Major
Established
Mô tả
Aspirin reduces methotrexate clearance by competing for renal tubular secretion, raising plasma methotrexate levels and toxicity risk.
Cơ chế
Salicylates compete with methotrexate for organic anion transporter-mediated renal excretion; they may also displace methotrexate from plasma proteins, transiently increasing free drug concentrations.
Ý nghĩa lâm sàng
Methotrexate toxicity (bone marrow suppression, mucositis, nephrotoxicity) has been reported when NSAIDs/aspirin are added; high-dose MTX regimens carry the greatest risk.
Xử trí
Avoid combination with high-dose MTX; monitor CBC and renal function with low-dose rheumatology regimens; withhold aspirin for 48 h around weekly MTX dose.