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Allegaert K, Smits A, Annaert P. Interdisciplinary Collaboration on Real World Data to Close the Knowledge Gap: A Reflection on "De Sutter et al. Predicting Volume of Distribution in Neonates: Performance of Physiologically Based Pharmacokinetic Modelling". Pharmaceutics 2024; 16:128. [PMID: 38276498 PMCID: PMC10819087 DOI: 10.3390/pharmaceutics16010128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/28/2023] [Accepted: 01/16/2024] [Indexed: 01/27/2024] Open
Abstract
This commentary further reflects on the paper of De Sutter et al. on predicting volume of distribution in neonates, and the performance of physiologically based pharmacokinetic models We hereby stressed the add on value to collaborate on real world data to further close this knowledge gap. We illustrated this by weight distribution characteristics in breastfed (physiology) and in asphyxiated (pathophysiology), with additional reflection on their kidney and liver function.
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Affiliation(s)
- Karel Allegaert
- Clinical Pharmacology and Pharmacotherapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium;
- Department of Hospital Pharmacy, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands
| | - Anne Smits
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium;
- Neonatal Intensive Care Unit, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Pieter Annaert
- Drug Delivery and Disposition, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium;
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Authement AK, Isoherranen N. The impact of pregnancy and associated hormones on the pharmacokinetics of Δ 9-tetrahydrocannabinol. Expert Opin Drug Metab Toxicol 2024; 20:73-93. [PMID: 38258511 DOI: 10.1080/17425255.2024.2309213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/19/2024] [Indexed: 01/24/2024]
Abstract
INTRODUCTION (-)-Δ9-tetrahydrocannabinol (THC) is the main psychoactive component of cannabis. Cannabis is the most widely used drug of abuse by pregnant individuals, but its maternal-fetal safety is still unclear. The changes in THC disposition during pregnancy may affect THC safety and pharmacology. AREAS COVERED This review summarizes the current literature on THC metabolism and pharmacokinetics in humans. It provides an analysis of how hormonal changes during pregnancy may alter the expression of cannabinoid metabolizing enzymes and THC and its metabolite pharmacokinetics. THC is predominately (>70%) cleared by hepatic metabolism to its psychoactive active metabolite, 11-OH-THC by cytochrome P450 (CYP) 2C9 and to other metabolites (<30%) by CYP3A4. Other physiological processes that change during pregnancy and may alter cannabinoid disposition are also reviewed. EXPERT OPINION THC and its metabolites disposition likely change during pregnancy. Hepatic CYP2C9 and CYP3A4 are induced in pregnant individuals and in vitro by pregnancy hormones. This induction of CYP2C9 and CYP3A4 is predicted to lead to altered THC and 11-OH-THC disposition and pharmacodynamic effects. More in vitro studies of THC metabolism and induction of the enzymes metabolizing cannabinoids are necessary to improve the prediction of THC pharmacokinetics in pregnant individuals.
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Affiliation(s)
- Aurora K Authement
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA, USA
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De Sutter PJ, Rossignol P, Breëns L, Gasthuys E, Vermeulen A. Predicting Volume of Distribution in Neonates: Performance of Physiologically Based Pharmacokinetic Modelling. Pharmaceutics 2023; 15:2348. [PMID: 37765316 PMCID: PMC10536587 DOI: 10.3390/pharmaceutics15092348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/12/2023] [Accepted: 09/17/2023] [Indexed: 09/29/2023] Open
Abstract
The volume of distribution at steady state (Vss) in neonates is still often estimated through isometric scaling from adult values, disregarding developmental changes beyond body weight. This study aimed to compare the accuracy of two physiologically based pharmacokinetic (PBPK) Vss prediction methods in neonates (Poulin & Theil with Berezhkovskiy correction (P&T+) and Rodgers & Rowland (R&R)) with isometrical scaling. PBPK models were developed for 24 drugs using in-vitro and in-silico data. Simulations were done in Simcyp (V22) using predefined populations. Clinical data from 86 studies in neonates (including preterms) were used for comparison, and accuracy was assessed using (absolute) average fold errors ((A)AFEs). Isometric scaling resulted in underestimated Vss values in neonates (AFE: 0.61), and both PBPK methods reduced the magnitude of underprediction (AFE: 0.82-0.83). The P&T+ method demonstrated superior overall accuracy compared to isometric scaling (AAFE of 1.68 and 1.77, respectively), while the R&R method exhibited lower overall accuracy (AAFE: 2.03). Drug characteristics (LogP and ionization type) and inclusion of preterm neonates did not significantly impact the magnitude of error associated with isometric scaling or PBPK modeling. These results highlight both the limitations and the applicability of PBPK methods for the prediction of Vss in the absence of clinical data.
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Tyagi P, Ganguly A, Chermansky C, Tarin TV, Yoshimura N, Maranchie J. Does large volume of distribution of lidocaine masks its systemic uptake from bladder? Am J Clin Exp Urol 2023; 11:121-135. [PMID: 37168943 PMCID: PMC10165228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/17/2023] [Indexed: 05/13/2023]
Abstract
PURPOSE To assess whether therapeutic and toxic effects of intravesical lidocaine are determined by coincident serum levels. MATERIAL AND METHODS Published clinical trials and case studies on instilled lidocaine 1-2% that reported serum lidocaine levels were analyzed using model independent pharmacokinetic equations to compute the absorbed dose fraction (F) for linear regression with the respective dwell times. RESULTS Rapid absorption of intravesical lidocaine is evinced by the serum levels of 0.16±0.3 mg/L at 5 min in bladder cancer patients coinciding with the rapid onset of pain relief (<5 min) and blood pressure drop (≥10 mm Hg) in spinal cord injured patients. Serum levels at 5 min are raised five-fold by alkalinization for a tertiary amine with pKa of 7.8 and a linear rise in F with longer dwell time (r2 = 0.80; P<0.005) conforms to passive, paracellular diffusion of amphiphilic lidocaine (log P of 1.68) around umbrella cell borders with absorption rate at least five times faster than the terminal elimination rate, and therefore the delay in blood sampling after instillation is unwarranted. A rapid resolution of therapeutic and toxic effects is predicated on the extensive dilution of absorbed lidocaine with a rapid distribution half-life of 3.6 min in body weight dependent Vd - 15 times larger than blood volume, 0.13-4.5 L/kg which necessitates dose adjustment in children. CONCLUSION Whether rapid absorption of instilled lidocaine is complicated by an equally rapid and extensive dilution in body weight dependent Vd can be resolved by early blood sampling (<30 min) for: evidence-based medicine, avoidance of lidocaine toxicity in children and to educate the evolution of lidocaine solution to gel and devices.
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Affiliation(s)
- Pradeep Tyagi
- Department of Urology, University of Pittsburgh Pittsburgh, PA 15213, USA
| | - Anirban Ganguly
- Department of Urology, University of Pittsburgh Pittsburgh, PA 15213, USA
| | | | - Tatum V Tarin
- Department of Urology, University of Pittsburgh Pittsburgh, PA 15213, USA
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh Pittsburgh, PA 15213, USA
| | - Jodi Maranchie
- Department of Urology, University of Pittsburgh Pittsburgh, PA 15213, USA
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Hughes EA, Zieliński R, Ray AE, Priebe W, Douglass EF. Development of a Novel Tool to Demystify Drug Distribution at Tissue-Blood Barriers. Chembiochem 2023:e202200804. [PMID: 36951632 DOI: 10.1002/cbic.202200804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/24/2023]
Abstract
Tissue endothelial cells express ABC-transporter enzymes that change the concentration of small molecule within different tissue-compartments. These "blood-tissue barriers" have been shown to directly affect the efficacy and toxicity of anti-cancer, anti-microbial, psychiatric, and anti-epileptic drugs. Currently this phenomenon is best studied for the blood-brain barrier but remains enigmatic for most other tissues. In addition, canonical pharmacokinetic theory specifically assumes an equal concentration of free drug within all tissue compartments. Inspired by Lipinski's "rule of 5," we here clarify current knowledge on drug-tissue distribution by: (1) curating the in vivo literature on 73 drugs across 23 tissues and (2) developing two graphical web-based applications to visually describe and interpret data. This curated in vivo dataset and visualization tools enabled us to achieve new insights into the logic of the barrier-tissues organization and showed remarkable correspondence to whole-body imaging of radiolabeled molecules.
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Affiliation(s)
- Elizabeth A Hughes
- University of Georgia College of Pharmacy, Pharmaceutical and Biomedical Sciences, 240 West Green Street, 30602-0001, Athens, UNITED STATES
| | - Rafał Zieliński
- The University of Texas MD Anderson Cancer Center, Department of Experimental Therapeutics, 1901 East Rd., 77054, Houston, UNITED STATES
| | - Ashley E Ray
- University of Georgia College of Pharmacy, Pharmaceutical and Biomedical Sciences, 240 W Green St, 30602, Athens, UNITED STATES
| | - Waldemar Priebe
- The University of Texas MD Anderson Cancer Center, Department of Experimental Therapeutics, 1901 East Rd., 77054, Houston, UNITED STATES
| | - Eugene F Douglass
- University of Georgia College of Pharmacy, Pharmaceutical and Biomedical Sciences, 240 W Green St, 30602, Athens, UNITED STATES
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Bakulina NV, Tikhonov SV, Okovityi SV, Lutaenko EA, Bolshakov AO, Prikhodko VA, Nekrasova AS. [Pharmacokinetics and pharmacodynamics of rebamipide. New possibilities of therapy: A review]. TERAPEVT ARKH 2023; 94:1431-1437. [PMID: 37167190 DOI: 10.26442/00403660.2022.12.202000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 01/15/2023] [Indexed: 01/18/2023]
Abstract
The MedLine database contains 570 publications, including 71 randomized clinical trials and 6 meta-analyses on the rebamipide molecule in 2022. Indications for the use of rebamipide are gastric ulcer, chronic gastritis with hyperacidityin the acute stage, erosive gastritis, prevention of damage to the gastrointestinal mucosa while taking non-steroidal anti-inflammatory drugs, eradication of Helicobacter pylori. Currently trials are studying the efficacy and safety of the drug in gouty and rheumatoid arthritis, osteoarthritis, Sjögren's syndrome, bronchial asthma, vitiligo, atherosclerosis, diseases of the kidneys and liver; using in traumatology to accelerate bone regeneration; in ophthalmology to improve the regeneration of corneal epithelium; in oncology to reduce inflammatory changes in the oral mucosa after chemoradiotherapy. The review article is about the main pharmacokinetic and pharmacodynamic characteristics of rebamipide. A detailed understanding of pharmacodynamics and pharmacokinetics allows for individual selection of therapy based on the characteristics of the patient's body - gender, age, comorbidities; choose the optimal route of administration and dosing regimen; predict adverse effects and drug interactions; be determined with new clinical indications.
