An Ultrafast Ultrahigh-Performance Liquid Chromatography Coupled With Tandem Mass Spectrometry Method for Cannabidiol Monitoring in Pediatric Refractory Epilepsy
Conclusions: A simple and sensitive method for rapidly monitoring CBD and identifying relevant metabolites was developed. Its applicability in samples from children treated for epilepsy was demonstrated, making it an excellent alternative for performing pharmacokinetic studies. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Simulation-Based Interpretation of Therapeutically Monitored Cabozantinib Plasma Concentration in Advanced Adrenocortical Carcinoma with Hemodialysis
Conclusions: After establishing an liquid chromatography with tandem mass spectrometry detection method for therapeutic drug monitoring of CAB, our analyses involving a single patient undergoing hemodialysis indicated that higher than expected doses of CAB were required to achieve reasonable plasma concentrations. Our study demonstrates the usefulness of therapeutic drug monitoring for the evaluation of “new” drugs in patients with renal impairment. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Untimed Efavirenz Drug Levels After Switching From Brand to Generic Formulations: A Short Communication
Conclusions: There were no statistically significant differences between untimed EFV levels in patients switching from the brand to generic EFV combination pill. Given the long elimination half-life of EFV, untimed drug levels may be a convenient way to estimate product bioequivalence. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Unexpected Vancomycin Pharmacokinetic Profile Secondary to Macromolecular Complexing: A Case Series
Conclusions: In cases of unusual or unexpected vancomycin pharmacokinetics in the absence of renal dysfunction, an abnormal protein-binding profile should be considered. Bound vancomycin may yield elevated serum levels, leading to poorly informed dose adjustments and risk for treatment failure. Given implications for therapeutic drug monitoring and unknown impacts on efficacy and toxicity, further investigations into population incidence and risk factors for abnormal protein binding of vancomycin are warranted. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Comparison of SB2-Infliximab With Originator-Infliximab in the Measurement of Serum Concentrations: A Short Communication
Conclusions: The originator and SB-2 biosimilar-infliximab behaved similarly in several currently used assays in their concentrations in biological fluids. Clinicians can be confident that therapeutic drug monitoring using platforms designed and developed for the originator-infliximab can be applied to SB-2-infliximab. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Intravenous Infusion of Fentanyl Has No Effect on Blood Concentration of Tacrolimus in Patients Receiving Hematopoietic Stem-Cell Transplantation
Conclusions: Intravenous infusion of fentanyl does not affect the pharmacokinetics of TAC. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Short Communication Source Type: research

Effects of CYP2D6 Genotypes on Venlafaxine Metabolism in Japanese Psychiatric Patients With Depression
This study evaluated the effects of the CYP2D6*10 and CYP2D6*5 genotypes on the steady-state plasma concentrations of VEN and ODV in Japanese patients. Methods: This study included 75 Japanese patients with depression who were treated with VEN. Steady-state plasma concentrations of VEN and ODV were measured using liquid chromatography. Polymerase chain reaction was used to determine CYP2D6 genotypes. A stepwise multiple regression analysis was performed to analyze the relationship between independent variables (sex, age, smoking habit, and number of mutated alleles, CYP2D6*10 and CYP2D6*5), subject-dependent variabl...
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Therapeutic Drug Monitoring of Psychotropics as a Diagnostic Tool for CYP2D6 Poor Metabolizer Phenotype
Conclusions: If therapeutic drug monitoring is available, the thresholds presented here could serve as a diagnostic tool for the CYP2D6 PM phenotype of psychiatric patients prescribed the aforementioned psychotropic medications. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

A Broad Range High-Throughput Assay for Lenvatinib Using Ultra-High Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry With Clinical Application in Patients With Hepatocellular Carcinoma
Conclusions: A novel high-throughput UHPLC-MS/MS assay for quantification of lenvatinib in human plasma was successfully developed. This method can be applied to PPK analysis for patients receiving lenvatinib in the clinical setting. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Quality Control of Busulfan Plasma Quantitation, Modeling, and Dosing: An Interlaboratory Proficiency Testing Program
Conclusions: A proficiency testing program by which laboratories are alerted to inaccuracies in their quantitation, pharmacokinetic modeling, and dose recommendations for busulfan in hematopoietic cell transplant recipients was developed. These rounds of proficiency testing suggests that additional educational efforts and proficiency rounds are needed to ensure appropriate busulfan dosing. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Manuscript Source Type: research

