myelosuppression
2 interactions related to myelosuppression
azathioprine + allopurinol
Allopurinol inhibits xanthine oxidase, the enzyme responsible for inactivating azathioprine's active metabolite 6-mercaptopurine. Combined use shunts more 6-MP into the active 6-thioguanine pathway, increasing azathioprine's effects 3-4 fold and producing potentially fatal myelosuppression, pancytopenia, and hepatotoxicity.
azathioprineallopurinolxanthine oxidasemyelosuppressionpancytopenia6-mercaptopurinecontraindicationtpmt
methotrexate + nsaids
NSAIDs reduce renal blood flow through prostaglandin inhibition and compete with methotrexate at renal tubular transporters, decreasing methotrexate clearance and raising serum levels. The risk is greatest with high-dose methotrexate or pre-existing renal impairment, where the combination can precipitate myelosuppression, mucositis, hepatotoxicity, and acute kidney injury.
methotrexatensaidsibuprofennaproxenkidneymyelosuppressiondrug interactionrenal toxicity