scholarly journals A combined assay for quantifying remdesivir and its metabolite, along with dexamethasone, in serum

2021 ◽  
Author(s):  
Andrew Reckers ◽  
Alan H B Wu ◽  
Chui Mei Ong ◽  
Monica Gandhi ◽  
John Metcalfe ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Dose Adjustment ◽  
Therapeutic Drug ◽  
Pharmacokinetic Studies ◽  
Serum Samples ◽  
Limits Of Detection ◽  
Analytical Utility

Abstract Background As global confirmed cases and deaths from coronavirus disease 2019 (COVID-19) surpass 100 and 2.2 million, respectively, quantifying the effects of the widespread treatment of remdesivir (GS-5734, Veklury) and the steroid dexamethasone is becoming increasingly important. Limited pharmacokinetic studies indicate that remdesivir concentrations in serum decrease quickly after dosing, so its primary serum metabolite GS-441524 may have more analytical utility. Objectives We developed and validated a method to quantify remdesivir, its metabolite GS-441524 and dexamethasone in human serum. Methods We used LC-MS/MS and applied the method to 23 serum samples from seven patients with severe COVID-19. Results The method has limits of detection of 0.0375 ng/mL for remdesivir, 0.375 ng/mL for GS-441524 and 3.75 ng/mL for dexamethasone. We found low intra-patient variability, but significant inter-patient variability, in remdesivir, GS-441524 and dexamethasone levels. Conclusions The significant inter-patient variability highlights the importance of therapeutic drug monitoring of COVID-19 patients and possible dose adjustment to achieve efficacy.

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.

An UHPLC-UV Method for Determination of Vancomycin in human serum

2020 ◽  
Vol 16 ◽  
Author(s):  
Fang Fang ◽  
Ning Li ◽  
Chunli Xu ◽  
Rong Tan ◽  
Jihong Yang ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Internal Standard ◽  
Sample Pretreatment ◽  
Gradient Elution ◽  
Therapeutic Drug ◽  
Serum Samples ◽  
Column Temperature ◽  
Limit Of Quantitation

Objective: To develop a rapid ultra-performance liquid chromatographic (UHPLC)-UV method for vancomycin determination in human serum for therapeutic drug monitoring (TDM). Methods: Human serum samples were precipitated with 10% perchloric acid, and the supernatant after centrifugation was analyzed on an ACQUITY UHPLC BEH C18 column (2.1 × 50mm, 1.7 μm) via gradient elution with a flow rate at 0.3 mL/min. The mobile phase consisted of acetonitrile and 0.005M KH2PO4 buffer (containing 0.1% triethylamine, pH 3.4). The detection wavelength was set at 210 nm, and the column temperature was set at 40. The total runtime was 6.0 min per analysis. Results: After comprehensive validation, the method was applied to determine the concentration of vancomycin in human serum. The chromatographic peaks of vancomycin and internal standard were not interfered by endogenous matrixes. The retention time (RT) of vancomycin was 1.91 min, while the internal standard was 1.58 min. The good linearity range of vancomycin concentration was 2.5-120 μg/mL (R2>0.999). The lower limit of quantitation (LLOQ) was 2.5 μg/mL. The precision at three quality control (QC) levels (including LLOQ) was restricted within 85-115%. The extraction recovery rate of QC samples (4.0, 20.0, 60.0 μg/mL) were 101.16%、97.70%、94.90%, respectively. Inter- and intra-day precision was less than 8% (RSD). Stability tests under different storage conditions were satisfactory. In patients, the concentration of vancomycin ranged from 7.30 to 89.12 μg/mL determined by the fully validated method. Conclusion: The simple, rapid sample pretreatment procedures and short analysis time made this UHPLC-UV method suitable for therapeutic drug monitoring (TDM) of vancomycin.

scholarly journals Evaluation of the dose-related concentration approach in therapeutic drug monitoring of diuretics and β-blockers – drug classes with low adherence in antihypertensive therapy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sabrina Ritscher ◽  
Milena Hoyer ◽  
Cora Wunder ◽  
Nicholas Obermüller ◽  
Stefan W. Toennes
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Antihypertensive Drugs ◽  
Therapeutic Drug ◽  
Pharmacokinetic Studies ◽  
Reference Ranges ◽  
Serum Samples ◽  
Drug Concentrations ◽  
Adherence Assessment ◽  
Β Blockers

