1
|
Gouju J, Legeay S. Pharmacokinetics of obese adults: Not only an increase in weight. Biomed Pharmacother 2023; 166:115281. [PMID: 37573660 DOI: 10.1016/j.biopha.2023.115281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/04/2023] [Indexed: 08/15/2023] Open
Abstract
Obesity is a pathophysiological state defined by a body mass index > 30 kg/m2 and characterized by an adipose tissue accumulation leading to an important weight increased. Several pathologies named comorbidities such as cardiovascular disease, type 2 diabetes and cancer make obesity the fifth cause of death in the world. Physiological changes impact the four main phases of pharmacokinetics of some drugs and leads to an inappropriate drug-dose. For absorption, the gastrointestinal transit is accelerated, and the gastric empty time is shortened, that can reduce the solubilization and absorption of some oral drugs. The drug distribution is probably the most impacted by the obesity-related changes because the fat mass (FM) increases at the expense of the lean body weight (LBW), leading to an important increase of the volume of distribution for lipophilic drugs and a low or moderately increase of this parameter for hydrophilic drugs. This modification of the distribution may require drug-dose adjustments. By various mechanisms, the metabolism and elimination of drugs are impacted by obesity and should be considered as similar or lower than that non-obese patients. To better understand the necessary drug-dose adjustments in obese patients, a narrative review of the literature was conducted to highlight the main elements to consider in the therapeutic management of adult obese patients.
Collapse
Affiliation(s)
- Julien Gouju
- MINT, INSERM U1066, CNRS 6021, UNIV Angers, SFR-ICAT 4208, IBS-CHU Angers, 4 rue Larrey, Angers 49933 Cedex 9, France; CHU Angers, 4 rue Larrey, Angers 49933 Cedex 9, France.
| | - Samuel Legeay
- MINT, INSERM U1066, CNRS 6021, UNIV Angers, SFR-ICAT 4208, IBS-CHU Angers, 4 rue Larrey, Angers 49933 Cedex 9, France
| |
Collapse
|
2
|
Zhang T, Krekels EHJ, Smit C, Knibbe CAJ. Drug pharmacokinetics in the obese population: challenging common assumptions on predictors of obesity-related parameter changes. Expert Opin Drug Metab Toxicol 2022; 18:657-674. [PMID: 36217846 DOI: 10.1080/17425255.2022.2132931] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Obesity is associated with many physiological changes. We review available evidence regarding five commonly accepted assumptions to a priori predict the impact of obesity on drug pharmacokinetics (PK). AREAS COVERED The investigated assumptions are: 1) lean body weight is the preferred descriptor of clearance and dose adjustments; 2) volume of distribution increases for lipophilic, but not for hydrophilic drugs; 3) CYP-3A4 activity is suppressed and UGT activity is increased, implying decreased and increased dose requirements for substrates of these enzyme systems, respectively; 4) glomerular filtration rate is enhanced, necessitating higher doses for drugs cleared through glomerular filtration; 5) drug dosing information from obese adults can be extrapolated to obese adolescents. EXPERT OPINION Available literature contradicts, or at least limits the generalizability, of all five assumptions. Clinical studies should focus on quantifying the impact of duration and severity of obesity on drug PK in adults and adolescents, and also include oral bioavailability and pharmacodynamics in these studies. Physiologically-based PK approaches can be used to predict PK changes for individual drugs, but can also be used to define in general terms based on patient characteristics and drug properties, when certain assumptions can or cannot be expected to be systematically accurate.
Collapse
Affiliation(s)
- Tan Zhang
- Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Elke H J Krekels
- Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Cornelis Smit
- Department of Clinical Pharmacy, Antonius Hospital Sneek, The Netherlands
| | - Catherijne A J Knibbe
- Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.,Department of Clinical Pharmacy, St. Antonius Hospital Nieuwegein, The Netherlands
| |
Collapse
|
3
|
Gerhart JG, Carreño FO, Loop MS, Lee CR, Edginton AN, Sinha J, Kumar KR, Kirkpatrick CM, Hornik CP, Gonzalez D. Use of Real-World Data and Physiologically-Based Pharmacokinetic Modeling to Characterize Enoxaparin Disposition in Children With Obesity. Clin Pharmacol Ther 2022; 112:391-403. [PMID: 35451072 PMCID: PMC9504927 DOI: 10.1002/cpt.2618] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/13/2022] [Indexed: 01/02/2023]
Abstract
Dosing guidance for children with obesity is often unknown despite the fact that nearly 20% of US children are classified as obese. Enoxaparin, a commonly prescribed low-molecular-weight heparin, is dosed based on body weight irrespective of obesity status to achieve maximum concentration within a narrow therapeutic or prophylactic target range. However, whether children with and without obesity experience equivalent enoxaparin exposure remains unclear. To address this clinical question, 2,825 anti-activated factor X (anti-Xa) surrogate concentrations were collected from the electronic health records of 596 children, including those with obesity. Using linear mixed-effects regression models, we observed that 4-hour anti-Xa concentrations were statistically significantly different in children with and without obesity, even for children with the same absolute dose (P = 0.004). To further mechanistically explore obesity-associated differences in anti-Xa concentration, a pediatric physiologically-based pharmacokinetic (PBPK) model was developed in adults, and then scaled to children with and without obesity. This PBPK model incorporated binding of enoxaparin to antithrombin to form anti-Xa and elimination via heparinase-mediated metabolism and glomerular filtration. Following scaling, the PBPK model predicted real-world pediatric concentrations well, with an average fold error (standard deviation of the fold error) of 0.82 (0.23) and 0.87 (0.26) in children with and without obesity, respectively. PBPK model simulations revealed that children with obesity have at most 20% higher 4-hour anti-Xa concentrations under recommended, total body weight-based dosing compared to children without obesity owing to reduced weight-normalized clearance. Enoxaparin exposure was better matched across age groups and obesity status using fat-free mass weight-based dosing.
Collapse
Affiliation(s)
- Jacqueline G. Gerhart
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Fernando O. Carreño
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Matthew Shane Loop
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Craig R. Lee
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | | | - Jaydeep Sinha
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
- Department of PediatricsUniversity of North Carolina School of MedicineThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Karan R. Kumar
- Duke Clinical Research InstituteDurhamNorth CarolinaUSA
- Department of PediatricsDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Carl M. Kirkpatrick
- Centre for Medicine Use and SafetyMonash UniversityMelbourneVictoriaAustralia
| | - Christoph P. Hornik
- Duke Clinical Research InstituteDurhamNorth CarolinaUSA
- Department of PediatricsDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| |
Collapse
|
4
|
van Nuland M, Ververs TF, Lam MGEH. Dosing Therapeutic Radiopharmaceuticals in Obese Patients. Int J Mol Sci 2022; 23:ijms23020818. [PMID: 35055005 PMCID: PMC8775906 DOI: 10.3390/ijms23020818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 02/07/2023] Open
Abstract
The prevalence of obesity has increased dramatically in the Western population. Obesity is known to influence not only the proportion of adipose tissue but also physiological processes that could alter drug pharmacokinetics. Yet, there are no specific dosing recommendations for radiopharmaceuticals in this patient population. This could potentially lead to underdosing and thus suboptimal treatment in obese patients, while it could also lead to drug toxicity due to high levels of radioactivity. In this review, relevant literature is summarized on radiopharmaceutical dosing and pharmacokinetic properties, and we aimed to translate these data into practical guidelines for dosing of radiopharmaceuticals in obese patients. For radium-223, dosing in obese patients is well established. Furthermore, for samarium-153-ethylenediaminetetramethylene (EDTMP), dose-escalation studies show that the maximum tolerated dose will probably not be reached in obese patients when dosing on MBq/kg. On the other hand, there is insufficient evidence to support dose recommendations in obese patients for rhenium-168-hydroxyethylidene diphosphonate (HEDP), sodium iodide-131, iodide 131-metaiodobenzylguanidine (MIBG), lutetium-177-dotatate, and lutetium-177-prostate-specific membrane antigen (PSMA). From a pharmacokinetic perspective, fixed dosing may be appropriate for these drugs. More research into obese patient populations is needed, especially in the light of increasing prevalence of obesity worldwide.
Collapse
Affiliation(s)
- Merel van Nuland
- Department of Clinical Pharmacy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; (M.v.N.); (T.F.V.)
| | - Tessa F. Ververs
- Department of Clinical Pharmacy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; (M.v.N.); (T.F.V.)
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Marnix G. E. H. Lam
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- Correspondence:
| |
Collapse
|
5
|
Abstract
Obesity-related glomerulopathy (ORG) and other obesity-associated kidney diseases pose a major challenge to the treating nephrologist. We review the benefits of weight loss and optimal management of ORG and kidney disease in the setting of obesity. Therapeutic strategies in ORG were limited mainly in the past to weight loss through lifestyle interventions and bariatric surgery, antihypertensive treatment, and renin-angiotensin-aldosterone system blockade. Current approaches to obtain the desired weight loss include novel pharmacologic therapies that have been approved for the treatment of diabetes while offering kidney protection, such as sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1-receptor agonists. This review focuses on the nephroprotective role of the renin-angiotensin-aldosterone system blockade and of these new pharmacologic agents, and on the renal effects of bariatric surgery in chronic kidney disease.
Collapse
Affiliation(s)
- Michal Herman-Edelstein
- Nephrology Department, Rabin Medical Center, Petach Tikva, Israel; Nephrology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel.
| | - Talia Weinstein
- Department of Nephrology and Hypertension, Tel Aviv Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | | |
Collapse
|
6
|
Ullah S, Zoller M, Jaehde U, Huseyn-Zada M, Weig T, Fuhr U, Arshad U, Zander J, Taubert M. A Model-Based Approach to Assess Unstable Creatinine Clearance in Critically Ill Patients. Clin Pharmacol Ther 2021; 110:1240-1249. [PMID: 34137456 DOI: 10.1002/cpt.2341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/01/2021] [Indexed: 11/07/2022]
Abstract
Creatinine clearance is an important tool to describe the renal elimination of drugs in pharmacokinetic (PK) evaluations and clinical practice. In critically ill patients, unstable kidney function invalidates the steady-state assumption underlying equations, such as Cockcroft-Gault. Although measured creatinine clearance (mCrCL) is often used in nonsteady-state situations, it assumes that observed data are error-free, neglecting frequently occurring errors in urine collection. In contrast, compartmental nonlinear mixed effects models of creatinine allow to describe dynamic changes in kidney function while explicitly accounting for a residual error associated with observations. Based on 530 serum and 373 urine creatinine observations from 138 critically ill patients, a one-compartment creatinine model with zero-order creatinine generation rate (CGR) and first-order CrCL was evaluated. An autoregressive approach for interoccasion variability provided a distinct model improvement compared to a classical approach (Δ Akaike information criterion (AIC) -49.0). Fat-free mass, plasma urea concentration, age, and liver transplantation were significantly related to CrCL, whereas weight and sex were linked to CGR. The model-based CrCL estimates were superior to standard approaches to estimate CrCL (or glomerular filtration rate) including Cockcroft-Gault, mCrCL, four-variable modification of diet in renal disease (MDRD), six-variable MDRD, and chronic kidney disease epidemiology collaboration as a covariate to describe cefepime and meropenem PKs in terms of objective function value. In conclusion, a dynamic model of creatinine kinetics provides the means to estimate actual CrCL despite dynamic changes in kidney function, and it can easily be incorporated into population PK evaluations.