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Affiliation(s)
- N V Bakulina
- Mechnikov North-Western State Medical University
| | - S V Tikhonov
- Mechnikov North-Western State Medical University
| | - S V Okovityi
- Saint Petersburg State Chemical Pharmaceutical University
| | - E A Lutaenko
- Mechnikov North-Western State Medical University
| | | | - V A Prikhodko
- Saint Petersburg State Chemical Pharmaceutical University
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Saunders LJ, Nichols JW. Models Used to Predict Chemical Bioaccumulation in Fish from in Vitro Biotransformation Rates Require Accurate Estimates of Blood-Water Partitioning and Chemical Volume of Distribution. Environ Toxicol Chem 2023; 42:33-45. [PMID: 36282023 PMCID: PMC10824487 DOI: 10.1002/etc.5503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/11/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Methods for extrapolating measured in vitro intrinsic clearance to a whole-body biotransformation rate constant (kB ) have been developed to support modeled bioaccumulation assessments for fish. The inclusion of extrapolated kB values into existing bioaccumulation models improves the prediction of chemical bioconcentration factors (BCFs), but there remains a tendency for these methods to overestimate BCFs relative to measured values. Therefore, a need exists to evaluate the extrapolation procedure to assess potential sources of error in predicted kB values. We examined how three different approaches (empirically based, composition based, and polyparameter linear free energy relationships [ppLFERs]) used to predict chemical partitioning in vitro (liver S9 system; KS9W ), in blood (KBW ), and in whole fish tissues (KFW ) impact the prediction of a chemical's hepatic clearance binding term (fU ) and apparent volume of distribution (VD ), both of which factor into the calculation of kB and the BCF. Each approach yielded different KS9W , KBW , and KFW values, but resulted in fU values that were of similar magnitude and remained relatively constant at log octanol-water partition ratios (KOW ) greater than 4. This is because KBW and KS9W values predicted by any given approach exhibit a similar dependence on log KOW (i.e., regression slope), which results in a cancelation of "errors" when fU is calculated. In contrast, differences in KBW values predicted by the three approaches translate to differences in VD , and by extension kB and the BCF, which become most apparent at log KOW greater than 6. There is a need to collect KBW and VD data for hydrophobic chemicals in fish that can be used to evaluate and improve existing partitioning prediction approaches in extrapolation models for fish. Environ Toxicol Chem 2023;42:33-45. © 2022 SETAC.
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Affiliation(s)
- Leslie J. Saunders
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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Matsumoto S, Uehara S, Kamimura H, Cho N, Ikeda H, Maeda S, Kagiyama K, Miyata A, Suemizu H, Fukasawa K. Selection of the candidate compound at an early stage of new drug development: retrospective pharmacokinetic and metabolic evaluations of valsartan using common marmosets. Xenobiotica 2022; 52:613-624. [PMID: 36148579 DOI: 10.1080/00498254.2022.2127131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Shogo Matsumoto
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Shotaro Uehara
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan
| | - Hidetaka Kamimura
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan.,Business Promotion Department, CLEA Japan, Inc., Tokyo, Japan
| | - Naoki Cho
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Hiroshi Ikeda
- Tokyo Animal & Diet Department, CLEA Japan, Inc., Tokyo, Japan
| | - Satoshi Maeda
- Yaotsu Breeding Center, CLEA Japan, Inc., Gifu, Japan
| | | | - Atsunori Miyata
- Drug & Discovery & Management Department, R&D Division, Meiji Seika Pharma Co., Ltd., Tokyo, Japan
| | - Hiroshi Suemizu
- Department of Applied Research for Laboratory Animals, Central Institute for Experimental Animals, Kawasaki, Japan
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Fagerholm U, Hellberg S, Alvarsson J, Arvidsson McShane S, Spjuth O. In silico prediction of volume of distribution of drugs in man using conformal prediction performs on par with animal data-based models. Xenobiotica 2021; 51:1366-1371. [PMID: 34845977 DOI: 10.1080/00498254.2021.2011471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Volume of distribution at steady state (Vss) is an important pharmacokinetic endpoint. In this study we apply machine learning and conformal prediction for human Vss prediction, and make a head-to-head comparison with rat-to-man scaling, allometric scaling and the Rodgers-Lukova method on combined in silico and in vitro data, using a test set of 105 compounds with experimentally observed Vss.The mean prediction error and % with <2-fold prediction error for our method were 2.4-fold and 64%, respectively. 69% of test compounds had an observed Vss within the prediction interval at a 70% confidence level. In comparison, 2.2-, 2.9- and 3.1-fold mean errors and 69, 64 and 61% of predictions with <2-fold error was reached with rat-to-man and allometric scaling and Rodgers-Lukova method, respectively.We conclude that our method has theoretically proven validity that was empirically confirmed, and showing predictive accuracy on par with animal models and superior to an alternative widely used in silico-based method. The option for the user to select the level of confidence in predictions offers better guidance on how to optimise Vss in drug discovery applications.
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Affiliation(s)
| | | | - Jonathan Alvarsson
- Department of Pharmaceutical Biosciences and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Staffan Arvidsson McShane
- Department of Pharmaceutical Biosciences and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ola Spjuth
- Department of Pharmaceutical Biosciences and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Grensemann J, Pfaffendorf C, Wicha SG, König C, Roedl K, Jarczak D, Iwersen-Bergmann S, Manthey C, Kluge S, Fuhrmann V. Voriconazole Pharmacokinetics Are Not Altered in Critically Ill Patients with Acute-on-Chronic Liver Failure and Continuous Renal Replacement Therapy: An Observational Study. Microorganisms 2021; 9:2087. [PMID: 34683408 DOI: 10.3390/microorganisms9102087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/25/2021] [Accepted: 09/28/2021] [Indexed: 11/28/2022] Open
Abstract
Infection and sepsis are a main cause of acute-on-chronic liver failure (ACLF). Besides bacteria, molds play a role. Voriconazole (VRC) is recommended but its pharmacokinetics (PK) may be altered by ACLF. Because ACLF patients often suffer from concomitant acute renal failure, we studied the PK of VRC in patients receiving continuous renal replacement therapy (RRT) with ACLF and compared it to PK of VRC in critically ill patients with RRT without concomitant liver failure (NLF). In this prospective cohort study, patients received weight-based VRC. Pre- and post-dialysis membrane, and dialysate samples obtained at different time points were analyzed by high-performance liquid chromatography. An integrated dialysis pharmacometric model was used to model the available PK data. The recommended, 50% lower, and 50% higher doses were analyzed by Monte-Carlo simulation (MCS) for day 1 and at steady-state with a target trough concentration (TC) of 0.5–3mg/L. Fifteen patients were included in this study. Of these, 6 patients suffered from ACLF. A two-compartment model with linear clearance described VRC PK. No difference for central (V1) or peripheral (V2) volumes of distribution or clearance could be demonstrated between the groups. V1 was 80.6L (95% confidence interval: 62.6–104) and V2 106L (65–166) with a body clearance of 4.7L/h (2.87–7.81) and RRT clearance of 1.46L/h (1.29–1.64). MCS showed TC below/within/above target of 10/74/16% on day 1 and 9/39/52% at steady-state for the recommended dose. A 50% lower dose resulted in 26/72/1% (day 1) and 17/64/19% at steady-state and 7/57/37% and 7/27/67% for a 50% higher dose. VRC pharmacokinetics are not significantly influenced by ACLF in critically ill patients who receive RRT. Maintenance dose should be adjusted in both groups. Due to the high interindividual variability, therapeutic drug monitoring seems inevitable.
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Rechberger JS, A Power E, Millesi E, Daniels DJ. Antibody-drug conjugates for H3K27M-mutant diffuse midline gliomas: prospects and challenges. Ther Deliv 2021; 12:553-7. [PMID: 34286602 DOI: 10.4155/tde-2021-0045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Rechberger JS, Power EA, Daniels DJ. Convection-enhanced delivery for H3K27M diffuse midline glioma: how can we efficaciously modulate the blood-brain barrier? Ther Deliv 2021; 12:419-22. [PMID: 33949200 DOI: 10.4155/tde-2021-0026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Graphical abstract [Formula: see text].
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Monaghan KN, Labato MA, Papich MG. Ampicillin pharmacokinetics in azotemic and healthy dogs. J Vet Intern Med 2021; 35:987-992. [PMID: 33474795 PMCID: PMC7995374 DOI: 10.1111/jvim.16026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Little is known about effects of factors such as kidney disease, affecting ampicillin pharmacokinetics in dogs. OBJECTIVES Determine the pharmacokinetics of ampicillin after a single intravenous dose in healthy and azotemic dogs. ANIMALS Nine dogs presenting with acute kidney injury and 10 healthy dogs. METHODS This was a prospective study. An ampicillin dose of 22.2 mg/kg (mean dose) was administered once intravenously. Blood samples were obtained at timed intervals (just before administration, 1, 2, 4, 12, and 24 hours), analyzed using high-pressure liquid chromatography followed by pharmacokinetic analysis of the plasma drug concentrations. RESULTS Peak ampicillin concentration (mcg/mL; 97.07 (36.1) vs 21.3 (50.26)), P<.001 (geometric mean (coefficient of variation, CV%)), half-life (hours; 5.86 (56.55) vs 0.97 (115.3)), P<.001) and AUC (h × mcg/mL; 731.04 (83.75) vs 33.57 (53.68)), P<.001) were greater in azotemic dogs than in healthy dogs. Azotemic dogs also had significantly lower clearance (30.06 (84.19) vs 655.03 (53.67); mL/kg h, P < .001) and volume of distribution (253.95 (30.14) vs 916.93 (135.24); mL/kg, P <.001) compared to healthy dogs. CONCLUSION AND CLINICAL IMPORTANCE Increased drug concentrations and slower clearance of ampicillin in azotemic dogs could have clinical importance in contributing to antibiotic associated morbidity requiring indicating the need to adjust ampicillin dosing in dogs with decreased kidney function.
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Affiliation(s)
- Kelly N. Monaghan
- Cummings School of Veterinary MedicineTufts University, Veterinary Clinical ScienceNorth GraftonMassachusettsUSA
- Present address: Kelly N. Monaghan, Aspen Meadow Veterinary Specialists, 104 South Main StreetLongmontCOUSA
| | - Mary Anna Labato
- Cummings School of Veterinary MedicineTufts University, Veterinary Clinical ScienceNorth GraftonMassachusettsUSA
| | - Mark G. Papich
- Department of Molecular Biomedical SciencesNorth Carolina State University, College of Veterinary MedicineRaleighNorth CarolinaUSA
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Rechberger JS, Power EA, Lu VM, Zhang L, Sarkaria JN, Daniels DJ. Evaluating infusate parameters for direct drug delivery to the brainstem: a comparative study of convection-enhanced delivery versus osmotic pump delivery. Neurosurg Focus 2021; 48:E2. [PMID: 31896090 DOI: 10.3171/2019.10.focus19703] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/03/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Convection-enhanced delivery (CED) and osmotic pump delivery both have been promoted as promising techniques to deliver drugs to pediatric diffuse intrinsic pontine gliomas (DIPGs). Correspondingly, the aim of this study was to understand how infusate molecular weight (MW), duration of delivery, and mechanism of delivery (CED or osmotic pump) affect volume of distribution (Vd) in the brainstem, to better inform drug selection and delivery in future DIPG investigations. METHODS A series of in vivo experiments were conducted using rat models. CED and osmotic pump delivery systems were surgically implanted in the brainstem, and different MW fluorescent dextran beads were infused either once (acute) or daily for 5 days (chronic) in a volume infused (Vi). Brainstems were harvested after the last infusion, and Vd was quantified using serial sectioning and fluorescence imaging. RESULTS Fluorescence imaging showed infusate uptake within the brainstem for both systems without complication. A significant inverse relationship was observed between infusate MW and Vd in all settings, which was distinctly exponential in nature in the setting of acute delivery across the 570-Da to 150-kDa range. Chronic duration and CED technique resulted in significantly greater Vd compared to acute duration or osmotic pump delivery, respectively. When accounting for Vi, acute infusion yielded significantly greater Vd/Vi than chronic infusion. The distribution in CED versus osmotic pump delivery was significantly affected by infusate MW at higher weights. CONCLUSIONS Here the authors demonstrate that infusate MW, duration of infusion, and infusion mechanism all impact the Vd of an infused agent and should be considered when selecting drugs and infusion parameters for novel investigations to treat DIPGs.
