Adverse effects of mycophenolate mofetil in pediatric renal transplant recipients with presumed chronic rejection

Background. Mycophenolate mofetil (MMF) has been shown to be superior to azathioprine in reducing the incidence of acute rejection in adult renal transplant recipients. Although MMF is also being widely used in pediatric transplant patients, data documenting its safety are limited. Methods. A retrospective review of the transplant records at St. Christopher's Hospital for Children was conducted to identify patients who had received MMF. Results. Twenty-four children were switched from azathioprine to MMF, 4.8+/-2.9 years after transplantation. After an additional 0.8+/-0.4 years, MMF had been discontinued in 13 patients (54%) because of adverse effects (AE). The only variable that predicted the development of AE was a lower calculated creatinine clearance at the time of initiation of MMF. Conclusions. In pediatric renal transplant recipients with impaired renal function, the use of MMF at the recommended dose is associated with an unacceptably high incidence of AE; in such patients, the MMF dose may require modification for the level of renal function.