European Journal of Drug Metabolism and Pharmacokinetics最新文献

{"title":"Clinical Pharmacokinetics of Radiopharmaceuticals from SPECT/CT Image Acquisition by Contouring in Patients with Gastroenteropancreatic Neuroendocrine Tumors: Lu-177 DOTATATE (Lutathera^®) Case.","authors":"Anissa Barakat,&nbsp;Lore Santoro,&nbsp;Myrtille Vivien,&nbsp;Pierre-Olivier Kotzki,&nbsp;Emmanuel Deshayes,&nbsp;Sonia Khier","doi":"10.1007/s13318-023-00829-5","DOIUrl":"https://doi.org/10.1007/s13318-023-00829-5","url":null,"abstract":"<p><strong>Background and objective: </strong>Lu-177 DOTATATE (Lutathera^®) is a radiolabeled analog of somatostatin administered intravenously in patients with somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors. Biodistribution of Lu-177 DOTATATE in tumor and healthy tissues can be monitored by serial post-injection scintigraphy imaging. Patient exposure to the drug is variable with the recommended fixed dosage, and hence there is a variable response to treatment. The aim of this work was to study the pharmacokinetics of Lu-177 DOTATATE by a population modeling approach, based on single-photon emission computed tomography (SPECT)/computed tomography (CT) images used as surrogate of plasma concentrations to study the interindividual variability and finally optimize an individual dosage.</p><p><strong>Methods: </strong>From a retrospective study, SPECT/CT images were acquired at 4 h, 24 h, 72 h, and 192 h postadministration. From these images, volumic activities were calculated in blood and bone marrow. An individual non-compartmental pharmacokinetic analysis was performed, and the mean pharmacokinetic parameters of each tissue were compared together and with reference data. Blood volumic activities were then used to perform a population pharmacokinetic analysis (NONMEM).</p><p><strong>Results: </strong>The pharmacokinetic parameters (non-compartmental analysis) obtained from blood (clearance [CL] = 2.65 L/h, volume of distribution at steady state [Vss] = 309 L, elimination half-life [t_1/2] = 86.3 h) and bone marrow (CL =1.68 L/h, Vss = 233 L, t_1/2 = 98.8 h) were statistically different from each other and from reference values (CL = 4.50 L/h, Vss = 460 L, t_1/2 = 71.0 h) published in the literature. SPECT/CT blood images were used as a surrogate of plasma concentrations to develop a population pharmacokinetic model. Weight was identified as covariate on volume of the central compartment, reducing the interindividual variability of all population pharmacokinetic parameters.</p><p><strong>Conclusion: </strong>This study is a proof of concept that obtaining pharmacokinetic parameters with image-based blood concentration is possible. Obtaining observed concentrations from SPECT/CT images, without the need for blood sampling, is a real advantage for the patient and the drug monitoring. Pharmacokinetic modeling could be combined with a deep learning model for automatic contouring and allow precise patient-specific dose adjustment in a non-invasive manner.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9849595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Study on the Pharmacokinetics of Paeoniflorin, White Peony Root Water Extract, and Taohong Siwu Decoction After Oral Administration in Rats.","authors":"Wei-Chun Chen,&nbsp;Xiao-Yi Liang,&nbsp;Li-Yuan Xie,&nbsp;Ming-An Wu,&nbsp;Qi Shen,&nbsp;Li-Mei Yao,&nbsp;Wei Zhao,&nbsp;Shi-Jie Zhang,&nbsp;Qi Wang,&nbsp;Yong Liang,&nbsp;Wei-Rong Li","doi":"10.1007/s13318-023-00825-9","DOIUrl":"https://doi.org/10.1007/s13318-023-00825-9","url":null,"abstract":"<p><strong>Background and objective: </strong>Taohong Siwu Decoction (TSD) is a classic traditional Chinese medicine (TCM) compound with pharmacological effects such as vasodilation and hypolipidemia. Paeoniflorin (PF) is one of the active ingredients of TSD. The aim of this study was to evaluate the pharmacokinetics of PF in herbal extracts and their purified forms in rats.</p><p><strong>Method: </strong>A sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) method for the determination of PF in rat plasma was developed. Rats were divided into three groups, and given PF solution, water extract of white peony root (WPR), or TSD by gavage. At different predetermined timepoints after gavage, blood was collected from the orbital vein. The pharmacokinetic parameters of PF in the plasma of rats in the three groups was determined.</p><p><strong>Results: </strong>The pharmacokinetic studies showed that the time to reach maximum concentration (T_max) of PF in the purified forms group was relatively high, while the half-lives (T_½) of PF in the TSD and WPR groups were longer. Among the three groups, PF in the purified forms group had the maximum area under the concentration-time curve (AUC_0-t = 732.997 µg/L·h) and the largest maximum concentration (C_max = 313.460 µg/L), which showed a significant difference compared with the TSD group (P < 0.05). Compared with the purified group, the clearance (CL_z/F = 86.004 L/h/kg) and the apparent volume of distribution (V_z/F = 254.787 L/kg) of PF in the TSD group increased significantly (P < 0.05).