigni ◽  
Giulia Boiardi ◽  
Lorenzo Tofani ◽  
Elisabetta Venturini ◽  
Carlotta Montagnani ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Age Groups ◽  
Real Life ◽  
Therapeutic Drug ◽  
Blood Samples ◽  
Drug Concentrations

Abstract Background Low plasma levels of first-line antitubercular drugs can be counted among the main causes of poor response to antitubercular therapy, and therapeutic drug monitoring has been proposed as a method to promote tailored treatments for both child and adult patients. The main aim of the study was to evaluate serum concentrations of isoniazid (INH) and rifampicin (RIF) and to investigate reasons for sub-therapeutic plasma concentrations in order to fix dosages. Methods Children with TB were prospectively enrolled from January to August 2019. Two venous blood samples were collected (the first at least 15 days after the beginning of antitubercular treatment, and the second between 1 and 8 weeks later). Plasma concentrations were determined by a validated high-performance liquid chromatography method. Results In all, 45 children were included. Seventy blood samples for INH plasma concentration were collected between 120 and 240 min after drug intake. Adjusting for dose (mg/kg/day) and time of INH administration, when considering three different age groups (≤ 2 years, 2–12 years, > 12 years), a statistically significant lower INH plasma concentration was observed in younger children compared to the older age groups in the multivariate analysis (p < 0.001 and p < 0.001). A total of 68 blood samples were evaluated for RIF concentrations. Both for INH and RIF a statistically significant lower plasma concentration was also observed in adolescents (p < 0.001). Fifteen children (15/45, 33%) presented drug concentrations under the referral therapeutic range. Conclusions Based on our findings, monitoring patients’ drug plasma concentrations in children under 2 years of age and in adolescents can make treatment more patient-tailored.

scholarly journals Interest of Dosing of Ibrutinib in B-Cell Lymphoid Malignancies: Data from a Real-Life, Phase 4 Study

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3960-3960
Author(s):  
Anne Calleja ◽  
Sandra De Barros ◽  
Camille Vinson ◽  
Caroline Protin ◽  
Lucie Oberic ◽  
...  
Keyword(s):  
Adverse Events ◽  
B Cell ◽  
Conflicts Of Interest ◽  
Plasma Concentrations ◽  
Real Life ◽  
Therapeutic Drug ◽  
Therapeutic Effects ◽  
Lymphoid Malignancies ◽  
Oncology Nurse ◽  
Drug Concentrations

