Leucovorin and Trimethoprim interaction
Leucovorin and Trimethoprim: the Leucovorin prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Leucovorin (VYKOURA) label · effective 2026-03-12
Trimethoprim-Sulfamethoxazole Avoid concomitant use of VYKOURA with trimethoprim-sulfamethoxazole .
The effectiveness of trimethoprim-sulfamethoxazole can be decreased if used concomitantly with VYKOURA which was associated with increased rates of treatment failure and mortality in patients with HIV infection who receive trimethoprim-sulfamethoxazole for the acute treatment of Pneumocystis jirovecii pneumonia.
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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.