</p><p><strong>Conclusions: </strong>A highly specific, sensitive, and rapid HPLC-MS-MS method was developed and applied for the determination of PF in rat plasma. It was found that TSD and WPR can prolong the action time of paeoniflorin in the body.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9450214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Analysis of Pethidine Pharmacokinetics in Newborn Saliva, Plasma, and Brain Extracellular Fluid After Prenatal Intrauterine Exposure from Pregnant Mothers Receiving Intramuscular Dose Using PBPK Modeling.","authors":"Mo'tasem M Alsmadi,&nbsp;Nasir Idkaidek","doi":"10.1007/s13318-023-00823-x","DOIUrl":"https://doi.org/10.1007/s13318-023-00823-x","url":null,"abstract":"<p><strong>Background and objective: </strong>Pethidine (meperidine) can decrease labor pain-associated mother's hyperventilation and high cortisol-induced newborn complications. However, prenatal transplacentally acquired pethidine can cause side effects in newborns. High pethidine concentrations in the newborn brain extracellular fluid (bECF) can cause a serotonin crisis. Therapeutic drug monitoring (TDM) in newborns' blood distresses them and increases infection incidence, which can be overcome by using salivary TDM. Physiologically based pharmacokinetic (PBPK) modeling can predict drug concentrations in newborn plasma, saliva, and bECF after intrauterine pethidine exposure.</p><p><strong>Methods: </strong>A healthy adult PBPK model was constructed, verified, and scaled to newborn and pregnant populations after intravenous and intramuscular pethidine administration. The pregnancy PBPK model was used to predict the newborn dose received transplacentally at birth, which was used as input to the newborn PBPK model to predict newborn plasma, saliva, and bECF pethidine concentrations and set correlation equations between them.</p><p><strong>Results: </strong>Pethidine can be classified as a Salivary Excretion Classification System class II drug. The developed PBPK model predicted that, after maternal pethidine intramuscular doses of 100 mg and 150 mg, the newborn plasma and bECF concentrations were below the toxicity thresholds. Moreover, it was estimated that newborn saliva concentrations of 4.7 µM, 11.4 µM, and 57.7 µM can be used as salivary threshold concentrations for pethidine analgesic effects, side effects, and the risk for serotonin crisis, respectively, in newborns.</p><p><strong>Conclusion: </strong>It was shown that saliva can be used for pethidine TDM in newborns during the first few days after delivery to mothers receiving pethidine.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9827090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive Potential of BCS and Pharmacokinetic Parameters on Study Outcome: Analysis of 198 In Vivo Bioequivalence Studies.","authors":"Dejan Krajcar,&nbsp;Iztok Grabnar,&nbsp;Rebeka Jereb,&nbsp;Igor Legen,&nbsp;Jerneja Opara","doi":"10.1007/s13318-023-00821-z","DOIUrl":"https://doi.org/10.1007/s13318-023-00821-z","url":null,"abstract":"<p><strong>Background and objectives: </strong>Understanding predictive potential of parameters to perform early bioequivalence (BE) risk assessment is crucial for good planning and risk mitigation during product development. The objective of the present study was to evaluate predictive potential of various biopharmaceutical and pharmacokinetic parameters on the outcome of BE study.</p><p><strong>Methods: </strong>Retrospective analysis was performed on 198 Sandoz (Lek Pharmaceuticals d.d., A Sandoz Company, Verovskova 57, 1526 Ljubljana, Slovenia) sponsored BE studies [52 active pharmaceutical ingredients (API)] where characteristics of BE study and APIs were collected for immediate-release products and their predictive potential on the study outcome was assessed using univariate statistical analysis.</p><p><strong>Results: </strong>Biopharmaceutics Classification System (BCS) was confirmed to be highly predictive of BE success. BE studies with poorly soluble APIs were riskier (23% non-BE) than with highly soluble APIs (0.1% non-BE). APIs with either lower bioavailability (BA), presence of first-pass metabolism, and/or being substrate for P-glycoprotein substrate (P-gP) were associated with higher non-BE occurrence. In silico permeability and time at peak plasma concentrations (T_max) were shown as potentially relevant features for predicting BE outcome. In addition, our analysis showed significantly higher occurrence of non-BE results for poorly soluble APIs with disposition described by multicompartment model. The conclusions for poorly soluble APIs were the same on a subset of fasting BE studies; for a subset of fed studies there were no significant differences between factors in BE and non-BE groups.