Abstract Introduction: Therapeutic drug monitoring (TDM) entails the measurement of drug concentrations and the individualization of drug dosages or schedules to maximize therapeutic effects and minimize toxicity. Ibrutinib (IBR), the first-in-class inhibitor of BTK (Bruton tyrosine kinase) is approved for the therapy of relapsed/refractory chronic lymphocytic leukemia (R/R CLL), mantle cell lymphoma (MCL) and Waldenström's disease (WM), at the dose of 420-560mg/d. Drug-drug interactions (DDI), older age, liver diseases have been reported to impact PK parameters of ibrutinib, but dosing is not yet part of clinical practice, despite TDM of imatinib and other kinase inhibitors is routinely used in chronic myeloid leukemia. In this study, we sought to determine whether TDM of ibrutinib should be proposed for patients, in a preliminary cohort of 73 patients included in the PK-e3i trial (NCT02824159). Methods: Serial plasma PK samples were collected at steady-state after one month of therapy in 73 patients: before intake (residual concentration), and then at time 0.5-1-2-4-6h. Key PK parameters for ibrutinib and its metabolite DHD-ibrutinib were calculated: Cmax, Cmin, tmax,AUC24h. Analysis of DDI was made by an oncology pharmacist in 49/73 patients. Treatment-related adverse events were monitored by phonecalls given by an oncology nurse (AMA procedure) and during consultations with hematologist (at least twice a month the first 6 months, then monthly until 12 months, then every 3 months), and severity graded according CTCAE version 4 scale. Efficacy of therapy in CLL patients was assessed with an "effect marker" to demonstrate biological efficacy, the redistribution hyperlymphocytosis seen in 70% of patients the first month of therapy. Results: we reported very similar PK results for ibrutinib as compared to pivotal phase 1 trials in CLL and other B-cell lymphoid malignancies (Advani RH, J Clin Oncol 2013, Byrd JC, New Engl J Med 2013). Mean peak plasma concentrations were observed 1-2h after dosing, Cmax and AUC results showing an important inter-patient heterogeneity. Median Cmax was 150ng/ml (8.2-596ng/ml), and median AUC24h was 412.4 ng h/mL ((32.2-2906 ng h/mL). According to published phase I trials, complete or near complete BTK occupancy was observed in patients with AUCs exceeding 160 ng h/mL, suggesting ibrutinib dose might have been supramaximal in 67 of our patients. Adverse events the first 3 months were seen in 96% (grade 1), 63% (grade 2), 25% (grade 3) and 6.5% (grade 4), respectively. We plotted AUC results for the total cohort of 73 patients (Figure 1), and for 49 patients with adverse events monitoring available at 3 months (9/49 needed drug dose reduction due to toxicity) (Figure 2), both emphasizing the absence of correlations between AUC levels and toxicities. We next splited up toxicities into 10 sub-groups (bleeding, cardiac, liver, muscle, joint, skin, infection, gastro-intestinal, hematologic, neurologic disorders). Again, we could not identify a specific organ toxicity associated with a significant increase of Cmax or AUC24h, nor we could identify a specific DDI signature explaining side effects in our patents (data not shown: 13/49 had CYP3A4 inhibitors, 25/49 had pgp inhibitors). In 45 CLL patients with PK parameters and lymphocyte counts available after one month of therapy, we made the intriguing observation that lower Cmax correlated with the lack of observable, transient hyperlymphocytosis (a class-effect of ibrutinib, correlating with PFS in the Resonate trial) (Figure 3). Altogether, our data did not find any positive correlation between high ibrutinib exposure and efficacy or safety profile. Conclusions: our preliminary results suggested that higher Cmax and AUC24h did not correlate neither to efficacy nor to classical toxicities reported with ibrutinib intake. On one hand, we think that dosing intra-cellular concentrations could be more reliable than in plasma. On the other hand, we could consider TDM of ibrutinib in the context of a clinical trial reducing the doses of drug over time, to limit clinical and financial toxicity of this highly efficient drug. Disclosures No relevant conflicts of interest to declare.

scholarly journals Relationship Between the Free and Total Methotrexate Plasma Concentration in Children and Application to Predict the Toxicity of HD-MTX

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei-Chong Dong ◽  
Jia-Liang Guo ◽  
Xi-Kun Wu ◽  
Meng-Qiang Zhao ◽  
Hao-Ran Li ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
High Plasma ◽  
Therapeutic Drug ◽  
High Dose ◽  
Plasma Samples ◽  
Simple Method ◽  
Drug Molecules ◽  
Validation Parameters ◽  
Toxic Reactions

High-dose methotrexate (HD-MTX) can be highly effective as well as extremely toxic. Many drug molecules can bind to plasma proteins to different extents in vivo, whereas only the free drug can reach the site of action to exert a pharmacological effect and cause toxicity. However, free MTX concentrations in plasma have not been reported. Traditional analyses of free drugs are both cumbersome and inaccurate. We collected 92 plasma samples from 52 children diagnosed with ALL or NHL or other lymphomas that were treated with HD-MTX. The hollow fiber centrifugal ultrafiltration (HFCF-UF) was used to prepare plasma samples for analysis of the free MTX concentration. Protein precipitation was employed to measure the total MTX concentration. The HFCF-UF is a simple method involving a step of ordinary centrifugation; the validation parameters for the methodological results were satisfactory and fell within the acceptance criteria. A linearity coefficient r2 of 0.910 was obtained for the correlation between the free and total MTX plasma concentrations in 92 plasma samples. However, the free and total MTX concentrations was only weakly correlated in 16 clinical plasma specimens with total MTX concentrations &gt;2 μmol L−1 (r2 = 0.760). Both the free and total MTX concentrations at 42 h were negatively correlated with the creatinine clearance (CCr) level (P = 0.023, r = −0.236 for total MTX and P = 0.020, r = −0.241for free MTX, respectively). The free MTX concentration could not be accurately estimated from the total MTX concentration for patients with high MTX levels which are conditions under which toxic reactions are more likely to occur. High plasma MTX levels could become a predictor of the occurrence of MTX nephrotoxicity to draw people's attention. The proposed HFCF-UF method is a simple and accurate way to evaluate efficacy and toxicity in clinical therapeutic drug monitoring.

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