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

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