</p><p><strong>Conclusion: </strong>Understanding the association of parameters and BE outcome is important for further development of early BE risk assessment tools where focus should be first in finding additional parameters to differentiate BE risk within a group of poorly soluble APIs.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/8c/c3/13318_2023_Article_821.PMC10175306.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10139050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship Between Serum Ustekinumab Trough Concentration and Clinical and Biochemical Disease Activity: A Real-World Study in Adult Patients with Crohn's Disease.","authors":"Khue M Nguyen,&nbsp;Vandita Y Mattoo,&nbsp;Sara Vogrin,&nbsp;Chamara Basnayake,&nbsp;William R Connell,&nbsp;Nik S Ding,&nbsp;Emma Flanagan,&nbsp;Michael A Kamm,&nbsp;Mark Lust,&nbsp;Ola Niewiadomski,&nbsp;Julien D Schulberg,&nbsp;Emily K Wright","doi":"10.1007/s13318-023-00824-w","DOIUrl":"https://doi.org/10.1007/s13318-023-00824-w","url":null,"abstract":"<p><strong>Background and objectives: </strong>The role of therapeutic drug monitoring for ustekinumab in the treatment of Crohn's disease has not been defined. This study aimed to explore the relationship of serum ustekinumab trough concentration (UTC) with clinical and biochemical disease outcomes in a real-world setting.</p><p><strong>Methods: </strong>We performed a retrospective analysis of Crohn's disease patients treated at a single tertiary centre. Ustekinumab was given as a single intravenous induction dose, followed by maintenance subcutaneous injections every 4 to 8 weeks. Rates of clinical remission (Harvey-Bradshaw Index ≤ 4), biochemical remission (C-reactive protein < 5 mg/l and faecal calprotectin < 150 μg/g) and complete remission were assessed at baseline and at the time of UTC testing during maintenance therapy. The association between baseline variables and UTC was tested using linear regression. We also performed an external validation analysis of UTC cut-offs established in four previously published studies.</p><p><strong>Results: </strong>This study included 43 patients. Compared to 8-weekly dosing, a 2.49- and 2.65-fold increase in UTC was associated with 6-weekly and 4-weekly dosing respectively. However, there was no significant difference in clinical, biochemical or complete remission among the dosing groups. An external validation of previously published optimal UTC cut-offs found low predictive value for our patient population.</p><p><strong>Conclusions: </strong>In this study, dosing interval was the only determinant significantly associated with a higher UTC for patients on maintenance ustekinumab therapy. While a higher UTC may be achieved with dose escalation, it was not associated with improved rates of clinical or biochemical response in our cohort.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9456476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetics of N,N-dimethyltryptamine in Humans.","authors":"Meghan Good,&nbsp;Zelah Joel,&nbsp;Tiffanie Benway,&nbsp;Carol Routledge,&nbsp;Chris Timmermann,&nbsp;David Erritzoe,&nbsp;Richard Weaver,&nbsp;Graham Allen,&nbsp;Charlotte Hughes,&nbsp;Helen Topping,&nbsp;Amy Bowman,&nbsp;Ellen James","doi":"10.1007/s13318-023-00822-y","DOIUrl":"https://doi.org/10.1007/s13318-023-00822-y","url":null,"abstract":"<p><strong>Background and objective: </strong>N,N-dimethyltryptamine (DMT) is a psychedelic compound under development for the treatment of major depressive disorder (MDD). This study evaluated the preclinical and clinical pharmacokinetics and metabolism of DMT in healthy subjects.</p><p><strong>Methods: </strong>The physiochemical properties of DMT were determined using a series of in vitro experiments and its metabolic profile was assessed using monoamine oxidase (MAO) and cytochrome P450 (CYP) inhibitors in hepatocyte and mitochondrial fractions. Clinical pharmacokinetics results are from the phase I component of a phase I/IIa randomised, double-blind, placebo-controlled, parallel-group, dose-escalation trial (NCT04673383). Healthy adults received single escalating doses of DMT fumarate (SPL026) via a two-phase intravenous (IV) infusion. Dosing regimens were calculated based on pharmacokinetic modelling and predictions with progression to each subsequent dose level contingent upon safety and tolerability.