Initial Serum C-reactive Protein Level as a Predictor of Increasing Serum Vancomycin Concentration During Treatment
Conclusions: A high serum CRP level on the initial day of TDM is an independent predictor of increasing vancomycin concentration-to-dose ratio in patients receiving intravenous vancomycin treatment, even if eGFR remains unchanged. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Adalimumab Concentration Changes After Dose Escalation in Inflammatory Bowel Disease
Background: Dose escalation of adalimumab (ADA) for loss or response in inflammatory bowel disease (IBD) is a common practice. Recent data suggest improved outcomes with an ADA concentration of 12 mcg/mL, but limited data are available on the ability to achieve a target concentration. The aim of this study was to determine the expected change in serum ADA concentration after a dose escalation performed every 7 days in patients with IBD. Methods: A retrospective cohort of patients with IBD receiving ADA was divided into every fourteen-day dosing, every 7-day dosing, and dose escalation (ie, q14 to q7 day dosing)....
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Apixaban Level and Its Influence on Immunosuppression and Graft Outcome in Kidney Transplant Recipients With Atrial Fibrillation
Conclusions: Similar to nontransplant patients, KT patients administered the standard 5-mg bid dosage had apixaban levels that were well within the recommended manufacturers' expected ranges. In addition, this dosage had minimal influence on immunosuppression and no effect on graft function. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Comparison of a Point-of-Care Testing with Enzyme-Multiplied Immunoassay Technique and Liquid Chromatography Combined With Tandem Mass Spectrometry Methods for Therapeutic Drug Monitoring of Mycophenolic Acid: A Preliminary Study
Conclusions: The consistency of the new FICA using a point-of-care testing device with LC-MS/MS and EMIT was inadequate, and the accuracy of EMIT and LC-MS/MS was inappropriate. Clinicians should be informed when switching MPA detection methods to avoid misleading results. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

High Intrapatient Variability in Tacrolimus Exposure Calculated Over a Long Period Is Associated With De Novo Donor-Specific Antibody Development and/or Late Rejection in Thai Kidney Transplant Patients Receiving Concomitant CYP3A4/5 Inhibitors
Conclusions: Tac IPV6–24 was higher and more significantly associated with DSA development and/or late rejection than Tac IPV6–12, independent of Tac trough level. This is the first study to demonstrate the impact of high IPV on DSA development in Asian patients, and that Tac IPV is comparable between patients with and without CYPinh. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Relationship Between Thiopurine S-Methyltransferase Genotype/Phenotype and 6-Thioguanine Nucleotide Levels in 316 Patients With Inflammatory Bowel Disease on 6-Thioguanine
In this study, the authors aimed to investigate the role of 6-thioguanine nucleotide (TGN) measurements, geno/phenotyping of thiopurine S-methyltransferase (TPMT), and their mutual relationship with TG therapy in IBD. Methods: An international retrospective, multicenter cohort study was performed at 4 centers in the Netherlands (Máxima Medical Centre) and the United Kingdom (Guy's and St. Thomas' Hospital, Queen Elizabeth Hospital, and East Surrey Hospital). Results: Overall, 526 6-TGN measurements were performed in 316 patients with IBD. The median daily dosage of TG was 20 mg/d (range 10–40 mg/...
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Systematic Review and Meta-Analysis of Thiopurine Metabolite Levels and Biochemical Remission in Autoimmune Hepatitis
Conclusions: This meta-analysis suggests a link between 6-TGN levels and biochemical remission in AIH. Further high-quality studies are required to determine the therapeutic cutoff of 6-TGN. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Review of the Preanalytical Errors That Impact Therapeutic Drug Monitoring
Conclusions: The identification of preanalytical factors that may negatively impact TDM is critical. Developing workflows that can standardize TDM practices, align appropriate timing and blood collection techniques, and specimen processing will eliminate errors. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - September 19, 2021 Category: Drugs & Pharmacology Tags: Review Article Source Type: research