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Affiliation(s)
| | - Erica A Power
- 1Department of Neurologic Surgery, Mayo Clinic.,2Mayo Clinic Graduate School of Biomedical Sciences
| | - Victor M Lu
- 1Department of Neurologic Surgery, Mayo Clinic
| | - Liang Zhang
- 1Department of Neurologic Surgery, Mayo Clinic
| | | | - David J Daniels
- 1Department of Neurologic Surgery, Mayo Clinic.,4Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
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Bruno CD, Harmatz JS, Duan SX, Zhang Q, Chow CR, Greenblatt DJ. Effect of lipophilicity on drug distribution and elimination: Influence of obesity. Br J Clin Pharmacol 2021; 87:3197-3205. [PMID: 33450083 DOI: 10.1111/bcp.14735] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/11/2020] [Accepted: 12/26/2020] [Indexed: 12/11/2022] Open
Abstract
AIMS For a given passively-distributed lipophilic drug, the extent of in vivo distribution (pharmacokinetic volume of distribution, Vd ) in obese individuals increases in relation to the degree of obesity. The present study had the objective of evaluating drug distribution in relation to in vitro lipophilicity, and the relative increase in Vd associated with obesity across a series of drugs. METHODS Cohorts of normal-weight control and obese subjects received single doses of drugs ranging from hydrophilic (acetaminophen, salicylate) to lipophilic (imipramine, verapamil). Lipid solubility was measured by the log-transformed values of the high-pressure liquid chromatographic (HPLC) retention index (Log10 (HPLC)), and the octanol-water partition coefficient (LogP). RESULTS Among normal-weight controls, Vd normalized for protein binding was highly correlated with Log10 (HPLC) (R2 = .65) and with LogP (R2 = .78). Vd of all drugs was increased in the obese cohort, but the relative increase (compared to controls) for individual drugs was disproportionately greater as lipid solubility increased. Since clearance was unrelated to lipophilicity, the increased Vd produced a parallel disproportionate increase in elimination half-life in the obese cohort that was associated with Log10 (HPLC) (R2 = .62). CONCLUSION Lipophilicity is a principal correlate of in vivo Vd , as well as the increased Vd of drugs in obese patients. The consequent prolongation of half-life in obesity has clinical safety implications in terms of delayed drug accumulation and washout during and after chronic dosage. The magnitude and importance of this effect for a given drug depends on the degree of obesity, as well as the lipid-solubility of the specific drug.
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Affiliation(s)
| | | | - Su X Duan
- Tufts University School of Medicine, Boston, MA, USA
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16
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Miyahara T, Yamaguchi I, Tamai T. [A New Method for Calculating Iodine Dose in Abdominal Dynamic Contrast-enhanced Computed Tomography: Calculation Based on Patients' Body Size Parameters and Estimated Volume of Distribution of Non-ionic Contrast Medium]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:932-940. [PMID: 34544917 DOI: 10.6009/jjrt.2021_jsrt_77.9.932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
PURPOSE This study aimed at analyzing the relationship between the estimated volume of distribution on computed tomography (eVdCT) of non-ionic contrast medium and four different patients' body size parameters (BSPs) (total body weight, body mass index, body surface area, and lean body weight) in abdominal dynamic contrast-enhanced computed tomography (ADCE-CT) . Moreover, this study intended to derive a method for calculating the iodine dose to target contrast enhancement. METHODS We measured enhanced CT values of the equilibrium phase of the abdominal aorta in 527 patients who underwent ADCE-CT. The eVdCT of the ADCE-CT equilibrium phase was calculated from enhanced CT values based on the pharmacokinetic model. The optimal iodine dose (OID) was calculated from the regression analysis of eVdCT and BSP. RESULTS The eVdCT was 7741.1±1799.5 ml. The eVdCT showed a strong positive correlation with BSP and could be calculated using a linear regression equation. The correlation coefficients for total body weight, body surface area, and lean body weight were 0.83, 0.84, and 0.81, respectively. The OID per unit BSP required for target iodine concentration of the abdominal aorta on ADCE-CT (TIC) could be calculated as "OID [mgI/BSP]=[(a・BSP+b)×TIC]/BSP". CONCLUSION The OID calculation method based on the patients' body size parameters and estimated volume of distribution can normalize contrast enhancement in abdominal dynamic contrast-enhanced CT.
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Affiliation(s)
- Tetsuya Miyahara
- Department of Medical Technology, Division of Radiology, Osaka General Medical Center
| | - Isao Yamaguchi
- Faculty of Health Sciences, Department of Radiological Sciences, Morinomiya University of Medical Sciences
| | - Toshihisa Tamai
- Department of Medical Technology, Division of Radiology, Osaka General Medical Center
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Hillmer AT, Carson RE. Quantification of PET infusion studies without true equilibrium: A tissue clearance correction. J Cereb Blood Flow Metab 2020; 40:860-874. [PMID: 31088233 PMCID: PMC7168787 DOI: 10.1177/0271678x19850000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/21/2019] [Indexed: 11/16/2022]
Abstract
In some positron emission tomography (PET) studies, a reversibly binding radioligand is administered as a constant infusion to establish true equilibrium for quantification. This approach reduces scanning time and simplifies data analysis, but assumes similar behavior of the radioligand in plasma across the study population to establish true equilibrium in all subjects. Bias in outcome measurements can result if this assumption is not met. This work developed and validated a correction that reduces bias in total distribution volume (VT) estimates when true equilibrium is not present. This correction, termed tissue clearance correction (TCC), took the form V T = V T ( A ) / ( 1 + β γ V T ( A ) ) , where β is the radioligand clearance rate in tissue, γ is a radiotracer-specific constant, and VT(A) is the apparent VT. Simulations characterized the robustness of TCC across imperfect values of γ and β and demonstrated reduction to false positive rates. This approach was validated with human infusion data for three radiotracers: [18F]FPEB, (-)-[18F]flubatine, and [11C]UCB-J. TCC reduced bias in VT estimates for all radiotracers and significantly reduced intersubject variance in VT for [18F]FPEB data in some brain regions. Thus, TCC improves quantification of data acquired from PET infusion studies.
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Affiliation(s)
- Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Yale University PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Yale University PET Center, Yale University School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, CT, USA
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Dao K, Thoueille P, Decosterd LA, Mercier T, Guidi M, Bardinet C, Lebon S, Choong E, Castang A, Guittet C, Granier LA, Buclin T. Sultiame pharmacokinetic profile in plasma and erythrocytes after single oral doses: A pilot study in healthy volunteers. Pharmacol Res Perspect 2020; 8:e00558. [PMID: 31990440 PMCID: PMC6986439 DOI: 10.1002/prp2.558] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 12/13/2019] [Indexed: 12/02/2022] Open
Abstract
A pilot study was conducted aiming at specifying sultiame's pharmacokinetic profile, completed by in vitro assays evaluating the intraerythrocytic transfer of sultiame and by a pharmacokinetic model assessing its distribution. Single oral doses of sultiame (Ospolot® 50, 100, and 200 mg) were administered in open‐label to four healthy volunteers. Serial plasma, whole blood, and urine samples were collected. A spiking experiment was also performed to characterize sultiame's exchanges between plasma and erythrocytes in vitro. Pharmacokinetic parameters were evaluated using standard noncompartmental calculations and nonlinear mixed‐effect modeling. The plasma maximal concentrations (Cmax) showed striking nonlinear disposition of sultiame, with a 10‐fold increase while doses were doubled. Conversely, whole blood Cmax increased less than dose proportionally while staying much higher than in plasma. Quick uptake of sultiame into erythrocytes observed in vivo was confirmed in vitro, with minimal efflux. A two‐compartment model with first‐order absorption, incorporating a saturable ligand to receptor binding, described the data remarkably well, indicating apparent plasma clearance of 10.0 L/h (BSV: 29%) and distribution volume of 64.8 L; saturable uptake into an intracellular compartment of 3.3 L with a maximum binding capacity of 111 mg accounted for nonlinearities observed in plasma and whole blood concentrations. Pharmacokinetic characteristics of sultiame are reported, including estimates of clearance and volume of distribution that were so far unpublished. The noticeable nonlinearity in sultiame disposition should be taken into account for the design of future studies and the interpretation of therapeutic drug monitoring results.
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Affiliation(s)
- Kim Dao
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Paul Thoueille
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Laurent A Decosterd
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Thomas Mercier
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Monia Guidi
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,School of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of western Switzerland, Geneva, Switzerland
| | - Carine Bardinet
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Sébastien Lebon
- Unit of Paediatric Neurology and Neurorehabilitation, Department Mother-Woman-Child, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Eva Choong
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | | | | | | | - Thierry Buclin
- Service of Clinical Pharmacology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
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Fayyaz A, Ranta VP, Toropainen E, Vellonen KS, Ricci GD, Reinisalo M, Heikkinen EM, Gardner I, Urtti A, Jamei M, Del Amo EM. Ocular Intracameral Pharmacokinetics for a Cocktail of Timolol, Betaxolol, and Atenolol in Rabbits. Mol Pharm 2020; 17:588-594. [PMID: 31794668 DOI: 10.1021/acs.molpharmaceut.9b01024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mechanisms of drug clearance from the aqueous humor are poorly defined. In this study, a cocktail approach was used to simultaneously determine the pharmacokinetics of three β-blocker agents after intracameral (ic) injection into the rabbit eyes. Aqueous humor samples were collected and analyzed using LC-MS/MS to determine drug concentrations. Pharmacokinetic parameters were obtained using a compartmental fitting approach, and the estimated clearance, volume of distribution, and half-life values were the following: atenolol (6.44 μL/min, 687 μL, and 73.87 min), timolol (19.30 μL/min, 937 μL, and 33.64 min), and betaxolol (32.20 μL/min, 1421 μL, and 30.58 min). Increased compound lipophilicity (atenolol < timolol < betaxolol) resulted in higher clearance and volume of distributions in the aqueous humor. Clearance of timolol and betaxolol is about 10 times higher than the aqueous humor outflow, demonstrating the importance of other elimination routes (e.g., uptake to iris and ciliary body and subsequent elimination via blood flow).
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Affiliation(s)
- Anam Fayyaz
- Certara UK, Simcyp Division , Level 2-Acero, 1 Concourse Way , Sheffield S1 2BJ , U.K.,University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Veli-Pekka Ranta
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Elisa Toropainen
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Kati-Sisko Vellonen
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Giuseppe D'Amico Ricci
- University of Sassari , Department of Biomedical Sciences , Sassari , Italy.,Asl Città di Torino, Ospedale Oftalmico di Torino , U.O.C Oculistica 2, Ospedale San Giovanni Bosco di Torino , Torino , Italy
| | - Mika Reinisalo
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland.,Institute of Clinical Medicine, Department of Ophthalmology, Faculty of Health Sciences , University of Eastern Finland , 70210 Kuopio , Finland
| | - Emma M Heikkinen
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Iain Gardner
- Certara UK, Simcyp Division , Level 2-Acero, 1 Concourse Way , Sheffield S1 2BJ , U.K
| | - Arto Urtti
- University of Eastern Finland , School of Pharmacy, Biopharmaceutics , Yliopistonranta 1 , 70210 Kuopio , Finland
| | - Masoud Jamei
- Certara UK, Simcyp Division , Level 2-Acero, 1 Concourse Way , Sheffield S1 2BJ , U.K
| | - Eva M Del Amo
- University of Manchester , Division of Pharmacy & Optometry , Oxford Road , Manchester M13 9PL , U.K
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20
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Pilková A, Hartinger JM. Obesity-associated changes in drug pharmacokinetics. Vnitr Lek 2020; 66:465-471. [PMID: 33740844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pharmacokinetics of drugs in obese patients can be affected by changes in drug distribution and/or changes in elimination functions. Drug dosing based on patients weight or body surface area may not be satisfactory in terms of safety or efficacy, especially for patients with a higher degree of obesity. However, current knowledge about most drugs does not provide sufficient guidance for dose adjustment in this group of patients. This article provides an overview of factors influencing changes in pharmacokinetics of drugs in obese, including some examples (eg. analgesics, antibiotics, anticoagulants and others). Due to different changes in pharmacokinetics, which cannot always be estimated from the physical and chemical properties of drug molecular structure, it is important to assess pharmacokinetic properties of a particular drug rather than looking for general rules for the most appropriate dosing. In case of drugs with a narrow therapeutic index (aminoglycoside antibiotics and vancomycin, anticonvulsants, immunosuppressants, lithium, digoxin and theophylline), it is always advisable to measure drug plasma levels and use therapeutic drug monitoring.
