Interleukin-2 receptor antibodyinduced alterations of ciclosporin dose requirements in paediatric transplant recipients

In a retrospective analysis of paediatric renal-transplant recipients receiving basiliximab, we noted significantly increased blood concentrations of ciclosporin, early ciclosporin toxicity, and a lower dose requirement within the first 10 days compared with controls. As the CD25 saturation fades at days 28–50, ciclosporin concentrations decline and 20% higher doses are required to maintain adequate trough concentrations. We suggest that an interleukin-2 receptor-mediated alteration of the cytochrome P450 system causes this systemic drug interaction and propose that the initial ciclosporin dose should be limited to 400 mg/m2 if used in combination with basiliximab.