NextDose – A web based dosing tool – Development version 2017

Background: NextDose is a web based Bayesian dosing tool (1, 2). Dosing guidance is currently offered for intravenous busulfan, intravenous methotrexate and oral tacrolimus. It has been used at Auckland Starship Hospital and Auckland City Hospital to guide dosing of busulfan since 2012 (3).


1. To describe the features of a new release of NextDose.

2. To gather feedback for consideration during development of a future version of NextDose.

Methods: NextDose provides an encrypted web based user interface to a server located in a physically secured environment at the University of Auckland. Web access is by single factor authentication using credentials approved by each group administrator. Users provide demographic, covariate, dose and observation data. A target concentration and proposed dosing interval are defined by the user. Calculations are performed on the secure server and a dosing guidance report is displayed along with a graph of observations and predictions.

Results: Twenty groups around the world have used NextDose for clinical dose guidance or for research evaluation (4). A development version of NextDose is available for user testing and evaluation (

The target may be an AUC, concentration or other biomarker (average or trough steady state). Antibiotic targets may scaled by the minimum inhibitory concentration. Support for warfarin, linezolid and voriconazole dosing has recently been added. The user may choose among different models for Bayesian estimation of parameters.

Conclusion: The NextDose tool has been extended to provide more options for target concentration intervention and a wider range of drugs and models. Opinions are sought from the pharmacometric community to guide development of the next version of NextDose.


1.         Holford SD, Turkistani A, Madhavaram H, Holford NHG. NextDose – A web based collaborative tool for dose individualisation. PAGANZ 2012 ; Accessed 23 Jan 2017.

2.         Holford SD. NextDose ( a web-based collaborative tool for target concentration intervention.  World Congress of Pharmacology; 2014; Cape Town, South Africa. ; Accessed 23 Jan 2017.

3.         Holford NHG. Busulfan target concentration intervention audit and model evaluation. PAGANZ 2015 2015 ; Accessed 23 Jan 2017.

4.         Paterson LG, Lawson R, Hennig S. Bayesian forecasting versus clinical practice for intravenous busulfan dose adjustment in paediatric stem cell transplantations. WCOP 2016 2016 ; Accessed 23 Jan 2017.

Nick Holford