Abstract Detection of antihypertensive drugs in biological samples is an important tool to assess the adherence of hypertensive patients. Urine and serum/plasma screenings based on qualitative results may lead to misinterpretations regarding drugs with a prolonged detectability. The aim of the present study was to develop a method that can be used for therapeutic drug monitoring (TDM) of antihypertensive drugs with focus on adherence assessment. Therefore, a method for quantification of four diuretics and four β-blockers using high-performance liquid chromatography-mass spectrometric analysis (LC-MS/MS) of combined acidic and basic serum extracts was developed and validated. The method was applied to 40 serum samples from 20 patients in a supervised medication setting (trough and peak serum samples). Literature data on therapeutic concentration ranges, as well as dose-related drug concentrations (calculated from data of pharmacokinetic studies) were used to evaluate adherence assessment criteria. Concentrations were measured for bisoprolol (n = 9 patients), metoprolol (n = 7), nebivolol (n = 1), canrenone (n = 2, metabolite of spironolactone), hydrochlorothiazide (n = 10) and torasemide (n = 8). The measured concentrations were within the therapeutic reference ranges, except for 24% of the samples (mainly β-blockers). In contrast, all measured concentrations were above the lower dose-related concentration (DRC), which appears superior in evaluating adherence. In conclusion, the quantitative analysis of antihypertensive drugs in serum samples and its evaluation on the basis of the individually calculated lower DRC is a promising tool to differentially assess adherence. This method could possibly detect a lack of adherence or other causes of insufficient therapy more reliably than qualitative methods.

Therapeutic drug monitoring of linezolid: HPLC-based assays for routine quantification of linezolid in human serum and cerebrospinal fluid

2022 ◽  
pp. ejhpharm-2021-003036
Author(s):  
Stefan Günther ◽  
Andreas Reimer ◽  
Horst Vogl ◽  
Stephan Spenke ◽  
Hanns-Christian Dinges ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Therapeutic Drug

scholarly journals N22 Nurse led therapeutic drug monitoring (TDM) of Infliximab in IBD

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S667-S668
Author(s):  
S Gleeson ◽  
K Sugrue ◽  
M Buckley ◽  
J McCarthy
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Trough Concentration ◽  
Drug Monitoring ◽  
Response Assessment ◽  
Symptom Improvement ◽  
Therapeutic Drug ◽  
Serum Samples ◽  
Drug Concentrations ◽  
Biologic Response ◽  
Trough Levels

Abstract Background Therapeutic drug monitoring (TDM) is the clinical practice of measuring serum drug concentrations to guide clinical decision making. Achieving therapeutic drug concentrations has been associated with clinical, endoscopic and histological outcomes in IBD. The use of TDM offers a more personalised treatment approach and is associated with sustained clinical remission. Proactive TDM was introduced to the Mercy University Hospital in 2014 for all patients on biologics. Methods One hundred patients receiving biologic infusion (Infliximab) were evaluated post induction (week 12) for therapeutic drug trough concentration and for clinical response. Serum samples were taken from all IBD patients at week 12. Biologic response assessment forms were complete for all patients to assess symptom improvement. Results Thirty-five per cent of patients had sub therapeutic trough levels at week 12. They subsequently received 3 increased doses of 10mgs/kg and levels were rechecked. Of these 90% achieved therapeutic levels after the dose escalation. 65% of patients had therapeutic levels at week 12. There was a correlation between therapeutic trough levels and patient reported improvement of clinical symptoms in 85% of respondents. Conclusion TDM in our unit facilitates appropriate dose 100 patients receiving biologic infusion (Infliximab) were evaluated post induction (week 12) for therapeutic drug trough concentration and for clinical response. Serum samples were taken from all IBD patients at week 12. Biologic response assessment forms were complete for all patients to assess symptom improvement.

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