Randomized crossover study to assess the inter‐ and intrasubject variability of morning mycophenolic acid concentrations from enteric‐coated mycophenolate sodium and mycophenolate mofetil in stable renal transplant recipients

Tedesco‐Silva H, Felipe CR, Park SI, Pinheiro‐Machado PG, Garcia R, Slade A, Schmouder R, Medina‐Pestana JO. Randomized crossover study to assess the inter‐ and intrasubject variability of morning mycophenolic acid concentrations from enteric‐coated mycophenolate sodium and mycophenolate mofetil in stable renal transplant recipients.
Clin Transplant 2010: 24: E116–E123.
© 2009 John Wiley & Sons A/S. Abstract: The delayed release of mycophenolic acid (MPA) from enteric‐coated mycophenolate sodium (EC‐MPS, myfortic^®) may have an impact on the variability of MPA trough (C_{0 h}) levels. A randomized, two‐period crossover study was performed in 24 maintenance renal transplants to evaluate the inter‐ and intrasubject variability of MPA predose levels from EC‐MPS and mycophenolate mofetil (MMF, CellCept^®), both in combination with cyclosporine. Patients received EC‐MPS (720 mg b.i.d.) and MMF (1000 mg b.i.d.) for a period of 21 d each. MPA plasma levels were measured over the final seven consecutive days at ?1, 0, 1, 2, and 3 h after the morning MPA dose. Intersubject coefficients of variation (%CV) for MPA troughs were 47.5% (95% CI, 34.1–80.3) and 54.4% (40.0–86.8) for EC‐MPS and MMF, respectively; intrasubject %CVs were 62.7% (55.1–72.9) and 42.8% (37.9–49.2). High MPA C_{0 h} levels >10 μg/mL were rarely observed with both EC‐MPS (1.8%) and MMF (0.6%). Mean MPA area under the curve (AUC)_{0–3 h} was comparable between treatments, while MPA C_{0 h} was on average 46% higher with EC‐MPS. In conclusion, predose MPA trough level monitoring appears of limited value during EC‐MPS and MMF therapy given the large intrasubject variability in MPA C_{0 h} levels with both treatments.