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21
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Benet LZ, Bowman CM, Sodhi JK. How Transporters Have Changed Basic Pharmacokinetic Understanding. AAPS J 2019; 21:103. [PMID: 31482335 DOI: 10.1208/s12248-019-0373-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/16/2019] [Indexed: 12/17/2022]
Abstract
The emergence and continued evolution of the transporter field has caused re-evaluation and refinement of the original principles surrounding drug disposition. In this paper, we emphasize the impact that transporters can have on volume of distribution and how this can affect the other major pharmacokinetic parameters. When metabolic drug-drug interactions or pharmacogenomic variance changes the metabolism of a drug, the volume of distribution appears to be unchanged while clearance, bioavailability, and half-life are changed. When transporters are involved in the drug-drug interactions or pharmacogenomic variance, the volume of distribution can be markedly affected causing counterintuitive changes in half-life. Cases are examined where a volume of distribution change is significant enough that although clearance decreases, half-life decreases. Thus, drug dosing decisions must be made based on CL/F changes, not half-life changes, as such volume of distribution alterations will also influence the half-life results.
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Affiliation(s)
- Leslie Z Benet
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, 533 Parnassus Avenue, Room U-68, UCSF Box 0912, San Francisco, California, 94143, USA.
| | - Christine M Bowman
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, 533 Parnassus Avenue, Room U-68, UCSF Box 0912, San Francisco, California, 94143, USA
| | - Jasleen K Sodhi
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, 533 Parnassus Avenue, Room U-68, UCSF Box 0912, San Francisco, California, 94143, USA
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Abstract
Guidelines recommend that patients treated with continuous renal replacement therapy be delivered an effluent dose of 20 to 25 mL/kg/h. There is debate, especially at the extremes of body mass index, as to whether actual or ideal body weight (IBW) should be used in these dose calculations. A middle-aged woman with severe anorexia presented with 48 hours of altered mental status. Laboratory tests showed severe metabolic acidosis necessitating intubation, which was ultimately found to be due to nonprescribed use of metformin for weight loss. The patient became anuric and was initiated on continuous venovenous hemodialysis. Due to refractory acidosis, the modality was converted to continuous venovenous hemodiafiltration by adding postfilter hypertonic bicarbonate solution. Based on changes in sodium and bicarbonate levels over 4 hours with hypertonic bicarbonate solution, we were able to calculate an “effective” volume of distribution for this severely underweight patient. Our calculations suggest that IBW gives a better approximation of effective volume of distribution than actual body weight in a severely underweight woman. Inadequate effluent flow rate calculated based on actual rather than IBW may lead to insufficient correction of metabolic derangements in extremely underweight patients.
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Affiliation(s)
- Benjamin R Griffin
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO
| | - Sophia Ambruso
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO.,Renal Section, VA Eastern Colorado Health Care System, Denver, CO
| | - Anna Jovanovich
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO.,Renal Section, VA Eastern Colorado Health Care System, Denver, CO
| | - Anip Bansal
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO
| | - Stu Linas
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO.,Division of Nephrology, Denver Health Medical Center, Denver, CO
| | - James Dylewski
- Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Campus, Aurora, CO.,Division of Nephrology, Denver Health Medical Center, Denver, CO
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Millar SA, Stone NL, Yates AS, O'Sullivan SE. A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans. Front Pharmacol 2018; 9:1365. [PMID: 30534073 PMCID: PMC6275223 DOI: 10.3389/fphar.2018.01365] [Citation(s) in RCA: 290] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/07/2018] [Indexed: 12/02/2022] Open
Abstract
Background: Cannabidiol is being pursued as a therapeutic treatment for multiple conditions, usually by oral delivery. Animal studies suggest oral bioavailability is low, but literature in humans is not sufficient. The aim of this review was to collate published data in this area. Methods: A systematic search of PubMed and EMBASE (including MEDLINE) was conducted to retrieve all articles reporting pharmacokinetic data of CBD in humans. Results: Of 792 articles retireved, 24 included pharmacokinetic parameters in humans. The half-life of cannabidiol was reported between 1.4 and 10.9 h after oromucosal spray, 2–5 days after chronic oral administration, 24 h after i.v., and 31 h after smoking. Bioavailability following smoking was 31% however no other studies attempted to report the absolute bioavailability of CBD following other routes in humans, despite i.v formulations being available. The area-under-the-curve and Cmax increase in dose-dependent manners and are reached quicker following smoking/inhalation compared to oral/oromucosal routes. Cmax is increased during fed states and in lipid formulations. Tmax is reached between 0 and 4 h. Conclusions: This review highlights the paucity in data and some discrepancy in the pharmacokinetics of cannabidiol, despite its widespread use in humans. Analysis and understanding of properties such as bioavailability and half-life is critical to future therapeutic success, and robust data from a variety of formulations is required.
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Affiliation(s)
- Sophie A Millar
- Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Nicole L Stone
- Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | | | - Saoirse E O'Sullivan
- Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
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24
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Rzeczycki P, Woldemichael T, Willmer A, Murashov MD, Baik J, Keswani R, Yoon GS, Stringer KA, Rodriguez-Hornedo N, Rosania GR. An Expandable Mechanopharmaceutical Device (1): Measuring the Cargo Capacity of Macrophages in a Living Organism. Pharm Res 2018; 36:12. [PMID: 30421091 PMCID: PMC6501569 DOI: 10.1007/s11095-018-2539-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/31/2018] [Indexed: 12/14/2022]
Abstract
PURPOSE Clofazimine (CFZ) is an FDA-approved, poorly soluble small molecule drug that precipitates as crystal-like drug inclusions (CLDIs) which accumulate in acidic cytoplasmic organelles of macrophages. In this study, we considered CLDIs as an expandable mechanopharmaceutical device, to study how macrophages respond to an increasingly massive load of endophagolysosomal cargo. METHODS First, we experimentally tested how the accumulation of CFZ in CLDIs impacted different immune cell subpopulations of different organs. Second, to further investigate the mechanism of CLDI formation, we asked whether specific accumulation of CFZ hydrochloride crystals in lysosomes could be explained as a passive, thermodynamic equilibrium phenomenon. A cellular pharmacokinetic model was constructed, simulating CFZ accumulation driven by pH-dependent ion trapping of the protonated drug in the acidic lysosomes, followed by the precipitation of CFZ hydrochloride salt via a common ion effect caused by high chloride concentrations. RESULTS While lower loads of CFZ were mostly accommodated in lung macrophages, increased CFZ loading was accompanied by organ-specific changes in macrophage numbers, size and intracellular membrane architecture, maximizing the cargo storage capabilities. With increasing loads, the total cargo mass and concentrations of CFZ in different organs diverged, while that of individual macrophages converged. The simulation results support the notion that the proton and chloride ion concentrations of macrophage lysosomes are sufficient to drive the massive, cell type-selective accumulation and growth of CFZ hydrochloride biocrystals. CONCLUSION CLDIs effectively function as an expandable mechanopharmaceutical device, revealing the coordinated response of the macrophage population to an increasingly massive, whole-organism endophagolysosomal cargo load.
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Affiliation(s)
- Phillip Rzeczycki
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Tehetina Woldemichael
- Biophysics Program, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, MI, USA
| | - Andrew Willmer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mikhail D Murashov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jason Baik
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Rahul Keswani
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Gi Sang Yoon
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kathleen A Stringer
- Department of Clinical Pharmacy, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
| | - Nair Rodriguez-Hornedo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Gus R Rosania
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA.
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Singleton WGB, Bienemann AS, Woolley M, Johnson D, Lewis O, Wyatt MJ, Damment SJP, Boulter LJ, Killick-Cole CL, Asby DJ, Gill SS. The distribution, clearance, and brainstem toxicity of panobinostat administered by convection-enhanced delivery. J Neurosurg Pediatr 2018; 22:288-296. [PMID: 29856296 DOI: 10.3171/2018.2.peds17663] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The pan-histone deacetylase inhibitor panobinostat has preclinical efficacy against diffuse intrinsic pontine glioma (DIPG), and the oral formulation has entered a Phase I clinical trial. However, panobinostat does not cross the blood-brain barrier in humans. Convection-enhanced delivery (CED) is a novel neurosurgical drug delivery technique that bypasses the blood-brain barrier and is of considerable clinical interest in the treatment of DIPG. METHODS The authors investigated the toxicity, distribution, and clearance of a water-soluble formulation of panobinostat (MTX110) in a small- and large-animal model of CED. Juvenile male Wistar rats (n = 24) received panobinostat administered to the pons by CED at increasing concentrations and findings were compared to those in animals that received vehicle alone (n = 12). Clinical observation continued for 2 weeks. Animals were sacrificed at 72 hours or 2 weeks following treatment, and the brains were subjected to neuropathological analysis. A further 8 animals received panobinostat by CED to the striatum and were sacrificed 0, 2, 6, or 24 hours after infusion, and their brains explanted and snap-frozen. Tissue-drug concentration was determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). Large-animal toxicity was investigated using a clinically relevant MRI-guided translational porcine model of CED in which a drug delivery system designed for humans was used. Panobinostat was administered at 30 μM to the ventral pons of 2 juvenile Large White-Landrace cross pigs. The animals were subjected to clinical and neuropathological analysis, and findings were compared to those obtained in controls after either 1 or 2 weeks. Drug distribution was determined by LC-MS/MS in porcine white and gray matter immediately after CED. RESULTS There were no clinical or neuropathological signs of toxicity up to an infused concentration of 30 μM in both small- and large-animal models. The half-life of panobinostat in rat brain after CED was 2.9 hours, and the drug was observed to be distributed in porcine white and gray matter with a volume infusion/distribution ratio of 2 and 3, respectively. CONCLUSIONS CED of water-soluble panobinostat, up to a concentration of 30 μM, was not toxic and was distributed effectively in normal brain. CED of panobinostat warrants clinical investigation in patients with DIPG.