Collapse
Affiliation(s)
- Sami Ullah
- Department I of Pharmacology, Center for Pharmacology, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Pharmacy, Clinical Pharmacy, University of Bonn, Bonn, Germany
| | - Michael Zoller
- Department of Anaesthesiology, Hospital of the Ludwig Maximilians University of Munich, Munich, Germany
| | - Ulrich Jaehde
- Institute of Pharmacy, Clinical Pharmacy, University of Bonn, Bonn, Germany
| | - Mikayil Huseyn-Zada
- Department of Anaesthesiology, Hospital of the Ludwig Maximilians University of Munich, Munich, Germany
| | - Thomas Weig
- Department of Anaesthesiology, Hospital of the Ludwig Maximilians University of Munich, Munich, Germany
| | - Uwe Fuhr
- Department I of Pharmacology, Center for Pharmacology, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Usman Arshad
- Department I of Pharmacology, Center for Pharmacology, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Pharmacy, Clinical Pharmacy, University of Bonn, Bonn, Germany
| | - Johannes Zander
- Institute of Laboratory Medicine, Hospital of the Ludwig Maximilians University of Munich, Munich, Germany
| | - Max Taubert
- Department I of Pharmacology, Center for Pharmacology, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
7
|
Zingerman B, Erman A, Mashraki T, Chagnac A, Rozen-Zvi B, Rahamimov R. Association of obesity and muscle mass with risk of albuminuria in renal transplant recipients. J Nephrol 2020; 34:1315-1325. [PMID: 33098523 DOI: 10.1007/s40620-020-00883-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/28/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Increased albuminuria is a predictor of graft loss in kidney graft recipients. It is unknown whether obesity is an independent risk factor for the development of increased albuminuria in this population. The aim of this study was to elucidate the association between obesity and albuminuria in renal transplant recipients. METHODS We enrolled 330 renal transplant recipients and prospectively collected demographic, anthropomorphic, clinical and laboratory variables susceptible to influence albumin excretion. The outcome was albuminuria, measured using accurately timed urine collections. Data from 201 patients were analyzed after exclusion of participants with missing data and patients enrolled less than 6 months since renal transplantation. Analysis was carried out for an early and a late period, defined according to the 2.4-year median follow-up time. RESULTS Body mass index (BMI), waist circumference and urinary creatinine excretion rate were independent predictors of albuminuria in the late post-transplant period, indicating that the predictive value of body mass index for albuminuria is related to both increased abdominal fat mass and increased muscle mass. BMI was an independent predictor of microalbuminuria. Waist circumference and urinary creatinine were independent predictors of microalbuminuria for values above certain cutoffs: 110% of the accepted thresholds defining abdominal obesity and 1500 mg/day, respectively. CONCLUSIONS These associations, which have not previously been reported, suggest, but do not prove, that an imbalance between metabolic demand and nephron mass may be responsible for increased albuminuria in the renal transplant population.
Collapse
Affiliation(s)
- Boris Zingerman
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arie Erman
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tiki Mashraki
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel
| | - Avry Chagnac
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel.
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Benaya Rozen-Zvi
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Rahamimov
- Department of Nephrology and Hypertension, Rabin Medical Center, 4941492, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
8
|
Speed V, Green B, Roberts LN, Woolcombe S, Bartoli-Abdou J, Barsam S, Byrne R, Gee E, Czuprynska J, Brown A, Duffy S, Vadher B, Patel R, Scott V, Gazes A, Patel RK, Arya R, Patel JP. Fixed dose rivaroxaban can be used in extremes of bodyweight: A population pharmacokinetic analysis. J Thromb Haemost 2020; 18:2296-2307. [PMID: 32511863 DOI: 10.1111/jth.14948] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/28/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Emerging safety and efficacy data for rivaroxaban suggest traditional therapy and rivaroxaban are comparable in the morbidly obese. However, real-world data that indicate pharmacokinetic (PK) parameters are comparable at the extremes of body size are lacking. The International Society of Thrombosis and Haemostasis Scientific and Standardisation Committee (ISTH SSC) suggests avoiding the use of direct oral anticoagulants (DOACs) in patients weighing >120 kg or with a body mass index >40 kg/m2 and gives no recommendation on the use of DOACs in those <50 kg. OBJECTIVES To generate a population PK model to understand the influence of bodyweight on rivaroxaban exposure from clinical practice data. METHOD Rivaroxaban plasma concentrations and patient characteristics were collated between 2013 and 2018 at King's College Hospital anticoagulation clinic. A population PK model was developed using a nonlinear mixed effects approach and then used to simulate rivaroxaban concentrations at the extremes of bodyweight. RESULTS A robust population PK model derived from 913 patients weighing between 39 kg and 172 kg was developed. The model included data from n = 86 >120 kg, n = 74 BMI >40 kg/m2 , and n = 30 <50 kg. A one-compartment model with between-subject variability on clearance and a proportional error model best described the data. Creatinine clearance calculated by Cockcroft-Gault, with lean bodyweight as the weight descriptor in this equation, was the most significant covariate influencing rivaroxaban exposure. CONCLUSIONS Our work demonstrates rivaroxaban can be used at extremes of bodyweight provided renal function is satisfactory. We recommend that the ISTH SSC revises the current guidance with respect to rivaroxaban at extremes of body size.
Collapse
Affiliation(s)
- Victoria Speed
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
- Institute of Pharmaceutical Science, King's College London, London, UK
| | | | - Lara N Roberts
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Sarah Woolcombe
- Department of Oral Surgery, King's College Hospital NHS Foundation Trust, London, UK
| | - John Bartoli-Abdou
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Sarah Barsam
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Rosalind Byrne
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Emma Gee
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Julia Czuprynska
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Alison Brown
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Sinead Duffy
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Bipin Vadher
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Rachna Patel
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Valerie Scott
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Anna Gazes
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Raj K Patel
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Roopen Arya
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Jignesh P Patel
- King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK
- Institute of Pharmaceutical Science, King's College London, London, UK
| |
Collapse
|
9
|
Assessment of Kidney Function in Patients With Extreme Obesity: A Narrative Review. Ann Pharmacother 2020; 55:80-88. [DOI: 10.1177/1060028020935580] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Objectives: To discuss the evidence and caveats associated with estimated and measured creatinine clearance (eClCr and mClCr) and glomerular filtration rate (eGFR and mGFR) assessments of kidney function in patients with more extreme forms of obesity. Data Sources: PubMed (1976 to mid-May 2020) was used, with bibliographies of retrieved articles searched for additional articles. Study Selection and Data Extraction: Articles using gold standard mGFR to evaluate eClCr, mClCr, and eGFR assessments of kidney function in patients with more extreme forms of obesity were included. Data Synthesis: The overestimation of GFR by mClCr is well established, but mClCr is an alternative to mGFR assessments for determining medication dosing in patients with extremes of body size or muscle mass, or in patients receiving narrow therapeutic index medications when eGFR is likely to be inaccurate. The vast majority of studies comparing eGFR assessments with gold standard indicators of kidney function were attempts to validate eGFR equations for diagnosing and staging chronic kidney disease (CKD). Relevance to Patient Care and Clinical Practice: For dosing medications in patients with stable kidney function and extreme obesity, a deindexed 4-variable Modification of Diet in Renal Disease or CKD Epidemiology Collaboration equation is an alternative to Cockcroft-Gault. Consistent use of the same equation by provider and between providers within any given setting is of paramount importance. Conclusions: In patients with extreme obesity and stable kidney function, eClCr or eGFR using deindexed values provides estimates of function for dosing adjustments of medications with elimination by the kidneys, but more research is needed with respect to the best size descriptor to use with estimating equations.
Collapse
|
10
|
May M, Schindler C, Engeli S. Modern pharmacological treatment of obese patients. Ther Adv Endocrinol Metab 2020; 11:2042018819897527. [PMID: 32030121 PMCID: PMC6977225 DOI: 10.1177/2042018819897527] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/09/2019] [Indexed: 12/21/2022] Open
Abstract
There are many angles to consider in drug treatment of obese patients. On the one hand, some specific weight loss drugs are available, on the other, several drugs are associated with unintentional weight changes. When treating an obese patient for any given disease, several physiological changes may influence the pharmacokinetic properties of the drugs required. Thus, increased body weight may influence the efficacy and safety of some drug treatments. Even more complicated is the situation after weight reduction surgery. Due to the various changes to the gastrointestinal tract induced by the different surgical techniques used, and the dynamic changes in body composition thereafter, drug dosing has to be constantly reconsidered. Whereas all of these issues are of clinical importance, none of them have been investigated in the necessary depth and broadness to ensure safe and efficacious drug treatment of the massively obese patient. Individual considerations have to be based on comorbidities, concomitant medication, and on specific drug properties, for example, lipophilicity, volume of distribution, and metabolism. In this article we summarize the data available on different aspects of drug treatment in the obese patient with the hope of improving patient care.
Collapse
Affiliation(s)
| | - Christoph Schindler
- MHH Clinical Research Center Core Facility (OE 8660) and Center for Pharmacology and Toxicology, Hannover, Germany
| | - Stefan Engeli
- Hannover Medical School, Institute of Clinical Pharmacology, Hannover, Germany
| |
Collapse
|
11
|
Kaburaki S, Yoshimura E, Kojima N, Ueno H, Sugawara M, Takekuma Y. Improvement of renal function estimation equations for elderly Japanese people. Health Sci Rep 2018; 1:e85. [PMID: 30623041 PMCID: PMC6266418 DOI: 10.1002/hsr2.85] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/25/2018] [Accepted: 07/27/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND AND AIM The Cockcroft-Gault (C-G) equation for estimation of creatinine clearance (CCr) is still used in a clinical setting for drug dosage adjustment. Because differences between measured and estimated CCr values have been reported, particularly for Japanese elderly people, the aim of this study was to improve the accuracy of CCr estimation equations, such as C-G and Orita-Horio, by fitting to newly obtained data. Also, glomerular filtration rate (GFR) estimation equations, such as the Modification of Diet in Renal Disease (MDRD), the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and the eGFR equation for Japanese people, were studied to compare with measured CCr. METHOD Data from 313 subjects over the age of 40 years with laboratory data available were used for analysis in this study. Special attention was paid to elderly people, and approximately 70% of the subjects were over the age of 65 years. RESULTS The accuracy of estimation by the two conventional (C-G, Orita-Horio) CCr estimation equations was greatly improved by introducing adjusted body weight for which the degree of obesity is over 30% instead of measured body weight. By fitting the coefficients of the estimation equations to the present population, the mean error was reduced by almost half, particularly for people over the age of 75. Although all the values calculated by the GFR estimation equations were underestimated compared with measured CCr due to secretion, a coefficient of determination of above 0.65 was obtained for all GFR estimation equations. CONCLUSIONS Improvement of the fitted CCr estimation equations suggests that reconstruction of renal function estimation equations is required, especially for old people. Further work is required to find optimal renal function (CCr and/or GFR) estimation equations for drug dosage adjustment.