Lithium Level in Cerebrospinal Fluid Cannot be a Reliable Indicator of Severity of Chronic Lithium Intoxication
No abstract available (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Letters to the Editor Source Type: research

Relationship of Prolactin Concentrations to Steady-State Plasma Concentrations of Aripiprazole in Patients With Schizophrenia
Background: Aripiprazole is regarded as the first-line antipsychotic medication. Long-term aripiprazole therapy can cause hypoprolactinemia, which may result from its activity as a dopamine agonist. However, there is little information on hypoprolactinemia and steady-state aripiprazole concentrations. Methods: The subjects included 66 male and 177 female patients diagnosed with schizophrenia who were treated with aripiprazole. The plasma concentrations of aripiprazole and dehydroaripiprazole and the plasma concentration of prolactin were measured using high-performance liquid chromatography and enzyme immunoassa...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Rapid Simultaneous Determination of 14 Antidepressants and 13 Antipsychotics in Human Plasma by Using High-Performance Liquid Chromatography–Tandem Mass Spectrometry With Dynamic Multiple Reaction Monitoring and Its Application to Therapeutic Drug Monitoring
Conclusions: This dynamic method is comprehensive (includes most antidepressants and antipsychotics listed in China), reliable (stably used for almost 2 years), and efficient (convenient sample processing and short run time) and provides a large amount of meaningful data for optimized pharmacotherapy. Our experimental data from the plasma concentrations of supra–alert-level samples could serve as a reference for the interpretation of the pharmacokinetics of patients with a high risk of toxicity or loss of tolerability. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Development and Validation of a Simple and Rapid Ultrahigh-Performance Liquid Chromatography Tandem Spectrometry Method for the Quantification of Hydroxychloroquine in Plasma and Blood Samples in the Emergency Context of SARS-CoV-2 Pandemic
Abstract: Therapeutic drug monitoring of hydroxychloroquine (HCQ) has been recommended to optimize the treatment of patients with COVID-19. The authors describe an ultrahigh-performance liquid chromatography tandem spectrometry method developed in a context of emergency, to analyze HCQ in both human plasma and blood samples. After adding the labeled internal standard and simple protein precipitation, plasma samples were analyzed using a C18 column. Blood samples required evaporation before analysis. The total chromatographic run time was 4 minutes (including 1.5 minutes of column equilibration). The assay was linear ov...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Relationship Between Amphetamine Concentrations in Saliva and Serum in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder
In this study, 28 patient samples (mean age, 11.3 years; boys, 23; and girls, 5) treated with lisdexamfetamine were included. The active compound amphetamine was extracted and derivatized before quantification by high-performance liquid chromatography with fluorescence detection. Nonparametric Spearman rank correlations were used for correlation analyses; for clinical validation, Bland–Altman analysis was applied. Results: The median amphetamine concentrations in saliva were 2.7 times higher (range 0.7–23.6) than those in serum (257.8 ng/mL versus 77.2 ng/mL; z = −4.51, P (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Quantitative Method for the Analysis of Ivacaftor, Hydroxymethyl Ivacaftor, Ivacaftor Carboxylate, Lumacaftor, and Tezacaftor in Plasma and Sputum Using Liquid Chromatography With Tandem Mass Spectrometry and Its Clinical Applicability
Background: The novel cystic fibrosis transmembrane conductance regulator (CFTR) modulators, ivacaftor, lumacaftor, and tezacaftor, are the first drugs directly targeting the underlying pathophysiological mechanism in cystic fibrosis (CF); however, independent studies describing their pharmacokinetics are lacking. The aim of this study was to develop a quantification method for ivacaftor and its 2 main metabolites, lumacaftor and tezacaftor, in plasma and sputum using liquid chromatography with tandem mass spectrometry. Methods: The developed method used a small sample volume (20 µL) and simple pretreatmen...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Theoretical Performance of Nonlinear Mixed-Effect Models Incorporating Saliva as an Alternative Sampling Matrix for Therapeutic Drug Monitoring in Pediatrics: A Simulation Study
Conclusions: Saliva as an alternative matrix for noninvasive TDM is possible using nonlinear mixed-effect models combined with Bayesian optimization. This article provides a workflow to explore TDM performance for compounds measured in saliva and can be used for evaluation during model building. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Using Population Pharmacokinetic Modeling to Estimate Exposure to Δ9-Tetrahydrocannabinol in an Observational Study of Cannabis Smokers in Colorado
Background: Self-report questionnaires, weighing products consumed, and Δ9-tetrahydrocannabinol (THC) biomarkers are established techniques for estimating cannabis exposure. Population pharmacokinetic modeling of plasma THC and metabolite concentrations by incorporating self-reported and weighed products as covariates could improve estimates of THC exposure in regular cannabis users. Methods: In this naturalistic study, blood samples were obtained from 36 regular smokers of cannabis for analysis of THC and its 2 metabolites at 4 time points: recruitment and during an experimental mobile laboratory assessme...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Performance Evaluation of Warfarin Dose Prediction Algorithms and Effects of Clinical Factors on Warfarin Dose in Chinese Patients
Conclusions: In Chinese patients, OHNO should be given priority during the prediction and selection of warfarin dose. When using OHNO to predict warfarin dose (≤3 mg/d or>5 mg/d), HUANG or KIM algorithms can provide precise predictions. At the same time, physicians should pay close attention to clinical factors, such as VKORC1 (rs9923231), concurrent atrial fibrillation status, CYP2C9*3 (rs1057910), body mass index, and sex, to improve warfarin dose adjustment strategies in Chinese patients. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Population Pharmacokinetics of Teicoplanin and Its Dosing Recommendations for Neutropenic Patients With Augmented Renal Clearance for Hematological Malignancies
Conclusions: The PPK model may help optimize dose regimens and evaluate dosing methods, using comparative simulations, in patients with hematological malignancies. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

