Switchover to generic cyclosporine in stable renal transplant recipients: A single unit experience

Abstract

The introduction of the immunosuppressant cyclosporine has significantly improved renal transplant survival. It is an expensive drug and generic alternatives may offer cost advantages. However, generic alternatives must be shown to provide equivalent therapeutic efficacy and safety. This study reports our experience of a switch from the microemulsion formulation of cyclosporine, Neoral (Novartis), to the generic equivalent, Cysporin (Mayne Pharma). A two-period, single-sequence, cross-over study was done to compare cyclosporine blood levels and the area under the curve (AUC) of Neoral with Cysporin 2 weeks after a 1:1 dose switch. cyclosporine blood levels were measured at time points 0, 2, 4 and 8 h (C0, C2, C4, C8) after the switch. The cyclosporine AUC at 0-4 h and 0-12 h were calculated using the trapezoidal method. The two formulations were considered to result in equivalent blood levels if the 95% confidence interval (CI) of the ratio of the two levels was within 0.8-1.25. A total of 38 stable renal transplant patients aged 49.79 +/- 11.38 years (mean +/- SD), who were 7.84 +/- 3.97 years postrenal transplantation, were studied. The Neoral dose at the time of the switch was 2.38 +/- 1.21 mg per kg bodyweight. At all measured time points the 95% CI for the cyclosporine drug level ratio was between 0.9 and 1.15. There were no significant adverse events during the period of study. We conclude that the generic formulation of cylosporin, Cysporin, after a 1:1 switch from Neoral results in equivalent blood levels in stable renal transplant recipients. After switchover cyclosporine levels at C0 or C2 can continue to be monitored as per the institution's current monitoring practice.