A comparative analysis of the use of mycophenolate mofetil in pediatric vs. adult renal allograft recipients.

Mycophenolate mofetil (MMF) is a new immunosuppressive drug used in combination with cyclosporin A (CsA) or tacrolimus and prednisone to prevent rejection of renal allografts in both adult and pediatric recipients. It has been shown in several large studies that MMF significantly decreases the incidence of acute rejection in adults and has acceptable adverse effects. In this retrospective study, we compare the incidence of adverse events between pediatric and adult renal allograft recipients. Twenty-two children and 37 adult renal allograft recipients were included in the study. The initial dose of MMF was 1.5 g b.i.d. for the adult patients and ranged from 15 to 30 mg/kg/d for the pediatric patients. All patients received p.o. acyclovir as prophylaxis for cytomegalovirus (CMV). The two groups were similar regarding gender distribution and graft source. Acute rejections occurred in 10 of the 22 pediatric patients (45%) and in nine of the 37 adults (24%), p = NS. The incidence of infections was similar in both groups except for the occurrence of CMV (n = 5), which was seen only in adults. The incidence of GI symptoms was significantly higher in the pediatric population (54.5% vs. 21.6%; p = 0.02). Significant weight loss was seen more often in the smaller pediatric patients (weight < or = 15 kg) compared to the larger pediatric patients, 60% vs. 11.7%, p = 0.05. Among the patients who had significant GI symptoms 50% of the adults and 75% of the pediatric recipients required either dose reduction or, most commonly, discontinuation of the MMF. The need to discontinue MMF was significantly higher in the pediatric patients, especially in those that weighed less than 15 kg. We suggest the possibility that the optimum dose, dosing interval or preparation of MMF has not yet been established for pediatric patients. One should therefore monitor pediatric patients closely, especially the small ones, to avoid significant nutritional problems and other adverse GI events.