A Population Pharmacokinetic Modeling and Simulation Study of Posaconazole Oral Suspension in Immunocompromised Pediatric Patients: A Short Communication
Background: Posaconazole oral suspension emerged as a promising candidate for prophylaxis of invasive fungal infections in immunocompromised children. Its pharmacodynamic advantages include a broad-spectrum activity and a favorable safety profile; however, they are overshadowed by its large pharmacokinetic (PK) variability, which might cause subtherapeutic exposure. The aim of this study was to develop a population (pop) PK model based on rich sampling data to better understand the PK of posaconazole oral suspension in pediatric patients. Methods: Data were obtained from a prospective interventional study involv...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Bayesian Forecasting for Intravenous Tobramycin Dosing in Adults With Cystic Fibrosis Using One Versus Two Serum Concentrations in a Dosing Interval
The objective of this study was to determine the potential for a sparse-sampling strategy using a single postinfusion tobramycin concentration and Bayesian forecasting to assess the AUC24 in routine practice. Methods: Adults with cystic fibrosis receiving once-daily tobramycin had paired concentrations measured 2 hours (c1) and 6 hours (c2) after the end of infusion as routine monitoring. AUC24 exposures were estimated using Tucuxi, a Bayesian forecasting application that incorporates a validated population pharmacokinetic model. Simulations were performed to estimate AUC24 using the full data set using c1 and c2, c...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