Collapse
Affiliation(s)
- Soyoko Kaburaki
- Graduate School of Life ScienceHokkaido UniversitySapporoJapan
| | - Eri Yoshimura
- Department of PharmacySunagawa City Medical CenterSunagawaJapan
| | - Nozomi Kojima
- Department of PharmacySunagawa City Medical CenterSunagawaJapan
| | - Hidefumi Ueno
- Department of PharmacySunagawa City Medical CenterSunagawaJapan
| | - Mitsuru Sugawara
- Faculty of Pharmaceutical SciencesHokkaido UniversitySapporoJapan
| | - Yoh Takekuma
- Faculty of Pharmaceutical SciencesHokkaido UniversitySapporoJapan
| |
Collapse
|
12
|
Gade C, Christensen HR, Dalhoff KP, Holm JC, Holst H. Inconsistencies in dosage practice in children with overweight or obesity: A retrospective cohort study. Pharmacol Res Perspect 2018; 6:e00398. [PMID: 29721323 PMCID: PMC5909170 DOI: 10.1002/prp2.398] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 03/12/2018] [Indexed: 01/21/2023] Open
Abstract
Obesity can affect the pharmacokinetics of most drugs, which may result in under- or overdosing if traditional pediatric dosing strategies are used. To investigate currently applied dosage strategies in children with overweight or obesity (overweight/obesity), in a clinical treatment facility. In particular, whether dosing guidelines were available and metrics of body size applied. A retrospective cohort study of 200 patients admitted to the Danish Children's Obesity Clinic. Data were collected from 2007 to 2015. Overweight/obese children 3-18 years were included if they had at least one drug prescription. Overall there were 658 prescriptions, primarily analgesics, psychotropics, asthma medications, and antibiotics. Except for one prescription, guidelines for dosage of overweight/obese children were not available in the clinic. In one prescription of gentamicin, the dose was adjusted by a metric body size. Otherwise dose was predominately prescribed either by total body weight or as fixed dose by age, in accordance with the recommendations of normal weight children. In drugs with a narrow therapeutic interval, we found large interindividual variations in dosing regimens, that is, for gentamicin, paracetamol, and prednisolone. Reduction of dose to the maximum recommended adult dose was common practice, when the dose calculated by total body weight (ie, mg/kg) exceeded this maximum. This study highlights the shortage of dosing guidelines in overweight/obese children. We found a large interindividual variability in dosage regimens, even in drugs with narrow therapeutic intervals. The clinicians rely on "best practice", as evidence-based dosage regimens are missing for many drugs prescribed during childhood.
Collapse
Affiliation(s)
- Christina Gade
- Department of Clinical PharmacologyCopenhagen University HospitalBispebjerg and FrederiksbergCopenhagen NVDenmark
| | - Hanne R. Christensen
- Department of Clinical PharmacologyCopenhagen University HospitalBispebjerg and FrederiksbergCopenhagen NVDenmark
| | - Kim P. Dalhoff
- Department of Clinical PharmacologyCopenhagen University HospitalBispebjerg and FrederiksbergCopenhagen NVDenmark
| | - Jens Christian Holm
- Children's Obesity ClinicEuropean Center of Management (EASO)Department of PaediatricsZealand University HospitalHolbaekDenmark
| | - Helle Holst
- Department of Clinical PharmacologyCopenhagen University HospitalBispebjerg and FrederiksbergCopenhagen NVDenmark
| |
Collapse
|
13
|
Smit C, De Hoogd S, Brüggemann RJM, Knibbe CAJ. Obesity and drug pharmacology: a review of the influence of obesity on pharmacokinetic and pharmacodynamic parameters. Expert Opin Drug Metab Toxicol 2018; 14:275-285. [PMID: 29431542 DOI: 10.1080/17425255.2018.1440287] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The rising prevalence of obesity confronts clinicians with dosing problems in the (extreme) overweight population. Obesity has a great impact on key organs that play a role in the pharmacokinetics (PK) and pharmacodynamics (PD) of drugs, however the ultimate impact of these changes on how to adapt the dose may not always be known. Areas covered: In this review, physiological changes associated with obesity are discussed. An overview is provided on the alterations in absorption, distribution, drug metabolism and clearance in (morbid) obesity focusing on general principles that can be extracted from pharmacokinetic studies. Also, relevant pharmacodynamic considerations in obesity are discussed. Expert opinion: Over the last two decades, increased knowledge is generated on PK and PD in obesity. Future research should focus on filling in the knowledge gaps that remain, especially in connecting obesity-related physiological changes with changes in PK and/or PD and vice versa. Ultimately, this knowledge can be used to develop physiologically based PK and PD models on the basis of quantitative systems pharmacology principles. Moreover, efforts should focus on thorough prospective evaluation of developed model-based doses with subsequent implementation of these dosing recommendations in clinical practice.
Collapse
Affiliation(s)
- Cornelis Smit
- a Department of Clinical Pharmacy , St. Antonius Hospital , Nieuwegein , The Netherlands.,b Division of Pharmacology , Leiden Academic Centre for Drug Research, Leiden University , Leiden , the Netherlands
| | - Sjoerd De Hoogd
- a Department of Clinical Pharmacy , St. Antonius Hospital , Nieuwegein , The Netherlands
| | - Roger J M Brüggemann
- c Department of Pharmacy , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Catherijne A J Knibbe
- a Department of Clinical Pharmacy , St. Antonius Hospital , Nieuwegein , The Netherlands.,b Division of Pharmacology , Leiden Academic Centre for Drug Research, Leiden University , Leiden , the Netherlands
| |
Collapse
|
14
|
Conway JM, Eberly LE, Collins JF, Macias FM, Ramsay RE, Leppik IE, Birnbaum AK. Factors in Variability of Serial Gabapentin Concentrations in Elderly Patients with Epilepsy. Pharmacotherapy 2017; 37:1197-1203. [PMID: 28801938 PMCID: PMC9949609 DOI: 10.1002/phar.2012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To characterize and quantify the variability of serial gabapentin concentrations in elderly patients with epilepsy. METHODS This study included 83 patients (age ≥ 60 yrs) from an 18-center randomized double-blind double-dummy parallel study from the Veterans Affairs Cooperative 428 Study. All patients were taking 1500 mg/day gabapentin. Within-person coefficient of variation (CV) in gabapentin concentrations, measured weekly to bimonthly for up to 52 weeks, then quarterly, was computed. Impact of patient characteristics on gabapentin concentrations (linear mixed model) and CV (linear regression) were estimated. RESULTS A total of 482 gabapentin concentration measurements were available for analysis. Gabapentin concentrations and intrapatient CVs ranged from 0.5 to 22.6 μg/ml (mean 7.9 μg/ml, standard deviation [SD] 4.1 μg/ml) and 2% to 79% (mean 27.9%, SD 15.3%), respectively, across all visits. Intrapatient CV was higher by 7.3% for those with a body mass index of ≥ 30 kg/m2 (coefficient = 7.3, p=0.04). CVs were on average 0.5% higher for each 1-unit higher CV in creatinine clearance (coefficient = 0.5, p=0.03) and 1.2% higher for each 1-hour longer mean time after dose (coefficient = 1.2, p=0.04). CONCLUSIONS Substantial intrapatient variability in serial gabapentin concentration was noted in elderly patients with epilepsy. Creatinine clearance, time of sampling relative to dose, and obesity were found to be positively associated with variability.
Collapse
Affiliation(s)
- Jeannine M. Conway
- Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota
| | - Lynn E. Eberly
- Division of Biostatistics, School of Public Health, University of Minnesota
| | | | | | | | - Ilo E. Leppik
- Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota,Department of Neurology, University of Minnesota
| | - Angela K. Birnbaum
- Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota
| |
Collapse
|
15
|
Ariano RE, Zelenitsky SA, Poncsak KR, Davis JC, Vercaigne LM. No role for patient body weight on renal function assessment for drug dosing. J Antimicrob Chemother 2017; 72:1802-1811. [PMID: 28369383 DOI: 10.1093/jac/dkx036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/18/2017] [Indexed: 12/23/2022] Open
Abstract
Objectives To evaluate the ability of body-weight-driven renal function assessment (RFA) formulae to predict on-target elimination rate ranges for gentamicin in patients with varying degrees of renal function. Methods A 6 year retrospective pharmacokinetic study was conducted at a university teaching hospital. Results A total of 85 patients met the inclusion criteria and 127 pharmacokinetic files were analysed from patients on medical-surgical wards (53%) and medical-surgical ICUs (13%) receiving intravenous gentamicin for treatment, as well as those for patients receiving it for surgical prophylaxis (34%). Each RFA formula was examined against standard dosing tables for gentamicin. A table of acceptable elimination rates was generated using a traditional peak of 8 mg/L and trough between 0.5 and 2 mg/L associated with each of the dosing interval extensions. The ability of each RFA formula to select on-target elimination rates was evaluated. The RFA formula assuming a normalized body weight of 72 kg and a modified creatinine reagent adjustment factor of 90% provided the most accurate on-target elimination rate selection. This method was superior to dosing interval selection based on the Modification in Diet Renal Disease (MDRD) formula, Sanford's guide method, as well as the Cockcroft-Gault formulae using total body weight, ideal body weight or lean body weight ( P < 0.0001). Conclusions Based on the use of gentamicin as a surrogate guide for renally adjusted drugs, these results support dosing interval selection based on a normalized body weight method and a formula reagent adjustment factor of 90% within the Cockcroft-Gault formula.
Collapse
Affiliation(s)
- Robert E Ariano
- Department of Pharmacy, St Boniface General Hospital, 409 Tache Avenue, Winnipeg, Manitoba, Canada.,College of Pharmacy, University of Manitoba, Winnipeg, Canada
| | - Sheryl A Zelenitsky
- Department of Pharmacy, St Boniface General Hospital, 409 Tache Avenue, Winnipeg, Manitoba, Canada.,College of Pharmacy, University of Manitoba, Winnipeg, Canada
| | | | - J Christine Davis
- Department of Pharmacy, St Boniface General Hospital, 409 Tache Avenue, Winnipeg, Manitoba, Canada.,College of Pharmacy, University of Manitoba, Winnipeg, Canada.,Manitoba Renal Program, Winnipeg, Canada
| | - Lavern M Vercaigne
- College of Pharmacy, University of Manitoba, Winnipeg, Canada.,Manitoba Renal Program, Winnipeg, Canada
| |
Collapse
|
16
|
Duong JK, Kroonen MYAM, Kumar SS, Heerspink HL, Kirkpatrick CM, Graham GG, Williams KM, Day RO. A dosing algorithm for metformin based on the relationships between exposure and renal clearance of metformin in patients with varying degrees of kidney function. Eur J Clin Pharmacol 2017; 73:981-990. [PMID: 28451709 DOI: 10.1007/s00228-017-2251-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/30/2017] [Indexed: 02/02/2023]
Abstract
PURPOSE The aims of this study were to investigate the relationship between metformin exposure, renal clearance (CLR), and apparent non-renal clearance of metformin (CLNR/F) in patients with varying degrees of kidney function and to develop dosing recommendations. METHODS Plasma and urine samples were collected from three studies consisting of patients with varying degrees of kidney function (creatinine clearance, CLCR; range, 14-112 mL/min). A population pharmacokinetic model was built (NONMEM) in which the oral availability (F) was fixed to 0.55 with an estimated inter-individual variability (IIV). Simulations were performed to estimate AUC0-τ, CLR, and CLNR/F. RESULTS The data (66 patients, 327 observations) were best described by a two-compartment model, and CLCR was a covariate for CLR. Mean CLR was 17 L/h (CV 22%) and mean CLNR/F was 1.6 L/h (69%).The median recovery of metformin in urine was 49% (range 19-75%) over a dosage interval. When CLR increased due to improved renal function, AUC0-τ decreased proportionally, while CLNR/F did not change with kidney function. Target doses (mg/day) of metformin can be reached using CLCR/3 × 100 to obtain median AUC0-12 of 18-26 mg/L/h for metformin IR and AUC0-24 of 38-51 mg/L/h for metformin XR, with Cmax < 5 mg/L. CONCLUSIONS The proposed dosing algorithm can be used to dose metformin in patients with various degrees of kidney function to maintain consistent drug exposure. However, there is still marked IIV and therapeutic drug monitoring of metformin plasma concentrations is recommended.
