What the FDA labels say about taking them together
Methotrexate and probenecid
Methotrexate's FDA label of May 27, 2026 names probenecid in its drug interactions section, and probenecid's label names methotrexate too. The methotrexate label: “Renal tubular transport is also diminished by probenecid; use of Rasuvo with this drug should be carefully monitored.”
Check it at the source: the methotrexate FDA label on DailyMed (effective May 27, 2026, Accord Healthcare Inc.); the probenecid FDA label on DailyMed (effective January 5, 2021, Lannett Company, Inc.).
What does the methotrexate label say about probenecid?
Methotrexate label, drug interactionsOral antibiotics (including neomycin) Antifolate drugs (e.g., dapsone, pemetrexed, pyrimethamine and sulfonamides) Oral or intravenous penicillin or sulfonamide antibiotics Aspirin and other nonsteroidal anti-inflammatory drugs Highly protein-bound drugs (e.g., oral anticoagulants, phenytoin, salicylates, sulfonamides, sulfonylureas, and tetracyclines) Hepatotoxic products Proton pump inhibitors Weak acids (e.g., salicylates) Nephrotoxic products Probenecid Nitrous Oxide Coadministration of methotrexate with nitrous oxide anesthesia potentiates the effect of methotrexate on folate-dependent metabolic pathways, which may increase the risk of severe methotrexate adverse reactions.
Rasuvo label (Medexus Pharma Inc., December 15, 2025), drug interactionsRenal tubular transport is also diminished by probenecid; use of Rasuvo with this drug should be carefully monitored.
Source: FDA drug label (Rasuvo, NDA205776), Medexus Pharma Inc., effective December 15, 2025 (SPL set d0075461-0e7e-4967-9c9b-d6440e912c0e), via openFDA
Source: FDA drug label (Otrexup, NDA204824), Antares Pharma, Inc., effective January 31, 2025 (SPL set 9ab8ce16-f7de-41d4-a4c8-1c742621b6d5), via openFDA
Source: FDA drug label (Methotrexate), Accord Healthcare Inc., effective May 27, 2026 (SPL set 874c7f43-a3be-4236-89cc-24c44e3c5813), via openFDA; the full label on DailyMed
What does the probenecid label say about methotrexate?
Probenecid label, drug interactionsIn animals and in humans, probenecid has been reported to increase plasma concentrations of methotrexate (see WARNINGS ).
Probenecid label, warningsProbenecid increases plasma concentrations of methotrexate in both animals and humans.
Source: FDA drug label (Probenecid), Lannett Company, Inc., effective January 5, 2021 (SPL set ab497fd8-00c3-4364-b003-b39d21fbdf38), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Methotrexate | Probenecid | |
|---|---|---|
| Labeled for | Rheumatoid arthritis, Psoriasis, Leukemia, lymphoma and myeloma, Breast cancer | Gout |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.158 per tablet 2.5 mg tablet | $0.636 per tablet 500 mg tablet |
| Shortage now | In shortage | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once