Tag Archives | PAGANZ ISOP Student Prize for Pharmacometrics

Evaluation of assumptions underpinning pharmacometric models

Background: All models are underpinned by assumptions. The validity of any inference drawn from a model depends on the appropriateness and likely impact of the underlying assumptions [1]. However, in the literature surrounding quantitative pharmacology models and pharmacometrics, assumptions inherent to model development and use are not routinely acknowledged, described, or evaluated. This casts doubt […]

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Internal Deterministic Identifiability of PK and PKPD Models

Introduction: Identifiability analysis is an important aspect of the PKPD modelling framework and is divided into structural and deterministic identifiability. Structural identifiability (SI) relates to the uniqueness of outputs to parameters and inputs. Deterministic identifiability (DI) relates to the precision of parameter estimates. Here we introduce two subcategories of DI: (1) external deterministic identifiability (EDI) […]

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Simplification of a pharmacokinetic model for red blood cell methotrexate disposition

Background: Methotrexate (MTX, MTXGlu1) is the gold standard treatment of rheumatoid arthritis. The time course of clinical outcomes is difficult to predict after commencing oral or subcutaneous MTX treatment. A 9-compartment pharmacokinetic (PK) model is available for describing the time course of the concentrations of MTXGlu1 and its polyglutamated metabolites (MTXGlu2-5) in red blood cells […]

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Identification of continuous covariate relationships

Objective: The objective of this presentation was to demonstrate a new method to identify continuous covariates. The investigation of time after kidney transplant as a covariate on tacrolimus bioavailability was used as an example. Methods: A total of 3100 tacrolimus concentration-time points were obtained from 242 patients who underwent kidney transplantation at Oslo University Hospital […]

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