Ferrous sulfate does not affect mycophenolic acid pharmacokinetics in kidney transplant patients.

ABSTRACT

BACKGROUND: Oral administration of ferrous-sulfate was reported to decrease intestinal absorption of mycophenolate mofetil (MMF) in healthy Japanese individuals by 90%. METHODS: We examined the effect of a single oral dose of ferrous sulfate on steady-state mycophenolic acid pharmacokinetics in 10 iron-deficient (hypochromic red blood cells >2.5%), Caucasian, long-term kidney graft recipients using a randomized, open-label, crossover design. On days A and B, MMF (1,000 mg) was given orally at 800 am. On day C, MMF and ferrous sulfate (105 mg) were coadministered at 800 am. On day D, MMF was given at 800 am and ferrous sulfate was given orally 4 hours later. RESULTS: The interindividual variability of the 12-hour area under the plasma mycophenolic acid concentration versus time curves (AUC(0-12)) under control conditions was small (89.5 +/- 27.8 and 87.6 +/- 39.1 mg x h/L, respectively). Concomitant or subsequent administration of MMF and ferrous sulfate did not affect the bioavailabilty of MMF (AUC(0-12), 91.9 +/- 30.4 mg x h/L and 96.0 +/- 31.7 mg x h/L). CONCLUSION: Oral therapy of iron deficiency using ferrous sulfate in long-term kidney graft recipients does not impede intestinal absorption of MMF; hence, exposure to this immunosuppressive agent is not reduced.