Collapse
Affiliation(s)
- Janna K Duong
- School of Medical Sciences, Medicine, University of New South Wales, Sydney, Australia. .,Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, Australia. .,Faculty of Pharmacy, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - M Y A M Kroonen
- Department of Pharmacy and Pharmacology, University of Groningen, Groningen, The Netherlands
| | - S S Kumar
- School of Medical Sciences, Medicine, University of New South Wales, Sydney, Australia.,Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, Australia
| | - H L Heerspink
- Department of Pharmacy and Pharmacology, University of Groningen, Groningen, The Netherlands
| | - C M Kirkpatrick
- Centre for Medicine Use and Safety, Monash University, Parkville, Australia
| | - G G Graham
- School of Medical Sciences, Medicine, University of New South Wales, Sydney, Australia.,Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, Australia
| | - K M Williams
- School of Medical Sciences, Medicine, University of New South Wales, Sydney, Australia.,Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, Australia
| | - R O Day
- School of Medical Sciences, Medicine, University of New South Wales, Sydney, Australia.,Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital, Sydney, Australia.,St Vincent's Clinical School, Medicine, University of New South Wales, Sydney, Australia
| |
Collapse
|
17
|
Population Pharmacokinetics and Target Attainment of Ertapenem in Plasma and Tissue Assessed via Microdialysis in Morbidly Obese Patients after Laparoscopic Visceral Surgery. Antimicrob Agents Chemother 2016; 61:AAC.00952-16. [PMID: 27795367 DOI: 10.1128/aac.00952-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/07/2016] [Indexed: 11/20/2022] Open
Abstract
Ertapenem provides broad-spectrum activity against many pathogens, and its use is relevant for the prophylaxis and treatment of infections in morbidly obese patients undergoing surgery. However, its pharmacokinetics and tissue penetration in these patients are not well defined. We assessed the population pharmacokinetics and target attainment for ertapenem in the plasma, subcutaneous tissue, and peritoneal fluid of morbidly obese patients. Six female patients (body mass index, 43.7 to 55.9 kg/m2) received 1,000 mg ertapenem as 15-min infusions at 0 and 26 h. On day 2, the unbound ertapenem concentrations in plasma, subcutaneous tissue, and peritoneal fluid were measured by microdialysis; total plasma concentrations were additionally quantified. The probability of attaining a target of an unbound ertapenem concentration above the MIC for at least 40% of the dosing interval was predicted via Monte Carlo simulations. The population pharmacokinetic model contained two disposition compartments and simultaneously described all concentrations. For unbound ertapenem, total clearance was 12.3 liters/h (coefficient of variation, 21.6% for between-patient variability) and the volume of distribution at steady state was 57.8 liters in patients with a 53-kg fat-free mass. The area under the concentration-time curve (AUC) for ertapenem was 49% lower in subcutaneous tissue and 25% lower in peritoneal fluid than the unbound AUC in plasma. Tissue penetration was rapid (equilibration half-life, <15 min) and was variable in subcutaneous tissue. Short-term ertapenem infusions (1,000 mg every 24 h) achieved robust (>90%) target attainment probabilities for MICs of up to 1 mg/liter in plasma, 0.25 to 0.5 mg/liter in subcutaneous tissue, and 0.5 mg/liter in peritoneal fluid. Ertapenem presents an attractive choice for many pathogens relevant to morbidly obese patients undergoing surgery. (This study has been registered at ClinicalTrials.gov under identifier NCT01407965.).
Collapse
|
18
|
Lin YS, Kerr SJ, Randolph T, Shireman LM, Senn T, McCune JS. Prediction of Intravenous Busulfan Clearance by Endogenous Plasma Biomarkers Using Global Pharmacometabolomics. Metabolomics 2016; 12:161. [PMID: 28827982 PMCID: PMC5562150 DOI: 10.1007/s11306-016-1106-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION High-dose busulfan (busulfan) is an integral part of the majority of hematopoietic cell transplantation conditioning regimens. Intravenous (IV) busulfan doses are personalized using pharmacokinetics (PK)-based dosing where the patient's IV busulfan clearance is calculated after the first dose and is used to personalize subsequent doses to a target plasma exposure. PK-guided dosing has improved patient outcomes and is clinically accepted but highly resource intensive. OBJECTIVE We sought to discover endogenous plasma biomarkers predictive of IV busulfan clearance using a global pharmacometabolomics-based approach. METHODS Using LC-QTOF, we analyzed 59 (discovery) and 88 (validation) plasma samples obtained before IV busulfan administration. RESULTS In the discovery dataset, we evaluated the association of the relative abundance of 1885 ions with IV busulfan clearance and found 21 ions that were associated with IV busulfan clearance tertiles (r2 ≥ 0.3). Identified compounds were deoxycholic acid and/or chenodeoxycholic acid, and linoleic acid. We used these 21 ions to develop a parsimonious seven-ion linear predictive model that accurately predicted IV busulfan clearance in 93% (discovery) and 78% (validation) of samples. CONCLUSION IV busulfan clearance was significantly correlated with the relative abundance of 21 ions, seven of which were included in a predictive model that accurately predicted IV busulfan clearance in the majority of the validation samples. These results reinforce the potential of pharmacometabolomics as a critical tool in personalized medicine, with the potential to improve the personalized dosing of drugs with a narrow therapeutic index such as busulfan.
Collapse
Affiliation(s)
- Yvonne S. Lin
- Department of Pharmaceutics, University of Washington, Seattle, WA
| | - Savannah J. Kerr
- Department of Pharmaceutics, University of Washington, Seattle, WA
| | | | | | - Tauri Senn
- Department of Pharmaceutics, University of Washington, Seattle, WA
| | - Jeannine S. McCune
- Department of Pharmaceutics, University of Washington, Seattle, WA
- Department of Pharmacy, University of Washington, Seattle, WA
- Fred Hutchinson Cancer Research Center, Seattle, WA
| |
Collapse
|
19
|
Drug therapy management in patients with renal impairment: how to use creatinine-based formulas in clinical practice. Eur J Clin Pharmacol 2016; 72:1433-1439. [PMID: 27568310 PMCID: PMC5110609 DOI: 10.1007/s00228-016-2113-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 07/27/2016] [Indexed: 01/26/2023]
Abstract
Purpose The use of estimated glomerular filtration rate (eGFR) in daily clinical practice. Methods eGFR is a key component in drug therapy management (DTM) in patients with renal impairment. eGFR is routinely reported by laboratories whenever a serum creatinine testing is ordered. In this paper, we will discuss how to use eGFR knowing the limitations of serum creatinine-based formulas. Results Before starting a renally excreted drug, an equally effective drug which can be used more safely in patients with renal impairment should be considered. If a renally excreted drug is needed, the reliability of the eGFR should be assessed and when needed, a 24-h urine creatinine clearance collection should be performed. After achieving the best approximation of the true GFR, we suggest a gradual drug dose adaptation according to the renal function. A different approach for drugs with a narrow therapeutic window (NTW) is recommended compared to drugs with a broad therapeutic window. For practical purposes, a therapeutic window of 5 or less was defined as a NTW and a list of NTW drugs is presented. Considerations about the drug dose may be different at the start of the therapy or during the therapy and depending on the indication. Monitoring effectiveness and adverse drug reactions are important, especially for NTW drugs. Dose adjustment should be based on an ongoing assessment of clinical status and risk versus the benefit of the used regimen. Conclusion When determining the most appropriate dosing regimen serum creatinine-based formulas should never be used naively but always in combination with clinical and pharmacological assessment of the individual patient. Electronic supplementary material The online version of this article (doi:10.1007/s00228-016-2113-2) contains supplementary material, which is available to authorized users.
Collapse
|
20
|
Correia-Costa L, Schaefer F, Afonso AC, Bustorff M, Guimarães JT, Guerra A, Barros H, Azevedo A. Normalization of glomerular filtration rate in obese children. Pediatr Nephrol 2016; 31:1321-8. [PMID: 27008644 DOI: 10.1007/s00467-016-3367-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Glomerular filtration rate (GFR) is conventionally indexed to body surface area (BSA), but this may lead to biased results when applied to subjects of abnormal body size. The aim of our study was to examine the impact of normalization to the BSA and alternative body size descriptors on measured and estimated GFR in overweight and obese children. METHODS This was a cross-sectional study of 313 children aged 8-9 years old. GFR was measured by 24-h creatinine clearance (CrCl) and additionally estimated from serum creatinine and cystatin C (CysC) using the combined Zappitelli formula, both as absolute values and adjusted to various body size descriptors. The results were compared between 163 normal-weight, 89 overweight and 61 obese children. RESULTS Compared to the normal-weight children, mean absolute GFR (both measured and estimated) was higher in the overweight and obese children, whereas BSA-adjusted GFR was lower. Linear regression models fitted in normal-weight children revealed equally close associations between absolute GFR and squared height, ideal body weight (IBW) and BSA derived from IBW. Normalization of GFR to the IBW-derived BSA completely eliminated the discrepancy between absolute and BSA-indexed GFR in overweight and obese children. CONCLUSIONS Indexing of GFR to BSA calculated from the ideal-rather than actual-body weight is a promising approach to avoid overcorrection when studying obese children. Further studies should assess the accuracy of this approach across the full range of age and BMI distribution.
Collapse
Affiliation(s)
- Liane Correia-Costa
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal. .,Division of Pediatric Nephrology, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal. .,Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal.
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Alberto Caldas Afonso
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Division of Pediatric Nephrology, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal.,Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Manuela Bustorff
- Department of Nephrology, Centro Hospitalar São João, Porto, Portugal
| | - João Tiago Guimarães
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Pathology , Centro Hospitalar São João, Porto, Portugal.,Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal
| | - António Guerra
- Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal.,Division of Pediatric Nutrition, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal
| | - Henrique Barros
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Epidemiology, Predictive Medicine and Public Health, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Ana Azevedo
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Epidemiology, Predictive Medicine and Public Health, Faculty of Medicine, University of Porto, Porto, Portugal
| |
Collapse
|
21
|
Chairat K, Jittamala P, Hanpithakpong W, Day NPJ, White NJ, Pukrittayakamee S, Tarning J. Population pharmacokinetics of oseltamivir and oseltamivir carboxylate in obese and non-obese volunteers. Br J Clin Pharmacol 2016; 81:1103-12. [PMID: 26810861 PMCID: PMC4876175 DOI: 10.1111/bcp.12892] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 01/19/2016] [Accepted: 01/24/2016] [Indexed: 01/21/2023] Open
Abstract
AIMS The aims of the present study were to compare the pharmacokinetics of oseltamivir and its active antiviral metabolite oseltamivir carboxylate in obese and non-obese individuals and to determine the effect of obesity on the pharmacokinetic properties of oseltamivir and oseltamivir carboxylate. METHODS The population pharmacokinetic properties of oseltamivir and oseltamivir carboxylate were evaluated in 12 obese [body mass index (BMI) ≥30 kg m(-2) ) and 12 non-obese (BMI <30 kg m(-2) ) Thai adult volunteers receiving a standard dose of 75 mg and a double dose of 150 mg in a randomized sequence. Concentration-time data were collected and analysed using nonlinear mixed-effects modelling. RESULTS The pharmacokinetics of oseltamivir and oseltamivir carboxylate were described simultaneously by first-order absorption, with a one-compartment disposition model for oseltamivir, followed by a metabolism compartment and a one-compartment disposition model for oseltamivir carboxylate. Creatinine clearance was a significant predictor of oseltamivir carboxylate clearance {3.84% increase for each 10 ml min(-1) increase in creatinine clearance [95% confidence interval (CI) 0.178%, 8.02%]}. Obese individuals had an approximately 25% (95% CI 24%, 28%) higher oseltamivir clearance, 20% higher oseltamivir volume of distribution (95% CI 19%, 23%) and 10% higher oseltamivir carboxylate clearance (95% CI 9%, 11%) compared with non-obese individuals. However, these altered pharmacokinetic properties were small and did not change the overall exposure to oseltamivir carboxylate. CONCLUSIONS The results confirmed that a dose adjustment for oseltamivir in obese individuals is not necessary on the basis of its pharmacokinetics.
