Abstract: Objective To determine the optimal dose range (therapeutic window) of mycophenolate mofetil (MMF) for
preventing acute graft rejection following renal transplantation. Methods The trough concentration of MMF (MPA-C0) at 12 h
after oral administration of the drug (two doses daily given at an interval of 12 h) was monitored in 110 renal transplant
recipients within a month, in 2-3 months, and over 4 months after the transplantation using EMIT method. The occurrence of
acute graft rejection and drug toxicity were observed in all the patients during the one-year follow-up. Results The incidence
of acute graft rejection after transplantation was 13.64% (15/110) in these patients. Drug toxicity and complications occurred in
32.73% (36/110) of the patients, including 12 cases with reduced white blood cell counts, 10 with MMF cid-associated diarrhea,
10 with infection, 4 with liver function damage. Acute rejection was successfully reversed after methylprednisolone treatment
and drug toxicity was managed by corresponding treatment and adjustment of MMF dose. No deaths or graft removal
occurred in these patients. The ROC curve showed that a MPA-C0 of 1.40-2.80 mg/L was optimal in preventing acute rejection
after the transplantation and reducing adverse drug effects. Conclusion Monitoring MPA-C0 and individualized MMF dosing
help to prevent acute graft rejection, reducing drug toxicity and complications, and improving graft survival rate after renal
transplantation.