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Affiliation(s)
- William G B Singleton
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | - Alison S Bienemann
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | - Max Woolley
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol.,2Neurological Applications Department, Renishaw PLC, Wotton under Edge, Gloucestershire; and
| | - David Johnson
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol.,2Neurological Applications Department, Renishaw PLC, Wotton under Edge, Gloucestershire; and
| | - Owen Lewis
- 2Neurological Applications Department, Renishaw PLC, Wotton under Edge, Gloucestershire; and
| | - Marcella J Wyatt
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | | | - Lisa J Boulter
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | - Clare L Killick-Cole
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | - Daniel J Asby
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol
| | - Steven S Gill
- 1Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol.,2Neurological Applications Department, Renishaw PLC, Wotton under Edge, Gloucestershire; and
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Soubret A, Pang Y, Yu J, Dahlke M. Population pharmacokinetics of serelaxin in patients with acute or chronic heart failure, hepatic or renal impairment, or portal hypertension and in healthy subjects. Br J Clin Pharmacol 2018; 84:2572-2585. [PMID: 30014598 DOI: 10.1111/bcp.13714] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/04/2018] [Indexed: 12/18/2022] Open
Abstract
AIMS Serelaxin is a recombinant human relaxin-2 peptide being developed for the treatment of acute heart failure (AHF). The present analyses aimed to evaluate serelaxin pharmacokinetics following intravenous administration and to identify covariates that may explain pharmacokinetic variability in healthy subjects and patients. METHODS Serum concentration-time data for 613 subjects from nine phase I and II studies were analysed using a nonlinear mixed-effects model to estimate population pharmacokinetics and identify significant covariates. A quantile regression analysis was also conducted to assess the relationship between clearance and covariates by including sparse data from a phase III study. RESULTS A three-compartment disposition model was established to describe serelaxin pharmacokinetics. Three out of 23 covariates, including baseline body mass index (BMI) and estimated glomerular filtration rate (eGFR) and study A1201, were identified as significant covariates for clearance but with a moderate impact on steady-state concentration, reducing the intersubject variability from 44% in the base model to 41% in the final model with covariates. The steady-state volume of distribution (Vss) was higher in patients with AHF (544 ml kg-1 ) or chronic heart failure (434 ml kg-1 ), compared with typical nonheart failure subjects (347 ml kg-1 ). Quantile regression analysis showed that a 20% increase in BMI or a 20% decrease in eGFR decreased serelaxin clearance by 9.2% or 5.2%, respectively. CONCLUSIONS Patients with HF showed higher Vss but similar clearance (and therefore steady-state exposure) vs. non nonheart failure subjects. BMI and eGFR were identified as the main covariates explaining intersubject variability in clearance; however, the impact of these covariates on steady-state concentration was moderate and therefore unlikely to be clinically relevant.
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Affiliation(s)
- Antoine Soubret
- Disease Modeling - Clinical Pharmacology, Roche Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Yinuo Pang
- AbbVie Clinical Pharmacology and Pharmacometrics, AbbVie Inc., Chicago, IL, USA
| | - Jing Yu
- Pharmacometrics, Novartis Institutes for BioMedical Research, Cambridge, MA, USA
| | - Marion Dahlke
- Translational Medicine, Novartis Pharma A.G., Basel, Switzerland
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Roberts DM, Sevastos J, Carland JE, Stocker SL, Lea-Henry TN. Clinical Pharmacokinetics in Kidney Disease: Application to Rational Design of Dosing Regimens. Clin J Am Soc Nephrol 2018; 13:1254-1263. [PMID: 30042221 PMCID: PMC6086693 DOI: 10.2215/cjn.05150418] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A change in pharmacokinetics can alter drug exposure and predispose the patient to either over- or underdosing, potentially resulting in adverse drug reactions or therapeutic failure. Kidney disease is characterized by multiple physiologic effects, which induce clinically significant changes in pharmacokinetics. These vary between individuals and may be quantitated in certain instances. An understanding of pharmacokinetic concepts is, therefore, important for a rational approach to the design of drug dosing regimens for the delivery of personalized medical care. Whether kidney disease is acute or chronic, drug clearance decreases and the volume of distribution may remain unchanged or increase. AKI is defined by dynamic changes in kidney function, which complicates attempts to accurately quantify drug clearance. In contrast, changes in drug clearance progress more slowly with CKD. In general, kidney replacement therapies increase drug clearance, but the extent to which this occurs depends on the modality used and its duration, the drug's properties, and the timing of drug administration. However, the changes in drug handling associated with kidney disease are not isolated to reduced kidney clearance and an appreciation of the scale of potential derangements is important. In most instances, the first dose administered in patients with kidney disease is the same as in patients with normal kidney function. However, in some cases, a higher (loading) initial dose is given to rapidly achieve therapeutic concentrations, followed by a lower maintenance dose, as is well described when prescribing anti-infectives to patients with sepsis and AKI. This review provides an overview of how pharmacokinetic principles can be applied to patients with kidney disease to personalize dosage regimens. Patients with kidney disease are a vulnerable population and the increasing prevalence of kidney disease means that these considerations are important for all prescribers.
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Affiliation(s)
- Darren M. Roberts
- Departments of Clinical Pharmacology and Toxicology, and
- Department of Renal Medicine, The Canberra Hospital, Woden, Australian Capital Territory, Australia
- Medical School, Australian National University, Acton, Australian Capital Territory, Australia
| | - Jacob Sevastos
- Nephrology and Renal Transplantation, St. Vincent’s Hospital, Darlinghurst, New South Wales, Australia
- Department of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia; and
| | - Jane E. Carland
- Departments of Clinical Pharmacology and Toxicology, and
- Department of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia; and
| | - Sophie L. Stocker
- Departments of Clinical Pharmacology and Toxicology, and
- Department of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia; and
| | - Tom N. Lea-Henry
- Department of Renal Medicine, The Canberra Hospital, Woden, Australian Capital Territory, Australia
- Nephrology and Transplantation Unit, John Hunter Hospital, Newcastle, New South Wales, Australia
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Abstract
Kidney disease is an increasingly common comorbidity that alters the pharmacokinetics of many drugs. Prescribing to patients with kidney disease requires knowledge about the drug, the extent of the patient's altered physiology, and pharmacokinetic principles that influence the design of dosing regimens. There are multiple physiologic effects of impaired kidney function, and the extent to which they occur in an individual at any given time can be difficult to define. Although some guidelines are available for dosing in kidney disease, they may be on the basis of limited data or not widely applicable, and therefore, an understanding of pharmacokinetic principles and how to apply them is important to the practicing clinician. Whether kidney disease is acute or chronic, drug clearance decreases, and the volume of distribution may remain the same or increase. Although in CKD, these changes progress relatively slowly, they are dynamic in AKI, and recovery is possible depending on the etiology and treatments. This, and the use of kidney replacement therapies further complicate attempts to quantify drug clearance at the time of prescribing and dosing in AKI. The required change in the dosing regimen can be estimated or even quantitated in certain instances through the application of pharmacokinetic principles to guide rational drug dosing. This offers an opportunity to provide personalized medical care and minimizes adverse drug events from either under- or overdosing. We discuss the principles of pharmacokinetics that are fundamental for the design of an appropriate dosing regimen in this review.
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Affiliation(s)
- Tom N. Lea-Henry
- Nephrology and Transplantation Unit, John Hunter Hospital, Newcastle, New South Wales, Australia
- Department of Renal Medicine, The Canberra Hospital, Woden, Australian Capital Territory, Australia; and
| | - Jane E. Carland
- Departments of Clinical Pharmacology and Toxicology and
- Department of Medicine, St. Vincent’s Clinical School, St. Vincent’s Hospital, University of New South Wales, Sydney, New South Wales, Australia
| | - Sophie L. Stocker
- Departments of Clinical Pharmacology and Toxicology and
- Department of Medicine, St. Vincent’s Clinical School, St. Vincent’s Hospital, University of New South Wales, Sydney, New South Wales, Australia
| | - Jacob Sevastos
- Nephrology and Renal Transplantation, St. Vincent’s Hospital, Darlinghurst, New South Wales, Australia
- Department of Medicine, St. Vincent’s Clinical School, St. Vincent’s Hospital, University of New South Wales, Sydney, New South Wales, Australia
| | - Darren M. Roberts
- Departments of Clinical Pharmacology and Toxicology and
- Department of Renal Medicine, The Canberra Hospital, Woden, Australian Capital Territory, Australia; and
- Medical School, Australian National University, Acton, Australian Capital Territory, Australia
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29
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Jy W, Rehni AK, Bidot C, Navarro-Quero H, Haase CR, Koch S, Ahn YS, Dave KR. Pharmacokinetics of Human Red Blood Cell Microparticles Prepared Using High-Pressure Extrusion Method. Front Pharmacol 2018; 9:599. [PMID: 29942257 PMCID: PMC6004370 DOI: 10.3389/fphar.2018.00599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/18/2018] [Indexed: 12/13/2022] Open
Abstract
Red blood cell microparticles (RMPs) is a high potency hemostatic agent, which may serve as a viable therapeutic approach. They generate thrombin in vitro and effective in arresting bleeding in animal bleeding models. However, prior to ascertaining the clinical efficacy of RMPs, detailed preclinical evaluation is necessary. Therefore, we aimed to characterize RMPs, ascertain their stability, and determine their pharmacokinetics in rats. RMPs were prepared from human RBCs by a high-pressure extrusion method. Pharmacokinetic parameters were computed from groups receiving various RMPs dosing regimens. Volume of distribution, elimination rate constant, and clearance for RMPs were also assessed. Major portion of prepared microparticles were RMPs and a very small portion of particles were from platelets and leukocytes. RMPs were stable when stored at 5 and -20°C for at least 12 months. In vivo half-life was found to vary for each paradigm, but in general, was less than 2 min for most of the paradigms evaluated. Our results demonstrate that RMPs are stable during prolonged storage and have a short half-life. Therefore, the clinical use of RMPs as a hemostatic agent, within a tailored treatment paradigm, may be advantageous in achieving prolonged systemic therapeutic benefit without provoking any thrombotic complications.
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Affiliation(s)
- Wenche Jy
- Wallace H. Coulter Platelet Laboratory, Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Ashish K Rehni
- Cerebral Vascular Disease Research Laboratories, Miller School of Medicine, University of Miami, Miami, FL, United States.,Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Carlos Bidot
- Wallace H. Coulter Platelet Laboratory, Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Hever Navarro-Quero
- Wallace H. Coulter Platelet Laboratory, Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Conner R Haase
- Cerebral Vascular Disease Research Laboratories, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Sebastian Koch
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Yeon S Ahn
- Wallace H. Coulter Platelet Laboratory, Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Kunjan R Dave
- Cerebral Vascular Disease Research Laboratories, Miller School of Medicine, University of Miami, Miami, FL, United States.,Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, United States.,Neuroscience Program, Miller School of Medicine, University of Miami, Miami, FL, United States
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Prunty L, Miskell D. Enhanced Vancomycin Elimination in an Infant Following an Unsuccessful Gastroschisis Repair Surgery. J Pharm Pract 2018; 32:595-598. [PMID: 29495915 DOI: 10.1177/0897190018760635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To report the case of an infant who required high-dose vancomycin therapy after an unsuccessful gastroschisis repair surgery. CASE SUMMARY An infant born at 35 weeks and 5 days of gestation underwent a gastroschisis repair on day of life 47. The repair was unsuccessful causing fluid backup and accumulation into the stomach. A replogle was placed to allow for suctioning of this fluid. During this admission, the patient received 3 courses of vancomycin. During the first course, the patient had minimal output via the replogle tube. On the infant's second and third courses of vancomycin, the infant necessitated vancomycin dosing above that of the neonatal protocol, and subsequent levels were still found to be below goal. Vancomycin was increased to a maximum of 15 mg/kg every 4 hours (90 mg/kg/d) in order to achieve serum trough levels greater than 10 mg/L. Residuals were drawn from the replogle ranging from 0.76 to 4.33 mL/kg/h during the second and third course of vancomycin. DISCUSSION A premature male infant required up to 90 mg/kg/d of vancomycin to achieve trough levels above 10 mg/L after an unsuccessful gastroschisis repair surgery and gastric suctioning. CONCLUSION Clinicians should be aware of the possibility for decreased vancomycin levels and the potential need for increased monitoring in postsurgical infants receiving gastric suctioning.
