説明
Methylprednisolone inhibits CYP3A4-mediated cyclosporine metabolism, raising cyclosporine levels; conversely, cyclosporine may increase methylprednisolone exposure — a bidirectional pharmacokinetic interaction.
機序
High-dose methylprednisolone (pulse therapy) can inhibit CYP3A4, reducing cyclosporine clearance and raising trough levels; cyclosporine itself inhibits P-gp and CYP3A4, potentially increasing methylprednisolone exposure. The net direction of the interaction depends on relative doses.
臨床的意義
Transplant cases document cyclosporine toxicity (nephrotoxicity, neurotoxicity) following methylprednisolone pulses for acute rejection; cyclosporine troughs may rise by 20–40%.
対処法
Monitor cyclosporine trough levels during and after methylprednisolone pulse therapy; adjust cyclosporine dose as needed; monitor renal function closely.