Mycophenolate sodium increases cyclosporine blood levels in renal transplant recipients

Cyclosporine is an immunosuppressive agent that displays a broad intra- and inter­individual pharmacokinetic variability. To evaluate the factors, which significantly influence cyclos­porine blood levels in our renal transplant recipients, we studied 611 consecutive patients trans­planted from living donors in Baqiyatallah hospital, Tehran, Iran from 1984 to 2005. The patients were divided into two groups: Group I included patients treated with mycophenolate sodium (MS) as an adjunctive immunosuppressive agent and Group II treated with azathioprine (AZA) as an adjunctive agent. Measurements of cyclosporine blood tough levels (C0) were performed 12 hours after the morning dose (just before the night dose). The mean age of the study population at time of transplantation was 38.7 ± 13.7 years and males formed 67% of it. Univariate analysis and multi­variable linear regression model showed that older age at transplantation, treatment with MS, and time interval from time of transplantation were significantly related with higher C0 levels. We conclude that there is an interaction of immunosuppressive agents in renal transplant patients with higher cyclosporine levels in the recipients of MS.