Sirolimus steady-state trough concentrations are not affected by bolus methylprednisolone therapy in renal allograft recipients

Aims To determine whether bolus doses of methylprednisolone affect the steady-state trough concentrations of sirolimus. Methods Fourteen renal transplant recipients received concentration-controlled sirolimus therapy in combination with azathioprine and steroids (n =8) or mycophenolate mofetil and steroids (n =6). Bolus doses of methylprednisolone (mean total dose over 1-5 days, 1694 mg; range, 500-3000 mg) were given for the treatment of acute rejection. For each patient, the sirolimus dose (mean, 24.1 mg; range, 3.3-52.5 mg) was the same before and during methylprednisolone therapy. Results Mean sirolimus whole blood trough concentrations before and after treatment with methylprednisolone were 28.8 ng ml(-1) (range, 13.9-45.3 ng ml(-1) ), and 28.5 ng ml(-1) (range, 13.0-47.9 ng ml(-1) ), respectively (P =0.85; 95% confidence interval on the difference -3.3, 4.0 ng ml(-1) ). Conclusions Bolus methylprednisolone treatment does not affect steady-state sirolimus trough concentrations.