Collapse
Affiliation(s)
- Kalayanee Chairat
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Podjanee Jittamala
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Warunee Hanpithakpong
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
22
|
Li L, Hongwei S, Ying Q, Jianzhong L, Zhifang W, Ling G, Sijin L. Influence of Weight-Age Normalization on Glomerular Filtration Rate Values of Renal Patients: A STROBE-Compliant Article. Medicine (Baltimore) 2016; 95:e2492. [PMID: 26817886 PMCID: PMC4998260 DOI: 10.1097/md.0000000000002492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
To explore whether weight-age (W-A) could be applied in clinical practice, this study was designed to verify the normalization ability of W-A by the data from another medical center, and to access the influence of the normalization on glomerular filtration rate (GFR) values in renal patients.Both plasma clearance (pGFR) and camera-based (gGFR), which were separately scaled to W-A and body surface area (BSA), were measured for patients with diffuse renal diseases. The patients (n = 298) were stratified according to the Chinese body mass index (BMI) criteria and were staged according to the Kidney Disease Outcome Quality Initiatives guideline based on gGFR and pGFR separately.The indices of intraclass correlation coefficient (ICC), concordance correlation coefficient (CCC), and ratio of residual standard deviation to pooled standard deviation (RSD/PSD) suggested that, for all patients and each BMI stratum, W-A was obviously better than BSA in scaling GFR. Both under pGFR or gGFR renal stages, only small amount of the patients encountered stage migrations from BSA to W-A scaled stages. The differences between any 2 of the unscaled, BSA scaled, and W-A scaled gGFR (or pGFR) were not obviously changed. Additionally, in some strata, W-A normalization is better than BSA normalization in decreasing the median bias between pGFR and gGFR.W-A is better than BSA in scaling GFR without obvious modifying GFR values and can be applied in routine clinical practice.
Collapse
Affiliation(s)
- Li Li
- From the Department of Nuclear Medicine, the First Affiliated Hospital of Shanxi Medical University, Taiyuan, Shanxi Province (LL, SH, QY, GL, LJ, WZ, LS)
| | | | | | | | | | | | | |
Collapse
|
23
|
Chew-Harris JSC, Florkowski CM, Elmslie JL, Livesey J, Endre ZH, George PM. Lean mass modulates glomerular filtration rate in males of normal and extreme body composition. Intern Med J 2015; 44:749-56. [PMID: 24863461 DOI: 10.1111/imj.12479] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 05/05/2014] [Indexed: 01/18/2023]
Abstract
BACKGROUND Understanding determinants of glomerular filtration rate (GFR) is important in aiding prediction and interpretation of kidney function. Body composition is known to affect GFR but is not included in current screening of kidney disease. We investigated the association between GFR and body composition in healthy young men with differing body mass but without known diabetes or kidney injury. METHODS Three groups were recruited: normal BMI (n = 22) with a body mass index (BMI) <25 kg/m(2) , muscular (n = 23) with BMI ≥30 kg/m(2) and bioelectrical impedance body fat ≤20% and obese (n = 22) with BMI ≥30 kg/m(2) and bioelectrical impedance body fat ≥30%. Dietary analyses, GFR clearance by (99m) Tc-DTPA, urine protein and body composition by dual-energy X-ray absorptiometry were measured in all participants. Linear and nonlinear associations of constituents of body composition with GFR were assessed. RESULTS Muscular men had a higher GFR (mean 186.4 mL/min; 95% CI 171.7-201.1) than normal BMI and obese groups (P = 0.0007). Urine protein and albumin excretion were not elevated in any participants. On multiple regression analysis (r(2) = 0.60), the variables with strong associations with GFR were age (P = 0.0009) and lean mass (P = 0.0001). Fat mass, protein intake and smoking status were not associated. Skeletal muscle mass correlated significantly with GFR in all subgroups. CONCLUSION Age and lean mass were strong determinants of GFR. Estimates of GFR should therefore be indexed to an estimate of lean mass.
Collapse
Affiliation(s)
- J S C Chew-Harris
- Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand; Christchurch School of Medicine, University of Otago, Christchurch, New Zealand
| | | | | | | | | | | |
Collapse
|
24
|
Knibbe CAJ, Brill MJE, van Rongen A, Diepstraten J, van der Graaf PH, Danhof M. Drug disposition in obesity: toward evidence-based dosing. Annu Rev Pharmacol Toxicol 2015; 55:149-67. [PMID: 25340929 DOI: 10.1146/annurev-pharmtox-010814-124354] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Obesity and morbid obesity are associated with many physiological changes affecting pharmacokinetics, such as increased blood volume, cardiac output, splanchnic blood flow, and hepatic blood flow. In obesity, drug absorption appears unaltered, although recent evidence suggests that this conclusion may be premature. Volume of distribution may vary largely, but the magnitude and direction of changes seem difficult to predict, with extrapolation on the basis of total body weight being the best approach to date. Changes in clearance may be smaller than in distribution, whereas there is growing evidence that the influence of obesity on clearance can be predicted on the basis of reported changes in the metabolic or elimination pathways involved. For obese children, we propose two methods to distinguish between developmental and obesity-related changes. Future research should focus on the characterization of physiological concepts to predict the optimal dose for each drug in the obese population.
Collapse
Affiliation(s)
- Catherijne A J Knibbe
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, 2333 CC Leiden, The Netherlands;
| | | | | | | | | | | |
Collapse
|
25
|
Celik F, Huitema ADR, Hooijberg JH, van de Laar AWJM, Brandjes DPM, Gerdes VEA. Fixed-Dose Enoxaparin After Bariatric Surgery: The Influence of Body Weight on Peak Anti-Xa Levels. Obes Surg 2014; 25:628-34. [DOI: 10.1007/s11695-014-1435-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
26
|
Chin PKL, Vella-Brincat JWA, Walker SL, Barclay ML, Begg EJ. Dosing of dabigatran etexilate in relation to renal function and drug interactions at a tertiary hospital. Intern Med J 2014; 43:778-83. [PMID: 23611064 DOI: 10.1111/imj.12170] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 04/15/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Plasma concentrations of the anticoagulant dabigatran are correlated with clinical outcomes, and are affected by renal function, intestinal P-glycoprotein (P-gp) activity and stomach acidity. AIMS To determine the adherence to dabigatran etexilate renal dosing guidelines, the frequency of co-prescription of potentially interacting drugs in patients on dabigatran, and how these related to dabigatran dosing. METHODS A retrospective chart review of 204 patients discharged from a tertiary hospital on dabigatran etexilate over a 12-month period. Creatinine clearance, using the Cockcroft-Gault equation, was used as the surrogate of renal function in the 86 patients where this was calculable. RESULTS Prescribed dabigatran etexilate dose rates in relation to creatinine clearance and the manufacturer's guidelines were classified as 'standard', 'low' and 'high' in 47% (40/86), 49% (42/86) and 5% (4/86) of patients respectively. Co-prescribed drugs that potentially interact with dabigatran etexilate were present in 75% (154/204) of patients and included strong P-gp inhibitors (16%, 32/204), proton-pump inhibitors (46%, 94/204) and anti-platelet drugs (47%, 95/204). Co-prescription of strong P-gp inhibitors was associated with the prescription of 'low' dose rates relative to renal function (P = 0.025). CONCLUSIONS Few patients were dosed excessively in relation to creatinine clearance. Around 50% was prescribed with 'low' dose rates in relation to creatinine clearance, which because of the association with co-prescription of strong P-gp inhibitors may be clinically appropriate. Most patients were co-prescribed with drugs that potentially interact with dabigatran etexilate.
Collapse
Affiliation(s)
- P K L Chin
- Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand.
| | | | | | | | | |
Collapse
|
27
|
Wong C, Kumar SS, Graham GG, Begg EJ, Chin PKL, Brett J, Ray JE, Marriott DJE, Williams KM, Day RO. Comparing dose prediction software used to manage gentamicin dosing. Intern Med J 2014; 43:519-25. [PMID: 23279297 DOI: 10.1111/imj.12067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 11/21/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Current Australian guidelines recommend initiating directed therapy of gentamicin if administration exceeds 48 h. Directed doses of gentamicin require the monitoring of plasma concentrations of gentamicin to determine the 24-h area under the time course of plasma gentamicin concentrations (AUC) and a dosage prediction program, for example TCIWorks or Aladdin. However, doses calculated by such programs have not been compared with an established program. AIM To compare the directed dosage of gentamicin calculated by TCIWorks, Aladdin and an Excel-based program, with an established program, Abbottbase. METHODS Peak and trough plasma concentrations after the first and second administered doses of gentamicin were available from three patient groups (n = 20-23) with varying creatinine clearances (<40, 40-80, >80 mL/min). The directed dose needed to produce 24-h AUC values of 80 mg.h/L was calculated using each program. RESULTS There was a strong correlation between the directed doses predicted by each of the three programs compared with Abbottbase, following the first administered dose (r(2) > 0.97, P < 0.0001). The mean ratio (90% confidence intervals) of these directed doses of the gentamicin were: TCIWorks/Abbottbase 106% (105-107%), Aladdin/Abbottbase 102% (101-103%) and Excel/Abbottbase 108% (106-109%). The correlations and dose ratios were also similar when comparisons were made following the second administered dose. For each of the three renal function groups, all programs yielded similar directed doses. CONCLUSIONS The four programs used in the calculation of directed doses of gentamicin yielded similar results. Any would be suitable for use in clinical practice.
Collapse
Affiliation(s)
- C Wong
- St Vincent's Clinical School, St Vincent's Hospital and University of New South Wales, Sydney, New South Wales, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Lemoine S, Guebre-Egziabher F, Sens F, Nguyen-Tu MS, Juillard L, Dubourg L, Hadj-Aissa A. Accuracy of GFR estimation in obese patients. Clin J Am Soc Nephrol 2014; 9:720-7. [PMID: 24482068 DOI: 10.2215/cjn.03610413] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Adequate estimation of renal function in obese patients is essential for the classification of patients in CKD category as well as the dose adjustment of drugs. However, the body size descriptor for GFR indexation is still debatable, and formulas are not validated in patients with extreme variations of weight. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study included 209 stages 1-5 CKD obese patients referred to the Department of Renal Function Study at the University Hospital in Lyon between 2010 and 2013 because of suspected renal dysfunction. GFR was estimated with the Chronic Kidney Disease and Epidemiology equation (CKD-EPI) and measured with a gold standard method (inulin or iohexol) not indexed (mGFR) or indexed to body surface area determined by the Dubois and Dubois formula with either real (mGFRr) or ideal (mGFRi) body weight. Mean bias (eGFR-mGFR), precision, and accuracy of mGFR were compared with the results obtained for nonobese participants (body mass index between 18.5 and 24.9) who had a GFR measurement during the same period of time. RESULTS Mean mGFRr (51.6 ± 24.2 ml/min per 1.73 m(2)) was significantly lower than mGFR, mGFRi, and eGFRCKD-EPI. eGFRCKD-EPI had less bias with mGFR (0.29; -1.7 to 2.3) and mGFRi (-1.62; -3.1 to 0.45) compared with mGFRr (8.7; 7 to 10). This result was confirmed with better accuracy for the whole cohort (78% for mGFR, 84% for mGFRi, and 72% for mGFRr) and participants with CKD stages 3-5. Moreover, the Bland Altman plot showed better agreement between mGFR and eGFRCKD-EPI. The bias between eGFRCKD-EPI and mGFRr was greater in obese than nonobese participants (8.7 versus 0.58, P<0.001). CONCLUSIONS This study shows that, in obese CKD patients, the performance of eGFRCKD-EPI is good for GFR ≤ 60 ml/min per 1.73 m(2). Indexation of mGFR with body surface area using ideal body weight gives less bias than mGFR scaled with body surface area using real body weight.
