The effect of oral iron admiinistration on mycophenolate mofetil absorption in renal transplant recipients: a randomized, controlled trial.
BACKGROUND
Oral iron supplements are frequently prescribed to renal transplant recipients in the early posttransplant period. A recent trial in seven healthy volunteers demonstrated a significant 91% reduction in mycophenolate mofetil (MMF) absorption when coadministered with oral iron. However, the effect of iron on MMF absorption in renal transplant patients has not been studied.


METHODS
An open-label, randomized, controlled trial was undertaken in which new renal transplant recipients were randomly allocated to receive iron supplements with a morning dose of MMF, iron supplements given 4 hr after MMF at midday, or no iron supplements. Blood samples were taken for estimation of mycophenolic acid (MPA) area under the curve (AUC) at day 5 posttransplant. The primary endpoint was the day 5 MPA AUC, with secondary endpoints including acute rejection and MMF toxicity in the first 4 weeks posttransplant. Prospective power calculations indicated that a minimum of 13 patients in each group would be required to have a 90% probability of detecting a clinically significant reduction (10 mg/hr/L) in MPA AUC for iron-treated patients.


RESULTS
Forty patients completed the study. There were no differences in baseline demographic data between the groups. The mean+/-standard deviation MPA AUC measurements for the groups receiving no iron (n=13), iron and MMF together (n=14), and iron and MMF spaced apart (n=13) were 34.5+/-8.7, 33.7+/-11.4, and 32.1+/-8.1 microg/hr/mL, respectively (P=0.82). Rates of acute rejection, cytopenia, infection, and gastrointestinal intolerance were comparable between the groups.


CONCLUSIONS
There is no significant effect of oral iron supplements on MMF absorption as determined by measured blood concentrations. The practice of routinely giving oral iron in such patients seems safe from an immunosuppression drug-interaction standpoint.
Mudge
David W
DW
Renal Transplant Unit, University of Queensland at Princess Alexandra Hospital, Brisbane, Australia.
Atcheson
Bronwyn
B
Taylor
Paul J
PJ
Sturtevant
Joanna M
JM
Hawley
Carmel M
CM
Campbell
Scott B
SB
Isbel
Nicole M
NM
Nicol
David L
DL
Pillans
Peter I
PI
Johnson
David W
DW
D000328:Adult; D019540:Area Under Curve; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D007408:Intestinal Absorption / Q000187:drug effects; D007501:Iron / Q000008:administration & dosage / Q000627:therapeutic use*; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D012044:Regression Analysis
D007166:Immunosuppressive Agents; D007501:Iron; D009173:Mycophenolic Acid