Mycophenolic Acid Concentration on Vietnamese Renal Transplant Recipients

Background: Kidney recipients often use a calcineurin inhibitor and a proliferation inhibitor after transplantation. The therapeutic drug monitoring for calcineurin inhibitor is more simple and feasible in clinical than proliferation inhibitor. In Vietnam, mycophenolic acid is a popular proliferation inhibitor used for transplantation patients. Although therapeutic mycophenolic acid monitoring is so important in treating kidney transplantation, the monitoring is still difficult to execute in Vietnam. Objectives: This study aimed to determine the MPA concentration on Vietnamese renal transplant recipients. Methods: This observational study was conducted on 35 adult kidney recipients to evaluate the MPA concentration at five sampling time points (predose, 1, 2, 3, and 6 hours) on day 3, day 10, and month 6 after transplantation. Results: Plasma MPA trough levels (C0) were 2.32±1.47;1.58±1.39; 2.29±1.4 mg/L and the MPA-AUC0-12 h values were 50.1±20.4; 41.9 ±14.5; 60.3±25.9 mg.h/L on day 3, day 10, and month 6. The number of patients who reached MPA-AUC0-12 h values of 30 - 60 mg.h/L was 18 (51.4%), 23 (65.7%) and 17 (51.5%) on day 3, day 10, and month 6, respectively. The number of patients who achieved the MPA C0 values of 1.5 - 2.5 mg/L was 15 (42.9 %), 14 (40%), and 10 (30.3%) on day 3, day 10, and month 6, respectively; and the linear correlation coefficients between AUC0-12 h and C0 were 0.652, 0.415, and 0.752, respectively. Conclusions: In renal transplant patients, the MPA-AUC0-12 h was lower on day 3 and day 10 post-transplantation than month 6 for the half dose of MMF or MPS. Therefore, MPA therapeutic drug level should be monitored usually in transplantation patients who use MPA.