A Population Pharmacokinetic Modeling Approach to Determine the Efficacy of Intravenous Amikacin in Children with Cystic Fibrosis
Conclusions: For intermediate pathogens, a dose of at least 40 mg/kg/d can improve efficacy, with an acceptable calculated residual trough level in cases of normal or hyperfiltration. Because amikacin undergoes renal clearance, which is immature until 1 year of age, dosing recommendations for this age group may be markedly high, warranting cautious interpretation. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Can We Predict Individual Concentrations of Tacrolimus After Liver Transplantation? Application and Tweaking of a Published Population Pharmacokinetic Model in Clinical Practice
Conclusions: A pharmacokinetic model can be used, and to improve the predictive performance, tweaking the literature model with the $PRIOR approach allows to obtain better predictions. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Impact of a Bayesian Individualization of Cyclosporine Dosage Regimen for Children Undergoing Allogeneic Hematopoietic Cell Transplantation: A Cost-Effectiveness Analysis
Background: Cyclosporine A (CsA) is the main drug used to prevent graft-versus-host disease in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). CsA therapeutic drug monitoring (TDM) has been performed for ages, with studies revealing clinical benefits, but failing to examine its economic impact. In this article, the main objective was to evaluate the economic impact of the CsA TDM strategy, based on a Bayesian approach, by assessing costs related to its clinical impact. Furthermore, TDM effectiveness was analyzed for pharmacokinetics and clinical outcomes. Methods: A cost-effective,...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Tacrolimus Bayesian Dose Adjustment in Pediatric Renal Transplant Recipients
Background: Immunosuppressant Bayesian Dose Adjustment (ISBA) is an online expert system that estimates the area under the curve (AUC) of immunosuppressive drugs through pharmacokinetic modelling and Bayesian estimation to propose dose adjustments to reach predefined exposure targets. The ISBA database was retrospectively analyzed to describe tacrolimus pharmacokinetics and exposure, evaluate the efficiency of ISBA dose recommendations, and propose tacrolimus AUC0–12h target ranges for pediatric renal allograft recipients treated with immediate release tacrolimus. Methods: The database included 1935 tacrol...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

To Estimate or to Forecast? Lessons From a Comparative Analysis of Four Bayesian Fitting Methods Based on Nonparametric Models
The objective of this study was to compare the performance of the maximum a posteriori (MAP) model, multiple model (MM), interacting MM (IMM), and novel hybrid MM(HMM) in estimating past concentrations and predicting future concentrations during therapy. Amikacin and vancomycin PK data were analyzed in older hospitalized patients using 2 strategies. First, the entire data set of each patient was fitted using each of the 4 methods implemented in BestDose software. Then, the 4 methods were used in each therapeutic drug monitoring occasion to estimate the past concentrations available at this time and to predict the subsequen...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Editorial: In Memory of Roger Jelliffe, MD
No abstract available (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Dr. Roger Jelliffe Memorial Issue: Focus on Personalized Dosing Strategies Source Type: research

Severe Inflammation, Acute Kidney Injury, and Drug–Drug Interaction: Triple Penalty for Prolonged Elimination of Apixaban in Patients With Coronavirus Disease 2019: A Grand Round
Abstract: In this article, we present a case of apixaban elimination prolonged by 450% in a patient with coronavirus disease 2019 because of multiple conditions, including drug–drug interaction, severe inflammation, and acute kidney injury. Therapeutic drug monitoring was used to explain unusual routine coagulation assays. This grand round highlights the importance of dialog between the clinician and a therapeutic drug monitoring consultant for optimal patient care. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Grand Rounds Source Type: research

Pharmacokinetic/Pharmacodynamic Dosage Individualization of Cefepime in Critically Ill Patients: A Case Study
Conclusion: This case report illustrates how physiological, microbiological, and drug concentration data can be used for model-based dosage individualization of cefepime in intensive care unit patients. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Grand Rounds Source Type: research

Therapeutic Drug Monitoring of Erlotinib in Non-Small Cell Lung Carcinoma: A Case Study
We describe a clinical case of an 84-year-old man diagnosed with non-small cell lung carcinoma and epidermal growth factor receptor mutation, who was treated with erlotinib, with doses adjusted by therapeutic drug monitoring. This case involved a clearance fluctuation leading to over-therapeutic drug concentrations of erlotinib and toxicity. The intrapatient and interpatient variability of erlotinib, in addition to other factors such as age or variations in liver clearance, create situations that are challenging in clinical practice. During treatment, erlotinib serum concentrations were measured, and the dose was according...
Source: Therapeutic Drug Monitoring - July 24, 2021 Category: Drugs & Pharmacology Tags: Grand Rounds Source Type: research

