MYCOPHENOLATE MOFETIL (MMF) IN HEART-TRANSPLANTATION - REJECTION PREVENTION AND TREATMENT

Mycophenolate mofetil (MMF), the morpholinoethylester of mycophenolic acid, inhibits the de novo pathway for purine synthesis. Evidence sugg ests that MMF suppresses lymphocyte function more than that of neutrop hils, erythrocytes, and other rapidly dividing cell lines that can uti lize salvage pathways for purine synthesis. While rigorous efficacy da ta await the completion of an ongoing, multicenter, prospectively rand omized, placebo-controlled trial, long-term safety data are, however, available from numerous uncontrolled trials in cardiac transplantation . Dose-ranging trials in 49 heart recipients suggest that doses greate r than or equal to 4000 mg/d are associated with significant, reversib le gastrointestinal toxicity when compared with doses <4000 mg/d (p<0. 001). Patients receiving greater than or equal to 1000 mg/d may have f ewer rejection episodes. Even in the long term, changing from azathiop rine to MMF is associated with increases in hematocrit (p<0.001), tota l WBC count (p<0.005), and absolute neutrophil count (p<0.005). Succes sful use of MMF in refractory cardiac allograft rejection suggests an advantage over azathioprine. MMF is safe and appears to be at least as effective as azathioprine for immunosuppression following heart trans plantation.