Graft function based on two hours peak level monitoring of cyclosporine A during the first six months of renal transplantation.

Inadequate cyclosporine blood levels may cause acute rejection in transplanted renal graft, and its increase is accompanied with graft toxicity. Cyclosporine has variable bioavailability and pharmacokinetics among patients at different times after transplantation. In this study, we compared the effects of cyclosporine blood levels (trough versus 2-hour peak, C2) on renal graft function during the first six months after transplantation in order to find better methods for drug levels assessment in our patients. We studied 50 patients who received grafts at Mashhad transplant centers from October 2006 to May 2007. Drug levels were monitored seven times during the study; in each assessment, more than 80% of the patients did not reach the therapeutic C2 levels. There was no significant correlation between age, sex, times of transplantation and acute rejection with drug C2 levels. There was no difference between graft function in patients with therapeutic C2 level and those with inadequate C2 levels. However, we found a significant correlation between trough levels and acute rejection (P <0.05). Only during the 6 th month after transplantation was the drug dosage significantly higher in patients with therapeutic C2 level than that in other patients (P >0.05). Apparently, peak levels were not a suitable method in drug monitoring in our patients, or peak levels might have occurred at a different time (like 1.5 or 3 or 4 h after ingestion of the drug) in our population. Based on this study, trough level may be a better method of evaluation of cyclosporine effects on renal allografts than 2-h peak levels in our patients.