Collapse
Affiliation(s)
- Sandrine Lemoine
- Departments of Renal Function Study and, †Nephrology, Edouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France;, ‡Institut National de la Santé et de la Recherche Médicale U1060, Laboratoire de Recherche en Cardiovasculaire, Métabolisme, Diabétologie et Nutrition, Lyon, France;, §University of Lyon, Université Lyon 1 Claude Bernard, Lyon, France, ‖Unité Mixte de Recherche 5305 Centre National de la Recherche Scientifique, Université Claude Bernard, Lyon, France
| | | | | | | | | | | | | |
Collapse
|
29
|
Duong JK, Kumar SS, Kirkpatrick CM, Greenup LC, Arora M, Lee TC, Timmins P, Graham GG, Furlong TJ, Greenfield JR, Williams KM, Day RO. Population pharmacokinetics of metformin in healthy subjects and patients with type 2 diabetes mellitus: simulation of doses according to renal function. Clin Pharmacokinet 2013; 52:373-84. [PMID: 23475568 DOI: 10.1007/s40262-013-0046-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Metformin is contraindicated in patients with renal impairment; however, there is poor adherence to current dosing guidelines. In addition, the pharmacokinetics of metformin in patients with significant renal impairment are not well described. The aims of this study were to investigate factors influencing the pharmacokinetic variability, including variant transporters, between healthy subjects and patients with type 2 diabetes mellitus (T2DM) and to simulate doses of metformin at varying stages of renal function. METHODS Plasma concentrations of metformin were pooled from three studies: patients with T2DM (study A; n = 120), healthy Caucasian subjects (study B; n = 16) and healthy Malaysian subjects (study C; n = 169). A population pharmacokinetic model of metformin was developed using NONMEM(®) version VI for both the immediate-release (IR) formulation and the extended-release (XR) formulation of metformin. Total body weight (TBW), lean body weight (LBW), creatinine clearance (CLCR; estimated using TBW and LBW) and 57 single-nucleotide polymorphisms (SNPs) of metformin transporters (OCT1, OCT2, OCT3, MATE1 and PMAT) were investigated as potential covariates. A nonparametric bootstrap (n = 1,000) was used to evaluate the final model. This model was used to simulate 1,000 concentration-time profiles for doses of metformin at each stage of renal impairment to ensure metformin concentrations do not exceed 5 mg/l, the proposed upper limit. RESULTS Creatinine clearance and TBW were clinically and statistically significant covariates with the apparent clearance and volume of distribution of metformin, respectively. None of the 57 SNPs in transporters of metformin were significant covariates. In contrast to previous studies, there was no effect on the pharmacokinetics of metformin in patients carrying the reduced function OCT1 allele (R61C, G401S, 420del or G465R). Dosing simulations revealed that the maximum daily doses in relation to creatinine clearance to prescribe to patients are 500 mg (15 ml/min), 1,000 mg (30 ml/min), 2,000 mg (60 ml/min) and 3,000 mg (120 ml/min), for both the IR and XR formulations. CONCLUSION The population model enabled doses of metformin to be simulated for each stage of renal function, to ensure the concentrations of metformin do not exceed 5 mg/l. However, the plasma concentrations of metformin at these dosage levels are still quite variable and monitoring metformin concentrations may be of value in individualising dosage. This study provides confirmatory data that metformin can be used, with appropriate dosage adjustment, in patients with renal impairment.
Collapse
Affiliation(s)
- Janna K Duong
- School of Medical Sciences, University of New South Wales, Kensington, Sydney, NSW, Australia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Brown DL, Masselink AJ, Lalla CD. Functional range of creatinine clearance for renal drug dosing: a practical solution to the controversy of which weight to use in the Cockcroft-Gault equation. Ann Pharmacother 2013; 47:1039-44. [PMID: 23757387 DOI: 10.1345/aph.1s176] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE To describe a practical solution for addressing body weight when using the Cockcroft-Gault equation to determine drug dosing. DATA SOURCES A literature search was conducted using PubMed MEDLINE (1980-April 2013) using creatinine clearance, Cockcroft and Gault, Cockcroft-Gault, body weight, and obesity as search terms. Reference citations from publications reviewed were included. STUDY SELECTION AND DATA EXTRACTION All English-language articles identified by the search were reviewed. Studies comparing the accuracy and bias of the Cockcroft-Gault equation using a variety of body weight designations in adult populations were included in the analysis. DATA SYNTHESIS Study results indicated that, for obese patients, ideal body weight (IBW) underestimates creatinine clearance (CrCl) and total body weight (TBW) overestimates CrCl. Some studies suggest that adjusted body weight with a factor of 0.4 is most accurate, while others suggest the use of lean body weight. These studies have failed to produce a definitive resolution to the controversy. Despite many well-designed studies, the Cockcroft-Gault body weight controversy remains unresolved and uncertainty continues to exist as to which form of weight should be used in the equation. A different perspective is warranted. Since renal dosing guidelines are generally based on ranges of CrCl, applying a CrCl range to describe a patient's renal function might be more practical than relying on a specific CrCl value. Ultimately, CrCl-based drug dosing involves the use of an imperfect mathematical approximation, which is then applied as precisely as possible to the benefit versus risk analysis for a specific patient. CONCLUSIONS We propose the use of a CrCl range for drug dosing purposes, with the lower boundary defined by using IBW in the Cockcroft-Gault equation and the upper boundary by using TBW.
Collapse
Affiliation(s)
- Daniel L Brown
- Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, FL, USA.
| | | | | |
Collapse
|
31
|
Stocker SL, McLachlan AJ, Savic RM, Kirkpatrick CM, Graham GG, Williams KM, Day RO. The pharmacokinetics of oxypurinol in people with gout. Br J Clin Pharmacol 2013; 74:477-89. [PMID: 22300439 DOI: 10.1111/j.1365-2125.2012.04207.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
AIMS Our aim was to identify and quantify the sources of variability in oxypurinol pharmacokinetics and explore relationships with plasma urate concentrations. METHODS Non-linear mixed effects modelling was applied to concentration-time data from 155 gouty patients with demographic, medical history and renal transporter genotype information. RESULTS A one compartment pharmacokinetic model with first order absorption best described the oxypurinol concentration-time data. Renal function and concomitant medicines (diuretics and probenecid), but not transporter genotype, significantly influenced oxypurinol pharmacokinetics and reduced the between subject variability in the apparent clearance of oxypurinol (CL/F(m)) from 65% to 29%. CL/F(m) for patients with normal, mild, moderate and severe renal impairment was 1.8, 0.6, 0.3 and 0.18 l h(-1), respectively. Model predictions showed a relationship between plasma oxypurinol and urate concentrations and failure to reach target oxypurinol concentrations using suggested allopurinol dosing guidelines. CONCLUSIONS In conclusion, this first established pharmacokinetic model provides a tool to achieve target oxypurinol plasma concentrations, thereby optimizing the effectiveness and safety of allopurinol therapy in gouty patients with various degrees of renal impairment.
Collapse
|
32
|
Luaces M, Martinez-Martinez E, Medina M, Miana M, Gonzalez N, Fernandez-Perez C, Cachofeiro V. The impact of bariatric surgery on renal and cardiac functions in morbidly obese patients. Nephrol Dial Transplant 2012; 27 Suppl 4:iv53-7. [DOI: 10.1093/ndt/gfs529] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
33
|
Brocks DR, Ben-Eltriki M, Gabr RQ, Padwal RS. The effects of gastric bypass surgery on drug absorption and pharmacokinetics. Expert Opin Drug Metab Toxicol 2012; 8:1505-19. [DOI: 10.1517/17425255.2012.722757] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
34
|
van Kralingen S, Diepstraten J, Peeters MYM, Deneer VHM, van Ramshorst B, Wiezer RJ, van Dongen EPA, Danhof M, Knibbe CAJ. Population pharmacokinetics and pharmacodynamics of propofol in morbidly obese patients. Clin Pharmacokinet 2012; 50:739-50. [PMID: 21973271 DOI: 10.2165/11592890-000000000-00000] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND OBJECTIVES In view of the increasing prevalence of morbidly obese patients, the influence of excessive total bodyweight (TBW) on the pharmacokinetics and pharmacodynamics of propofol was characterized in this study using bispectral index (BIS) values as a pharmacodynamic endpoint. METHODS A population pharmacokinetic and pharmacodynamic model was developed with the nonlinear mixed-effects modelling software NONMEM VI, on the basis of 491 blood samples from 20 morbidly obese patients (TBW range 98-167 kg) and 725 blood samples from 44 lean patients (TBW range 55-98 kg) from previously published studies. In addition, 2246 BIS values from the 20 morbidly obese patients were available for pharmacodynamic analysis. RESULTS In a three-compartment pharmacokinetic model, TBW proved to be the most predictive covariate for clearance from the central compartment (CL) in the 20 morbidly obese patients (CL 2.33 L/min × [TBW/70]^[0.72]). Similar results were obtained when the morbidly obese patients and the 44 lean patients were analysed together (CL 2.22 L/min × [TBW/70]^[0.67]). No covariates were identified for other pharmacokinetic parameters. The depth of anaesthesia in the morbidly obese patients was adequately described by a two-compartment biophase-distribution model with a sigmoid maximum possible effect (E(max)) pharmacodynamic model (concentration at half-maximum effect [EC(50)] 2.12 mg/L) without covariates. CONCLUSION We developed a pharmacokinetic and pharmacodynamic model of propofol in morbidly obese patients, in which TBW proved to be the major determinant of clearance, using an allometric function with an exponent of 0.72. For the other pharmacokinetic and pharmacodynamic parameters, no covariates could be identified. Trial registration number (clinicaltrials.gov): NCT00395681.
Collapse
Affiliation(s)
- Simone van Kralingen
- Department of Anesthesiology and Intensive Care, St Antonius Hospital, Nieuwegein, the Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Chigutsa E, Meredith S, Wiesner L, Padayatchi N, Harding J, Moodley P, Mac Kenzie WR, Weiner M, McIlleron H, Kirkpatrick CMJ. Population pharmacokinetics and pharmacodynamics of ofloxacin in South African patients with multidrug-resistant tuberculosis. Antimicrob Agents Chemother 2012; 56:3857-63. [PMID: 22564839 PMCID: PMC3393408 DOI: 10.1128/aac.00048-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/29/2012] [Indexed: 11/20/2022] Open
Abstract
Despite the important role of fluoroquinolones and the predominant use of ofloxacin for treating multidrug-resistant tuberculosis in South Africa, there are limited data on ofloxacin pharmacokinetics in patients with multidrug-resistant tuberculosis, no ofloxacin pharmacokinetic data from South African patients, and no direct assessment of the relationship between ofloxacin pharmacokinetics and the MIC of ofloxacin of patient isolates. Our objectives are to describe ofloxacin pharmacokinetics in South African patients being treated for multidrug-resistant tuberculosis and assess the adequacy of ofloxacin drug exposure with respect to the probability of pharmacodynamic target attainment (area under the time curve/MIC ratio of at least 100). Sixty-five patients with multidrug-resistant tuberculosis were recruited from 2 hospitals in South Africa. We determined the ofloxacin MICs for the Mycobacterium tuberculosis isolates from baseline sputum specimens. Patients received daily doses of 800 mg ofloxacin, in addition to other antitubercular drugs. Patients underwent pharmacokinetic sampling at steady state. NONMEM was used for data analysis. The population pharmacokinetics of ofloxacin in this study has been adequately described. The probability of target attainment expectation in the study population was 0.45. Doubling the dose to 1,600 mg could increase this to only 0.77. The currently recommended ofloxacin dose appeared inadequate for the majority of this study population. Studies to assess the tolerability of higher doses are warranted. Alternatively, ofloxacin should be replaced with more potent fluoroquinolones.