</p><p><strong>Results: </strong>In vitro clearance of DMT was reduced through the inhibition of MAO-A, CYP2D6 and to a lesser extent CYP2C19. Determination of lipophilicity and plasma protein binding was low, indicating that a high proportion of DMT is available for distribution and metabolism, consistent with the very rapid clinical pharmacokinetics. Twenty-four healthy subjects received escalating doses of DMT administered as a 10-min infusion over the dose range of 9-21.5 mg (DMT freebase). DMT was rapidly cleared for all doses: mean elimination half-life was 9-12 min. All doses were safe and well tolerated and there was no relationship between peak DMT plasma concentrations and body mass index (BMI) or weight.</p><p><strong>Conclusion: </strong>This is the first study to determine, in detail, the full pharmacokinetics profile of DMT following a slow IV infusion in humans, confirming rapid attainment of peak plasma concentrations followed by rapid clearance. These findings provide evidence which supports the development of novel DMT infusion regimens for the treatment of MDD.</p><p><strong>Clinical trial registration: </strong>Registered on ClinicalTrials.gov (NCT04673383).</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/09/c5/13318_2023_Article_822.PMC10122081.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10493415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Cytochrome P450 2C9 in COVID-19 Treatment: Current Status and Future Directions.","authors":"Sharoen Yu Ming Lim,&nbsp;Basel Al Bishtawi,&nbsp;Willone Lim","doi":"10.1007/s13318-023-00826-8","DOIUrl":"10.1007/s13318-023-00826-8","url":null,"abstract":"<p><p>The major human liver drug metabolising cytochrome P450 (CYP) enzymes are downregulated during inflammation and infectious disease state, especially during coronavirus disease 2019 (COVID-19) infection. The influx of proinflammatory cytokines, known as a 'cytokine storm', during severe COVID-19 leads to the downregulation of CYPs and triggers new cytokine release, which further dampens CYP expression. Impaired drug metabolism, along with the inevitable co-administration of drugs or 'combination therapy' in patients with COVID-19 with various comorbidities, could cause drug-drug interactions, thus worsening the disease condition. Genetic variability or polymorphism in CYP2C9 across different ethnicities could contribute to COVID-19 susceptibility. A number of drugs used in patients with COVID-19 are inducers or inhibitors of, or are metabolised by, CYP2C9, and co-administration might cause pharmacokinetic and pharmacodynamic interactions. It is also worth mentioning that some of the COVID-19 drug interactions are due to altered activity of other CYPs including CYP3A4. Isoniazid/rifampin for COVID-19 and tuberculosis co-infection; lopinavir/ritonavir and cobicistat/remdesivir combination therapy; or multi-drug therapy including ivermectin, azithromycin, montelukast and acetylsalicylic acid, known as TNR4 therapy, all improved recovery in patients with COVID-19. However, a combination of CYP2C9 inducers, inhibitors or both, and plausibly different CYP isoforms could lead to treatment failure, hepatotoxicity or serious side effects including thromboembolism or bleeding, as observed in the combined use of azithromycin/warfarin. Further, herbs that are CYP2C9 inducers and inhibitors, showed anti-COVID-19 properties, and in silico predictions postulated that phytochemical compounds could inhibit SARS-CoV-2 virus particles. COVID-19 vaccines elicit immune responses that activate cytokine release, which in turn suppresses CYP expression that could be the source of compromised CYP2C9 drug metabolism and the subsequent drug-drug interaction. Future studies are recommended to determine CYP regulation in COVID-19, while recognising the involvement of CYP2C9 and possibly utilising CYP2C9 as a target gene to tackle the ever-mutating SARS-CoV-2.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10123480/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9450235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population Pharmacokinetic and Pharmacodynamic Modeling of Fesoterodine in Pediatric Patients with Neurogenic Detrusor Overactivity.","authors":"Yamato Sano,&nbsp;Satoshi Shoji,&nbsp;Mohamed Shahin,&nbsp;Kevin Sweeney,&nbsp;Amanda Darekar,&nbsp;Bimal K Malhotra","doi":"10.1007/s13318-023-00818-8","DOIUrl":"https://doi.org/10.1007/s13318-023-00818-8","url":null,"abstract":"<p><strong>Background and objective: </strong>Fesoterodine is a muscarinic receptor antagonist approved for the treatment of overactive bladder (OAB) in adults and neurogenic detrusor overactivity (NDO) in pediatric patients. This work aimed to characterize the population pharmacokinetics of 5-hydroxymethyl tolterodine (5-HMT, the active metabolite of fesoterodine) and its pharmacokinetic/pharmacodynamic relationship in pediatric patients with OAB or NDO following administration of fesoterodine.