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Affiliation(s)
- Leesa Prunty
- Cabell Huntington Hospital, Department of Pharmacy Practice, Administration, and Research, Marshall University School of Pharmacy, Huntington, WV, USA
| | - David Miskell
- Department of Pharmacy, Cabell Huntington Hospital, Huntington, WV, USA
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Dehghani M, Kunz N, Lanz B, Yoshihara HAI, Gruetter R. Diffusion-weighted MRS of acetate in the rat brain. NMR Biomed 2017; 30:e3768. [PMID: 28796319 DOI: 10.1002/nbm.3768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 05/04/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Acetate has been proposed as an astrocyte-specific energy substrate for metabolic studies in the brain. The determination of the relative contribution of the intracellular and extracellular compartments to the acetate signal using diffusion-weighted magnetic resonance spectroscopy can provide an insight into the cellular environment and distribution volume of acetate in the brain. In the present study, localized 1 H nuclear magnetic resonance (NMR) spectroscopy employing a diffusion-weighted stimulated echo acquisition mode (STEAM) sequence at an ultra-high magnetic field (14.1 T) was used to investigate the diffusivity characteristics of acetate and N-acetylaspartate (NAA) in the rat brain in vivo during prolonged acetate infusion. The persistence of the acetate resonance in 1 H spectra acquired at very large diffusion weighting indicated restricted diffusion of acetate and was attributed to intracellular spaces. However, the significantly greater diffusion of acetate relative to NAA suggests that a substantial fraction of acetate is located in the extracellular space of the brain. Assuming an even distribution for acetate in intracellular and extracellular spaces, the diffusion properties of acetate yielded a smaller volume of distribution for acetate relative to water and glucose in the rat brain.
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Affiliation(s)
- Masoumeh Dehghani
- Laboratoire d'imagerie fonctionnelle et métabolique (LIFMET), École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Nicolas Kunz
- Centre d'Imagerie BioMédicale (CIBM)-AIT, École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bernard Lanz
- Laboratoire d'imagerie fonctionnelle et métabolique (LIFMET), École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Hikari A I Yoshihara
- Service de Cardiologie, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratoire d'imagerie fonctionnelle et métabolique (LIFMET), École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Centre d'Imagerie BioMédicale (CIBM), École polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Department of Radiology, Université de Lausanne (UNIL), Lausanne, Switzerland
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Abstract
BACKGROUND Delayed achievement of target vancomycin serum concentrations may adversely affect clinical outcomes. The objective of this retrospective study was to compare the prediction accuracy of different body weight descriptors for volume of distribution and to propose an optimal loading dose (LD) for continuous infusion regimens in adults. METHODS Pharmacokinetic variables were computed using one-compartmental analysis. Simulated LDs of vancomycin were evaluated for each patient. RESULTS Volume of distribution, clearance, and half-life median values (interquartile range) for vancomycin in the study population (n = 30) were 0.45 (0.39-0.61) L.kg-1, 0.026 (0.015-0.040) L.h-1.kg-1, and 10.3 (7.7-21.3) h, respectively. The observed volume of distribution was better predicted by total body weight (TBW) than by the ideal body weight or the adjusted body weight. CONCLUSIONS An LD of 10.7 mg per kg TBW was optimal in our study population. Using this LD, 17.9% of simulated vancomycin serum levels were just below the therapeutic range, only 10.7% concentrations exceeded the target range and no concentration was toxic. The use of a LD would lead to reduced median time to reach target concentrations from 17 to 1 h.
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Affiliation(s)
- Martin Šíma
- a Department of Pharmacology, First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Karolína Hronová
- a Department of Pharmacology, First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Jan Hartinger
- a Department of Pharmacology, First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Ondřej Slanař
- a Department of Pharmacology, First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
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Korzekwa K, Nagar S. Drug Distribution Part 2. Predicting Volume of Distribution from Plasma Protein Binding and Membrane Partitioning. Pharm Res 2017; 34:544-51. [PMID: 27966088 DOI: 10.1007/s11095-016-2086-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/08/2016] [Indexed: 01/03/2023]
Abstract
PURPOSE Volume of distribution is an important pharmacokinetic parameter in the distribution and half-life of a drug. Protein binding and lipid partitioning together determine drug distribution. METHODS Here we present a simple relationship that estimates the volume of distribution with the fraction of drug unbound in both plasma and microsomes. Model equations are based upon a two-compartment system and the experimental fractions unbound in plasma and microsomes represent binding to plasma proteins and cellular lipids, respectively. RESULTS The protein and lipid binding components were parameterized using a dataset containing human in vitro and in vivo parameters for 63 drugs. The resulting equation explains ~84% of the variance in the log of the volume of distribution with an average fold-error of 1.6, with 3 outliers. CONCLUSIONS These results suggest that Vss can be predicted for most drugs from plasma protein binding and microsomal partitioning.
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Vijay A, Wang S, Worhunsky P, Zheng MQ, Nabulsi N, Ropchan J, Krishnan-Sarin S, Huang Y, Morris ED. PET imaging reveals sex differences in kappa opioid receptor availability in humans, in vivo. Am J Nucl Med Mol Imaging 2016; 6:205-214. [PMID: 27648372 PMCID: PMC5004062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/17/2016] [Indexed: 06/06/2023]
Abstract
Opioid receptors may play critical roles in alcoholism and other addictions, addiction withdrawal, and depression and are considered pharmacological targets for treatment of these conditions. Sex differences have been demonstrated in mu (MOR) and delta (DOR) opioid receptors in humans, in vivo. In addition, sex differences have been observed in efficacy of treatment targeting kappa opioid receptors (KOR). Our goal in the present study was to compare the availability of KOR (1) between healthy control (HC) men and women. Twenty-seven subjects-18 males (M) and 9 females (F)-underwent PET scans with [(11)C] LY2795050, a selective kappa antagonist tracer. Partial volume correction was applied to all PET data. Volume of distribution (V T) of the tracer was estimated regionally as well as at the voxel level. V T values of males versus females were compared for 19 defined ROIs. Results at the regional and voxel levels were consistent. Males had significantly higher V T and thus a higher KOR availability than women in multiple brain regions. To our knowledge, this is the first report of sex differences in the KOR system in humans, in vivo. These findings could have implications for the treatment of pain with kappa opioid analgesics. The results may also have an impact on the diagnosis and treatment of addictive and other disorders.
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Affiliation(s)
- Aishwarya Vijay
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | - Shuo Wang
- Department of Radiology and Biomedical Imaging, Yale UniversitNew Haven, CT, USA; Department of Biomedical Engineering, Yale UniversityNew Haven, CT, USA
| | - Patrick Worhunsky
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | - Ming-Qiang Zheng
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | | | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale Universit New Haven, CT, USA
| | - Evan D Morris
- Department of Radiology and Biomedical Imaging, Yale UniversitNew Haven, CT, USA; Department of Biomedical Engineering, Yale UniversityNew Haven, CT, USA; Department of Psychiatry, Yale UniversityNew Haven, CT, USA
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Kiss K, Molnár M, Söndergaard S, Molnár G, Ricksten SE. Mannitol clearance for the determination of glomerular filtration rate-a validation against clearance of 51 Cr-EDTA. Clin Physiol Funct Imaging 2016; 38:10-16. [PMID: 27256921 DOI: 10.1111/cpf.12374] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/26/2016] [Indexed: 11/28/2022]
Abstract
We studied the agreement between plasma clearance of mannitol and the reference method, plasma clearance of 51 Cr-EDTA in outpatients with normal to moderately impaired renal function. Forty-one patients with a serum creatinine <200 μmol l-1 entered the study. 51 Cr-EDTA clearance was measured with the standard bolus injection technique and glomerular filtration rate (GFR) was calculated by the single-sample method described by Jacobsson. Mannitol, 0·25 g kg-1 body weight (150 mg ml-1 ), was infused for 4-14 min and blood samples taken at 1-, 2-, 3- and 4-h (n = 24) or 2-, 3-, 3·5- and 4-h after infusion (n = 17). Mannitol in serum was measured by an enzymatic method. Plasma clearance for mannitol and its apparent volume of distribution (Vd) were calculated according to Brøchner-Mortensen. Mean plasma clearance (±SD) for 51 Cr-EDTA was 59·7 ± 18·8 ml min-1 . The mean plasma clearance for mannitol ranged between 57·0 ± 20·1 and 61·1 ± 16·7 ml min-1 and Vd was 21·3 ± 6·2% per kg b.w. The between-method bias ranged between -0·23 and 2·73 ml min-1 , the percentage error between 26·7 and 39·5% and the limits of agreement between -14·3/17·2 and -25·3/19·9 ml min-1 . The best agreement was seen when three- or four-sample measurements of plasma mannitol were obtained and when sampling started 60 min after injection. Furthermore, accuracy of plasma clearance determinations was 88-96% (P30) and 41-63% (P10) and was highest when three- or four-sample measurements of plasma mannitol were obtained, including the first hour after the bolus dose. We conclude that there is a good agreement between plasma clearances of mannitol and 51 Cr-EDTA for the assessment of GFR.
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Affiliation(s)
- Katalin Kiss
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Miklós Molnár
- Faculty of Medicine, Institute of Pathophysiology, Semmelweis University, Budapest, Hungary
| | - Sören Söndergaard
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Gyula Molnár
- Faculty of Medicine, Institute of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Sven-Erik Ricksten
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
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Carasco CF, Fletcher P, Maconochie I. Review of commonly used age-based weight estimates for paediatric drug dosing in relation to the pharmacokinetic properties of resuscitation drugs. Br J Clin Pharmacol 2016; 81:849-56. [PMID: 26714256 DOI: 10.1111/bcp.12876] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/29/2015] [Accepted: 12/21/2015] [Indexed: 11/28/2022] Open
Abstract
AIM To study which weight estimate calculation used in paediatric resuscitation results in optimal drug dosing; Advanced Paediatric and Life Support (APLS) or the UK Resuscitation Council age-based formula. METHOD Commonly used drugs used in paediatric resuscitation were selected and a literature search conducted for each drug's pharmacokinetic properties, concentrating on the volume of distribution (Vd). Hydrophobic drugs have a higher Vd than hydrophilic drugs as they distribute preferentially to fat mass (FM). The larger the Vd, the higher the initial dose required to achieve therapeutic plasma concentrations. Actual body weight (ABW) estimates are a good indicator of Vd for hydrophobic drugs as they correlate well with FM. Ideal body weight (IBW) estimates may be a better indicator of Vd for hydrophilic drugs, as they correlate better with lean body mass. This highlights potential variation between ABW and IBW, which may result in toxic or sub-therapeutic dosing. RESULTS The new APLS formulae give higher estimates of expected weight for a wider age range. This may be a more accurate reflection of ABW due to increasing prevalence of obesity in children. The UK Resuscitation Council's formula appears to result in a lower estimate of weight, which may relate more closely to IBW. CONCLUSION The main drugs used in paediatric resuscitation are hydrophilic, thus the APLS formulae may result in too much being given. Therefore the UK Resuscitation Council's single formula may be preferred. In addition, a single formula may minimize error in the context of a child of unknown weight requiring administration of emergency resuscitation drugs.
