What the FDA labels say about taking them together
Methotrexate and sepiapterin
Sepiapterin's FDA label of April 24, 2026 names methotrexate in its drug interactions section; the methotrexate labels PlainMeds reads (4) do not name sepiapterin. The sepiapterin label: “DRUG INTERACTIONS Dihydrofolate Reductase (DHFR) Inhibitors: Avoid concomitant use. Sepiapterin Reductase (SR) Inhibitors:”
Check it at the source: the methotrexate FDA label on DailyMed (effective May 27, 2026, Accord Healthcare Inc.); the sepiapterin FDA label on DailyMed (effective April 24, 2026, PTC Therapeutics Inc.).
What does the methotrexate label say about sepiapterin?
Methotrexate's label (effective May 27, 2026) and its 3 other brand-application labels do not name sepiapterin in these sections. A label lists what its studies and reports found; it is not a complete list.
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 sepiapterin label say about methotrexate?
Sepiapterin label, drug interactionsDRUG INTERACTIONS Dihydrofolate Reductase (DHFR) Inhibitors: Avoid concomitant use (e.g., trimethoprim, methotrexate, trimetrexate, pemetrexed, pralatrexate, raltitrexed, or piritrexim). ( 7.1 ) Sepiapterin Reductase (SR) Inhibitors:
Source: FDA drug label (Sephience), PTC Therapeutics Inc., effective April 24, 2026 (SPL set 32ac719c-49f0-4105-9c46-18c19583a5c2), 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 | Sepiapterin | |
|---|---|---|
| Labeled for | Rheumatoid arthritis, Psoriasis, Leukemia, lymphoma and myeloma, Breast cancer | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.158 per tablet 2.5 mg tablet | n/a |
| 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