Collapse
Affiliation(s)
- Emmanuel Chigutsa
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Bucaloiu ID, Wood GC, Norfolk ER, Still CD, Hartle JE, Perkins RM. Fat-free weight prediction in morbidly obese females. Int J Nephrol Renovasc Dis 2011; 4:149-55. [PMID: 22163172 PMCID: PMC3234152 DOI: 10.2147/ijnrd.s24173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Precise estimation of creatinine clearance in obese individuals relies on the appropriate assessment of lean body weight (LBW). Anthropometric methods of predicting LBW have not been validated in morbidly obese populations. Patients and methods Using an existing dataset of anthropometric data for a female cohort with morbid obesity who had undergone measured FFW with dual energy absorptiometry, we evaluated the performance of five previously reported estimating equations for the prediction of LBW. Linear regression was used to derive a new LBW prediction formula and was then compared with the other formulae. Results Seventy females (mean [standard deviation] age, weight, and body mass index 43.0 [11.0] years, 128.1 [13.8] kg, and 48.3 [4.8] kg/m2, respectively) were identified. LBW as estimated by the method of Garrow and Webster correlated well (r = 0.87) with measured mass while demonstrating the highest accuracy, best precision, and smallest bias (93%, 2.1 kg, and 2.9 kg, respectively; P < 0.0001 for all comparisons). The derived formula further improved bias, precision, and accuracy. Conclusion Among females with morbid obesity, most previously reported estimating equations for LBW predicted FFW poorly. These findings have important clinical implications for the assessment of kidney function and for safe and effective drug dosing.
Collapse
Affiliation(s)
- Ion D Bucaloiu
- Department of Nephrology, Geisinger Medical Center, Danville, PA
| | | | | | | | | | | |
Collapse
|
37
|
Peters AM, Perry L, Hooker CA, Howard B, Neilly MDJ, Seshadri N, Sobnack R, Irwin A, Snelling H, Gruning T, Patel NH, Lawson RS, Shabo G, Williams N, Dave S, Barnfield MC. Extracellular fluid volume and glomerular filtration rate in 1878 healthy potential renal transplant donors: effects of age, gender, obesity and scaling. Nephrol Dial Transplant 2011; 27:1429-37. [PMID: 22076428 DOI: 10.1093/ndt/gfr479] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
UNLABELLED Aim. The aim of this study was to investigate the influence of age, gender, obesity and scaling on glomerular filtration rate (GFR) and extracellular fluid volume (ECV) in healthy subjects. METHODS This is a retrospective multi-centre study of 1878 healthy prospective kidney transplant donors (819 men) from 15 centres. Age and body mass index (BMI) were not significantly different between men and women. Slope-intercept GFR was measured (using Cr-51-EDTA in 14 centres; Tc-99m-DTPA in one) and scaled to body surface area (BSA) and lean body mass (LBM), both estimated from height and weight. GFR was also expressed as the slope rate constant, with one-compartment correction (GFR/ECV). ECV was measured as the ratio, GFR to GFR/ECV. RESULTS ECV was age independent but GFR declined with age, at a significantly faster rate in women than men. GFR/BSA was higher in men but GFR/ECV and GFR/LBM were higher in women. Young women (<30 years) had higher GFR than young men but the reverse was recorded in the elderly (>65 years). There was no difference in GFR between obese (BMI>30 kg/m2) and non-obese men. Obese women, however, had lower GFR than non-obese women and negative correlations were observed between GFR and both BMI and %fat. The decline in GFR with age was no faster in obese versus non-obese subjects. ECV/BSA was higher in men but ECV/LBM was higher in women. ECV/weight was almost gender independent, suggesting that fat-free mass in women contains more extracellular water. BSA is therefore a misleading scaling variable. CONCLUSION There are several significant differences in GFR and ECV between healthy men and women.
Collapse
Affiliation(s)
- A Michael Peters
- Department of Nuclear Medicine, Royal Sussex County Hospital, Brighton, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Wetmore JB, Honea RA, Vidoni ED, Almehmi A, Burns JM. Role of lean body mass in estimating glomerular filtration rate in Alzheimer disease. Nephrol Dial Transplant 2011; 26:2222-31. [PMID: 21098656 PMCID: PMC3145378 DOI: 10.1093/ndt/gfq695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/17/2010] [Accepted: 10/19/2010] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The association between estimated glomerular filtration rate (eGFR) and progression of Alzheimer disease (AD), as measured by cognitive decline and brain atrophy, has been infrequently studied. Since AD is characterized by sarcopenia and other changes in body composition, which are known to influence GFR, a determination of how lean mass (LM) affects estimation of GFR in AD patients is important. METHODS Participants were drawn from a prospective longitudinal study of brain ageing and AD in community-dwelling individuals. Control (n = 60) and AD (n = 61) participants were enrolled. Estimated GFR was calculated using the four-variable Modification of Diet in Renal Disease (MDRD), Cockroft-Gault, Macdonald appendicular LM and Taylor LM equations. Association of eGFR with 2-year change in cognitive function and brain volume was assessed. RESULTS Individuals with AD demonstrated a paradoxical finding in which lower baseline MDRD eGFR was associated with less cognitive decline (P = 0.04) and brain atrophy (P = 0.02), a phenomenon not observed in non-AD controls. This finding was abolished in the AD patients when either the Macdonald appendicular LM or Taylor LM equations were used. While significant group-by-eGFR interactions were present for cognitive decline (P = 0.006) and brain atrophy (P = 0.001) when the MDRD equation was used, no group-by-eGFR interactions were present when either the Macdonald LM (P = 0.58 and P = 0.10 for cognitive decline and brain atrophy, respectively) or Taylor LM (P = 0.97 and P = 0.55) equations were used. CONCLUSIONS Accounting for measures of LM in GFR estimation appears to significantly mitigate counterintuitive relationships between measures of AD progression and eGFR as calculated by more traditional measures of renal function. This suggests that consideration of LM in eGFR calculations may be important in patients with sarcopenia, such as the AD population.
Collapse
Affiliation(s)
- James B Wetmore
- Department of Medicine, Division of Nephrology and Hypertension and The Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | | | | | | | | |
Collapse
|
39
|
Jain R, Chung SM, Jain L, Khurana M, Lau SWJ, Lee JE, Vaidyanathan J, Zadezensky I, Choe S, Sahajwalla CG. Implications of obesity for drug therapy: limitations and challenges. Clin Pharmacol Ther 2011; 90:77-89. [PMID: 21633345 DOI: 10.1038/clpt.2011.104] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Obesity has become a worldwide challenge with significant health and socioeconomic implications. One of the major implications is its impact on drug therapy. In order to gain a better understanding of this impact, we surveyed the regulatory guidances, the newly approved molecular entity drug products, and drug product labels in the Physician's Desk Reference. This review summarizes the findings of the survey along with the existing knowledge on pharmacokinetic and pharmacodynamic changes associated with obesity.
Collapse
Affiliation(s)
- R Jain
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Wuerzner G, Bochud M, Giusti V, Burnier M. Measurement of glomerular filtration rate in obese patients: pitfalls and potential consequences on drug therapy. Obes Facts 2011; 4:238-43. [PMID: 21701241 PMCID: PMC6444551 DOI: 10.1159/000329547] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Epidemiological studies have shown that obesity is associated with chronic kidney disease and end stage renal disease. These studies have used creatinine derived equations to estimate glomerular filtration rate (GFR) and have indexed GFR to body surface area (BSA). However, the use of equations using creatinine as a surrogate marker of glomerular filtration and the indexation of GFR for BSA can be questioned in the obese population. First, these equations lack precision when they are compared to gold standard GFR measurements such as inulin clearances; secondly, the indexation of GFR for 1.73 m(2) of BSA leads to a systematic underestimation of GFR compared to absolute GFR in obese patients who have BSA that usually exceed 1.73 m(2). Obesity is also associated with pathophysiological changes that can affect the pharmacokinetics of drugs. The effect of obesity on both renal function and drug pharmacokinetics raises the issue of correct drug dosage in obese individuals. This may be particularly relevant for drugs known to have a narrow therapeutic range or excreted by the kidney.
Collapse
Affiliation(s)
| | | | - Vittorio Giusti
- Service of Endocrinology, Diabetology and Metabolism, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension
- *Service of Nephrology and Hypertension, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 17, 1011 Lausanne, Switzerland, Tel. +41 21 314 11-54, Fax -39
| |
Collapse
|
41
|
Mitchell SJ, Kirkpatrick CMJ, Le Couteur DG, Naganathan V, Sambrook PN, Seibel MJ, Blyth FM, Waite LM, Handelsman DJ, Cumming RG, Hilmer SN. Estimation of lean body weight in older community-dwelling men. Br J Clin Pharmacol 2010; 69:118-27. [PMID: 20233174 DOI: 10.1111/j.1365-2125.2009.03586.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT? * Lean mass decreases with age while total body fat increases, leading to changes in the pharmacokinetics and pharmacodynamics of drugs. * Dual-energy X-ray absorptiometry (DXA) is a useful reference method to measure lean body weight but may not be readily utilized clinically. * Limited methods for measurement of lean body weight using easily obtainable participant characteristics, such as height and weight, have been validated for use in people aged > or =65 years. WHAT THIS STUDY ADDS * This study has shown that lean body weight can be estimated using three different equations from easily obtainable participant characteristics with results comparable to DXA-derived estimates. * These equations may be useful tools to estimate lean body weight in situations where DXA is not practical. AIMS Lean body weight (LBW) decreases with age while total body fat increases, altering drug pharmacokinetics. The aim of this study was to evaluate the ability of the LBW equation to predict dual-energy X-ray absorptiometry (DXA)-derived fat free mass (FFM(DXA)) in older community-dwelling males compared with that of two existing FFM equations: the Heitmann and Deurenberg equations. METHODS Data were obtained from 1655 older men enrolled in the Concord Health and Ageing in Men Project. The predictive performance of the LBW and FFM equations to predict FFM(DXA) accurately was assessed graphically using Bland-Altman plots and quantitatively for precision and bias using the method of Sheiner and Beal in all participants and in frailty and body mass index (BMI) subgroups. RESULTS The LBW and Heitmann equations consistently overestimated FFM(DXA) for all frailty and BMI subgroups with a mean difference [95% confidence interval (CI)] of 5.5 kg (-0.65, 11.63 kg) and 3.34 kg (-2.84, 9.64 kg), respectively. The Deurenberg equation overestimated FFM(DXA) for overweight participants but underestimated FFM(DXA) for not-frail participants, with a mean difference (95% CI) of 1 kg (-7.23, 5.25 kg) for all participants. CONCLUSION LBW and FFM estimated using these equations give results comparable to DXA-derived FFM. The LBW and Heitmann equations provide a more consistent estimate of FFM(DXA) in all frailty and BMI groups despite the Deurenberg equation having the smallest mean difference. Further studies to determine whether the LBW equation is a clinically useful substitute for weight when determining drug dose in older people appear warranted.
