An age-structured population model was applied to describe red blood cell (RBC) survival data in normal rats treated with recombinant human erythropoietin (rHuEPO). The primary purpose was to estimate the mean lifespan and age of RBCs from a study employing the random labeling technique. The second objective was to assess an impact on the RBC […]
Tag Archives | 2011
Missing data
January 27, 2011
Authors Nick Holford
Affiliations Dept of Pharmacology & Clinical Pharmacology, University of Auckland
Presentation type Oral
A common challenge for pharmacokinetic modellers is what to do with measurements that are known to be less than the lower limit of quantification (LLOQ). These measurements are, unfortunately, often recorded as BLQ (Below Limit of Quantification), even though the chemical analyst was able to quantify the measurement below this limit. The limit is defined […]
Is Morphine Clearance Predictable in Humans?
January 27, 2011
Authors Nick Holford (1), Shu Chin Ma (1), Brian Anderson (2)
Affiliations (1) Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand, (2) Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
Presentation type Oral
Objectives: To evaluate pharmacokinetic models for prediction of morphine doses from premature neonates to adults. Design: External evaluation of published models for morphine clearance by comparison with literature reports of morphine clearance in individual patients and healthy subjects. Main Outcome Measures: Prediction of morphine dose rate in premature neonates, full term neonates, infants, children and […]
Population Pharmacokinetic-Pharmacodynamic Modeling: When Modeling Meets Reality
January 26, 2011
Authors Diane R Mould, Bill Frame
Affiliations Projections Research Inc
Presentation type Oral
Overview The pharmacokinetic and pharmacodynamic behaviors of many therapeutic agents have inherent complexities that require specialized modeling approaches in order to develop reliable, unbiased models. Several commonly encountered cases will be presented, including data that has a preponderance of zero values, subjects whose pharmacodynamic trajectories are not predictable based on a structural model, and evaluating models […]
Population pharmacokinetics of midazolam in critically ill septic patients
January 13, 2011
Authors Yoke-Lin Lo, Cheng-Cheng Tan, Toong-Chow Lee, Bruce G. Charles
Affiliations (1) University of Malaya, Malaysia, (2) Sultanah Aminah Hospital, Malaysia, (3) University of Queensland, Australia
Presentation type Oral
The aim of this study is to determine the pharmacokinetic parameters of midazolam (MDZ) and its active metabolites, namely 1-hydroxymidazolam (1-OH-MDZ) and 1-hydroxymidazolam glucuronide conjugate (1-OH-MDZG) in patients with various degrees of severity of sepsis syndrome. A 6-compartment disposition model with combined intermittent oral administration and continuous intravenous infusion with first-order elimination was used. The […]
Population pharmacokinetic and pharmacodynamics analysis of lipid emulsion propofol in pediatric patients
January 10, 2011
Authors Yookhwan Noh, Hee Soo Kim, Gyujeong Noh
Affiliations Department of Clinical pharmacology and Therapeutics, Asan Medical Center, University of Ulsan college of Medicine
Presentation type Poster
Aim: This study aimed to characterize the pharmacokinetics and pharmacodynamics of lipid emulsion propofol administered by a target-controlled infusion (TCI) anesthesia in pediatric surgery. Method: Forty patients (ASA PS 1,2) aged 2–12 years were given an intravenous bolus of 2% propofol (Fresofol?, Fresenius Kabi Korea Ltd., Korea) 3 mg/kg, followed by continuous infusion at the rate of 200 mg/kg/min for […]
Population Pharmacokinetics of Gentamicin in Saudi Newborns during the 1st Week of Life
December 28, 2010
Authors Khaled A Al-Faify, Ahmad Shaker Ali
Affiliations King Abdulaziz University
Presentation type Poster
Introduction: Preterm birth is associated with several complications and serious infections including sepsis. Gentamicin is an important drug approved for the treatment of suspected sepsis and has extensive variable pharmacokinetics in newborns. Objectives: To determine the pharmacokinetic parameters of gentamicin in Saudi newborns population of 92 preterm and term newborns and to identify the covariates that influences […]
Population Pharmacokinetics of Colistin Methanesulfonate and Formed Colistin in Critically-Ill Patients from a Multi-Center Study Provide Dosing Recommendations for Patients
December 27, 2010
Authors S. M. Garonzik (1), J. Li (2), V. Thamlikitkul (3), D. L. Paterson (4), S. Shoham (5), J. Jacob (6), F. P. Silveira (6), A. Forrest (1), R. L Nation (2)
Affiliations (1) School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, SUNY, Buffalo, NY, (2) Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia , (3) Division of Infectious Diseases and Tropical Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, (4) The University of Queensland Center for Clinical Research, Royal Brisbane and Women
Presentation type Oral
With increasing clinical emergence of multidrug-resistant Gram-negative pathogens and the paucity of new agents to combat these infections, colistin (administered as its inactive prodrug colistin methanesulfonate (CMS)) has re-emerged as a treatment option especially in critically-ill patients. Previously, there has been a dearth of pharmacokinetic (PK) data available to guide dosing in critically-ill patients including […]
Statisticians and Pharmacometricians: What can they learn from each other?
October 7, 2010
Authors Stephen Senn
Affiliations University of Glasgow
Presentation type Oral
Examples are given of how the practice of statistics could be improved if statisticians showed a greater awareness of pharmacokinetic and pharmacodynamic modeling. Some examples are also given where a wider appreciation of statistical theory would improve current approaches to pharmacometrics. Areas in which the two disciplines are in agreement but have failed to have […]
Missing data – the problem of silent evidence
October 7, 2010
Authors Stephen Senn
Affiliations University of Glasgow
Presentation type Oral
In his bestseller, The Black Swan, Nassim Nicholas Taleb refers to the problem of silent evidence: the graveyard of failed human endeavour that we never visit. To statisticians this problem is known by the more prosaic title of 'missing data'. I consider some famous examples of misinterpretations arising from missing data and lessons one might […]