Concentration Guided Dosing
Emeritus Professor Nick Holford
Professor Holford trained in internal medicine before becoming a clinical pharmacologist. Most of his career has been spent at Auckland City Hospital and the University of Auckland, New Zealand. His interests have been focused on the principles of pharmacokinetics, pharmacodynamics, disease progression, and individualized dosing. In response to clinical requests, he developed a web based dosing tool (www.nextdose.org) implementing the target concentration approach.
Individualized dosing for treatment of human disease takes many forms. Dosing based on pharmacological principles recognizes that drug effects are caused by drug concentration not dose. Concentration guided dosing (CGD) encompasses a variety of approaches that are based on pharmacokinetic and pharmacodynamic concepts even though these concepts may not be explicitly recognized. CGD may be based on patient information, such as measured drug concentrations but different approaches to determine an individualized dose, based these responses, may lead to different clinical outcomes.
The two most common approaches are the therapeutic window approach (TWA) and the target concentration approach (TCA). TWA is based on achieving a response within a range (the therapeutic window) while TCA is based on achieving a single target response (Holford & Petric 2025). Clinical studies have shown that TCA can improve clinical outcome when TWA does not (Holford, Ma & Metz 2022).
The webinar will explain the concepts of concentration guided dosing and illustrate the superiority of the TCA approach over the TWA approach.
Holford, N, Ma, G and Metz, D (2022). "TDM is dead. Long live TCI!" Br J Clin Pharmacol 88(4): 1406–1413.
Holford, N and Petric, Z (2025). "The Rational Basis for Personalized Treatment Using Concentration-Guided Dosing." Therapeutic Drug Monitoring 47(6): 705–712.