Collapse
Affiliation(s)
- Sarah J Mitchell
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Bucaloiu ID, Perkins RM, DiFilippo W, Yahya T, Norfolk E. Acute Kidney Injury in the Critically Ill, Morbidly Obese Patient: Diagnostic and Therapeutic Challenges in a Unique Patient Population. Crit Care Clin 2010; 26:607-24. [DOI: 10.1016/j.ccc.2010.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
43
|
Pai MP. Estimating the glomerular filtration rate in obese adult patients for drug dosing. Adv Chronic Kidney Dis 2010; 17:e53-62. [PMID: 20727504 DOI: 10.1053/j.ackd.2010.05.010] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 05/13/2010] [Accepted: 05/27/2010] [Indexed: 01/08/2023]
Abstract
One-third of adult Americans are currently classified as obese. Physiologic changes associated with obesity can potentially alter the clearance of commonly used drugs. Clearance of certain drugs by the kidneys occurs primarily through glomerular filtration and tubular secretion. Obesity has been associated with glomerular hyperfiltration, whereas obesity-related effects on tubular secretion are not well characterized. Estimation of the glomerular filtration rate (GFR) is currently performed using serum creatinine using the Modification of Diet in Renal Disease (MDRD) equation. However, drug dosing guidelines are often based on creatinine clearance (CLcr) using the Cockcroft-Gault equation as a surrogate of GFR. There is a lack of consensus on the most appropriate method for estimation of GFR or CLcr in patients with obesity. The controversy relates to the use of 2 body size descriptors that confound these equations. The Cockcroft-Gault equation relies on total body weight and so overestimates GFR in patients with obesity. The MDRD equation indexes GFR based on a normalized body surface area, that is, mL/min/1.73 m(2). Conversion of MDRD estimated GFR to non-normalized body surface area overestimates GFR in patients with obesity. The current review explores current approaches and controversies to estimation of GFR and CLcr among obese patients in clinical practice. The role of the alternate body size descriptor, lean body weight to estimate CLcr in obese patients is reviewed.
Collapse
|
44
|
Abstract
Clinical response to medication can differ between patients. Among the known sources of variability is an individual's nutrition status. This review defines some pharmacokinetic terms, provides relevant body size metrics and describes the physiologic influences of protein–energy malnutrition and obesity on drug disposition. Weight-based drug dosing, which presumes a healthy BMI, can be problematic in the protein–energy malnourished or obese patient. The use of total body weight, lean body weight, or an adjusted body weight depends on the drug and how it is differently handled in malnutrition or obesity. Most of the recognized influences are seen in drug distribution and drug elimination as a result of altered body composition and function. Distribution characteristics of each drug are determined by several drug-related factors (e.g. tissue affinity) in combination with body-related factors (e.g. composition). Drug elimination occurs through metabolic and excretory pathways that can also vary with body composition. The current data are limited to select drugs that have been reported in small studies or case reports. In the meantime, a rational approach to evaluate the potential influences of malnutrition and obesity can be used clinically based on available information. Antimicrobials are discussed as a useful example of this approach. Further advancement in this field would require collaboration between experts in body composition and those in drug disposition. Until more data are available, routine monitoring by the clinician of the protein–energy malnourished or obese patient receiving weight-based drug regimens is necessary.
Collapse
|
45
|
Individualized Dosing of Enoxaparin for Subjects With Renal Impairment Is Superior to Conventional Dosing at Achieving Therapeutic Concentrations. Ther Drug Monit 2010; 32:482-8. [DOI: 10.1097/ftd.0b013e3181e64846] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
46
|
McNeill GBS, Martin JH. How reliable is eGFR when calculating drug dosage in acute medical admissions? Intern Med J 2010; 41:327-31. [PMID: 20646094 DOI: 10.1111/j.1445-5994.2010.02307.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The Modification of Diet in Renal Disease-derived estimation of glomerular filtration rate (eGFR) is used widely. Although validated in stable chronic kidney disease (CKD) outpatients, it is not known how it performs in those presenting with acute medical illness. AIM We aimed to compare eGFR with Cockroft Gault (CG) - the renal function assessment tool available prior to eGFR - to assess the difference in clinical outcome that would occur when one over another estimation is used in practice. In particular, we wished to assess whether use of eGFR would have resulted in a change of dose of commonly used acutely administered medications. METHODS Acute medical admissions presenting to a tertiary hospital between August and December 2008 were included. Serum creatinine concentration, age, sex, height and weight were collected. Renal function was estimated by both estimates. Movement from CKD class 3 to 4 or 5 was measured - a clinically used cut-off point for changes in management. RESULTS A total of 54 patients was included. eGFR values were higher than those estimated by CG. Almost half of patients categorized as CKD stage 4-5 using CG were only categorized as CKD stage 3 using eGFR. CONCLUSION Although we did not use a gold standard estimation of GFR, this study shows that estimates of renal function vary in a clinically significant manner. As estimates of GFR are used to adjust drug dosages and to stratify for many other treatments, it is imperative that we find a method of estimating kidney function that is readily available, consistent and accurate.
Collapse
Affiliation(s)
- G B S McNeill
- Acute Medical Unit, Norfolk and Norwich Hospital, Norwich, UK.
| | | |
Collapse
|
47
|
Barras MA, Kirkpatrick CMJ, Green B. Current dosing of low-molecular-weight heparins does not reflect licensed product labels: an international survey. Br J Clin Pharmacol 2010; 69:520-8. [PMID: 20573088 PMCID: PMC2856053 DOI: 10.1111/j.1365-2125.2010.03626.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 12/15/2009] [Indexed: 12/01/2022] Open
Abstract
AIMS Low-molecular-weight heparins (LMWHs) are used globally to treat thromboembolic diseases; however, there is much debate on how to prescribe effectively for patients who have renal impairment and/or obesity. We aimed to investigate the strategies used to dose-individualize LMWH therapy. METHODS We conducted an online survey of selected hospitals in Australia, New Zealand (NZ), United Kingdom (UK) and the United States (US). Outcome measures included: the percentage of hospitals which recommended that LMWHs were prescribed according to the product label (PL), the percentage of hospitals that dose-individualized LMWHs outside the PL based on renal function, body weight and anti-Xa activity and a summary of methods used to dose-individualize therapy. RESULTS A total of 257 surveys were suitable for analysis: 84 (33%) from Australia, 79 (31%) from the UK, 73 (28%) from the US and 21 (8%) from NZ. Formal dosing protocols were used in 207 (81%) hospitals, of which 198 (96%) did not adhere to the PL. Of these 198 hospitals, 175 (87%) preferred to dose-individualize based on renal function, 128 (62%) on body weight and 48 (23%) by monitoring anti-Xa activity. All three of these variables were used in 29 (14%) hospitals, 98 (47%) used two variables and 71 (34%) used only one variable. CONCLUSIONS Dose-individualization strategies for LMWHs, which contravene the PL, were present in 96% of surveyed hospitals. Common individualization methods included dose-capping, use of lean body size descriptors to calculate renal function and the starting dose, followed by post dose anti-Xa monitoring.
Collapse
Affiliation(s)
- Michael A Barras
- School of Pharmacy, The University of QueenslandBrisbane, Queensland
- Therapeutic Advisory Service, Pharmacy Department, Mater Health ServicesBrisbane, Queensland
| | - Carl M J Kirkpatrick
- Therapeutic Advisory Service, Pharmacy Department, Mater Health ServicesBrisbane, Queensland
| | - Bruce Green
- Model Answers Pty LtdBrisbane, Queensland, Australia
| |
Collapse
|
48
|
La Colla L, Albertin A, La Colla G, Porta A, Aldegheri G, Di Candia D, Gigli F. Predictive Performance of the ‘Minto’ Remifentanil Pharmacokinetic Parameter Set in Morbidly Obese Patients Ensuing from a New Method for Calculating Lean Body Mass. Clin Pharmacokinet 2010; 49:131-139. [DOI: 10.2165/11317690-000000000-00000] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
|
49
|
Barras MA, Duffull SB, Atherton JJ, Green B. Modelling the occurrence and severity of enoxaparin-induced bleeding and bruising events. Br J Clin Pharmacol 2009; 68:700-11. [PMID: 19916994 PMCID: PMC2791976 DOI: 10.1111/j.1365-2125.2009.03518.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 07/17/2009] [Indexed: 12/22/2022] Open
Abstract
AIMS To develop a population pharmacokinetic-pharmacodynamic model to describe the occurrence and severity of bleeding or bruising as a function of enoxaparin exposure. METHODS Data were obtained from a randomized controlled trial (n = 118) that compared conventional dosing of enoxaparin (product label) with an individualized dosing regimen. Anti-Xa concentrations were sampled using a sparse design and the size, location and type of bruising and bleeding event, during enoxaparin therapy, were collected daily. A population pharmacokinetic-pharmacodynamic analysis was performed using nonlinear mixed effects techniques. The final model was used to explore how the probability of events in patients with obesity and/or renal impairment varied under differing dosing strategies. RESULTS Three hundred and forty-nine anti-Xa concentrations were available for analysis. A two-compartment first-order absorption and elimination model best fit the data, with lean body weight describing between-subject variability in clearance and central volume of distribution. A three-category proportional-odds model described the occurrence and severity of events as a function of both cumulative enoxaparin AUC (cAUC) and subject age. Simulations showed that individualized dosing decreased the probability of a bleeding or major bruising event when compared with conventional dosing, which was most noticeable in subjects with obesity and renal impairment. CONCLUSIONS The occurrence and severity of a bleeding or major bruising event to enoxaparin, administered for the treatment of a thromboembolic disease, can be described as a function of both cAUC and subject age. Individualized dosing of enoxaparin will reduce the probability of an event.
Collapse
Affiliation(s)
- Michael A Barras
- School of Pharmacy, University of QueenslandBrisbane, Queensland, Australia
- Therapeutic Advisory Service, Pharmacy Department, Mater Health ServicesBrisbane, Queensland, Australia
| | | | - John J Atherton
- Cardiology Department, Royal Brisbane and Women's HospitalBrisbane, Queensland, Australia
- Department of Medicine, University of QueenslandBrisbane, Queensland, Australia
| | - Bruce Green
- Model Answers Pty LtdBrisbane, Queensland, Australia
| |
Collapse
|
50
|
Ma P, Yang BB, Wang YM, Peterson M, Narayanan A, Sutjandra L, Rodriguez R, Chow A. Population pharmacokinetic analysis of panitumumab in patients with advanced solid tumors. J Clin Pharmacol 2009; 49:1142-56. [PMID: 19723673 DOI: 10.1177/0091270009344989] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Panitumumab is a fully human monoclonal antibody targeted to the extracellular domain of human epidermal growth factor receptor (EGFR). A comprehensive population pharmacokinetic model of panitumumab was developed using nonlinear mixed-effects modeling of 1200 patients with advanced solid tumors in 14 clinical studies. The disposition of panitumumab was best described with a 2-compartment model with parallel linear and nonlinear (Michaelis-Menten) elimination pathways. For a typical male patient with colorectal cancer (80 kg, 60 years old), the estimates for the linear clearance (CL), the maximum nonlinear clearance (V(max)/K(m)), the central volume of distribution (V(1)), the peripheral volume of distribution (V(2)), and the Michaelis-Menten constant (K(m)) are 0.273 L/d, 28.4 L/d, 3.95 L, 2.59 L, and 0.426 mcg/mL, respectively. Baseline covariates such as body weight, cancer type, age, sex, and race were studied for their influence on panitumumab pharmacokinetics. Body weight was found to be the most influential covariate on panitumumab exposure, affecting CL, V(max), and V(1). The administration of concomitant chemotherapy (IFL, FOLFIRI, or paclitaxel/carboplatin) or intensity of baseline tumor EGFR expression did not alter the pharmacokinetics of panitumumab. The presence of antipanitumumab antibodies in patients (immunogenicity rate 3.4%) did not appear to affect panitumumab exposure substantially (AUC difference 8%). In support of a new drug application in Japan, the model was used to assess panitumumab pharmacokinetics in Japanese patients compared to other racial groups; there were no significant differences in model-predicted steady-state panitumumab AUC, C(max), or C(min) after accounting for the effect of body weight.
Collapse
Affiliation(s)
- Peiming Ma
- Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc, One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
| | | | | | | | | | | | | | | |
Collapse
|