</p><p><strong>Methods: </strong>5-HMT plasma concentrations from 142 participants of age ≥ 6 years were analyzed, and a nonlinear mixed-effects model was developed. Weight-based simulations of 5-HMT exposure and maximum cystometric capacity (MCC) were conducted using the final models.</p><p><strong>Results: </strong>A one-compartment model with first-order absorption and a lag time, which included the effects of body weight, sex, cytochrome (CYP) 2D6 metabolizer status and fesoterodine formulation on pharmacokinetic parameters, best described the 5-HMT pharmacokinetics. An E_max model described the exposure-response relationship adequately. The median maximum concentration at steady state for pediatric patients weighing 25-35 kg and receiving 8 mg once daily (QD) was estimated to be 2.45 times greater than that in adults receiving 8 mg QD. Furthermore, simulation results showed dosing with fesoterodine 4 mg QD to pediatric patients weighing 25-35 kg and 8 mg QD to pediatric patients weighing >35 kg would achieve adequate exposure to demonstrate a clinically meaningful change from baseline (CFB) MCC.</p><p><strong>Conclusions: </strong>Population models were developed for 5-HMT and MCC in pediatric patients. Weight-based simulations indicated that 4 mg QD for pediatric patients weighing 25-35 kg and 8 mg QD for those weighing > 35 kg provided similar exposures to those in adults following 8 mg QD and a clinically meaningful CFB MCC.</p><p><strong>Clinical trial numbers: </strong>NCT00857896, NCT01557244.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/35/20/13318_2023_Article_818.PMC10175358.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10492951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population Pharmacokinetic Model for Unbound Concentrations of Daptomycin in Patients with MRSA Including Patients Undergoing Hemodialysis.","authors":"Saki Takahashi,&nbsp;Yasuhiro Tsuji,&nbsp;Nick Holford,&nbsp;Chika Ogami,&nbsp;Hidefumi Kasai,&nbsp;Hitoshi Kawasuji,&nbsp;Hideto To,&nbsp;Yoshihiro Yamamoto","doi":"10.1007/s13318-023-00820-0","DOIUrl":"https://doi.org/10.1007/s13318-023-00820-0","url":null,"abstract":"<p><strong>Background and objective: </strong>Unbound daptomycin concentrations are responsible for pharmacologically beneficial and adverse effects, although most previous reports have been limited to the use of total concentrations. We developed a population pharmacokinetic model to predict both total and unbound daptomycin concentrations.</p><p><strong>Methods: </strong>Clinical data were collected from 58 patients with methicillin-resistant Staphylococcus aureus including patients undergoing hemodialysis. A total of 339 serum total and 329 unbound daptomycin concentrations were used for model construction.</p><p><strong>Results: </strong>Total and unbound daptomycin concentration was explained by a model that assumed first-order distribution with two compartments, and first-order elimination. Normal fat body mass was identified as covariates. Renal function was incorporated as a linear function of renal clearance and independent non-renal clearance. The unbound fraction was estimated to be 0.066 with a standard albumin of 45 g/L and standard creatinine clearance of 100 mL/min. Simulated unbound daptomycin concentration was compared with minimum inhibitory concentration as a measure of clinical effectiveness and exposure-level-related induction of creatine phosphokinase elevation. The recommended doses were 4 mg/kg for patients with severe renal function [creatinine clearance (CLcr) ≤ 30 mL/min] and 6 mg/kg for patients with mild to moderate renal function (CLcr > 30 and ≤ 60 mL/min). A simulation indicated that dose adjusted by body weight and renal function improved target attainment.</p><p><strong>Conclusions: </strong>This population pharmacokinetics model for unbound daptomycin could help clinicians to select the appropriate dose regimen for patients undergoing daptomycin treatment and reduce associated adverse effects.</p>","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9480013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on \"Interchangeability between Generic and Reference Products: Limits of Average Bioequivalence Methodology\".","authors":"Patrick Nicolas,&nbsp;Xavier Bertagna","doi":"10.1007/s13318-022-00814-4","DOIUrl":"https://doi.org/10.1007/s13318-022-00814-4","url":null,"abstract":"","PeriodicalId":11939,"journal":{"name":"European Journal of Drug Metabolism and Pharmacokinetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9321740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}