Folic acid (folate) and Polymyxin B and trimethoprim ophthalmic interaction
Folic acid (folate) and Polymyxin B and trimethoprim ophthalmic: the Polymyxin B and trimethoprim ophthalmic prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Polymyxin B and trimethoprim ophthalmic (Polymyxin B Sulfate and Trimethoprim) label · effective 2026-01-27
Because trimethoprim may interfere with folic acid metabolism, trimethoprim should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
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.