Pharmacokinetic study of mycophenolic acid in pediatric kidney transplantation

Abstract

Mycophenolic acid (MPA) is among the drugs used to achieve effective immunosuppression in kidney transplantation (KT), which is characterized by complex pharmacokinetics and high intra- and inter-individual variability. Monitoring the trough concentration level (C0) of MPA for dosage adjustments is considered controversial, mainly due to its low correlation with the area under the curve (AUC).

Objective: To correlate the C0 and AUC of MPA in pediatric patients with KT.

Patients and Method: Prospective study carried out in 54 KT patients under treatment with MPA. Linear regressions and correlations were performed between ABC and C0. Multiple comparisons group analysis was performed according to post-transplant time and the two oral presentations of MPA.

Results: The plasma level that best correlates with AUC was C0 (r2 = 0.52). There was a significant group of patients with subtherapeutic levels (36.6% of all measurements). It was also determined that the C0 must be between 1.42 and 4.55 µg/ml for the AUC to be within the therapeutic range. It was shown that the correlation between C0 and AUC improves after three months post-transplantation and is even better when administering mycophenolate mofetil.

Conclusion: The use of C0 is recommended to adjust the dose of MPA in pediatric patients with KT, especially in those with more than 3 months post-transplantation. For patients with early KT or complex clinical pictures, monitoring using ABC is recommended.