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Affiliation(s)
| | | | - Ian Maconochie
- Accident and Emergency, Imperial College NHS Trust, London, UK
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37
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Abstract
Human dose prediction is increasingly recognized as an important parameter in Drug Discovery. Validation of a method using only in vitro and predicted parameters incorporated into a PK model was undertaken by predicting human dose and free Cmax for a number of marketed drugs and AZ Development compounds. Doses were compared to those most relevant to marketed drugs or to clinically administered doses of AZ compounds normalized either to predicted Cmin or Cmax values. Average (AFE) and absolute average (AAFE) fold-error analysis showed that best predictions were obtained using a QSAR model as the source of Vss, with Fabs set to 1 for acids and 0.5 for all other ion classes; for clearance prediction no binding correction to the well stirred model (WSM) was used for bases, while it was set to Fup/Fup(0.5) for all other ion classes. Using this combination of methods, predicted doses for 45 to 68% of the Cmin- and Cmax-normalized and marketed drug data sets were within 3-fold of the observed values, while 82 to 92% of these data sets were within 10-fold. This method for early human dose prediction is able to rank, identify, and flag risks or optimization opportunities for future development compounds within 10 days of first synthesis.
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Affiliation(s)
- Ken M Page
- Drug Safety and Metabolism, AstraZeneca, Mereside , Alderley Park, Macclesfield, Cheshire SK10 4TG, U.K
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Small DS, Ke AB, Hall SD, Mantlo N, Rotelli M, Friedrich S. Assessment of the persistence of anacetrapib and evacetrapib concentrations using two pharmacokinetic modeling approaches. J Clin Pharmacol 2015; 55:757-67. [PMID: 25651523 DOI: 10.1002/jcph.472] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 01/26/2015] [Indexed: 12/23/2022]
Abstract
Anacetrapib, a cholesterol ester transfer protein (CETP) inhibitor, has been reported to have longer elimination half-life after longer treatment. Two pharmacokinetic model-based approaches were used to assess whether evacetrapib, another CETP inhibitor, could behave similarly. Using population pharmacokinetic (PopPK) modeling, evacetrapib and anacetrapib pharmacokinetics were characterized using available concentration-time data, and steady-state conditions were simulated. Published 2-compartment models for each compound were adapted to include a hypothetical third compartment representing a depot into which drug could partition. Physiologically based pharmacokinetic (PBPK) modeling was used to predict steady-state conditions and terminal half-life based on known physicochemical and dispositional properties. The PopPK model described the anacetrapib data well, showing a likely third compartment with estimated apparent volume of 40,700 L. Anacetrapib's estimated half-life for this compartment was 550 days. Simulations for evacetrapib using a hypothetical 3-compartment model, the third compartment being consistent with that of the anacetrapib model, produced predictions inconsistent with reported results, indicating that evacetrapib did not substantially accumulate into a large compartment. The PBPK simulations were consistent with PopPK results, predicting accumulation for anacetrapib (but not evacetrapib) followed by very slow elimination. Based on available data and known physicochemical properties, evacetrapib is not expected to accumulate substantially during long-term treatment.
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Abstract
INTRODUCTION Interspecies allometric scaling provides a simple and fast option to interpolate or extrapolate drug dose or pharmacokinetic parameters to a species of interest. Over the years, new scaling methods have been developed in order to improve the performance of these predictions. It is critical to choose appropriate allometric scaling approach(es) to analyze the available pharmacokinetic data. AREAS COVERED This review provides updated information on the latest allometric scaling methods developed for the most frequently interpolated or extrapolated pharmacokinetic parameters. The different degrees of success and advantages/disadvantages of different methods are compared and contrasted. The pitfalls that affect the accuracy of prediction and the solutions to avoid the risk of prediction errors are discussed. The application of allometric scaling in veterinary medicine is presented. EXPERT OPINION Although interspecies allometric scaling needs further refinements and has limitations, it is still a potential tool and rational option for the estimate of pharmacokinetic parameters in species for which there are no data available or to better interpret preclinical efficacy and safety trials. Allometric scaling can offer insight into possible mechanisms of species-dependent drug disposition.
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Affiliation(s)
- Qingbiao Huang
- Institute of Computational Comparative Medicine, Kansas State University , Manhattan, KS 66506 , USA
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40
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Qiao JX, Wang TC, Hiebert S, Hu CH, Schumacher WA, Spronk SA, Clark CG, Han Y, Hua J, Price LA, Shen H, Chacko SA, Everlof G, Bostwick JS, Steinbacher TE, Li YX, Huang CS, Seiffert DA, Rehfuss R, Wexler RR, Lam PYS. 4-Benzothiazole-7-hydroxyindolinyl diaryl ureas are potent P2Y1 antagonists with favorable pharmacokinetics: low clearance and small volume of distribution. ChemMedChem 2014; 9:2327-43. [PMID: 24989964 DOI: 10.1002/cmdc.201402141] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Indexed: 11/10/2022]
Abstract
Current antithrombotic discovery efforts target compounds that are highly efficacious in thrombus reduction with less bleeding liability than the standard of care. Preclinical data suggest that P2Y1 antagonists may have lower bleeding liabilities than P2Y12 antagonists while providing similar antithrombotic efficacy. This article describes our continuous SAR efforts in a series of 7-hydroxyindolinyl diaryl ureas. When dosed orally, 4-trifluoromethyl-7-hydroxy-3,3-dimethylindolinyl analogue 4 was highly efficacious in a model of arterial thrombosis in rats with limited bleeding. The chemically labile CF3 group in 4 was then transformed to various groups via a novel one-step synthesis, yielding a series of potent P2Y1 antagonists. Among them, the 4-benzothiazole-substituted indolines had desirable PK properties in rats, specifically, low clearance and small volume of distribution. In addition, compound 40 had high i.v. exposure and modest bioavailability, giving it the best overall profile.
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Affiliation(s)
- Jennifer X Qiao
- Medicinal Chemistry, Molecular Sciences and Candidate Optimization, Bristol-Myers Squibb Company, Rt. 206 and Province Line Road, Princeton, NJ 08543 (USA).
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Roberts SA, Andrews PA, Blanset D, Flagella KM, Gorovits B, Lynch CM, Martin PL, Kramer-Stickland K, Thibault S, Warner G. Considerations for the nonclinical safety evaluation of antibody drug conjugates for oncology. Regul Toxicol Pharmacol 2013; 67:382-91. [PMID: 24012707 DOI: 10.1016/j.yrtph.2013.08.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 08/06/2013] [Accepted: 08/27/2013] [Indexed: 01/19/2023]
Abstract
Antibody drug conjugates (ADCs) include monoclonal antibodies that are linked to cytotoxic small molecules. A number of these agents are currently being developed as anti-cancer agents designed to improve the therapeutic index of the cytotoxin (i.e., cytotoxic small molecule or cytotoxic agent) by specifically delivering it to tumor cells. This paper presents primary considerations for the nonclinical safety evaluation of ADCs and includes strategies for the evaluation of the entire ADC or the various individual components (i.e., antibody, linker or the cytotoxin). Considerations are presented on how to design a nonclinical safety assessment program to identify the on- and off-target toxicities to enable first-in-human (FIH) studies. Specific discussions are also included that provide details as to the need and how to conduct the studies for evaluating ADCs in genetic toxicology, tissue cross-reactivity, safety pharmacology, carcinogenicity, developmental and reproductive toxicology, biotransformation, toxicokinetic monitoring, bioanalytical assays, immunogenicity testing, test article stability and the selection of the FIH dose. Given the complexity of these molecules and our evolving understanding of their properties, there is no single all-encompassing nonclinical strategy. Instead, each ADC should be evaluated on a case-by-case scientifically-based approach that is consistent with ICH and animal research guidelines.
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Affiliation(s)
- Stanley A Roberts
- SAR Safety Assessment, 14677 Via Bettona, Suite #100 - 432, San Diego, CA 92127, USA.
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Lorber M, Koch HM. Development and application of simple pharmacokinetic models to study human exposure to di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP). Environ Int 2013; 59:469-77. [PMID: 23955327 DOI: 10.1016/j.envint.2013.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 07/03/2013] [Accepted: 07/17/2013] [Indexed: 05/05/2023]
Abstract
In a published controlled dosing experiment, a single individual consumed 5mg each of labeled di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP) on separate occasions and tracked metabolites in his blood and urine over 48h. Data from this study were used to structure and calibrate simple pharmacokinetic (PK) models for these two phthalates, which predict urine and blood metabolite concentrations with a given phthalate intake scenario (times and quantities). The calibrated models were applied to a second published experiment in which 5 individuals fasted over the course of a 48-h weekend (bottled water only), and their full urine voids were captured and measured for DnBP and DiBP metabolites. One goal of this model application was to confirm the validity of the calibrated models - their validity would be demonstrated if a profile of intakes could be found which adequately duplicated the metabolite concentrations measured in the urine. A second goal was to study patterns of exposure for this group. It was found that all metabolites could be duplicated very well with individual-specific "best-fit" intake scenarios, with one exception. It appears that the model predicted much lower concentrations of the metabolite, 3carboxy-mono-propylphthalate (MCPP), than were observed in all individuals. Modeled as a metabolite of DnBP, this suggests that DnBP was not the major source of MCPP in the urine. For all 5 individuals, the reconstructed dose profiles of the two phthalates were similar: about 6 small bolus doses per day and an intake of about 0.5μg/kg-day. The intakes did not appear to be associated with diary-reported activities (personal hygiene and medication) of the participants. The modeled frequent intakes suggested one (or both) of two possibilities: ongoing exposures such as an inhalation exposure, or no exposure but rather an ongoing release of body stores of the phthalate metabolites from past exposures.
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Affiliation(s)
- Matthew Lorber
- Office of Research and Development, United States Environmental Protection Agency, 1200 Pennsylvania Ave, NW, Washington, DC 20460, United States.
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Abstract
Anesthesiologists are increasingly being faced with treating obese patients. Physiologic and anthropometric associated with obesity-most notably increases in cardiac output, changes in tissue perfusion and increases in total body weight (TBW), lean body weight (LBW), and fat mass affect the pharmacokinetics (PK) of anesthetic agents. In addition, redundancy of airway tissue, obstructive and central sleep apnea and CO2 retention affect the pharmacodynamics (PD) of anesthetics and narrow the therapeutic window of numerous anesthetic drugs. Safe and effective pharmacologic management of the obese patient requires a thorough understanding of how obesity affects the PK and PD of anesthetics.
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Affiliation(s)
- Jerry Ingrande
- Instructor, Department of Anesthesia, Stanford University School of Medicine, 300 Pasteur Drive Room H3580, Stanford, California 94305, (phone) 650-723-7377, (fax) 650-725-8544,
| | - Hendrikus JM Lemmens
- Professor, Department of Anesthesia, Stanford University School of Medicine, 300 Pasteur Drive Room H3580, Stanford, California 94305, (phone) 650-723-7377, (fax) 650-725-8544,
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Brooks J, Kramer CM, Salerno M. Markedly increased volume of distribution of gadolinium in cardiac amyloidosis demonstrated by T1 mapping. J Magn Reson Imaging 2013; 38:1591-5. [PMID: 23450747 DOI: 10.1002/jmri.24078] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/18/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To perform myocardial T1 mapping pre- and post-gadolinium (Gd) administration and determine the volume of distribution of Gd (VdGd ) in patients with cardiac amyloidosis to assess extracellular space expansion from amyloid protein deposition. MATERIALS AND METHODS T1 mapping was performed before contrast and 20 minutes following bolus administration of 0.15 mmol/kg of gadopentetate dimeglumine (Magnevist) in five subjects with cardiac amyloidosis and in eight healthy volunteers using previously validated 3-5 Modified Look-Locker Inversion (MOLLI) pulse sequence. The partition coefficient (λ) and VdGd were determined and compared between groups. RESULTS Before contrast the T1 of the blood and myocardium are longer in amyloidosis as compared to controls (1665 vs. 1509 msec; P = 0.03 and 1144 vs. 963 msec; P < 0.001, respectively). Postcontrast blood T1 was also significantly longer in amyloidosis (486 vs. 408 msec; P = 0.003) with a trend towards shorter T1 in the myocardium (503 vs. 544 msec; P = 0.15). The VdGd was 83% higher in amyloidosis than in controls (0.51 vs. 0.28; P = 0.005). CONCLUSION Myocardial VdGd is markedly increased in cardiac amyloidosis, reflecting the increased extracellular space occupied by amyloid proteins. The precontrast T1 of blood and myocardium are increased in amyloidosis extending diagnostic utility in patients who cannot receive Gd.