Measurement of Free Plasma Concentrations of Beta-Lactam Antibiotics: An Applicability Study in Intensive Care Unit Patients: Erratum
No abstract available (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Erratum Source Type: research

The Question of Accuracy Versus Interlaboratory Agreement for Monitoring the Immunosuppressants Everolimus and Sirolimus
No abstract available (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Letters to the Editor Source Type: research

Stability of Vancomycin in Whole Blood
No abstract available (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Letters to the Editor Source Type: research

Plasma Concentrations and Cardiovascular Effects of Citalopram Enantiomers After Oral Versus Infusion Citalopram Therapy in Dextromethorphan-Mephenytoin-Phenotyped Patients With Major Depression
Conclusions: Owing to CIT's high bioavailability, the plasma concentrations of its enantiomers remained largely independent on the administration route. CYP2C19 preferentially demethylated S-CIT after CIT therapy. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Impact of CYP2D6, CYP3A5, and ABCB1 Polymorphisms on Plasma Concentrations of Donepezil and Its Metabolite in Patients With Alzheimer Disease
Conclusions: Results indicate that the mean plasma concentration ratio of donepezil to 6ODD is associated with CYP2D6 polymorphism and the concomitant use of psychotropics in patients with Alzheimer disease. In intermediate metabolizers, CYP3A5 may play a significant role in the metabolism of donepezil. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Simple Liquid Chromatography–Tandem Mass Spectrometry Method for Quantitation of Total and Free Aprepitant and Its Active N-Dealkylated Metabolites in Human Plasma
Conclusions: The present developed method showed an acceptable analytical performance and can be used to evaluate total and free aprepitant and its N-dealkylated metabolites in patient plasma. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Development of a High-Throughput Quantification Method for Pazopanib Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry and Its Clinical Application in Patients With Soft Tissue Tumors
Conclusions: The authors succeeded in developing a novel high-throughput UHPLC-MS/MS method for quantifying pazopanib in human plasma. This method can be applied to TDM of patients receiving pazopanib in clinical settings. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Body Surface Area Dosing of High-Dose Methotrexate Should Be Reconsidered, Particularly in Overweight, Adult Patients
Conclusions: The results from this study provide additional information on the relationship between MTX concentration and nephrotoxicity. Patients with a plasma MTX concentration>6 µM at 36 hours were more likely to manifest AKI. In addition, the results suggest that overweight patients have a high AKI risk and that BSA-based adjustment of MTX dose is not appropriate. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Etiologies and Outcomes Associated With Tacrolimus Levels Out of a Typical Range That Lead to High Variability in Kidney Transplant Recipients
Conclusions: Although high tac IPV has many causes, only high tac IPV caused by nonadherence is consistently associated with poor allograft outcomes. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Original Article Source Type: research

Therapeutic Drug Monitoring of Lamotrigine, Lacosamide, and Levetiracetam in Dried Capillary Blood—Determination of Conversion Factors for Serum-Based Reference Ranges
Conclusions: The estimation of serum concentrations from measured capillary blood concentrations is feasible for LCM, LTG, and LEV. A simple ratio approach using the mean ratio and Passing–Bablok regression showed the best results for all 3 AEDs. The volumetric absorptive microsampling technique facilitates the quantitative sample collection of capillary blood and overcomes the drawbacks associated with the classical dried blood spot technique. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Focus Series: Alternative Sampling Strategies Source Type: research

Simultaneous Quantification of BCR-ABL and Bruton Tyrosine Kinase Inhibitors in Dried Plasma Spots and Its Application to Clinical Sample Analysis
Conclusions: An LC-MS/MS method for the simultaneous quantification of 6 TKIs in DPS was developed and validated. Further large-scale studies should be conducted to assess the consistency of concentration measurements obtained from plasma and DPS. (Source: Therapeutic Drug Monitoring)
Source: Therapeutic Drug Monitoring - May 20, 2021 Category: Drugs & Pharmacology Tags: Focus Series: Alternative Sampling Strategies Source Type: research