Methotrexate and Trimethoprim interaction
Methotrexate and Trimethoprim: the Methotrexate prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Moderate
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Methotrexate (Xatmep) label · effective 2026-05-28
Moderate
Trimethoprim/sulfamethoxazole has been reported to increase bone marrow suppression in patients receiving methotrexate.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.