TMP-SMX + methotrexate — marrow suppression
- Both can suppress marrow
- TMP-SMX also impairs folate pathways
- Renal methotrexate clearance may fall
- Severe pancytopenia/mucositis can occur
- Avoid combination when possible
- If unavoidable: CBC/Cr + close monitoring
Interaction at a glance
- Avoid combination when possible
- If unavoidable: CBC/Cr + close monitoring
Mechanism
- Both can suppress marrow
- TMP-SMX also impairs folate pathways
Magnitude / time course
- Renal methotrexate clearance may fall
- Severe pancytopenia/mucositis can occur
Monitoring
- Avoid combination when possible
- If unavoidable: CBC/Cr + close monitoring
Self-check
- How should TMP-SMX + methotrexate be managed?
Avoid combination when possible. - If TMP-SMX plus methotrexate is unavoidable, what monitoring is advised?
CBC/Cr and close monitoring.
Drugs in this interaction (3)
All interaction examples · Open TMP-SMX + methotrexate — marrow suppression in the interactive console ↗