This is a prospective observational study of MIPD in clinical practice for paediatric kidney transplant patients using tacrolimus and mycophenolic acid in Radboudumc. Dose individualization in paediatric kidney transplant patients using the InsightRX platform is performed as standard care, meaning that a pharmacokinetic model and drug levels measured at t=0, t=1 and t=2 hours will be used to calculate the exposure. Based on the estimated exposure, the pharmacist gives a dose recommendation to the physician, who can then modify the dosage of mycophenolic acid or tacrolimus. The selected dose and the measured MPA and tacrolimus concentrations will be used to predict the future exposure. A second exposure measurement will be performed to evaluate whether our model is able to predict future exposure.

Inclusion Criteria:

• Kidney transplant patients using tacrolimus and/or mycophenolic acid
• Age between 0 and 18 years
• Indication for an AUC measurement - judgement of clinician

Exclusion Criteria:

• Incapacitated patients
• No informed consent
• Not proficient in the Dutch language

Paediatric kidney transplant patients from Radboudumc using tacrolimus and/or mycophenolic acid.

We will collect data for one year, in this period we expect to include 30 patients.