PMXSolutions.com

This website was created to increase the documentation in the field of pharmacometrics. The website contains blog posts, pharmacometric tutorials, Shiny applications and a lot of example codes for R, mrgsolve and for NONMEM. All related to data analytics, population PK/PD, PBPK and pharmacometrics in general.

Latest posts

From Animals to Algorithms: Leveraging PK/PD Models to Drive the 3R’s in Pharmacology

In the pursuit of ethical and efficient drug development, the scientific community continues to embrace the 3R’s principle — Replacement, Reduction, and Refinement — to minimize the use of animals in research. While this framework has guided preclinical study design for decades, the rise of pharmacometrics, particularly PK (pharmacokinetics) and PK/PD (pharmacokinetic/pharmacodynamic) modelling, has given new momentum to making the …

Exploration of intra-individual variability in a multiple dose study during NCA

A non-compartmental analysis (NCA) is commonly performed to analyse the data of a pharmacokinetic study. It is an easy way of getting your pharmacokinetic parameters (such as the Cmax, tmax, AUC, etc.) without having to perform any advanced modelling techniques. If sufficiently dense data is collected, we can determine the PK parameters on an individual level and summarise them as …

A pharmacometrician’s job interview: the case study

In 2022 I was working as a senior pharmacometrician (primarily focused on clinical phase 1/2a PK/PD and scientific research) when I was contacted by a recruiter on LinkedIn to apply for an Associate Director Modelling & Simulation position in the ADME group of the early development (non-clinical) team of a clinical stage pharmaceutical company. The hiring process consisted of a …

Learn about pharmacometrics and clinical pharmacology during your workout

I love to listen to podcasts while I am working out or going for a walk. However, I must admit that some of these podcasts are just a background conversation with nothing meaningful being said. While scrolling through LinkedIn I was therefore pleasantly surprised to see a post from Nathan Teuscher showing that he started the Clinical Pharmacology podcast! Nathan …

Introduction to pharmacometrics and its importance in drug development

Pharmacometrics is a rapidly growing field that combines pharmacology, mathematics, and statistics to optimize drug development and dosing. It is the science of quantifying drug effects in patients and developing mathematical models to understand and predict drug behavior in humans. Pharmacometricians use mathematical models to describe the relationship between drug exposure and response, and this can help in making informed …

New shiny applications for PMX simulations!

A range of new shiny applications have been published on this website to visualise pharmacokinetic profiles over time and better understand the use of population models. All applications can be accessed from the Applications menu on this website. All code is updated on GitHub https://github.com/michielve PK profile over time Simulate an oral pharmacokinetic profile based on the dose and model …

Publishing the covariance matrix of population models. Why not?

The information in the covariance matrix Everyone that has worked for longer than a day with NONMEM has a high probability of encountering error messages mentioning the covariance matrix (nonpositive semidefinite…, R matrix algorithmically singular…, etc.) or people ask and discuss whether or why the covariance step of the model was not successful. However, we barely pay any attention to …

Parallel fast-slow absorption – Modelling the Tortoise AND the Hare

Introduction Unsurprisingly, the absorption of drugs is a complex process. Should you try a first-order input? Zero-order? Both?! Especially when a bias in the model fit of your absorption phase is visible, you should pay some attention on quantifying parallel absorption processes. Multiple absorption processes in one model may be used to describe complex absorption profiles of drugs. Indeed, a …

Applying MAP Bayes estimation for therapeutic drug monitoring (TDM) in R with mrgsolve

The development of population PK (and PD) models enable the use of individual Bayesian dose optimization. One could use the included covariates to derive the dose of an individual but one could also determine what an individual’s clearance and/or volume of distribution is by measuring one or multiple plasma concentrations after the first dose. Especially when a narrow therapeutic window …

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