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Affiliation(s)
- Jeremy Brooks
- Department of Medicine, Cardiology Division University of Virginia, Charlottesville, Virginia, USA
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Nunamaker EA, Halliday LC, Moody DE, Fang WB, Lindeblad M, Fortman JD. Pharmacokinetics of 2 formulations of buprenorphine in macaques (Macaca mulatta and Macaca fascicularis). J Am Assoc Lab Anim Sci 2013; 52:48-56. [PMID: 23562033 PMCID: PMC3548201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/15/2012] [Accepted: 06/18/2012] [Indexed: 06/02/2023]
Abstract
Buprenorphine is the cornerstone of pain management in nonhuman primates, but the pharmacokinetics of this widely used drug are unknown. The purpose of this study was to evaluate the pharmacokinetic profiles of buprenorphine (0.01 and 0.03 mg/kg IM) and sustained-release buprenorphine (0.2 mg/kg SC) in 2 macaque species (M. mulatta and M. fascicularis) by using mass spectrometry. The pharmacokinetics did not differ significantly between species, and buprenorphine was dose-proportional at the tested doses. The low and high doses of buprenorphine had elimination half-lives of 2.6 ± 0.7 and 5.3 ± 2.0 h, respectively, but the low-dose data were constrained by the sensitivity of the analytical method. Sustained-release buprenorphine had an elimination half-life of 42.6 ± 26.2 h. The AUC0-Tlast of buprenorphine were 9.1 ± 4.3 and 39.0 ± 25.1 ng × h/mL for the low and high doses, respectively, and sustained-release buprenorphine had an AUC0-Tlast of 177 ± 74 ng × h/mL. Assuming a hypothesized therapeutic buprenorphine plasma concentration threshold of 0.1 ng/mL in macaques, these results suggest that buprenorphine doses of 0.01 mg/kg IM should be administered every 6 to 8 h, whereas doses of 0.03 mg/kg IM can be administered every 12 h. These results further demonstrate that a single 0.2-mg/kg SC injection of sustained-release buprenorphine maintains plasma concentrations above 0.1 ng/mL for 5 d in macaques. These findings support a new dosing strategy using sustained-release buprenorphine to improve pain management, decrease animal stress, improve animal welfare, and simplify the postoperative management of nonhuman primates in laboratory animal and zoological settings.
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Affiliation(s)
- Elizabeth A Nunamaker
- Biologic Resources Laboratory, University of Illinois at Chicago, Chicago, Illinois, USA.
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Mehvar R. The importance of active learning and practice on the students' mastery of pharmacokinetic calculations for the intermittent intravenous infusion dosing of antibiotics. BMC Med Educ 2012; 12:116. [PMID: 23173740 PMCID: PMC3567988 DOI: 10.1186/1472-6920-12-116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 11/12/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Estimation of pharmacokinetic parameters after intermittent intravenous infusion (III) of antibiotics, such as aminoglycosides or vancomycin, has traditionally been a difficult subject for students in clinical pharmacology or pharmacokinetic courses. Additionally, samples taken at different intervals during repeated dose therapy require manipulation of sampling times before accurate calculation of the patient-specific pharmacokinetic parameters. The main goal of this study was to evaluate the effectiveness of active learning tools and practice opportunities on the ability of students to estimate pharmacokinetic parameters from the plasma samples obtained at different intervals following intermittent intravenous infusion. METHODS An extensive reading note, with examples, and a problem case, based on a patient's chart data, were created and made available to students before the class session. Students were required to work through the case before attending the class. The class session was devoted to the discussion of the case requiring active participation of the students using a random participation program. After the class, students were given additional opportunities to practice the calculations, using online modules developed by the instructor, before submitting an online assignment. RESULTS The performance of students significantly (P < 0.001) improved from a baseline of 11.3% (pretest) to 60.3% (posttest) after the class discussion. The grades of students further improved (P < 0.001) to 89.3% on the take-home assignment after they had a chance to study on their own and work on the online practices. Finally, students scored 82.6% in a formal mid-term examination, suggesting significant retention of the materials. CONCLUSIONS Despite being a difficult subject, students achieve mastery of pharmacokinetic calculations for the topic of intermittent intravenous infusion when appropriate active learning strategies and practice opportunities are employed.
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Affiliation(s)
- Reza Mehvar
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S, Coulter, Amarillo, TX 79106, USA.
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Puri A, Medhi B, Panda NB, Puri GD, Dhawan S. Propofol pharmacokinetics in young healthy Indian subjects. Indian J Pharmacol 2012; 44:402-6. [PMID: 22701256 PMCID: PMC3371469 DOI: 10.4103/0253-7613.96348] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 10/05/2011] [Accepted: 02/28/2012] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To analyze population pharmacokinetics of Propofol in Indian patients after single bolus dose of Propofol using WINNONLIN program. MATERIALS AND METHODS Population pharmacokinetics of Propofol was investigated in Indian subjects in 26 elective surgical patients (14 males and 12 females) following single bolus dose of 2 mg/kg propofol. A total of 364 samples were estimated by High Performance Liquid Chromatography and pharmacokinetic parameters were derived using WINNONLIN (5.2). The effect of demographic characters of the study population on pharmacokinetic parameters was investigated. RESULTS Three-compartment model was used to describe the pharmacokinetic data of Propofol in Indian subjects. Initial volume of distribution (V1) clearance (Cl) and steady state volume of distribution (Vd(ss)) was 13.5 ± 3.3 l, 1.08 ± 0.42 l/min, and 77.69 ± 48.0 l, respectively. Body weight best described the volume of central compartment (V1) as well as elimination clearance (P<0.01). CONCLUSION Pharmacokinetics of Propofol in young healthy Indian subjects show lower volume of distribution and clearance as compared with most of the western data. Body weight best describes the V1, Vd(ss), and Clearance in this group.
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Affiliation(s)
- Avinash Puri
- Department of Anesthesia, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
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Mente S, Doran A, Wager TT. Getting the MAX out of Computational Models: The Prediction of Unbound-Brain and Unbound-Plasma Maximum Concentrations. ACS Med Chem Lett 2012; 3:515-9. [PMID: 24900502 DOI: 10.1021/ml300029a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 05/16/2012] [Indexed: 11/28/2022] Open
Abstract
The objective of this work was to establish that unbound maximum concentrations may be reasonably predicted from a combination of computed molecular properties assuming subcutaneous (SQ) dosing. Additionally, we show that the maximum unbound plasma and brain concentrations may be projected from a mixture of in vitro absorption, distribution, metabolism, excretion experimental parameters in combination with computed properties (volume of distribution, fraction unbound in microsomes). Finally, we demonstrate the utility of the underlying equations by showing that the maximum total plasma concentrations can be projected from the experimental parameters for a set of compounds with data collected from clinical research.
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Affiliation(s)
- Scot Mente
- Groton Laboratories, Pfizer Worldwide Research and Development, 1 Eastern Point Road, Groton,
Connecticut 06340, United States
| | - Angela Doran
- Groton Laboratories, Pfizer Worldwide Research and Development, 1 Eastern Point Road, Groton,
Connecticut 06340, United States
| | - Travis T. Wager
- Groton Laboratories, Pfizer Worldwide Research and Development, 1 Eastern Point Road, Groton,
Connecticut 06340, United States
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Poulin P, Jones HM, Jones RD, Yates JWT, Gibson CR, Chien JY, Ring BJ, Adkison KK, He H, Vuppugalla R, Marathe P, Fischer V, Dutta S, Sinha VK, Björnsson T, Lavé T, Ku MS. PhRMA CPCDC initiative on predictive models of human pharmacokinetics, part 1: goals, properties of the PhRMA dataset, and comparison with literature datasets. J Pharm Sci 2011; 100:4050-73. [PMID: 21523782 DOI: 10.1002/jps.22554] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 03/04/2011] [Accepted: 03/04/2011] [Indexed: 11/06/2022]
Abstract
This study is part of the Pharmaceutical Research and Manufacturers of America (PhRMA) initiative on predictive models of efficacy, safety, and compound properties. The overall goal of this part was to assess the predictability of human pharmacokinetics (PK) from preclinical data and to provide comparisons of available prediction methods from the literature, as appropriate, using a representative blinded dataset of drug candidates. The key objectives were to (i) appropriately assemble and blind a diverse dataset of in vitro, preclinical in vivo, and clinical data for multiple drug candidates, (ii) evaluate the dataset with empirical and physiological methodologies from the literature used to predict human PK properties and plasma concentration-time profiles, (iii) compare the predicted properties with the observed clinical data to assess the prediction accuracy using routine statistical techniques and to evaluate prediction method(s) based on the degree of accuracy of each prediction method, and (iv) compile and summarize results for publication. Another objective was to provide a mechanistic understanding as to why one methodology provided better predictions than another, after analyzing the poor predictions. A total of 108 clinical lead compounds were collected from 12 PhRMA member companies. This dataset contains intravenous (n = 19) and oral pharmacokinetic data (n = 107) in humans as well as the corresponding preclinical in vitro, in vivo, and physicochemical data. All data were blinded to protect the anonymity of both the data and the company submitting the data. This manuscript, which is the first of a series of manuscripts, summarizes the PhRMA initiative and the 108 compound dataset. More details on the predictability of each method are reported in companion manuscripts.
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Affiliation(s)
- Patrick Poulin
- Leader Consultant, 4009 Sylvia Daoust, Québec city, Québec, Canada, G1X 0A6.
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D’Souza MJ, Alabed GJ, Wheatley JM, Roberts N, Veturi Y, Bi X, Continisio CH. A Database Developed with Information Extracted from Chemotherapy Drug Package Inserts to Enhance Future Prescriptions. Conf Comput Vis Pattern Recognit Workshops 2011; 2011:219-226. [PMID: 25302340 PMCID: PMC4187114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Package inserts of Food and Drug Administration (FDA) approved prescription drugs, including chemotherapy drugs, must follow a specific format imposed by the FDA. These inserts are created by unrelated pharmaceutical companies and as a result tend to be very different in the way the required information is reported. Chemical and pharmacokinetic properties including absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) are crucial elements to a prescribing information packet and are often missing from the reported data. This undergraduate research project analyzes the information packets of 85 randomly chosen chemically diverse chemotherapy drugs for four parameters important to patient care; viz, volume of distribution (VD), elimination half-life (t1/2), bioavailability, and water solubility. The prescribing information from the package inserts of each was analyzed in detail and pertinent information was consequently tabulated into a database using a commercial informatics platform. Then using a substructure search-tool, sixty-five chemotherapy drugs containing a carbonyl group in their chemical structure were selected and as hypothesized, it was found that many of these packets were significantly lacking in the reporting of the four parameters of interest. To further enhance this cataloged data, a freely available online database was consequently developed (http://annotation.dbi.udel.edu/CancerDB/) with the intention that the chemical, biological, and clinical community will now add some of the missing parameters.
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Affiliation(s)
| | - Ghada J. Alabed
- Department of Chemistry, Wesley College, Dover, DE 19901, USA
| | | | - Natalia Roberts
- Department of Computer & Information Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Yogasudha Veturi
- Department of Computer & Information Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Xia Bi
- Department of Computer & Information Sciences, University of Delaware, Newark, DE, 19716, USA
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