A web based collaborative tool has been developed for helping with dose individualisation. It has been applied to dosing busulphan for conditioning prior to marrow transplantation.
NextDose stores patient information seperately from the web interface for security. This information is stored in a non-identifiable format and requires authorised use of the NextDose application to combine the patient's identity with their information. Data come from different sources e.g. patient demographics such as age and weight from clinicians, doses from pharmacists, drug concentrations from laboratory scientists. NextDose allows patients to be shared within clinical teams so that these different people can access the same database and enter and modify data in real time.
A pharmacokinetic model based method is used for dose individualisation. Concentration measurements are used with a Bayesian mixed effect model incorportating between subject and between occasion variability.
With the example of busulphan, a target average steady state concentration of 0.77 mg/L is believed to provide a reasonable balance between effectiveness and toxicity. A maintenance dose rate to maintain the target concentration is calculated from the estimated clearance.
Results are provided to the clinical team in graphical format along with a recommended dose rate. Users are able to specify which information should be used for making predictions and can navigate between the different results for comparison.